Real-world tests of small wind turbines in Netherlands and the UK

This is a guest post by Kris de Decker. Kris is editor of Low Tech Magazine. Rembrandt and I saw a somewhat similar story in the Dutch version of Low Tech Magazine, and Kris was kind enough to put together this story in English for us.

Testing small windmills

Photo by Jeroen Haringman

Two real-world tests performed in the Netherlands and in the UK confirm our earlier analysis that small wind turbines are a fundamentally flawed technology. Their financial payback time is much longer than their life expectancy, and in urban areas, some poorly placed wind turbines will not even deliver as much energy as needed to operate them (let alone energy needed to produce them). Given their long payback period relative to their life expectancy, most small wind turbines are net energy consumers rather than net energy producers.

The machines face two fundamental problems: there is not enough wind at low altitudes in a built-up environment, and the energy production of a wind turbine declines more than proportionately to the rotor diameter. Wind power rules, but small wind turbines are a swindle.

12 Small Wind Turbines Tested in the Netherlands

The Dutch coastal province of Zeeland (a very windy place) placed twelve of these much hyped machines in a row on an open plain (picture above). Their energy yield was measured over a period of one year (April 1, 2008 - March 31, 2009). The average wind velocity during these 12 months was 3.8 metres per second (more on the wind speed later).

Three wind turbines broke. Find the disappointing results of the others below. (Original test results here, pdf in Dutch.)

- Energy Ball v100 (4,304 euro) : 73 kWh per year, corresponding to an average output of 8.3 watts
- Ampair 600 (8,925 euro) : 245 kWh per year or an average output of 28 watts
- Turby (21,350 euro) : 247 kWh per year or an average output of 28.1 watts
- Airdolphin (17,548 euro) : 393 kWh per year or an average output of 44.8 watts
- WRE 030 (29,512 euro) : 404 kWh per year or an average output of 46 watts
- WRE 060 (37,187 euro) : 485 kWh per year or an average output of 55.4 watts
- Passaat (9,239 euro) : 578 kWh per year or an average output of 66 watts
- Skystream (10,742 euro) : 2,109 kWh per year or an average power output of 240.7 watts
- Montana (18,508 euro) : 2,691 kWh per year or an average power output of 307 watts.

Keep in mind that these wind turbines would perform considerably worse in a built-up area.

47 windturbines to power a household

An average Dutch household consumes 3,400 kWh/year. Listed below is the amount of wind turbines required, and their total cost, to power a Dutch household entirely using wind energy:

- Energy Ball : 47 windmills (202,288 euro)
- Ampair : 14 windmills (124,950 euro)
- Turby : 14 windmills (298,900 euro)
- Airdolphin :  9 windmills (157,932 euro)
- WRE 030 : 9 windmills (265,608 euro)
- WRE 060 : 7 windmills (260,309 euro)
- Passaat : 6 windmills (55,434 euro)
- Skystream : 2 windmills (21,484 euro)
- Montana : 2 windmills (37,016 euro)

An average American household consumes almost 3 times as much electricity as a Dutch household. Simply multiply the above figures by three.

Rotor diameter

At first sight, the results seem to indicate that the design of the wind turbine matters. However, if you combine these figures with the rotor diameter, it becomes clear that the concept of small windmills is fundamentally flawed. The turbines that score best are simply the largest ones:

- Energy Ball : 1 metre
- Ampair : 1.7 metres
- Turby : 2 metres
- Airdolphin : 1.8 metres
- WRE 030 : 2.5 metres
- WRE 060 : 3.3 metres
- Passaat : 3.12 metres
- Skystream : 3.7 metres
- Montana : 5 metres

Wind turbines with a rotor diameter of 4 or 5 metres do not fit on most roofs, and are not easy to integrate into a built-up environment.

Size matters

Dutch wind energy expert Jaap Langenbach notes that close to the test site stands a (relatively) large wind turbine with a rotor diameter of 18 metres. It delivers 143,000 kWh per year, or an average power output of 16,324 watts. It can power 42 Dutch households. This large wind turbine costs only slightly more than all small wind turbines combined (17 percent more, to be exact, or 190,000 euro), but it delivers almost 20 times as much energy. This brings the cost down to 4,523 euro per household, which is 8 times more economical than the best performing small wind turbine (and 45 times cheaper than the worst performing small wind turbine).

If you double the rotor diameter of a wind turbine, the blades sweep an area that is four times as large. Material costs double, but the yield multiplies by four. The larger the rotor diameter, the more energy you get for your money, and for the energy invested. And the other way around, of course.

Doubts on the wind speed

The test results described above may give a too rosy picture of the performance of the machines. Following the publication of the results, some Dutch energy experts expressed their doubts regarding the measured average wind speed of 3.8 metres per second. After all, according to the wind map of the Netherlands, the average wind speed in Zeeland (at a height of ten metres) is 6 metres per second.

Jeroen Haringman determined that the measurements of other wind turbines in the same area over the same period was slightly higher than average. Jeroen van Agt reported that a weather station of the Dutch meteorological service, located 14 kilometres from the test site, measured a wind speed of 6 metres per second. Confronted with this information, the organizers of the test answered that the reported wind speed at the test site was "only indicative". If the wind speed at the location was indeed higher than 3.7 metres per second, then the performance of the machines is seriously overstated.

26 Small Windturbines Tested in the UK

Small wind turbinesA real-world test of 26 small wind turbines in the UK followed a different approach and is therefore an interesting addition to the results obtained in the Netherlands. The Warwick Wind Trials Project collected information on the electricity production of 5 different machines at 26 locations throughout the UK, from October 2007 to October 2008. The results were published in January 2009.

The machines were placed in a built-up environment. Half were attached to the facade or to the roof of single-family dwellings; the other half were attached to the roofs of apartment buildings. Unlike to the Dutch test, the intention was not to investigate how the machines operate with respect to one another, but how well or poorly small wind turbines work in a specific environment.

The maximum output of the turbines in the test according to the manufacturer were as follows:

78 kWh per year

The average electricity production of all 26 machines amounted to 78 kWh per year per wind turbine. This corresponds to an average output of 8.9 watts. This means that the turbines achieved on average less than 1% (actually 0.85%) of the maximum ouput stated by the manufacturers. For large wind turbines, the percentage of the maximum output achieved was between 10% and 30%. As mentioned above, half of the small wind turbines were placed on tops of apartment buildings.

Technical problems and damage

Ignoring the time that the machines were out of service due to technical problems or maintenance, the average yield rises to 230 kWh per year (or an average output of 26 watts). In this case, the machines achieve 4.15% of their maximum output (0.29% to 16.54%, depending on the location). Of course, this is a theoretical figure, since technical problems and maintenance do have a real influence on performance. Unlike solar panels, wind turbines consist of moving parts.

Two machines lost a sail, one machine lost its tail. These are not exactly desirable properties in a built-up environment. One turbine damaged the facade of a house (the fault of the installer, not the manufacturer).

Location matters

The best performing machine, mounted on top of a 45 metre high appartment building located on a hill, delivered 869 kWh per year (an average output of 99 watts). The worst performing machine, attached to the facade of a single-family dwelling, delivered 15 kWh per year (an average output of 1.7 watts). These results clearly indicate that the location is of decisive importance. The best placed turbines deliver as much electricity in one month as other turbines deliver in the course of a full year. 

Noise pollution

Unfortunately, the best performing machines had to be shut down because the residents complained about noise pollution. Noise pollution was an unexpected problem.

Electricity consumption & embodied energy

The UK study also gives figures for the electricity consumption of the electronics used in the wind turbines. On average, this averages only 29 kWh per wind turbine per year (varying from 3 kWh to 136 kWh per year, depending on the machine). This means that some of the small wind turbines consume more electricity than they deliver. And then we are not even talking about the energy required to produce the machines: according to a report by the UK Carbon Trust, Small-scale wind energy: Policy insights and practical guidance, wind turbines in urban environments will almost always have an energy payback of more than 20 years. The warranty of most small wind turbines is 2 to 5 years.

The UK report warns that the aggressive and misleading marketing of the manufacturers, combined with the gullibility of the consumers and the authorities, might damage the reputation of wind energy - including the image of large wind turbines, which do have an attractive electricity production and payback time.

Articles from Low Tech Magazine on Related Subjects

Interesting. I thought this was established years ago, but it is good to see it all mapped out like this.

I also wonder about the reliability of smaller turbines as well. I know several people (not well - acquaintances) who bought them, and they (the windmills) all died within a few years, requiring repairs. In two of the instances, the repairs were minor but took a long time to fix, in another, the motor itself burned out, and another some electronic parts had a fry up - expensive but simple to fix. All the people (four in all) who had small windmills went in different directions. Two went to the grid and simply paid for premium "green energy" another went to photovolt and a basement full of batteries. The other guy disappeared - moved somewhere, no idea.

Odd that these tests used turbines at such low altitudes. Based on typical wind speed profiles, I wouldn't think that a small turbine would be installed at anything less than 30 metres. The Dutch 'experiment' above installed them at 10 metres, which in my opinion was a setup for failure. From AWEA.ORG;

Most small wind turbine manufacturers recommend mounting turbines at least 65 feet high, but particular site conditions should be the primary factor when determining tower height. Towers from 80 to 140 feet tall may be optimal.

Note that on the UK experiment, the turbine at 45 metres dis remarkably well in an urban environment, delivering 869 kWh per year.

Also, the use of BAU demand criteria is inconsistent with the direction of low- and zero-energy building design that is emerging. It would be more appropriate to use a 60%-80% reduction in BAU energy to compare.

So this 'article' uses language and highly targeted 'analysis' to arrive at a predetermined answer. It's a shame to see something so slanted on TOD.

If you look at the data link for the Netherlands report, you will find that it shows 2 years and five months of data. The second year and the five months are very similar to the first year, which is all that is reported on. I had some of the same concerns that you had, so looked carefully at the underlying data, to see that it really supported by the data.

Regarding not putting these small turbines at higher heights, we are talking about installing the wind turbines in urban locations. I question how many people will in fact install these turbines at very high heights, in the middle of the city. What was being tested in the UK study was typical installations. The ones that appeared to have better chance of success--bigger turbines on top of tall apartment buildings--didn't work out in practice, because the residents of the apartment buildings complained to the authorities about the noise, and forced the owners to take them off line.

The conclusion of this article was "small wind turbines are a fundamentally flawed technology". The data provided did not support this wide-sweeping conclusion.

In looking at the UK report, the rooftop mounts were simple 5 metre poles, which is far below the minimum 15 metres above buildings mentioned in AWEA reference above.

Again, there were some turbines that performed well in the urban environment (e.g., 869kWh/yr) even at a poor height, though their contributions were ignored and buried in the noise.

Hence, the conclusion should have been "wind turbines in urban environments at sub-optimal heights do not provide sufficient payback."

The quote you are referring to in the report is

The best performing turbine in the trial generated an average of 2.382 kWh per day when in operation, equivalent to 869 kWh in a full year. The poorest site generated an average of 41Wh per day when in operation or 15 kWh per year, which is less than the energy it consumed to run the turbine’s electronics.

Energy consumption averages 80Wh per day per turbine (29kWh per year) which is significant on some sites.

Thus, the generation isn't really 869 kWh, it is equivalent to that, if the wind turbine had actually been in operation longer (and then reduced by the energy use). The only wind turbines that got that kind of performance were large wind turbines, on top of apartment buildings, on top of hills, without obstructions. But even in this location they didn't work, because residents of the apartment buildings found them so objectionable, they got city officials to require that they not be used.

The purpose of the report was to see whether small wind turbines worked in cities, so they did not get into speculation on whether these wind turbines might work better elsewhere.

"they did not get into speculation on whether these wind turbines might work better elsewhere."

...doesn't jive with:

Wind power rules, but small wind turbines are a swindle.

(from the opening section of the post).

Since there are clearly locations and situations where small wind turbines are appropriate and functional (and have been for nearly a century), this 'swindle' statement leads me to question the author's objectivity. Air conditioners aren't very useful in northern Alaska, but that doesn't make them a "swindle", though the seller may be a swindler and the buyer dumb as a rock. Putting a wind turbine (of any size) in the wrong place is like building a hydro plant in a dry river bed.

I agree Ghung, "location, location, location."

I don't know about the author's objectivity, but I do know that long-time wind users sometimes cringe at the extremely optimistic expectaions of newbs. Same with solar.

And Will is right about height. The rule of thumb for a small to mid-sized turbine is it should be placed 30 meters higher than the tallest object within 100 meters. And even then results will vary for a wide variety of reasons.

There are two turbines on farms near me. One is a restored Jacobs 1800 (~14ft diameter), on a 60 ft tower. It was installed at a poor location on the site, broke down 12 years ago and has since become an enormous lawn ornament.

The second is a mid-sized turbine (~27 ft diameter) that is helping to power a small farm. After the first year of operation the owners said it did not produce quite as much as they had calculated but was close enough.

I had a 400W model on a boat during a circumnavigation. It was a waste of money. Our usage was around 200 amp - hours per day at 24v and although theoretically it could meet this requirement, in practice in never did. Even with "clean" wind at sea it rarely delivered more than 2-5 amps. It was placed approx. 4m above the surface of the water at the stern of the boat. It's operating wind speed band was approx 10-25 kn and its braking technology never worked in a gale. It only worked really well in windy anchorages. Las Aves de Barlovento comes to mind, but then it does have "vento" in its name!

An SWWP Air 400 comes to mind......

It was a KISS.

Did you really go around the world? In a sail boat? Were you ever becalmed?

Yes, well UK to Oz actually, so 2/3 of a circumnavigation. And we were becalmed often. The Pacific is called the Pacific for a reason....... 24 days from Galapagos to Fatu Hiva in the Marquesas. The Atlantic was good though, running with 20-30kn all the way.

And we were becalmed often. The Pacific is called the Pacific for a reason....... 24 days from Galapagos to Fatu Hiva in the Marquesas.

