Photoblog: Another offshore wind farm under construction

I had the pleasure of accompanying my most famous client to visit another offshore wind farm under construction with the same turbines. We took the train to lovely Harwich an hour and a half away from London, and set out to visit the soon-to-be largest offshore wind farm.

This is part of my wind series. As noted before, I advise wind farm developers on their financing needs, including, as noted in the first link in the diary, US developers.

It will be the first of several massive wind farms which are larger than 500MW each (meaning they can produce close to 2 TWh of electricity per year), and a price tag in the EUR 1.5-2 billion range. That price can be split roughly in 3 similar-sized bits, being (i) the turbines, (ii) the marine construction work, including the foundations, and (iii) the rest, including development costs, electrical equipment (high voltage transformer station and cables) and, if relevant, financing costs. The size of the different fractions can vary depending on the distance to shore, water depth, site conditions and regulatory framework (in Germany, for instance, you don't need to build the high voltage export cable as this has to be taken care of by the grid operator).

:: ::

Construction typically starts with installation of the foundations, laying of the intra-array cables, and installation of the foundations. The offshore transformer station and main export cable are independent tasks which are typically done as early as possible as their absence prevents the operation of the wind farm - but these are "long lead items" - ie it takes time to order them and build them.

:: ::

Offshore transformer station

In this case, the project is so vast that it has 2 transformer platforms and 3 export cables. Here's one of the platforms. It is roughly 30 meters by 30 meters by 30 meters:

:: ::


Today, almost all of the foundations - the parts of the structure that are hammered, or anchored on the sea floor and carry the turbines - have been installed, as have most of the "transition pieces" - the intermediate part of the structure which sits between the foundation and the turbine, ensuring that the bit where the turbines are built is perfectly horizontal, and including the boat landing, cable tubes and sometimes some of the electrical equipment.

Here are some of the foundations with nothing on top:

(In the back, you can see the foundation laying vessel, a huge boat, but we were not allowed to approach, as it was engaged in manoeuvring with its anchors and the security distance was quite large)

Here's a transition piece:

:: ::

The turbines

And the same with the turbines on top:

Most of the turbines were still in the storage area at the port:

You can see the bottom part of the towers on the right, and nacelles on the left. Blades are also on site, but not visible on that picture

:: ::

As the first picture above suggests, a few of the turbines have been erected already, which means that there was activity across the different tasks on the wind farm, allowing it to see various bits of the construction. What is striking is the number of vessels engaged in work on such a wind farm; beyond a number of smaller crew vessels and various tug boats (not shown here), here's a sample.

Hotel boat

A hotel vessel for the construction crews, located on the edge of the wind farm. Workers typically spend 2 or 3 weeks in a row over there. With the site 20 miles from shore, you can save 3 hours of transfer per day for workers - plus they are not woozy or seasick when they get to their tasks...

It's like a cruise ship, except that there is no alcohol on board...

Transport vessel

This is a simple transport vessel, bringing the turbines from Denmark to the staging port. You can see the two tower sections (the bottom one is vertical, the second one is horizontal) and blades. I would guess the nacelles are transported by a separate boat.

Cable laying vessel

And here is a cable laying vessel. Notice the platform on the front of the boat, which can carry several kilometers of rolled up cable (in that case, the boat was not doing any installation):

With turbines typically situated 500-800 meters from each other (with larger distances in the prevailing wind directions, to limit wake effects), you typically need more internal cabling than export cable, and you need to know exactly where you put these cables, to avoid any damage (in a famous incident in an earlier wind farm, one of the vessels installing turbines jacked up through one of the cables, damaging it...)

:: ::

Installation vessels

The project was using at least 3 jack-ups at that point. Jackups are boats which are able to "stand" on the seafloor thanks to retractable legs which can be lowered to the seabed and carry the boat. Their usefulness is constrained, naturally, by the size of their legs (which limits the water depths they can be used in) and their carrying capacity, both in terms of useful loading area on board and of the capacity of their crane(s). The jackups used by the project were quite different:

The first one was a simple barge with no means of propulsion: it needs to be tugged to site. It was on its way to the construction site. We overtook it when we went there ourselves, and it still hadn't arrived when we left: the trip requires roughly 6 hours for such a barge. It can carry 3 full turbines:

As you can note, the tower sections have been pre-assembled onshore. Any work which can be done onshore is a huge time and cost saver as things are always more complicated offshore. In this case, blades must be installed individually.