LOL! I guess that proves beyond a shadow of a doubt that sailboats are a fundamentally flawed technology.

LOL! I guess that proves beyond a shadow of a doubt that sailboats are a fundamentally flawed technology.

well if they were being touted as seemlessly replacing the fossil fuel fired commercial fleet the hype would certainaly be fundamentally flawed ?- )

But if it seemed likely that we were going to face oil 'Issues' with our ICE fleet, then this unpredictability might still seem reasonable given the chance for getting an otherwise free ride.

Kites mounted on the bow of large container ships have been shown to provide 10-30% of ship's power - this is cost effective now. See an early article the leading company, Skysails, a followup article showing a commercial implementation, and the Skysails website. It's astonishing what can be done with modern materials, computer-aided design, and electronic control systems, to turn the old new again.

good stuff--I'd imagine that marine designs that incorporate features allowing maximun kite power could do much better than mere retrofits.

features allowing maximun kite power

What do you have in mind?

not being a marine architect I've just a general direction. Cargo ships would of course still have to be designed for mininizing that expensive loading and unloading dockside time, but there may be some hull shape modifications that could meet all cargo considerations that would facilitate the craft being pulled by kites while not overly detracting from the best shape for it being pushed by a prop. But mostly I was envisioning mulitple swing out (so they could be out of the way when loading and unloading) kite tethering platforms that might allow larger and possibly mulitple kites (at different altitudes) to be flown at the same time. This really arm chair stuff as I've no idea what sort of space between cables would be a minimum for safe operations.

I believe someone already posted that the kitegen concept was being employed on some craft to reduce the electrical generation fuel demand.

It is kind of cool to envision a modern kite clipper with a few kites in widely seperated altitude planes so all could make full advantage of the winds aloft without shadowing one another. But that might be a bit far from what would be pratical on lightly crewed modern cargo craft, though the trade offs between reduced fuel costs and added crew costs should be readily quantifiable. All other relative maintenance and equipment costs of course would also have to be figure in as well. It might just be that the cables needed to allow a kite to really pull a cargo vessel have to be so massive that one more or less 'square sail' forward is all that can really be used.

The issue with multiple kites, is not how well they might ideally work, but how badly it could all go wrong.
As soon as you have more than one kite, you have tangle scenarios, and the worst of those dumps the kites in the water, and then wraps the prop/rudder as the ship steams over them. Of course, that is a very bad thing.
KISS should win every time here.

KISS should win every time here

Clipper ships with their masts atop of masts, spars hanging everywhere, sails upon sails and matrix of lines were hardly simple--but the tech evolved over time and added risk of failure vs. increased performance trade offs were constantly being assessed.

Then again these fast, relatively small and complex sailing ships had fairly short life spans. Always trade offs.

Of course the whole multiple kite idea is 'out there' but a 'stowable' platform (for kite launch and retrieval) that could potentially allow a much larger kite to be sailed might be an interesting starting point. Of course more sail needs stronger more integrated ship structure to tug upon which brings me back to my initial point that far more kite power could likely be harnessed if the ship were designed to accommodate kite assist rather than merely retrofitted with it.

Certainly, like you say, in the early going KISS is a real good idea--the ocean can really magnify Murphy. Failure or worse of high performance but unforgiving designs could set widespread adoption of the tech way back.

Good thoughts. I'll use them...

LOL! I guess that proves beyond a shadow of a doubt that sailboats are a fundamentally flawed technology.

On the Pacific, yes. On the Atlantic, no.

"Small wind turbines are a fundamentally flawed technology"

In cities and all other places where there are low winds and/or obstacles and turbulence: yes
On the beach of a windy country: no

Very few of us live where small wind turbines can be useful, but the Atlantic is important enough to make sailboats a viable option, even when they cannot be used on the Pacific.

Kris, my point all along has been that none of these technologies are flawed, they are but a tool in the tool kit and they have to be used appropriately and expectations as to their performance must be set accordingly. Is an electric tool flawed if you don't have an outlet to plug it into?

BTW, though I myself have never sailed in the Pacific I have a good friend who has done three solo circumnavigations and he seemed to manage to sail the Pacific just fine, I won't even mention the South Pacific...

Did you use any PV?

The Atlantic can also be fickle, a boat that left 1 week after us had very little wind. Conversely the Pacific isn't doesn't always live up to its name. In El Nino years you can get reinforced trades and very fast passages. It is variable and it is called weather!

Yes we had PV - 200W nominal. It was OK, not brilliant, but OK - 5-6 amps at 24v was about the best I saw, but only for a few hours per day, maybe, depending on a large range of factors. Probably the best solution, which we didn't have, would have been a towed water generator (basically an alternator spun by a propellor towed behind the boat) , but it can cost 1kn in boat speed, which is quite a lot when you are only doing 7kn. Also I hear big fish and sharks sometimes eat the propellor!

You do learn about energy on a sailboat; and you learn how to manage a tight energy budget. One thing is for sure, there is nothing like diesel to spin a big alternator!

Thanks for the info.

Did you carry a small diesel generator? I presume you had at least a small outboard motor as a backup?

I'm guessing Saildog has a small Perkins or some such hooked up to a prop. Of course it would be hooked up to the alternator and it to the battery bank so it would act as a diesel generator when fired up. On diesel powered fishing boats a small Yamaha or Honda gasoline powered generator has become a major safety backup. It will charge your batteries so you can use your radio and electric bilge pumps when things go south. Of course that requires the boat to have gasoline on board which requires proper stowage and so on.

Before we started carrying a little gas generator we had a nasty experience when a nut spun off our alternator and was swallowed by the bilge of our little salmon boat. I can't remember if the loss of the alternator was instrumental in our engine dying (that seems unlikely with a diesel) or if we shut it off for some reason but I well remember the color and texture of the sea and sky as the tide and offshore wind were carrying us out into the Bering where decent little ten to fourteen foot seas were building--not what you want to be drifting around in powerlessly. Anyway we went to spin the engine and got nothing. We were lucky to have enough juice to power the VHF and a fellow fisherman making the same passage to Nelson Lagoon from Port Moller got to us in about half an hour just as we were picking up speed having lost the shelter from the low landward side.

Some of the 100 foot or so crabbers I've been on also had propane aboard for various applications--a leak and explosion of that substance in the forecastle of the North Point sent it to the bottom one night when it was anchored off Port Moller--maybe a ten years ago now. Fortunately all hands were rescued-I can't recall the extent of their injuries. I had delivered more than a few salmon to that boat and always was treated most hospitably by the crew when they gave me lifts back and forth from our fishing grounds to cannery (which had a grocery store, physician's assistant and ships chandlery--the only such in reasonable sailing range). Hearing the North Point went down sent a few shudders down my spine. Well I digressed enough there but it was good for me and I am trying to deal with postconcussive syndrome best I can. I hope my ramblings will be tolerated.

Anyway those last two stories were to show that having explosive elements on board a small craft has its safety trade offs. A small diesel powered generator would certainly be better than a gasoline one but I don't know that they make them at that handy little 800-1500 watt size.

Main engine used to drive the boat when not sailing was a Ford 2.5l producing 60HP at 3000 rpm. It was fitted with a 24v 375A alternator charging 500AH of lead acid "house" batteries. There was a separate 12v engine circuit similar to that found in a car. It was dedicated to engine start, but could be linked to half the house circuit as a back up.

In addition we had a Northern Lights 3kVA genset producing 220v 50Hz AC, the 400W KISS wind generator and 200W in solar panels. If I did it again I would have the same set up, but a Wispagen Stirling motor (external combustion) diesel genset (less than 1/2 litre per hour for 15A at 24v and hot water) in place of the Northern Lights genset, no wind generator and more solar. We also had a small Honda gasoline genset as backup, but hardly ever used it. We carried gasoline anyway because we had a 15HP Yamaha outboard for the dinghy.

It is variable and it is called weather!

Contrary to wind conditions in the Atlantic and the Pacific, wind conditions in the city are not only determined by the weather. In the first place, they are determined by a built-up environment, effectively blocking whatever wind there could be. The ocean is flat.

The ocean is flat. doesn't always look that way on a small boat.

Small wind generators trying to catch that broken up air all over the city seems a ridiculous idea and densley packing the generators there-even in multiple altitude planes-would just break up the air flow that much more. The whole concept seems more like a Monty Python cartoon lead in than a real alternative energy scheme.

seems more like a Monty Python cartoon

The "economics"-based laugh track can keep churning along for as long as the BAU power grid also keeps churning along.

But you would be surprised how quickly the snide chuckling turns into temporary respect when the grid goes down and Mr. McGoo's ham radio shack is the only place with a single lit light bulb and a still working communications link to emergency help.

There's the problem with all this "rational" and prudent economic analysis of the system.

It all goes to sh*t when the economic assumptions about a BAU power and communications grid go to sh*t.

Sure Mr. Goo will be the man to see during a fairly short lived grid shut downs but when you start talking systemic failures that bring BAU crashing down as a whole his little radio a light bulb will only do him any good if he has the luck and social skills to convince the prevailing local gang and war lords that he is useful as the powers shifts through them, otherwise....

Operating the odd small wind generator in the city is one thing (a better hobby than many) but trying to power the entire place with sky full of small propellers that take poor wind reliability and make it even worse is another.

but trying to power the entire place with sky full of small propellers

I don't think anyone was proposing that.

Clearly wind power has economies of scale just as do many other energy production techniques.

Photovoltaic (PV) doesn't work too well at night or on cloudy days. So just as an augmentation to a solar back up system, one might want to have a wind driven system ... not for powering the whole place ... but rather for those just in case times when having some electricity is better than having none.

The Energy Ball V-100 (the first machine in the Dutch test) is delivered with a mast of 10 to 12 metres. Same for most of the other machines I guess. They are clearly not intended to be installed at a height of "at least 30 metres".

You 'guess'? You are making wide-sweeping statements about all small scale wind turbines and you don't understand minimum and optimal mounting heights?

Your conclusion needs a drastic rewrite, as I noted above.

If you disagree with my conclusion, why don't *you* check the height of every single machine mentioned in the text? From the picture alone it shows that none of the machines is substantially higher than the Energy Ball.

You haven't supported your assertion "small wind turbines are fundamentally flawed", you've only shown that small wind turbines at suboptimal sites rarely perform as designed.

I've already provided the reference above which identifies the range of optimal heights (80 to 140 feet). Don't ask me to do the rest of your homework.

Will, if you put small wind turbines on masts of 80 to 140 feet, then you cannot call them small wind turbines anymore. Rather you should call them large wind turbines with ridiculously small rotor diameters.

You will have to argue with the American Wind Energy Association, not me. Please present your credentials and experience that show your opinions and recommendations are superior to theirs.

Well, since masts taller than 10m violate residential building codes in a lot of municipalities, I'd say it is a moot point whether they are considered small or not.

There are a number of municipalities that have wind turbine ordinances, where residential areas have one height limitation, though industrial and/or commercial areas have much higher height limitations.

Portland, Maine -

Google "wind turbine ordinance" shows many towns and cities with existing or developing wind turbine ordinances, which run the gamut.

The 10m (30') mast limitation is more general, but I note from the article you linked:

Roof-mounted and free-standing turbines would be allowed in residential zones. Roof-mounted turbines would limited to less than 10 feet above the tallest point on the roof, not to exceed 25 feet.

Free-standing turbines of up to 85 feet must be set back from the property line and public rights of way by 1.1 times the total system height. Setbacks from residences and hospitals increase to twice the system height.


Turbine heights are measured from the ground to the highest tip of the rotor blade. All moving parts must remain at least 12 feet off the ground.

Sounds like residential wind is a non-starter there.

I would certainly agree that urban/suburban residential is likely a non-starter in areas with low turbine height limitations. However, commercial and industrial locations have much better height allowances, and residential outside of the city/town are frequently conducive to small turbine deployment. Note the reference I have above that shows that less than 2% of US small wind turbine installations are in urban/suburban residential environs.

Does large scale windpower outperform small windpower? In virtually every modern case, no doubt. There are a few scams that pop up from time to time showing vertical axis wind turbines mounted directly on a roof, or similar situations.

My only complaint is that the conclusion of the article was written to be inclusive of ALL small wind power, not just urban/suburban residential.

I can't disagree with you, but the main article is about wind power systems that are sold specifically for residential power generation, so they would be subject to the residential rules.

And since the test followed typical residential rules in an obstruction-free area with good wind conditions, that the wind-generators under test failed to deliver adequate performance is particularly relevant to whether they are useful or not in their intended market.

The article stated "small wind turbines are a fundamentally flawed technology" and "small wind turbines are a swindle".

In keeping with the scope you believe the article was addressing, the above should have been written "small urban wind turbines with sub-optimal height restrictions do not provide sufficient energy return to justify their acquisition".

obstruction-free area with good wind conditions

The lack of obstructions has not been established. Indeed, to the contrary, I can see a number of obstructions in the Dutch study that violate basic wind siting guidelines.

My only real complaint here is the wide-sweeping nature of the conclusion. Again, such a conclusion does not apply to 98% of the small wind turbines sold in the US.

If anyone asks me whether they should buy a wind generator for power (as opposed to buying one for educational purposes), I would point to a study like this first.

Way too many people buy expensive junk that they can't use because some slick salesman has a persuasive pitch, and you aren't going to overcome that pitch with weasel words.

90% of people live in cities.

For 90% of people, small wind generators are guaranteed to be expensive junk.

For the other 10%, they know they are an exception already and don't trust broad-spectrum studies any more than they trust those fast talking salesmen.

10% is still a very large potential.

perhaps, but only a large potential to waste capital on a much-hyped technology that appears to be sub-optimal in the typical environments that humans live in. I was amazed that some of these windmills are net consumers of electricity after the high-tech electronics are factored in.

The report outlines how much of an economic bust this technology is for widespread usage to supply prevailing power consumption levels. Even if the numbers are out by an order of magnitude, I don't believe the gist of the conclusion changes.

Maybe small windmills fit best for pumping water at the local village well as a locally built product, but the hype used by manufacturers to peddle them as a green high-tech alternative for urban/suburban settings is very misleading.

perhaps, but only a large potential to waste capital on a much-hyped technology that appears to be sub-optimal in the typical environments that humans live in.

You missed the point above - if 10% of the population live where small wind turbines are viable, then that is still a large potential.

A bit more than 50% of the world{s population live in cities.

Homepower publishes an annual review of small wind turbines....
.....and has done many articles about potential output and doing site surveys.

It isn't hard for potential buyers to educate themselves about their location's potential for wind power, but there's always someone who'll buy a snow sled in Florida, just in case.

It isn't hard for potential buyers to educate themselves about their location's potential for wind power, but there's always someone who'll buy a snow sled in Florida, just in case.

Since most wind turbines are a large expense to the average homeowner, it is my opinion that potential buyers actually purchase a data-logging anemometer, and install it on a pole exactly as the turbine would be installed, to get real data for their site.

Sure, it is a big expense, but better to do that then spend around US$25k on a turbine pole and turbine, only to then discover they are not generating the kWH's they were hoping for.

Residential rules based on esthetics will change once brown outs and black outs occur. A very real problem is the stress on the towers from high wind speeds with larger rotors. If I recall correctly in a 100 kph wind each square meter of rotor sweep equals about 100 kg.

R4, et al;
I live on a fairly windy bluff looking down on Casco Bay in Portland. I wouldn't chance a tower on my property, since we're packed tight to neighbors, but the variety of landforms around here make the situation change from property to property. We have several island communities that are essentially part of the City, and there are considerable possibilities for wind there. Lots of spits of land, sticking out into the water, where obstacles are low.

The situation is in motion here, so you can't conclude 'Non Starter' just from that article. We have some reliable times of day/year for wind, too, with the ocean's help, while I see the Solar Potential as the priority here, since in the coldest parts of Winter, Portland has many clear sunny days, giving both heating and electric collectors a great source when it's needed most.

(But on those windy nights, the chance to turn some of that wind directly into resistance heat is a tough idea to banish from my thoughts..)

Hi Will and everybody else unhappy with the article,

I generally agree with what all of you have to say,technically, but today I believe you are misinterpreting or misconstrueing what the author has to say.

He is simply saying that small wind turbines in actual practice are all to often installed in unsatisfartory locations, and that the installations are suboptimal;he is not attacking sall wind turbines as such, but rather the bau approach to selling and installing small wind turbines.

Most of the readership here insists on reading every article and comment as if it were a blueprint or a specification on a drawing.

The keypost is not a TECHNICAL DOCUMENT as such; it is better read as COMMENTARY on business practices and the failure of people to understand the "on the ground" AND "UP ON THE (too short) TOWER" realities of small windpower.

And I must agree with Kris, speaking as a person who has spent much of his life in voled with machinery and construction work, that in common English usage, a tower thirty or more meters high capable of supporting even a small turbine cannot be described as "small".

Your average construction worker or real estate agent or banker or zoning official or NIEGHBOR accustomed to ordinary residential customs and practices would describe such a tower as a "Big Mxxxxx...r!"

At any rate , I expect given the prices quoted, most homeowners would be better off with solar pv than wind turbines, if they have even moderately good spots to mount pv modules.

He is simply saying that small wind turbines in actual practice are all to often installed in unsatisfactory locations, and that the installations are suboptimal;he is not attacking small wind turbines as such, but rather the bau approach to selling and installing small wind turbines.

I might agree with that, if the OP had actually written that somewhere.

Instead, he chose to say this :

"Wind power rules, but small wind turbines are a swindle."

I was able to find web test data on small turbines, that was much closer to claimed curves, and so the OP has overlooked a much more important question in his headlong rush to arm wave. (as often happens)

To me, it looks like wind speed alone, is NOT a good enough energy predictor.
The scatter graphs in the UK report, reveal a lot.

The big players may know this (but keep it close to their chests), and this could be another reason why capacity factors of newer sites, tend to be significantly better ?

Hi, jg,

I probably should have said "his message is" or something to that effect instead of "he's simply saying" but I believe I have captured the gist of the author's intended meaning.

We have a hard time here on this site reading for message and nuance.

A little hyperbole and exaggeration are customary parts of the day to day reality of written communication in our society.

It is needed to counter the advertising and renewables worshipping copy printed in so many forums, including major newspapers.

Sometime back I read a puff piece picturing a turbine of an oddball design mounted on the roof of a two story buildingsurrounded by similar buildings;the writer implied that it was goung to save a lot of energy of course.

This was in a major paper I have bookmarked ,but I can't remember which one.I strongly suspected at the time that some wind welfare money was coming up for grabs, and the paper was pushing the political angle of small wind for that reason.

I'm not knowledgeable in this respect but I doubt if that machine would ever generate enough power to pay its installation costs.

You sometimes must fight fire with fire.

I probably should have said "his message is"

The author should have stated his analysis and conclusions neutrally. That was not the case, hence his statements are unsupported by his admittedly narrow, limited evidence.

You sometimes must fight fire with fire.

I watch The Newshour to obtain as neutral reporting as possible. Give us the facts, and reason should suffice. There is far too much propaganda floating around from highly paid shills and politicians against renewables that we don't need more slanted coverage.


45 ft, 145ft, does not matter. In North America it's gonna be difficult to find a municipality that will allow 45 foot poles (I assume from the roof - average house is 20-30 ft tall to begin with, so a 45 foot pole sticks out 20 ft above the roof) with a rotating noisy object on it. Nobody will insure such a structure either. In Canada putting a ham antenna in a burb is a problem.

It would require quite a legislative change. Cell phone industry won this battle: they need federal approval (Industry Canada) which overrides all provincial and municipal rules, for better or worse, without that there would not be a single cell tower anywhere (NIMB). They can show a benefit. Can wind show it at 9000 euro for rated 600W? (Ampair 600)

Good point about the towers. So an industry was able to put incredibly huge towers just about everywhere in every city and suburb.

But that could never happen for wind? Every? Why?

On a related point, if you put a turbine on top of one of those gigantic cell phone towers, would it ruin the reception?

It would ruin the tower if it was big enough to be useful.

Added weight, vibration, and torque loads would cause additional stress on both the tower and the communication gear mounted on it.

Will, if you put small wind turbines on masts of 80 to 140 feet, then you cannot call them small wind turbines anymore. Rather you should call them large wind turbines with ridiculously small rotor diameters.

lol, well put :)

Paddling a kayak on the open ocean doesn't make it a ship. Just ask Fred ;-)

Oh yeah?! Wanna bet? Here is the SS FMagyar alongside that puny little Royal Caribbean cruise ship The Oasis of The Seas ;^)


OK, Capt! Which way to the Tiki Bar?

Aft deck, just past the steel drum can't miss it!

What's that gray thing coming out of the water above the smoke stacks? Looks like somekind of sea dragon...or could it be a plume of corexit?

What's that gray thing coming out of the water above the smoke stacks?

That is a plume of water from a fire boat. The picture was taken the first day The Oasis arrived at its home port of Port Everglades and the fire boat was part of the official reception ceremony.

That cruise ship is one ugly, bloated boat...

But for a given output is the large wind turbine with ridiculously small rotor diameter more economical than a large rotor diameter turbine with a ridiculously short tower?

Since the energy in the wind increases by the cube of the increase in wind speed and is reduced by turbulence it makes more sense to spend $ on adequate tower height. A larger (more expensive) turbine is just a waste of more money in the wrong place/wrong height. Get'em up there where the quality wind is! Put PV where the sun shines! Put hydro where the most water falls the farthest!

The nail, on it's head.

But for a given budget a taller mast make more sense that a bigger turbine, other factors permitting. Overall system cost may be a better metric for the words small and large than mast height or turbine size.

Just an opinion.


How about you find us instruction from small wind manufacturers, explaining that a height of at least 30 meters is needed?

Or provide us with some surveys, showing that home wind turbines are on average installed over 30 meters high?

I think you are imagining something that doesn't happen in practice.

I've already provided the AWEA reference above, which is 80-140 feet in height.

Note that I'm not the one writing this article, I'm merely pointing out that the 'experiments' cited do not meet minimal turbine heights.

In the US, small turbines are rarely placed in the urban environment, so the wide-sweeping conclusion in the article is not supported by where small wind turbines are normally installed (in the US, at least). From the AWEA 2010 Global Small Wind Market Study;

In 2009, 187 units were reported sold for use in urban/rooftop settings in the U.S., representing 400 kW of installed capacity and less than 2% of the U.S. market.

Here's a chart that illustrates the difference in wind energy at different heights;

Note there there are buildings and trees within the turbines' turbulence zone;

The general rule of thumb for siting wind turbines is that the bottom of the blades should be at least 30 feet above any obstruction within 500 feet.

The height of the tower should place the bottom of the turbine blades at least 10 meter / 30 feet above the top of any obstacle within 100 meters/300 feet of the tower. -

Do you know if anyone has tried lashing the tower to the top (sturdy) branches of a tall tree? I'm assuming that this is completely unfeasible for a variety of reasons, but it does seem like a way to get a lot of height without paying quite so much for the full tower.

How High?
The most common mistake made with small wind-energy
systems is putting a turbine on too short of a tower. As with
any renewable electricity system, the collector must have good
access to the fuel—it needs good wind, which is somewhat
different than other renewable sources. The power available
in the wind increases with the cube of the wind speed. This
means that there is nearly 100% more power available in 10
mph winds than in 8 mph winds.
While we might perceive some puffs and gusts at
ground or rooftop level, there is little usable fuel at these
heights. The rule used by experienced wind installers
is to place the whole rotor at least 30 feet above any
obstacle (usually trees) within 500 feet of the tower or the
prevailing tree line, whichever is higher. Keep in mind
that you are installing the wind turbine for decades of
productivity—trees your turbine may barely clear today
may be considerably taller in several years. Get it right
at installation time by estimating mature tree growth and
sizing the tower accordingly.
In addition to access to winds of sufficient quantity,
the 30-foot rule also gets the turbine rotor above much of
the turbulence created by any nearby obstructions. While
turbulent winds are reduced-quantity winds, they are also
reduced-quality winds, putting considerable stress on a wind
turbine by their constant buffeting and shifting. Turbulence’s
continuous pounding strains all wind turbine components,
adding to maintenance requirements and reducing the
equipment’s life.
Short towers result in a quadruple whammy: Reduced
wind speeds, more wear and tear from turbulence, less
electricity, and compromised reliability. Ampair is one of the companies in review. At the bottom of a page there is a real life picture of a 6kW system on a pole eyeballed to be 10m judging by th rotor size. In clearly rural area they put it quite low and within nice turbulence from trees, house and hedge. They clearly could not any higher

You don't by any chance sell small wind turbines ;-o

So this 'article' uses language and highly targeted 'analysis' to arrive at a predetermined answer. It's a shame to see something so slanted on TOD.

I think we should look at this article as a decision-making tool for the general public rather than a technical factsheet. Are small wind power plants *always* useless? Well, no, if you build them with 30-meter towers over open land in the right geographic region, they can work okay sometimes. And where grid power is unavailable, they can be the only workable option.

But that's not what the general public is asking. Right now, there are probably a million people out there who believe, or at least hope, that maybe they can put a little turbine on their suburban house that will help save the planet without breaking the bank or pissing off the neighbors.

The vast majority of them are wrong. They would be much better off buying renewable power from the grid (where possible) or pushing local government to support big wind projects and consumer choice of electricity suppliers, or maybe considering solar.

If you tell these folks that maybe, under certain conditions, if built right, wind power *might* be useful to them, wishful thinking will prevail, and even the best-informed of them will start chasing rainbows.

"Small wind turbines are a swindle" may not be a universally true statement, but it's good advice for most people.

Those statements are misleading. If the problem is urban/suburban residential spaces, then say so. But entire spectrum of small wind was attacked, so there is no reason to try to soft-pedal wrong statements.

I thought the article was spot on. In fact, it wouldn't hurt if a brief abstract of this post were affixed by law in big black letters on a white background on the packaging of small wind turbines, so that well-intentioned urban buyers can watch out.

" The Dutch 'experiment' above installed them at 10 metres, which in my opinion was a setup for failure. "

I obviously can't speak to Holland's rules, but the building codes here do not allow a tower over 35 ft. And this area is zoned rural. So 10 meters is very reasonable. Also, the tower must situated so that if it falls, it will land solely on your property.

Trees, or course are exempt from both rules, so we have 60 ft trees around most of the lots here, and the lots run 2 acres. So I have the space, but not the height to make a windmill practical.

A friend has a prime spot on a hill, and uses a 12' Aermoter to pump water. He's thinking of putting a wind generator in, and that should work on his site. Since he doesn't want to fuss with batteries he's looking at this or something similar; all comes back to expectations. Most folks these days don't appreciate the luxury and convenience of being able to flick a switch and turn on some lights. If there is nothing better to provide this convenience then small wind "turbines" are not a swindle. When I first worked on the stations they were fairly common in outback Queensland right up to the 'sixtys.
They were mostly 32volt and were used for charging "lighting plant" batteries. We had a little diesel that I started on Mondays for the Boss's Missus to run the washing machine and of the time the windmill kept the batteries on what we would call these days "float".
Never gave no bother. First job every day after breakfast was to "check the batteries" and first job every New Year was to lay the tower down and grease the bearings and replace the brushes if they needed it or not.
I'm guessing the three leg tower was about 50 foot and we had tackle and stands to lower it sideways with a tractor, never had no problems and generaly had it up again by lunch.
I can tell you maintainance is not an issue if you have a propper heavy duty unit and set it properly...I can't believe anyone would install a little homestead unit with all those guy wires and crap.

Thanks Kris!

I think it is awfully easy for manufacturers of any sort of renewable to make overstated claims for their product.