The second jackup is a self-propelled vessel (ie it can move with its own engines); it can carry 2 turbine sets. It has strong lifting capacity, but the positioning of the crane between the legs makes it more difficult to load the blades onto the vessel in the harbor.

A third jackup vessel was available; note how the cranes are located on the "legs," giving them a lot more freedom to move. However that boat is also relatively small.

:: ::

There have been two philosophies to build offshore wind farms: consider that it is a wind farm project that happens to be offshore, or consider that it is marine construction work which happens to include wind turbines. In either case, construction has been complicated until recently by the lack of adequate vessels and the need to make do with equipment which had not been specifically designed for the tasks involved in the offshore installation of wind turbines. A lot of oil and gas people scoff at the wind industry people when they explain how difficult it has been to build the turbines: after all, the few hundred tons which need to be lifted when the various large bits of a turbine are being installed are rather puny compared to the massive structures built for offshore oil and gas platforms; but oil&gas people tend to underestimate (i) the logistics involved in transporting and building dozens, and now hundreds, of identical structures at sea, and (ii) the specific requirements of below-centimeter tolerances to position multi-hundred ton items 80 meters above the sea...

The land requirements in harbors for storage (but with reinforced quays to bear the loads), the carrying capacity of the vessels (to transport the parts 20km - and in forthcoming projects 100km out at sea), the transfer times, the crane specifics (to install towers, nacelles and blades, which are very different animals) make this industry a very unique one, and it is now just beginning to work out the best way to do things - and of course, all sites have different characteristics (depth, distance to shore, nature of the subsea soil, size of the turbines selected) which make standardised, universal equipment a pipe dream...

But it's happening - and it's keeping an increasing number of people busy.

There are worries about how quickly the supply chain will ramp up to accommodate the massive investment plans being contemplated; ironically, I still think that the technical side will be easier to take care of than building up the commercial teams of the various key players (turbine manufacturers, project developers, financing institutions) which must put in place the highly complex contractual framework for these massive, and still risky, projects. Right now, it seems it's the same people on almost every other project...

Very impressive, thanks for sharing.

What MW rating is each turbine? And do you have an idea of the cost to the public of each KW/hr coming from this wind farm to make it profitable? I would like to compare that to what I pay now, and are those KW/hrs subsidized at all by HM Treasury?

Many thanks

These are 3.6MW turbines. There are various cost estimates for offshore wind, but long term average cost can be said to be 10-15c/kWh. It's more expensive than onshore wind, but, like onshore, that price is essentially fixed and will be the same 15 years from now (if anything, O&M costs are likely to go down as the industry benefits from economies of scale)

Nice article and pictures Jerome. The question that comes to mi9nd is why offshore? Is there more wind offshore to justify the additional cost and maintenence than onshore?

The wind is better offshore (stronger, no turbulence) and better correlated to demand. You can put bigger turbines. There is no NIMBY, and you can go for large scale utility-scale power plants. In Europe, some countries are running out of space inland, and the North Sea is conveniently shallow. In the US, offshore areas are next to load centers, so no need to worry about new transmission lines from the Midwest or equivalent.


The wind is ... better correlated to demand

Do you have any data (or links to data) that you could give? It would be interesting to analyze.

Is that Euro cents or US$ cents?

Most real costs are euro cents, but it's not obvious that they can be converted at the going rate, as the cost base can be different in each country, depending on local sourcing, cost of harbors and the like. And which conversion rate do you use?

How deep is the water? Somewhere you mentioned that it was relatively shallow.

most of the North Sea is 10-40m. That wind farm in in the 10-25m range.

"... long term average cost can be said to be 10-15c/kWh."

Euro cents? I.e. 13–20 US¢ ?


When you say that the long term average cost of offshore wind is ten to fifteen cents per kWh
do you mean by this the cost of getting this energy fed into the existing grid?

If so then I suppose the actual true cost to the consumer is typically going to be another five to ten cents per kWh after the distribution utility pays its expenses and earns a return.

Of course I do understand that this electricity is going to be commingled with hydro, nuclear, and ff derived electricity, and that the actual cost of windpower will probably not show up in any obvious fashion on the consumers monthly bill.

Another question that I have been asking for a long time without getting a satisfactory answer:

How much does the wind industry contribute to holding down the price of coal and natural gas?