In the case of small wind, the problem seems to be especially severe. Expected electricity production is based on models, and these models turned out to be pretty much wrong. If one reads the Warwick Wind Trials Summary Report, the reason the models are wrong is two-fold:

1. The estimates of wind speeds put out NOABL turned out to be way too optimistic.

2. The power curves, showing how much power can be estimated for a given wind speed, also turned out to way too optimistic.

When put together, the forecast capacity factors were an order of magnitude higher than the actual observed capacity factors. The Netherlands data is supportive of the same problems occurring with the wind turbines tested there.

This is a problem for wind buyers. It is also a problem if folks are trying to put together EROI calculations based on models, because the model EROIs will prove to be way too high.

I wanted to add a few exhibits from the Warwick summary report to explain how bad the difference between modeled and actual energy production was.

This is the section of the report showing how actual results compared to model:

And these are the power curves observed compared to those published for a couple of different wind turbines:

A person wonders whether the power curves reflected lack of knowledge of the true abilities of the wind turbines, or if the manufacturers were intentionally being optimistic.

The graphs above were based only on when the turbines were actually operating, so do not reflect the many problems with reliability. When reliability problems are added to the mix, the amount of electricity produced relative to what was promised drops even lower.

Low mounting heights subject a wind turbine to quite a bit of turbulence. An anemometer is very small and lightweight, able to quickly turn to respond to fast changes in wind direction. Wind turbines are heavier, and turn more slowly, so do not realize as much energy capture as an anemometer in turbulent settings.

Hence, low turbulent mounting locations will not provide a reliable means of assessing turbine performance.

That's really the only way to explain the huge amount of scatter in those curves. You see an upper envelope where the winds are steady. I assume everything below this is due to gustiness, where the rotor cannot react fast enough. The wind energy doesn't collect as it gets deflected off the blades as it accelerates to its maximum rotation speed.

I'm left unsure WHO the target reader was meant to be ?

small wind turbines are a swindle.

is a wild arm waving claim, needing qualification.
Clearly, small wind turbines are doing a great task, in many sites.

Gee, so they are not as efficient as LARGER TURBINES ?
The author may think that an Amazing Revelation, but it's hardly news to anyone.


I wanted to add a few exhibits from the Warwick summary report to explain how bad the difference between modeled and actual energy production was.

This is a much smarter angle to take.

A table of Watt outputs means very little, but starting to peel-back any variance between Claims and Delivery is important.

That leaves the question of WHY the variance.
It is unlikely any supplier just makes up a curve, and given the scatter dots, are similarly low on most graphs, we need to ask:

what is different about Supplier Test conditions, and the site measurements ?

I'll look for other 'reality checks', to see if a why is suggested.

More found:

I found vendor plots stating "turbulence reduces power", and this test report

BWEA Ref Power @ 11m/s 231w

Notice in Fig1, power pretty much saturates at 250W, which is similar to the scater graph given for "Figure 10 – Ampair 600 – Eden Court 2"
but distinctly different from the scatter graph given for
"Figure 9 – Ampair 600 – Misty Farm"

Figure 9 – Ampair 600 – scatter plots, suggest three 'fit candidates' - could those 3 be for three prevailing wind directions ?

- so it seems there is some 'wind quality' factor (turbulence perhaps?), that gives wide variations in graphed outputs.

There is a press release here, that rather deflects the issue
(I guess that's no real surprise... )

I still cannot find raw test data, that the vendor used to create their curves.

I doubt these curves are totally fictional, so the key question is, why the variance ?
Could wind-tunnel testing, yield higher air-densities/laminar combinations, that shift the power curves ?

Even the scatter data suggests high measurement variance, so again it would be good to see wind tunnel scatter-pair data ?

I find this older report site

Which seems able to get much closer correlation between claimed, and measured results. ( why? - much less urban, and so less turbulence ? )
He does say "The winds in the Tehachapi Pass are nearly bidirectional. Most power producing winds are west northwest."

This does not include the same models, but it does say this about a smaller sibling: Ampair 100

It is significant among micro turbines that at 10 mph and 15 mph the Ampair 100 meets its power curve; at 20 mph the Ampair exceeds its power curve by 33%; and at 25 mph it exceeds its power curve by 47%.

So it seems Ampair are not known for inflated numbers.

I think it is awfully easy for manufacturers of any sort of renewable to make overstated claims for their product.

No different from any other manufacturer, I suppose... Caveat emptor!

For starters, most ads tout the EPA's estimated mileage for highway driving. Unless you commute on lightly trafficked highways, you probably won't see that sort of mileage regularly

I also wonder how wind turbines like the Honeywell WT6500 would have done in the test? It claims to be able to generate electricity at much lower speeds than other designs?

It's an intriguing design (I know a guy who plans to order one), but I agree with this statement:

Too many whizbang wind generators advertise their unique features, but only years of enduring tough conditions on tower tops will reveal a machine’s durability and reliability.

Also it only has a swept area of 6 feet and since the energy contained in the wind increases by the cube of it's speed and turbine output increases exponentially with swept the math. It claims to produce at 2mph, but it ain't much. While it may produce more over time only long term testing against other designs will impress me.

It claims to be able to generate electricity at much lower speeds than other designs?

Yes, but when you drill down to the kWh data, the energy gained, is 43kWh out of 2752kWh, or 1.56%, at that low-area of the curve.

Seems it has higher wind-loading, so puts more force on the tower...
- and does not scale well, so interesting, but not a breakthrough...

Interesting. It looks like most of its mass (which seems large for its swept area) is around the blade circumference. My guess is that it wouldn't track turbulent or rapidly-shifting winds very well.

I don't know why they bother describing it as "gearless". The diagram labeled "Traditional Gearbox Turbine" also appears to show a gearless design, which is common for modern turbines of that size.

The FAQ also contains statements of doubtful truth and logic, such as "Because the HWT operates in low wind speeds, installation is simple too."

Here's what someone who knows a lot more than I do about small wind turbines has to say about it:

It's important to note that the power available in the wind increases with the cube of the wind speed. Because of this fact, using the yearly average as a metric does not give the true idea of the potential energy available from wind. Also, there is a boundary layer effect to consider, that is, the wind increases with height above the ground over open flat ground and in a location with buildings and/or trees, the boundary layer is affected by those obstacles. Over open ground, the mill should be located at 40 feet (12 m) or more above the surface for good performance. Thus, the location of the turbine is also very important and the claims that small devices mounted to buildings or on roofs is highly misleading.

Furthermore, the aerodynamics of most vertical axis wind mills is not as good as that of a bladed type design. It's thus not surprising that the best performing mills in the test were both bladed designs. The resulting cost per kwh delivered is lowest for these designs by a wide margin.

All this was well known more than 30 years ago, yet, the salesman's hype seems to be endless. It's sad that the result of the proliferation of bad turbine designs is the added public perception that wind energy is too expensive...

E. Swanson a nutshell.

I must admit that I am not surprised that small wind-electric fails to pay for itself, but I am quite surprised that several of the models didn't generate enough power to support their own control electronics.

This is the problem with "FREE" energy, it isn't free.

We jumped on the solar heating band in the 80's.

After a year we found it had cost more for electricity to run the thing that we saved in heating costs. Also our power came from Coal Fired plant. Sold unit and paid for new standard system and had enough left over to pay for about 5 years of fuel.

That wasn't a problem with Solar Heating, you just got ripped off.

The energy coming into a solar collector IS free. The collector isn't, but you have to be careful what you buy.. as with anything.

All energy is free, but collecting it in a usable form is the expensive part. Gasoline is free also,
its just those pesky little costs like drilling, refining, transporting that make it so costly.

The unit was on the house when purchased and was designed by an architect who specialized in solar systems. When you compare physics to "ripoff", I'll take physics everytime.

Look, you got at dud.

Clearly, Hot Water Panels are working all over the world. Sorry the system didn't do what it was supposed to, but what you've described is a breakdown or a fluke or bad design, but you present it as if 'Solar doesn't work'. You just got burned. It wasn't rare in that first push.. there were a lot of fly-by-night systems installed, and it left you thinking 'The Idea' is bad.. not just these bad systems.

After a year we found it had cost more for electricity to run the thing that we saved in heating costs.

There is something seriously wrong with your system! A well dimensioned solar hot water system should save you energy and money. Talk to a reputable pro in your area and have it checked out.

This house was purchased in 1980 with solar in place. I discounted the offered price to allow for a conventional system if necessary. You can't be ripped off when cost = $0.00

The operating costs were absolutely higher than the usable heat generated by the solar system.
Given the power used by circulation pumps and supplemental systems, the design of the system, climate, location, it didn't save or energy.

I wanted to make the point that ones eyes should not glaze over at the mention of wind, solar wave action geo-thermal etc. Each application is different and to immediately defend a source of energy without all the variables is unrealistic.

This amount of electricity generated relative to that used seems to be dependent on how good the location is. It seems to me that it would be a quite infrequent event that energy use would exceed energy generated, since if the wind turbine is broken, I would expect most folks would make certain the inverter is turned off as well. I would expect that the only time energy use would exceed that generated would be if the amount generated was quite low due to poor location, and the inverter used a lot of electricity for its operation.

Several thoughts on windmills.

Windmills of all sizes are maintenance hogs and one problem with the large units is trying to find people to work on them. My brother-in-law had no problem with the tech knowledge, it was the requirement to climb the tower a number of times in an allotted amount time that stopped him. The physical height will exclude many older highly qualified techs.

Windmills, especially in cold climates, require a fair amount of power to heat the lube oil for the turbines. The oil becomes so thick at the colder temps it refuses to flow without heat, even when the windmills are not turning.

With respect to noise, it is not just the high pitch noises of tip speed but also the low freq sound of the disturbed air that causes problems with people.

Besides they are UGLY. I have a great picture of bluff full of windmills shot across an oil field.
You can see the wind mills but no indication of an oil field (mesquite).

All this being said we just signed a contract with energy co. to place windmills on 120 acres of west Texas property. Just waiting for transmission lines. Another problem, areas with lots of wind have no lines.

Maintenance problems were issues in both studies. Sometimes it was the inverters that had problems, not just the wind turbines themselves.

Wind driven generators/alternators have been used in this area for years. Before rural electrification, almost all the homes outside towns had a wind-gen of some sort. Most were old car generators on windmill towers hooked to a couple car batteries. Generator failed..go to the junk yard for parts. No one attempted to power entire house with wind, not dependable enough.

Wildlife is affected as well. For example, Bats experience exploding lungs. Plus, what happens when a turbine goes haywire and explodes? (see youtube).

This year, driving along I-85 (Oregon) along the Columbia River, I observed hundreds of windmills where there had been none just two years earlier. It actually made the trip slightly more interesting - windmills to look at instead of desert scrub.

The greatest concentration (at least visible from the Interstate) of windmills is near the interchange to Arlington, Oregon along I-84. They are located on both sides of the Columbia river in this area. I thought it might be interesting to see them from Google maps, but either the satellite images are outdated or I can't find them aerially.

Many more are planned in the general area - 338, 2.5 MW turbines are planned. It will be close to the largest turbine installation in the world when complete.

  • However, BPA says 303, 3.0 MW turbines:

  • Interesting that they went with GE turbines - Vestas has their North American Headquarters in Portland.

    Of course I meant I-84 (wrote 85). Still, it's a tremendous number of turbines in such a short time. So, how many turbines does it take to equal a small hydroelectric dam? The reason I'm asking is because a dam, obviously, is a major structural undertaking whereas a windmill takes up just a few square yards each (plus all the cables, etc.)

    Sure, I could calculate it myself but I'm lazy.

    So, how many turbines does it take to equal a small hydroelectric dam?

    Hundreds. Somewhere between 100 and 1000, depending on what you mean by a "small dam", what kind of wind turbine you're talking about, and whether you count peak capacity or average.

    The Oregon wind farm you're talking about has less average capacity than any of the Columbia River dams in the region.

    I did a little more Research, as I'd observed more windmills on the Washington side of the Columbia River than the Oregon side, which as stated, are primarily around Arlington. The Washington windmills are visible from The Dalles (Oregon) for many miles before the Oregon ones become visible.

    That's a total of about 700 to 800 windmills along that stretch of the Columbia River! I guess those who managed to collect nice photographs of the river gorge pre-Windmill will see them increase in value ...

    Here's a link:

    SD - You can say all that again about windmills here in west Texas. I can't stand the looks of them turning or sitting still. Have lived here almost 50 years and can remember how the greenies would bitch and complain about the awful looking oil wells and pump jacks. Guess those folks haven't been thru here lately or don't care.

    Was talking to a power company guy a few months ago and he said maintenance is awful and if it wasn't for the subsidies they would turn them all to scrap.

    And now, we are looking to buy a quarter section or so and have found out about "wind rights"!!!! What's next???

    Hey, gotta find some way to keep all those once rich oil men living in the mansions of East TX cool in summer! Given that the oil money is mostly gone, what else you gonna do but listen to us "greenies", who been trying to tell you for 3 decades that there's a problem with energy supply?

    E. Swanson

    I personally think the field near Salina, KS adds interest to the area. There are 400 miles of otherwise similar views, and it's an interesting change. I don't mind a few pump jacks here and there, but a tall white turbine looks nicer than a row of rusty, oily tanks.

    But I'm adult enough to know the value of both, and will accept them versus the alternatives. Nobody really wants either in their backyard, but we need to accept them.

    If the maintenance is awful the vendor was poorly selected. Note that the maintenance work is a "good job" which requires some skill and cannot be off-shored. Not a bad power-down career choice, in my book.

    My brother-in-law had no problem with the tech knowledge, it was the requirement to climb the tower a number of times in an allotted amount time that stopped him.

    What was the climb requirements, and why was it there ?

    Was it safety, or coronary avoidance ;)

    I can't imagine the climb time is significant in service turnovers ?

    I just talked to brother-in-law and to best of his memory the requirement was at least 5 climbs of a 200' tower. My recall of the original conversation was 10 times and 300' tower. As to requirement I can only guess, but I would assume it is a combination of safety and efficiency.

    Regardless of the exact requirement or the reason behind it, limiting the number of qualified techs available is the result.

    I expect that before too long some handicapped or crippled up tech will win a discrimination case in labor court and after that elevators will be added to wind turbine towers, along with a dandy handicapped parking spot near the base of the tower. :)

    Seriously, they cost so much that adding a sling on a rope powered up and down with a small electric winch would be a trivial expense.

    Riding such a rig, properly designed, inside a safety caged ladder would be safer and faster than climbing the ladder anyway, for everybody.

    Furthermore I have worked on towers,but never a wind tower, being a rolling stone sort of maintainence guy, and I can say from experience that lots of tools and parts have to be took up and down;the heavier stuff often requires some sort of winch anyway.

    Having one permanently installed would not be that big a deal,it need be no bigger than a suitcase, and it would speed up inspections, maintainence, and repair work. It could easily be located within the last few feet at the top of the tower structure itself, there should be plenty of room for it in there.

    I checked a number of Wind Turbine job sites and all have physical requirements. Imagine the OSHA regs on a winch to haul a man 250' in the air. The turbine units I'm familiar with have an external system for parts but not for people.

    Especially if they weigh 300-400lbs.

    NAOM seem perturbed by renewables. I'm curious about your solar system. You don't mention its purpose. Was it a water heater? The solar water heaters I installed in the early days of the technology worked well, as primitive as those systems were. The ones that were maintained properly still work to this day Solar water heaters are simple systems. Why yours didn't work well is not the failure of the technology. Please accurately describe what type of solar system you had.

    Regarding your remarks about wind turbines, let me address a couple of your statements. I began climbing wind turbines in February, 2007. Here are some of the facts. Wind turbines are fairly maintenance intensive because they are large machines doing very stressful work. Your brother-in-law's reticence to climb tells me a lot. I've climbed as many as six 80 meter turbines in a day (as a now 58 year old) and am pleased that I can still do that. Most turbines are being equipped with climb assist devices that make climbing much easier. I've installed one version of this device. Many turbines are equipped with elevators (in Europe elevators are mandatory). Tell you brother-in-law that climbing is not an issue,

    Wind turbines OVERHEAT in cold climates, the single most common cause of faults. Gearbox oil does not have to be heated. Turbines with hydraulic systems employ hydraulic reservoir heaters as a safety provision. Gearboxes are the Achilles heel of large scale wind. Direct drive turbines are manufactured and could become the preferred configuration as the industry evolves.

    Your description of blade noise suggests you've never been close to a wind turbine. The sound the blade makes as its tip passes by at 240 mph is a "swoosh" that conveys the enormous power of these machines. The sensation is quite something.

    The lack of high voltage transmission is widely known as THE biggest problem for utility scale wind. We choose to spend 2 billion dollars per week fighting wars instead of building these lines.

    Your opinion about the aesthetic of wind turbines is as vapid as your ignorance of wind turbines is vast. I'd be glad to share pictures of the wind farm at which I worked along the shores of Lake Nicaragua.

    Let me guess.....climate change is a hoax and peak oil is a theory too.


    I'm not the least bit perturbed by renewables. And if fact if you had read my initial comment you will note we have a signed contract for a number of wind turbines on a piece of property in Texas.

    As to the solar system, it was a full house system. It simply did not work. That doesn't mean a newer or even properly designed unit wouldn't work.

    As to tower maintenance, the information was given to him when he checked on a position. I did not claim that all towers or operators were the same. I didn't say that anyone past a certain age could not climb a tower, only that some would not be able to pass physicals and that would lead to a restricted work force. I took a few minutes to look at job openings and almost everyone in the field required physical and contained language about ability to climb.

    Wind turbines may overheat in cold weather when turning but I fail to see how they would overheat if theyr'e not turning. Furthermore; I checked an old file and the RFQ was for "lubrication oil heaters". Yes I built thousands of parts for wind turbines over the years!

    I will agree that the newest turbines are much quieter but not all were created equal. One particular field was at "South Point" on the Big Island of Hawaii which is now shut down and I think is being salvaged. Another unit that was annoying was located in Clayton NM, it has also been removed. I was talking to a number farmers whose land is now covered by wind turbines who weren't thrilled by the noise but felt the checks they were receiving offset the annoyance.

    The evidence that climates have changed for millions of years hot-cold, cold hot is overwhelming.
    The evidence that man had anything to do with recent changes is not overwhelming.

    Oil like any other natural resource is finite. I had a number of conversations with a fried who had been in the upper management at Schlumberge(?) and we came to the conclusion Oil production will end when it costs more to produce than it's worth or when a sub that's cheaper is available. How's that for a gigantic DUH.

    All the time I've been answering this, I've been staring at my O'Keefe landscape and wondering what that mesa would look like with Wind Turbines horizon to horizon.

    The skystream generated about as much electricity as my family uses at home in a year. However, we use about half the UK domestic average.

    Also, we live in a built up area, with only moderate average wind speed, and several large trees in the immediate area. I would not get planning permission to erect such a large (ironic) turbine on my property, and it would be throwing money away.

    Unfortunately, we are not ideally situated for solar PV either. My best bet is to invest in a community owned small wind farm, if there were to be any built around here. That way, the profits would pay the cost of diesel fuel for a generator for when our power supply inevitably cuts out in a few years time.

    Two real-world tests performed in the Netherlands and in the UK confirm our earlier analysis that small wind turbines are a fundamentally flawed technology. Their financial payback time is much longer than their life expectancy, and in urban areas, some poorly placed wind turbines will not even deliver as much energy as needed to operate them (let alone energy needed to produce them).

    And recent real world tests performed in a stangnant pool of water confirm that micro hydro generators are a flawed technology as well, *NOT!*

    Sorry guys, but small wind turbines are most definitely not a flawed technology but you do have to do your homework and deploy them properly and in places where there is sufficient wind... Only a lousy carpenter blames his hammer when what he should have used was his saw.


    How would you rate a similarly priced PV installation at a similar latitude, in terms of yearly output?

    Even though I was just in Germany I really don't have a very good grasp of the pricing structure of PV systems in Europe to be be able to make a fair comparison. However if I just do a rough Euro to dollar conversion of the prices my guess is Solar PV would be the better choice. Granted in Germany I saw both large scale wind and PV and I didn't see any small wind turbines. Where I live in South Florida I discourage any potential customer from residential small scale wind turbines because we just don't have the wind for it. Of course the Germans still have great incentives for solar as can be seen by this poster at the local bank!

    German Incentives for PV

    This is a typical home installation, this one is probably about a 15KW system

    PV in Germany

    Great looking roof.

    I wonder what it would look like after 10 minutes of 2"-3" hail blowing around at 60-70 mph like we experienced here in west Texas in June of last year?

    I wonder what it would look like after 10 minutes of 2"-3" hail blowing around at 60-70 mph

    Here in South Florida where I live they have to be impact resistance rated to withstand hail larger than 2" and also the mounting structure has to be able to sustain a cat 5 hurricane with winds of 150 mph. If they don't, no permit.

    The hail in our storm broke all our skylights (.187" POLY), knocked chunks off bricks and destroyed 5 hurricane rated roll-up doors on my shop. That's just the unusual stuff...the usual stuff like windows, roofs, house doors, SS barbies etc. were also totaled.

    The hail in our storm broke all our skylights (.187" POLY).

    PV cover glass is typically 1/4" tempered glass. I don't know how that compares to .187" POLY, but they're not the same thing.

    I don't want to dismiss hail damage concerns completely, but I have not seen or heard a lot of evidence that PV panels from major manufacturers are vulnerable to hail. Search google images for "solar panel hail damage" and the best hit you get is a possibly very old panel made by who know who. And you also get things like this/ Perhaps you have some real world evidence (even anecdotal) to share regarding hail damage to solar panels, as opposed to all the things you listed above that are not solar panels?

    For places where hail is a concern, I think the wise course is to write local codes on the basis of, say, 50 year storms (twice the life of a PV system) and take out insurance policies. I'm sure that PV will be adopted more slowly in places where hail is a concern, but it should not be a show stopper. I think it also needs to be said that for the overwhelming majority of potential customers severe hail is not a concern.

    Get that damn satellite dish outa there! (Sorry, that's one of my pet peeves..)

    Yep, Nice roof ya got there, be a shame if a hailstorm or cyclone happened by.

    Not only that, if you install something like that in a city, cropping or open-cut mining area, you will have to clean the array every few months at a minimum. How many installations have riggers hard-points for such occasions? How many householders will fall to their deaths trying to clean their panels? Alternately, what will it cost to have a "government certified" cleaner/inspector come to visit on a regular basis? EVERYTHING has to be rethought.

    In rural areas, it makes a lot more sense to mount the panels on posts so that they are above human head-height and "grazing height" of livestock, but low enough to be able to drive or walk around them (carrying a ladder and mop) for inspection and cleaning. A cattle-grazing friend has a neat "panel farm" with a large battery bank and inverter system in the home paddock of his house. It works quite well for their domestic requirements, which include a couple of fridge / freezers, satellite TV system, all lighting, microwave oven etc.

    Power for activities in the "shed" comes from a serious, diesel-powered 3Phase unit mounted on a trailer, so he can take welders and other power tools anywhere on the property.

    Not only that, if you install something like that in a city

    I don't know why you think cities present cleaning concerns. Please provide some empirical evidence.

    cropping or open-cut mining area,

    What percentage of people live near such things?

    you will have to clean the array every few months at a minimum.

    Sounds more like a maximum to me. When it rains most of the work is done for you. It takes a lot of dust accumulation to affect PV panel performance.

    How many installations have riggers hard-points for such occasions?

    Pretty much all commercial installations do. It's something that more residential installations should probably also have, but the garden hose and the squeegee on a pole are other options.

    Alternately, what will it cost to have a "government certified" cleaner/inspector come to visit on a regular basis?

    For the life of me I can't see why the government would have to be involved. They don't inspect when someone paints your house or replaces your water heater.

    EVERYTHING has to be rethought.

    No, what you've mentioned are a few fairly trivial details that don't even affect most systems.

    The great incentive in no downpayment. With subsidized price one would be silly not to do it. Just free money, but only for the rich. No downpayment is one thing, but you still have to carry a long term mid-five digit loan.

    FMagyar - can they tie these loans with mortgages?

    Hey Canuck,

    In Germany at least Solar is most definitely not just for the rich.

    What inspires ordinary Germans to invest in renewable energy? Part of the answer is that it’s about as safe as government bonds—and brings a better return. Under the German system, renewable energy producers are given long-term, fixed-rate contracts, designed to deliver a profit of 7 to 9 percent. This makes green energy a secure bet for both investors and banks.

    The German system contains another ingenious feature: every year, the rate paid for new contracts falls, so a company that installs a large rooftop solar array this year will lock in a rate that is nearly 20 percent higher than one that waits until 2011. This has two salutary effects. First, it creates an incentive for would-be entrepreneurs to get in the game as soon as possible, thereby spurring a rush of investment (which helps explain why Germany was able to meet its renewable energy targets three years early). Second, it forces the green energy sector to innovate. If they want to stay in business and hold on to their margins, manufacturers have no choice but to continually seek out new efficiencies.

    My own 'Sunshine State' of Florida has a pilot project in Gainsvile based on this model.

    However here in the US of A we still have a class of scumbag lawyers and @#$%&!! bankers who are working overtime to scuttle PACE... (Property Assessed Clean Energy)Act.

    California filed a lawsuit against Fannie, Freddie, and the FHFA over their opposition to a home energy-improvement program backed by the Obama administration.

    The FHFA's Acting Director Edward J. DeMarco had this to say: “In keeping with our safety and soundness obligations, the Federal Housing Finance Agency will defend vigorously its actions that aim to protect taxpayers, lenders, Fannie Mae and Freddie Mac. Homeowners should not be placed at risk by programs that alter lien priorities and fail to operate with sound underwriting guidelines and consumer protections. Mortgage holders should not be forced to absorb new credit risks after they have already purchased or guaranteed a mortgage.” Emphasis mine, they get to say this with a straight face and a with a shining little halo over their heads?!...

    This is happening because the FHFA has directed Fannie & Freddie to avoid participating in the PACE program. PACE encourages home-energy improvements whereby municipalities make loans through special property-tax assessments for homeowners to install solar panels, energy-efficient heating systems and other upgrades. Local governments sell municipal bonds to fund loans that property owners pay off over 15 to 20 years. PACE liens, like all property-tax assessments, are senior to existing mortgage debt.

    There are days when my blood pressure gets quite high thinking about how the good folk at Fannie and Freddie get away with this stuff...

    Hi Fred,

    I do agree with you in principle in respect to a PACE law or something similar; such a law could eventually go a long way towards solving our energy and environmental problems.

    But we have more kinds of scumbags in this country than just bankers and thier mouthpiece lawyers.

    There is no doubt in my mind that there are enough scumbag wannabes ready to jump into any sort of gauranteed renewables scheme to cost unwary homeowners and lenders(wary but with thier hands tied) a substantial fortune, collectively, within a very short time.

    Most people, regardless of how many letters and titles are appended to thier names, are not in the habit of expending the time and effort to do thier own research and critical thinking.Once something has the "govt seal of approval" on it, they cease to think ALTOGETHER in all too many cases.

    A huge number of mortgage loans in this country are already underwater, and any small "leak" in the form of a questionable additional lien could affect individual house prices and house prices in general in a very significant fashion.

    I have no sympathy for banks and bankers, but they did not price such extra complications into existing loans when they wrote them.

    Perhaps a good solution would be for the "PACE " law to be restricted to new mortgages written after a certain date,and/or mortgages that are well above water by say at least twenty percent,or by gauranteeing the value and performance of the system by requiring the contractor/manufacturer to post performance bonds good for the life of the loan to cover such possible problems as water damage associated with roof leaks-which are going to be very common when lots of newbies jump into roof mounted anything, including solar.