I strongly suspect that the public at large is already or soon will be a net winner -at the expense of those who own the coal and gas industries of course-in terms of saving more in reduced fuel costs than it pays out in wind subsidies.

Another question:Will recreational boaters be allowed in most cases to use the waters occupied by offshore wind farms?If not, how big will the exclusion zones be in relation to the size of the wind farms?

yes, this is the long term wholesale cost, delivered to the grid.

I have discussed the merit-order effect of wind in several past diaries, check the link near the top of this story. Yes, wind brings wholesale prices down in marginally priced markets, and that effect in Germany and Spain is larger than the added cost of the fixed guaranteed price to the wind producers.

Thank you,Jerome.

Wind power will be supplying over two percent of US electricity before long.Some other countries already get a far higher percentage of thier consumption from wind.

This implies a very substantial savings in the actual purchase of coal and natural gas by generating utilities of course.

Such a reduction in demand for these fuels must have a measurable impact on the actual selling prices, not only here but everywhere, since there is a world wide market for these commodities.

So for the numbers crunchers out there-what are some current estimates of the price elasticity of coal and natural gas?My seat of the pants estimate is that a one percent reduction in sales will produce a greater than one percent reduction in the selling price,meaning demand is inelastic.

Thanks anybody in advance.

Thanks, Jerome.

It's useful to see some of the details in the approaches for installing these offshore farms, and why it's still such a growing art, and is being approached with different philosophies that will have to be weeded out given their relative successes and failures.

We've been hearing a lot of challenges to Renewables here at TOD lately, with them being derided as 'Fossil Fuel Extenders'. I wondered what your take is on this WRT offshore wind?

Do you feel that the materials, replacement parts, maintenance and new turbines will be especially beholden to Oil inputs or an Oil-driven economy?

Are there ways to run cranes and maintenance or installation ships once they are at a windfarm using some of the power from the windfarm itself? I don't know what kind of electrical connections are feasible at this point out on the ocean.. or is that a job that really needs to be driven by on-board fuels?

Would a large offshore windfarm tend to keep maintenance gear onsite, or otherwise directly tied to a particular farm, or would such services more likely be contracted when needed?


Offshore windfarms use "normal" boats, fuelled by oil, but the energy input required remains very low compared to the output. O&M typically requires a few crew boats, and a larger jackup barge for big (and rare) interventions. Even big windfarms will share out such vessels with others.

How about all of the wiring to the wind farm? Who pays for that? How much does that cost--you say the wind farm is 20 miles off shore. Will the wiring be finished at the same time as the wind farm?

And why does the wind farm need to be 20 miles from shore?

Offshore wind farms are located in areas of lower depth, because the cost increases with depth. So sandbanks are typical locations for wind farms. Other constraints include shipping lanes, natural reserves, military areas, fishing grounds, etc. They are usually built far enough not to be visible from shore (although some of the early Danish and UK wind farms are quite close to shore)

Yes, of course, all the internal cabling is part of the construction budget of the wind farm, and it is a key part of the construction itself, as is the connexion to the onshore grid (although in some countries this may be contracted separately as it may be the responsibility of the grid operator). What would be the point of turbines unconnected to the grid?

Hi Gail,

Jerome stated near the top of the post that the export cable is included in the cost. He also noted that this can vary in some countries where the utility is required to provide the cable (Germany). Note that the 2 TWH of output assumes a 46 % output of rated capacity which seems a bit optimistic even for offshore wind. I think on Wikipedia this windfarm has a load factor of more than 40 %. At 40 % load the 500 MW would give 1.75 TWH per year. It would be interesting for Jerome to comment on how much this equates to in cost per kwh for the life of the turbines when all costs (such as financing and rate of return) are included. He may have already covered this in earlier posts.


Also, how much land area does an offshore windfarm require? And will the cows swimming around the windfarm area be able to avoid the poles?

I read that the UK has an onshore/offshore wind capacity of 1000 Twh(due to very long coastline), more than twice 2007 UK electricity consumption of 400 Twh.

If the UK simply devoted its resources to building out wind it seems like its electricity problem would disappear.

What to do about pesky wind intermittency?

The wind-gas hybrid of CAES like the unit demonstated at the McIntosh in Alabama uses 66% of expensive and limited natural gas as do CCGT units(UK preferred generation) for the same electrical output.
At that rate CAES could achieve a 350g of CO2 per kwh low emission rate.