    Such complications as these are a fine example of what Tainter was writing about in his book about collapse;efforts made to solve newly arising problems tend to lead to increasing complexity and rising costs in terms of both money and energy-although of course we can hope in the case of renewables that the efforts expended on the increased complexity will pay off-that the marginal returns will exceed the marginal costs.

    But once a program is embedded within the structure of our govt, it seems to assume a life of its own, and it rapidly develops a constituency of its own, consisting of every body who benefits in the short term.

    The beneficiaries have no incentives to consider the welfare of the overall society, and they are able to CONCENTRATE thier efforts at maintaining thier positions in effective ways,whereas the people opposed find themselves necessarily scattering and diffusing thier efforts by fighting thousands of kinds of freeloaders.

    The business of insuring farm crops from weather hazards is a perfect example;these programs are MARBLED with fraud, and everybody knows it.

    But if I spend my day at a public hearing opposing them, and hours sending emails and so forth in opposition,I might manage to save a single dollar, but more likely only a penny or two, out of my total tax bill,if I succeed.

    (In essence, given the fact that I can't spend all my time on the problem, my only real solution at present is to vote Tea Party.I am extremely reluctant to even say that, let alone actually do it, but both wings of American politics are now deep in the pockets of special interests of one sort or another;and none of these interests gives a damn if the SOCIETY thrives;thier primary interest is that society MERELY SURVIVES to serve as a host so they may continue thier more or less parasitic ways.)

    On the other hand, the people who sell and buy this insurance stand to make from thousands to hundreds of thousands quick and easy, and do so, due to the subsidies.They have EVERY incentive to plug away at getting what they want;at the upper end of the size scale, they can and do buy up the media such as newspapers in order to control the debate, and send thier people to state houses and congress-even to the White House.

    Now forgive me folks, but I have BEEN a so called "public servant"-words that make me retch and gag sometimes-and I have never yet met one who advocates redistrubuting the money currently spent on THIER OWN cushy health insurance and/or retirement benefits package equally and equitably among the poor people of the country.Public servants ALWAYS look after themselves first and foremost.

    I know of several ways to put an apple crop out of existence that cannot be proven, except if somebody stands an HONEST 24 hour gaurd-that is the only way you can ever be SURE your wife or husband has not cheated, right ?

    Example:A couple of perfectly legal but uncalled for and undetectable(after a few days) applications of Sevin will cause the fruit to fall off;voila, you get paid , a lot of times more than the crop would have sold for,while avoiding a great deal of expense and hard work the rest of the season.Go fishing, man, you are now on welfare.

    I have been unable to persaude my immediate family to participate in this gravy train because they are afraid of burning in everlasting fire for stealing, so you may take this as possible evidence that religion does possess a certain amount of utility.;)

    The chance of being prosecuted for this fraud certainly appears to be less than the chance of getting seriously hurt falling off of a ladder picking the apples, so any rational risk assessment would lead the grower to cheat.

    Incidentally the local program is being shut down after losing megabucks, but it will arise from the ashes again in a few years in slightly different form, as it has several times already;such a program has been known to encourage farmers to expand thier production of a particular crop as much as ten times in some localities-temporarily.

    (Will Stewart you are generally a very astute guy, but when it comes to communicating technical truths to the public, I fear you are too much the gentleman and the scholar.People hear the ads, which are repeated endlessly,but the politely worded warning labels, if they exist, are not emphasized and are buried in the small print.

    I strongly urge you to read The Douglas Adams series about life and the universe, you will roll in the floor when you read how required public notices are dealt with by people intent on having thier own way.I read quite a lot, and I promise everybody that these books are among the top tenth of one percent funniest and most entertaining written in the last half century.)

    For what it is worth, the thoughts laid out above have a lot to do with my being what I call a conservative, but of course that fine old word has been hijacked by politicians and businessmen and does not mean the same thing to anyone else.

    I recognize the need, the necessity of govt;govt necessarily serves many functions that can no longer be fulfilled safely or reliably by any other institution due to the complexity of today's society;but it can grow so big and so set in its ways that society may fail as the ultimate result of social/governmental paralysis.

    For what it is worth, let us suppose that there had never been any medicare or social security programs enacted;certainly many millions of people would have suffered grieviously as a result, including many people important to me,but perhaps most people-including your truly- would have been considerably more careful about preparing for thier own old age.

    Had this been the case, we would now be in far less hot deep water in terms of facing a possible economic collapse tied to impossibly large promises backed by ever shrinking means.The current level of social complexity may prove to be unsustainable;in my opinion it will so prove;but I am still glad we have medicare and ss, as I would have had to actually work much harder to help look after my old folks otherwise.

    I am not certain if I will be on the losing or winning side of the great ponzi scheme personally;If I get really sick, I will "win " at the cost of being sick.

    But I feel sorry for the little kids who are goibng to be entering adulthood over the next few decades;they are on what is locally referred to as "the shxtty end of the stick".

    My definition of the rich was not exactly right :-) Borrow 100,000. pay 6000 per year to pay off. get 8000 back from utility for electricity. Keep 2000. I suspect even I could borrow 100,000 under such conditions eh'

    FMagyar: Apparently we work for the banks. Didn't we just bail out those Bozos? And What do we get? I think the PACE program is a good bet. It helps the energy conservation and renewables industries. That puts people to work, rather than giving away free money for people to stand around and look at each other. I think we should send our financiers to reeducation camp and have them building compost piles, a la Chairman Mao. Our President, if he is actually for the Pace should twist arms to get it. Let the banks cry foul. The really odd thing is the talk about putting people to work. Yup. They got the talking part done. Steven J. Scannell Try the tripe.

    The great incentive in no downpayment. With subsidized price one would be silly not to do it. Just free money, but only for the rich. No downpayment is one thing, but you still have to carry a long term mid-five digit loan.

    The latest thing is the "solar lease", that goes along with a power-purchase agreement. Look up Sun Run, for example. The idea is that you 'lease' your roof to the solar company and then pay them for electricity, while your regular utility bill for electricity gets lowered.

    In California the rate you pay the solar company is usually around $.22/kWh, which if you are on a time of use rate schedule is 2/3 of summer peak rates from PG&E. So it's plausibly sound from a financial point of view, especially if you think that electricity rates are going to go up, and you're locking in a fixed rate on your solar. That rate is also more or less the real cost of a well designed and properly installed solar system.

    If you look at solar day maps the greatest installed base of solar PV is in some of the worst locations for it to be.

    If you look at solar day maps the greatest installed base of solar PV is in some of the worst locations for it to be.


    The solar irradiance at Mars’ mean distance from the Sun (1.52 AU) is S0 = 590 Wm-2. Note that this is about 44% of the Earth’s solar constant (1350 Wm-2).

    Dear Reader, remember the remote-controlled Mars rovers, Spirit and Opportunity? How long is it since the last time you thought of them? Spirit landed on Mars six Earth calendar years ago today, Opportunity on 25 January -- and both still work fine! Sadly, though, Spirit has been stuck on the edge of a small dust-filled crater since May last year, one set of wheels inside and one outside the crater. Its future looks dim as the Martian winter approaches and it is in a poor position for continued solar power.

    Emphasis mine, therefore solar is a bad option on Mars... maybe they should of thought about adding a diesel generator!

    Dang it, FM!
    You know how to hurt a guy! My Favorite PVEV's, millions of miles from a service station, but they've served so much beyond their expected missions.

    All they need is a little dusting and they'd be in far better shape, alas!


    All they need is a little dusting and they'd be in far better shape, alas!

    A couple of illegal aliens from Venus, armed with squeegees might do the trick...

    Small wind certainly has it's place, as the picture you include shows.

    The suburbs are not that place, as the study shows.

    r4ndom: I would like to think we could innovate some more, if only we weren't so stiff about trying new ideas. I've mostly specialized in big offshore wind mill designs, but I toy with the small stuff, looking for ideas that may work. Suburbs have many sticks at the ready (almost) waiting for windmills. The telephone poles would work as bases for small wind mills. A retro-fit for the purpose would work, and if we do not try innovation in suburbs, and any where else, we will then deserve our failures. For the problems we are facing, we are pretty darned anti-innovation, and anti testing. Are we afraid to make 999 failed experiments for that golden ring of success? We had to wait for the silly test to be done, (Where?) at a height of 2 feet? What value, really. Test properly. Then the results speak for themselves. America should be testing 2000 windmills, of a small toy nature, because ideas are of value. I'm on Cape Cod. We used to have many wind mills in the old days.

    Solar already works in suburban environments and is cost competitive.

    I am certainly in favor of continued experimentation, but any suburb dweller buying any current generation wind generator is not getting their money's worth if they expect the payout to be in electrical power. If they are after an education, they will certainly get that.

    If typical residential codes supported higher masts and the small wind generators were more efficient and reliable that would be different, but right now that is simply not the case.

    Solar already works in suburban environments and is cost competitive.

    Not at night.

    Not during dark stormy days.

    We need to think outside the sunnyside farm box.

    And wind power doesn't work on calm days.

    Any home not connected to a reliable power grid must deal with inconsistent power supplies.

    The simple fact is that commercially produced, small wind power units sold at retail will never be cost effective.

    If you want cost effective wind power in the suburbs you'd better be able and willing to roll your own, and even then the odds are that you get an unreliable tertiary power source instead of a reliable flow of plentiful electricity into your home.

    r4ndom: Yes, I agree with your post. The possible exceptions to the rule would be here where I am on Cape Cod and places like Nantucket, possible exceptions. I was surprised by the results of the experimental small wind systems, as I thought that they were more efficient. Thanks.

    Well, you sure hammered their screw(y) conclusion. Micro hydro in stagnant water. Ouch.

    However, although they've missed the mark, you'd have to be a half bubble off level, or just plumb stupid, to completely dismiss the old saw that bigger is better. The facts don't always square with the idea that the best things come in small packages.

    I wouldn't use such language about other commentors here, but I believe the best solution for most urban residents is to purchase renewable energy (if they can) through their utility. Indeed, for any power I need above and beyond what my PV system generates comes from a 100% renewable energy option offered by my utility.

    And yes, the utility-grade large wind turbines are far more efficient, and gather much more wind at their greater heights.

    I agree. Except that I would use such language in some cases. But Fred is not one of them. In fact, I don't even consider him a case. His point was excellent, as yours have been. It is about appropriateness, which gets to the heart of the matter. Or rather to the matter in the head, the truly indispensable energy conversion unit.

    Who is completely dismissing anything?!
    See my response to Paleocon above

    Sheesh. A guy's got to be careful with the use of the conditional.

    What I in fact took from your remark was that you were right on the money, to use a different metaphor. It is about appropriateness and I'm very glad that you and others have made that point.

    I also believe that the keypost authors might be well motivated by the apparent naivete of many regarding the appropriate deployment of wind energy technology.

    Has there ever been a study done to determine the climatic effect of a large wind farm downstream? When you take energy from the wind, you don't get something for nothing. The downstream wind has less energy, probably as a combination of speed, coherence, and temperature. Climate patterns can be sensitive to such changes. I submit that it would be a hell of a note to spend a fortune on a wind farm and then discover that something like a farming area has been badly impacted.

    I think there's a study showing that the crop failures in 15th century Europe which led to the hunger which was the necessary precondition for the success of the bubonic plague were caused by the huge expansion in sailing ships which absorbed so much wind energy that the climate cooled throughout the continent leading to crop killing frosts.

    I should say that I only read the summary as the math in the body of the study was way beyond my grasp.

    I sincerely hope you forgot the sarconol tag.
    Otherwise, I wouold love to read that study. Better than monty python.

    Sacronol tag?? Is that what a half century of canned laughter and applause lights has led to?

    Sufficiently advanced sarcasm is indistinguishable from wingnuttery.

    Poe's Law, paraphrased.

    I've always prided myself on my ability to pick out the wingnuts in the crowd. True, as Plato said, it takes one to know one.

    Maybe, it's all relativism, but I get kinda jumpy when I think I see someone flapping his gums in an attempt to whip up a blinding storm.

    Why of course, that fits perfectly with the 'TRUTH'

    Does this mean the Somalis are fighting Global Warming?!

    Or does that just apply to the Pittsburgh Pirates?

    Understandably we view turbines from a position where grid mains electricity and grid natural gas are available easily and relatively cheaply.

    Photovoltaic and small scale wind power will never manage to compete .... unless huge subsidies are made available.

    However the situation changes when the main supply grids fail or falter.

    How much is that paltry 20 or 30 watts worth then?

    A home with say 20 watts available long term can run lighting, TVs, radios, computers, maybe water pumps and microwave ovens (in short bursts).

    Living in such a home sure beats living in a dark house without any facilities.

    These 'baby' power sources aren't worthwhile for most people - but are ideal for 'doomers'.

    Almost, Meta.

    'These 'baby' power sources aren't worthwhile for most people - but are ideal for 'doomers'.'

    These sources aren't worthwhile for 'people with the power on at an affordable rate', but are ideal for anyone (regardless of philosophy) whose power is out or undependable.

    Truth is that if their net energy return is less than 1, they aren't a solution for anybody in the long run, just something using current cheap energy to transfer it for a short while (untill it gets broken) ...

    Energy Return..

    Well that's always the IF, no?
    Then again, how many things do you have that are permanent solutions and return anything close to the energy they consume?
    You haven't bought AA batteries or a car lately, have you?

    Why are renewable energy tools supposed to meet that standard when little else does?

    "Why are renewable energy tools supposed to meet that standard when little else does?"

    If not, what is the point of buying renewable energy? Why not get electricity off the grid?

    'Why not get it off the grid?'

    Ask our friends in Peshawar or Baghdad. One reason is to have your own options available. The advantage of a diversified supply might be worth something beyond a mere kwh/$ comparison, and not just in a power outage, but also for girding against price changes, or simply to start moving towards a lifestyle where you discover HOW to live with independent power, where you can learn about batteries, and what Low-Voltage tools and appliances you might need to know about.

    There are several reasons to get Renewable sources of power, and yet I still hold the things I would buy to a high standard. I'm not justifying getting bad gear. What I'm asking is when are people holding them to impossible standards? (Like saying 'They'll never replace BAU')

    How many purchases, even Homes or Cars do people gauge with some kind of Payback yardstick? How about a cruise or a week camping? There's no payback. Cheap or expensive, it's rarely a standard, except when you've got something that DOES pay you back, just slowly. Then, it's a crime.. what a sham!

    The farmstead wind turbines of the 1930's were not all that different from modern backyard or rooftop machines in basic capability. It's mostly the expectations of the householder that have changed.

    Back then the old "WinCharger" was only supposed to charge a single 12 volt battery to run the radio set for an hour or two each night, plus maybe a few light bulbs. That was it. Today we want our new "Skystream" to support the full-time operation of all our modern appliances, high-intensity lighting and communication devices, plus make the utility meter run backwards and maybe top off the EV as well.

    These unrealistic specifications are the byproduct of seven decades of nuclear and fossil-fueled energy abundance. Until we dial back our desires to realistic levels, we will never be satisfied by renewables alone.

    These unrealistic specifications are the byproduct of seven decades of nuclear and fossil-fueled energy abundance. Until we dial back our desires to realistic levels, we will never be satisfied by renewables alone.

    Bravo!!!!!!! Just made the same point over dinner while discussing this item. We even had a short, 1/2 hour, power outage to provide the proper context. I want my wind to keep my batteries charged and sell whatever excess produced to the grid. As the fossil fuel supply available to generate electricty wanes and the spot-market prices explode, I can dump my whole discressionary load and use it to power the essentials. The person benefitting most will be my daughter since she'll be living through more future than I.

    Our family have a cabin here in Norway. Its not connected to the powergrid so heating is done with wood, cooking is done with natural gas/wood and for lighting we have a small Solar panel connected to a battery.
    One year the battery was broken so we had to go back to candles and kerosene lamps.
    And we quickly found out that you need a lot of candles to get a desent amount of light, and you need even more to get the same amount of light that you get from a 60W lighbulb. A simple lamp is way better
    than using candles or kerosene lamps.
    Everything exept the battery is over 20 years old. Only part we have needed to do anything with or replace was the battery.

    I see that none of the low-tech turbines from my favorite company Windside were tested. Given the applications these turbines are used for and the real world results they provide, I think it's clear why they weren't chosen--They Work.

    I've looked at their site many times. I'd love to see an independent review of these windmills. With all the challengers against VAWT's, I think they need to put their numbers on the table and show that they stack up.

    Anyone ever seen any info about them?

    Looking at Windside's published data, one sees that their WS-4a mill with a 4 meter area produces 400 watts at 10 m/s (22 mph). The rated output is at 15 m/s and supposedly gives 20 amps at 12 volts, or 240 watts. Not a lot of power, is it? Perhaps you are interested in one of their larger versions, the WS-30, with a 30 meter cross sectional area, which appears to actually be two turbines on a tower. That one is supposed to produce 3kw, but, with the tower(?), etc, it's weight is 3500 kg. There's no price data, so one can only guess what the charge for these contraptions.

    I must have missed your sarcanol tag...

    E. Swanson

    Are you accusing Windside of lying--that its machines don't perform for the applications they're designed to mate with? I avered they work, and they do.

    I quoted their data from their web page. That they work is not an issue, it's how well do they work. Like most Savonious Rotor designs, they are "drag turbines", which have low conversion efficiency. And, what's the cost per delivered kwh? With low conversion efficiency, it's likely that their cost per kilowatt is much higher than a horizontal axis machine and thus the cost per kwh is greater also.

    Whether they are lying is another question entirely...

    E. Swanson

    The main benefits of a VAWT are that they work well in turbulent air and that the generator can be mounted low down for easier maintenance. Being a drag type also means that they are nearly silent. For these reasons alone I would go for one as an urban solution - I just wouldn't expect a lot of power from one.

    Build one yourself out of an old drum and the cost of installation drops massively. Then right off that cost as being a hobby, and you might just be on the limits of worth doing.

    Yes, there's the now classic approach for the back woods types who want to experiment (like me). Using two drums cut in half and mounted 90 degrees apart on the shaft instead of one makes the torque on the shaft much steadier and the starting torque is better as well. Close to the ground, they would work reasonable well, but the wind resource is higher up in the faster air. Since they have relatively low efficiency, the horizontal force per kilowatt is rather large, thus the tower to mount the turbine of necessity becomes rather massive for a turbine sized for household generation. Thus, proper mounting is the biggest problem, IMHO. Then too, on occasion, the turbine must be lowered to the ground for maintenance and the larger mass of the turbine only adds to the headaches for the owner...

    E. Swanson

    Some new headaches, but building Towers isn't ALL that bad, and if you wanted to use a classic Four-legged Trussed design, you might find you could pack those Savonius Wings in a bit and simply hoist the beast straight down the middle for servicing. Might even look to having a set of weights that ride up when it's coming down, to make the process even easier, as you tweak out variations on your design. (I'd want a crow's nest at 25 feet anyway, just to have a nice Reading Spot.)

    Verticals, for all the lost efficiency, have some design advantages that make them much more accessible to the simple craftsperson, with bearings and blades that have lower speeds and less specific tensions to them, so can be created from a far broader range of materials.

    This also means they COULD be made far lighter than the 55gal drum versions we see depicted all the time. Fabrics like Sailcloth is not at all unthinkable, and the single-bearing axis means one could put the generator many feet below the Sails, so all the bearingsets are in between, and the heaviest portions need not be hoisted as high as the 'collector'.

    Such Simplicity means that if you want to double your power, it's not that hard to just build another one, two or three.

    Another design alternative I saw for a homebuilt Savonius (VAWT) to accomodate the lower RPMs, was to reconfigure the Alternator below over a much larger radius in order to reclaim the Magnet Passing Speed that determines output voltage. This size change allows the unit to retain direct drive for eliminating Gear, Belt or Chain losses, (and overall Turbine Weight) and again could be separated from the Sails by enough distance that it has no serious effect on aerodynamics.


    Thanks for your addition to this discussion. I hadn't considered making my own machines, but now I'm convinced that's the correct path to follow. I thought I'd posted a reply, but it must have gotten lost on its way to being published. My location is very wind-rich, and gusts over 100mph are likely with the severest of our winter storms, plus we have huge numbers of birds. I'm also not interested in generating enough juice to power a McMansion--refrigeration, back-up water heating and lighting constitute the primary load. I'm not getting any younger, so the very low maintenence requirements of these types is also very attractive.

    Thanks, Karlof;
    This is why the Windside ( has appealed to me. It seems quite buildable and repairable, fairly tolerant to imperfections, as long as you can tweak out the spinning balance in the end, and its basic tolerance for high and receptivity to low windspeeds. (As they allege)

    I found one article that shows a Windside mounted about 20ft off the ground in Madison Wi. which seemed as much of a setup for disappointment as the Keypost's testing, but otherwise really haven't seen any fair, real-world data on them.

    The arguments abound, I'm bound to try it out and see for myself. (I built a two-phase 4' high 'Split Barrel' type, only using Stovepipe metal, but have nowhere to loft it safely just yet. I think I'll drag it out to the woods Saturday, where I have lots of Maple sprouts just waiting to become a tough little test-tower.)

    I've also toyed with putting up a Fabric Horizontal that just looks like Neohippie Cheezy Nylon Lawn art.. up on the roof. Put some slogans on it and I get to keep it up there as part of my Free Speech or my Poor Taste. At least those values are still revered in this country, even if clean power makes 'em yawn!


    Does anyone have an estimate of how much it would cost for an installation big enough and high enough to power the average home (and how much it would cost for yearly maintenance)?

    And how would this cost compare to that for solar PV?

    Asking for it in relation to the 'Average Home' is trouble. The average home uses way too much energy, and so you're going to get an energy system that is pricey because it's feeding wasteful systems.

    The big problem is, there is no average home. Geographic location, presence of nearby hills, trees, and other buildings will change the answer by a factor of, oh, 5 or so, and local building regulations may limit the height to which you can build, which affects the number of turbines you need, and the cost, by a factor of 2-3.

    If we consider the "average home" in the U.S. to be in a relatively flat suburban neighborhood on 1/2 acre of land, with building regulations on structure height and setbacks, I'd say that it's *impossible* to put enough turbines on it to meet its power needs. In more rural areas with multi-acre lots, it may become possible, though probably not cost-effective.

    Great article and studies, really the kind of things that we need these days.

    Allways the same, people can get hooked on concepts without the slightest look at the quantitative aspects, and investing on insulation for instance might not look as green as a wind turbine ...

    Question on underlying fundamentals of diameter squared law:

    I'm trying to square away in my head what the origin of the (turbine diameter)^2 law is.

    Maybe WHT can help?
    Anybody? Bueller? Anybody?

    So assume we have wind blowing against a turbine blade and exerting pressure P.
    And the area of the blade is A.
    And the velocity of the wind is V =dx/dt.

    Since power (energy per unit time) is F * dx/dt

    then for the power W of a wind device we should get:

    W= P * A * dx/dt * k, where k is a fudge factor for adjusting for the attack angle of the wind against the blade.

    Is that about right?
    I don't know much about wind energy and am just trying to get a mental grasp around this thing.
    Wiki has not been very helpful on this one: Wiki link

    From basic aerodynamics, the power available from the wind is:

    Power = 1/2 * rho * Area * velocity3 * Cp


    rho is the density of air
    Area is the intercepted area, ie the area of the rotor disk
    Velocity is the free stream velocity of the wind
    Cp =( power output from wind machine) / (power available in wind ), and is the efficiency of conversion, which has a maximum value of 0.59, according to the Betz Law.

    Betz published in 1919...

    E. Swanson

    Step Back: close, but not quite. Wings in general, and rotors in particular, have an influence on the air well beyond their physical surface.

    For a spinning rotor, the best approximation is that all the air that passes through the disk-shaped area swept out by the rotor as it turns is affected by the blades. Wind power devices generally remove a fraction of the wind kinetic energy passing through the disk swept by their rotors.

    If you take this as given, you should have no trouble proving that the wind power is proportional to diameter squared and wind velocity cubed.

    But why should the fraction of kinetic energy removed from the airstream be a constant? Why doesn't it depend on the rotor size and shape? Well, it does, but there's an optimum. If you use the fattest blade possible, a solid disk with a slit cut in it (think of the slicing blade on a Cuisinart), the velocity in the lee of the turbine is minimized, but most of the air gets deflected *around* the turbine rather than through it. And of course, if you use thread-thin blades, the air doesn't slow down as it passes through the turbine at all.

    It turns out that the optimum ("Betz Limit") is to have the turbine slow the air down so that its speed in the lee of the turbine is 1/3 the speed upwind.


    Thank you for the link and the explanation.

    Very helpful.
    (This is the kind of shared stuff that makes TOD worth visiting.)

    Why the fall off in output per unit area with the smaller turbines? Perhaps they should stick winglets on the ends of the blades to reduce wing-tip vortex loss.

    Many of them do:

    But no matter how you slice it, small turbines will have bigger problems with wingtip effects than large ones. The power generated by the turbine depends on the area of the circle swept out by the rotor blades, while the wingtip effects depend on the perimeter of this circle. The bigger the turbine, the bigger the ratio of power-generating area to power-wasting perimeter.

    The best performing machine, mounted on top of a 45 metre high appartment building located on a hill, delivered 869 kWh per year (an average output of 99 watts). The worst performing machine, attached to the facade of a single-family dwelling, delivered 15 kWh per year (an average output of 1.7 watts). These results clearly indicate that the location is of decisive importance.

    So what kind of data is needed to determine if a site is windy enough to warrant a possible purchase of a turbine? (And how much would it cost to get such data?) What kind of wind speeds do you need to be getting? My mother keeps talking about how windy their neighborhood is (due to ocean weather effects) and I have wondered whether turbines are at all worth looking into.


    That depends on it's projected end use. If you're planning on replacing or supplanting "The Grid" and are looking at it purely in dollars and cents, I would do a "site survey" and determine if your local wind conditions are suitable as well as any required maintenance. You may find that it does not "pay" in a conventional sense, but if as many here at TOD suspect will happen sooner rather than later, energy availability whether oil or electricity, becomes erratic or fails altogether, than the "ecomonics" is a moot point. I've seen a few coastal communities with what seems either an onshore or offshore breeze going most all of the time, yet looking around see no wind turbines, PV or anything else, yet the power fails even briefly, the screams of outrage can be heard for miles...

    At a rather low cost, a small, well engineered turbine with inverter and storage might well help to ensure that (depending on your home loads of course), that you could have power to at least run lights, furnace power (for a gas or fuel oil furnace, etc.), microwave etc. In these circumstances as the TV commercial used to say..."Priceless"!

    I can crunch cost numbers myself. What I was really asking for is technical help on how to do a site survey, and how to translate data on wind speed into expected kWh for a given turbine, in light of the studies above.

    I can crunch cost numbers myself. What I was really asking for is technical help on how to do a site survey, and how to translate data on wind speed into expected kWh for a given turbine, in light of the studies above.

    You are right to be cautious, as one detail that DOES come from these test graphs,
    is that Wind Speed alone, is NOT enough of an indicator.

    There are variances in result, that are a lot larger than the wind differences, so there are clearly additional factors that can lower delivery (turbulence ?)

    Sadly, no one seems to be focused on finding and removing that variance, with better metering tools.

    In the absence of proven metering tools, you next best step would be to hire/borrow a real turbine, and do a pilot scatter graph, where you make you own site correlation between Indicated Wind speed, and actual kW delivered.

    I have a bergey xl1 atop an 85 foot tower. The tower is atop a little mountain of 2100 feet and there is little vegetation and no structures that can create turbulence. It is considered one of the best sites in southern Vermont. I've had it operational for nearly five years.
    Here's some of my experience with it:
    It does make noise
    It is difficult to know how much it actually generates unless you spend more money for meters and etc. or make recordings and keep a record,
    My best estimate/guess is that mine generates at most about 25% or our power.
    Wind here in Vermont is very seasonal.
    Mine was struck by lightening and cooked the rectifier – had to drop it to replace that
    During that process it was noted that the blades are de-laminating and I'll need to buy a new set
    Two winters ago it was seized up by an ice storm. No wind to keep it moving and it became completely immobile due to a thick ice crust. With a little more bad luck it could have accumulated enough to collapse it..
    What would have happened if strong winds blew up while it was heavy with ice?
    It does take up space for the guy wires.
    One needs to keep vegetation cleared away from the guy wires and to keep access to the turbine.
    I'm now 67 and may not wish to perform the maintenance much longer.

    Maybe you could sell tickets and let your local Rock-climbers earn their stripes to become 'Wind Service Techs' .. I hear that a lot of Wandering Cliff-junkies are making a living this way now.

    For those that have a constant wind resource (> 10 mph) and want to know more, Check out Paul Gipe's books at:

    Wind energy can be ~ half cost of PV, If you have the location- most of us don't.
    Best site for latest on Feed in Tariffs. FIT's make RE happen.

    Having lurked for years on TOD, I am very compelled to comment. I happen to agree with much of Kris' report. My agreement is not based on third party hearsay, but personal experience. Perhaps some of the words used could be toned down a bit, but small scale wind is super tricky and more likely to siphon money that would be better spent on photovoltaic or domestic solar hot water systems. At one point Ace hardware was to sell a turbine to mount on a house. This really demonstrated how naive and dangerous the rush to small scale wind may potentially be.

    I often wonder how many readers actually own anything RE related and are willing to actually speak of the less attractive realities of the investment/production and had to deal with the bureaucratic processes involved to permit and grid-tie small scale wind.

    In my area, I found the knowledge base was so low and painfully incorrect, notably among the utility engineers, county development planners and worse still RE contractors that I produced a presentation I give to the community every so often describing these technologies and their realities from personal experience as opposed to marketing spew and trade group publications.

    Sometimes, however, it is disappointing when so many in the RE and PO crowd debate and argue about things that they as individuals have never even bothered to deploy or use themselves. Examples in this thread demonstrate that a bit.

    What makes small scale wind difficult is that to truly know the limits of the site, a year's worth of data logging is required. Many people think where they live is 'windy' and assume it is good. A consistent 15-20 MPH wind is not common in most places and this is when the best kW production is realized. And for those recommending huge towers to put a 2kW turbine on, the costs to do so and maintain are not worth the effort. Might as well buy fireworks or hit Vegas.

    For residential and commercial installations, wind is great if the fuel cycle is well known and the politics/regulations to install are reasonable. Otherwise, PV/DSHW is a much better choice if the site allows for it.

    Looks like you did a good job putting together your presentation. I did notice one issue (not with your presentation) on page 49. The photo shows two expansion tanks in the DSHW system, and (I am told) these are mounted upside down. That's because the way they are mounted causes any gas within the working fluid will be trapped within the expansion tank. This also makes it difficult to remove the air when the loop is filled. A simple problem, yet one which could cause the system to fail over time. Also, I think your cost estimates are a bit high, as we hear around this area that a system with 2 4x8 panels installed would cost the owner $6000-$7000 total, before tax breaks, etc...

    E. Swanson

    Thanks for taking a look and the feedback. Regarding the cost estimate, I assume you are talking about DSHW, there isn't one..... So, I don't really follow the comment on the estimates being high since there is no installed package cost estimate on slide 55. The numbers only reflect a generalized estimate of the major individual components if a person were to go out and purchase themselves these devices. One must also factor in the consumables, pipe and pumps along with labor. DSHW will vary widely depending on many factors. Labor is the primary one given new construction in the US never includes DSHW plumbing and the space for a 80+ gallon storage tank for "future" deployment.

    If in your area 64sq ft of collector with say a 100 gallon storage tank sells for $7k installed, that is the price I paid for exactly this setup in a retrofit of a single story home with the tank in the basement four years ago.

    Helping the contractor out where I could, it is easy to see how in the course of intellectual contemplation we go through how we completely obscure the details of both installation (lots of unknown gotchas in retrofitting....) and operation (lots of unknowns as our assumptions prove to be different....). I see the same issue, more so, with PV. If PO is so scary and daunting, it is interesting to witness the physical and psychological barriers which exist that prevent PO's most ardent proponents, notably the ones who can afford it, from biting the bullet with renewables of any kind, let alone conservation, in their own personal space.

    What would be really cool is if you actually went out and invested in a DSHW or PV system. Then you could participate in the daily process of owning and operating such a system. It changes everything as you'll get to witness first hand how such technology and apparatus operates within your household under behaviors you control and the performance it does and does not return w/o relying on assumptions or intellectual contemplation. Let us know how your system ends up. I bet you'll love it! ;)

    Domestic solar hot water system costs, diy:

    reservoir tank, 250 gallon approximately-lumber and rubber roofing liner, one pieceliner donated, 150 bucks

    Circulator pump-140 bucks

    Collecter, one 4x8 feet- mounted on post so that it can be oriented in a few seconds to daily and seasonal sun-about six hundred dollars if all materials were purchased newexcepting copper tubing

    Copper tubing-saved up pack rat fashion when bought at sales over the last few years, new cost probably around 700 dollars

    Various plumbing and hardware supplies, including insulation, for entire system if purchased new 400 bucks today

    Total around two large-for a system that is of average complexity, manually controlled-I am going to switch on the pump when the thermometers say I need to, I will be passing by it several times a day

    My costs, around a grand, using lots of salvaged materials, plus my own unpaid labor.

    Yeah, Mac, it pays to be handy.

    These guys spec a homebuilt 4x8 collector for around $600 including copper. Lots of other DIY projects at this site as well.

    I pay about 90 bucks for my Grundfos circ pumps, $125 for stainless. Good differential controller about $140. Poly tanks can be had at salvage fairly cheap, good to about 160 f.

    Also, one can call dealer/installers for damaged/returned/blemished components. I found two nice 3x8 flat plate collectors with broken glass for a friend. He payed $500 for both and ordered new glass for $300. Total cost about 40% of their retail price. The seller also had two 120 gal tanks with internal heat exchangers, slightly damaged in a fire, $800 for both.

    I view all of my RE production as untaxed income.

    "If PO is so scary and daunting, it is interesting to witness the physical and psychological barriers which exist that prevent PO's most ardent proponents, notably the ones who can afford it, from biting the bullet with renewables of any kind, let alone conservation, in their own personal space. "

    Why do you seem to insist that PO advocates here are NOT doing this? A great many posters here have detailed their efforts in both Alt-E installations and in Reducing Consumption in various ways.

    Just the same, I do see the obstacles in my own way, beyond the 'mere' handicap of the high threshhold of many system costs and the disruption of having all the other fires of life to keep putting out in the meantime.. I'm not sanquine about the number of times This Site has flailed the words 'False' 'Fake' and 'Fraud' in conjunction with the kinds of efforts you are talking about.

    Self-doubt, Public Opinion and Inertia are certainly real forces to contend with, even if challengers might deride them as mere imaginings. ('Imagine we had a can-opener', eh?) Fear and Doubt are real opponents.. they seem a lot easier to beat when watching from the outside.

    Just heard Chrissie Hynde on the FM today..

    "The Powers that Be.. Force us to live like we do;
    Bring me to my knees, when I see what they've done to you .. "

    Gail, thanks for publishing this useful article. Kris puts out a fine magazine. The subjects and the writing are always interesting. The pictures and other illustrations he finds are amazing.

    "If you double the rotor diameter of a wind turbine, the blades sweep an area that is four times as large. Material costs double, but the yield multiplies by four."

    Not true. If you double the diameter, then other things being equal you double all other dimensions, and the material required will rise by a factor of eight.

    Asiawatcher, the outside domensions-diameter -are relevant -but cubic volume isn't, as the area and/or volume of space occupied by the turbine as it turns is mostly EMPTY,except for the air of course.

    Most turbines have three blades;doubling the length of the blades does indeed square the area swept by the blades, but it does not cube the amount of material needed to build the blades or the tower, at least not at any given tower hieght..

    The thing that really puts the hurt on wind power is that as towers get taller, putting the turbine up where the REALLY good wind is, the cost of building the tower DOES go up exponentially;I can't remember the formula, but one of the engineering types surely will post it.

    Schemes involving the building or repurposing very tall buildings to be used as factory sized greenhouses strike me as the hieght of absurdity for several reasons, but someday perhaps the stripped bare steel sketetons of otherwise unneeded tall buildings may serve as the skeleton of wind farms composed of many smaller turbines and a couple of big ones up top.

    I actually have no idea if this might be econimic- it's just a stray thought.

    It's a shame no one investigated this vertical:

    There are some vertical axis models, in the Dutch tests.

    They did not show very good numbers, even allowing for the low wind skew of this test.

    Only one model really came close to supplier indications, and that was the Skystream, which came in above the quoted equivalent capacity factor.

    Seems if your wind/install profiles match the Dutch site, then Skystream is a good fit.

    The design looks similar to other VAWT's with fixed blades. One well known design is the Darrieus Turbine and there were a couple of designs in the test work on the same principle. The Quiet Revolution system is going to exhibit similar aerodynamic efficiency as the ones in the test, such as the "Turby", and I think the main difference might be the possibility of lower noise...

    E. Swanson

    I was recently reading about Windbelt Technology. The company web site can be found here. There is even an instructable on how to build one yourself.

    I dont have the skills to know if this is viable, and from the vids it looks more useful for low power devices.

    I notice considerable kerfuffling about windmill height, so I looked into the heights of the axes ofr smock windmills (the ones that look like those in old postcards from the Netherlands). Scaling from photographs I googled up, assuming a typical tall man is about six feet tall, these ancient windmills were typically forty to sixty feet tall. They didn't need much power to knock don Quijote off Rocinante, but they did have power aplenty to grind a lot of grain and pump a lot of water out of low-lying polders.

    Obviously, once steam engines of greater efficiency than Newcomen's built up steam, and coal mined by expendable miners was cheaply available, the smock windmills turned into quaint vestiges from the past and enjoyed no great attention. Still, for a long time they ground away, quite practical and economical in their day.

    Aside from the various technologies (perhaps scaling down the classic windmill is the wrong approach for home wind power ... maybe something like this deserves a test: ), there is also the stance of the electric power utilities toward consumer-generated power

    Duke Energy, at least, does not care for the role of a power broker. If you are connected to the Duke Energy grid here in the midwestern US, they cheerfully stockpile any surplus that you generate (via the miracle of accounting), banking it to return to you in the form of free electricity when you need to draw from the grid (up to the limits of your stockpiled energy), and when you die, they get to keep the balance. Not much of an incentive for the homeowner to contribute to the grid, and no opportunity whatsoever to generate free cash.

    If distributed energy production is to become a reality, old-line utilities are going to have to adopt the role of power brokers as well as power producers and distributors. There is little effort to move them in that direction at present.

    Sounds like Duke are being pretty generous to me, for modest home generation systems. They are providing an electricity storage service at no cost. And it's not just "accounting" - they're varying the generation from other sources to keep the grid safe and working.

    The expectation of free cash, particuarly in cases where the homeowner generates less electricity than they use, but in other cases too, is simple greed. And, in the cases where a utility pays for solar or wind power at prices above grid prices, there's the potential for significant fraud.

    Some states use a "feed in tariff" system which forces the power company to buy consumer-generated electricity, generally at a higher rate than it is sold to the consumer. This adds incentive for consumers to add renewable systems.

    ... but I've always wondered: is it possible to game this system to operate as a mini-Enron? Suppose I throw a couple solar panels on my roof for show and secretly install an underground cable to my neighbor's house. We buy power from the power co at my neighbor's regular rate, and sell it right back to the power company at "feed in tarrif" rates.

    Anyway, apparently constantnormal doesn't live in such a state, so the power company can make whatever sort of crappy deal they like. But I wouldn't say Duke is being "pretty generous". They're not actually storing electricity, or doing any regulating and monitoring they wouldn't otherwise do: domestic generation just looks like a slight dip in the neighborhood consumption to them.

    You can argue that "stockpiling" is fair, but if Duke is keeping the balance when you die, that's just wrong. They're taking electricity from the consumer without paying for it, which is just as much theft as if I installed a bootleg transformer and stole power from them.

    I confess I ignored the "keep it when I die" line as hyperbole. If it's true, yes, it could arguably be theft.

    However while you are right that typically the variations won't incur much large-scale load-balancing work from Duke, because the contribution is small, they do involve changing the way their system works - especially metering, maintenance and substation control - which won't be free.

    The connection-deadline solar frauds in Spain were not exactly the same, although reports of PV generation at night are pretty damning. One wonders if the feed-in tariff there is generous enough to use high-efficiency lamps on grid power to keep the PV running and earning...

    One wonders if the feed-in tariff there is generous enough to use high-efficiency lamps on grid power to keep the PV running and earning...

    Haha, that's fantastic, but probably not. It only works if

    lighting efficiency * panel efficiency > buy price / sell price

    In the Spanish fraud case, the buy/sell price ratio was about 1/10, which is greater than the net efficiency of electricity -> lights -> panels -> electricity.

    This is all in good fun for now, but governments should probably be thinking about the perverse incentives feed-in tariffs provide...

    Altitude is everything High Altitude Wind Power: An era of abundance?

    What became of Kitegen?

    If you read the comments, you will find that I thought Kitegen wouldn't work. Perhaps my assessment was correct...

    E. Swanson