Clearly wind is being ignored.
Big Carbon really hates wind.

Fossil fuel heating systems and hot water systems will need to be replaced by electric heat pumps. And the UK requires much more energy for heating and hot water than for electricity:

And heat energy can be stored cheaply, thus intermittency issues are taken care of.

The solution for fossil fuel heating and hot water is to eliminate them completely not replacing with other energy sources. This is the only (but a big) part of our energy consumption which can easily be brought down to zero, with technology.

Hot water and space heating are a waste of electric energy. They should be done with solar systems.

Not so easy during the winter. Six hours per day of weak to moderate sunshine on about one day out of three.

Insulation upgrades, electric heat pumping, and smart solar capture of new build will reduce but by no means eliminate the problem.

Forget heat pumps. Expensive, bad overall COP if you include power plant and distribution.

Passive houses (using about 10% heating energy compared to average) is already easy today. Zero energy house is also possible (not yet profitable), but will also easily be possible and will be mandatory in the near future.

The combined seasonal COP of our two ductless heat pumps is approximately 3.0, although there are newer, more advanced systems that will get you into the range of 3.5 or better (and our Canadian climate is significantly colder than that of the UK). I also pay a 2-cent premium for green power, so 100 per cent of our electricity is renewable, principally wind. The alternative is to burn fuel oil, at 85% AFUE. So why is it that I should "forget" heat pumps?


Most of heat pumps run on electricity made from fossils. If you include the efficiency of the power plant and the losses of the distribution, the COP will look much less attractive.

While the situation in Canada is remarkable good, with high percentage of electricity made from renewable sources, it would still be better to leave that electricity for other purposes than heating houses.

Heating houses is the share of our energy consumption which is the easiest to eliminate without giving up our living standards. It is easy to build houses needing about 10% heating energy compared to todays average. If being more ambitious, houses with no heating need at all are also possible and I am sure will be the future standard.

There are many articles here in TOD, how we will be forced to abandon our living standards, because impossible to replace all current fossils with renewables. That's why I believe it is better to spend the price of a heat pump system to reduce the heating need of the house.

Most of heat pumps run on electricity made from fossils. If you include the efficiency of the power plant and the losses of the distribution, the COP will look much less attractive.

With a seasonal average COP of 3.0, I would still expect a good quality heat pump to come out ahead of a gas or oil-fired boiler, even if 100 per cent of the electricity consumed is generated using fossil fuels. According to the U.S. Department of Energy, the 2008 average heat rate for coal and gas-fired generating plants in that country is 10,378 BTU and 8,305 BTU per kWh respectively (source: If we assume 50 per cent of our electricity is generated through the burning of coal and the remainder is gas-fired, our blended heat rate is 9,342 BTU/kWh. The DOE also estimates 2007 transmission and distribution losses at 6.5% (source:, so after adjusting for these losses, our blended heat rate increases to 9,991 BTU/kWh. However, a heat pump with a seasonal average COP of 3.0 would provide us with 10,236 BTU/kWh.

In our worst case scenario whereby 100 per cent of our electricity is coal-fired generated, our heat rate after adjusting for transmission and distribution losses is 11,099 BTU, which means a heat pump at a COP of 3.0 operates at 92.2 per cent efficiency, comparable to a condensing gas-fired boiler.

That's why I believe it is better to spend the price of a heat pump system to reduce the heating need of the house.

In terms of cost, our replacement oil-fired boiler, indirect water heater, Tekmar control system and installation came to just over $8,500.00, whereas our two ductless heat pumps totalled $4,200.00, installed. In hindsight, I should have simply left the old boiler in place and discontinued its use.

As mentioned here before, in the year prior to our purchase, the previous owners of our home consumed 5,700 litres of fuel oil and 14,000+ kWh of electricity. After numerous efficiency upgrades, the installation of a small electric water heater and by using our heat pumps to supply virtually all of our spacing heating demand, we've reduced that to 160 litres and less than 12,000 kWh a year. Our ultimate goal is to eliminate oil altogether and get under the 10,000 kWh mark. That will require replacing our older heat pump with a new ultra high efficiency model.


The one thing I'd note is that the carbon emissions in the PCC-heat pump scenario are quite a bit larger than the condensing gas furnace scenario, because the emissions per BTU of coal are roughly double that of gas.

If the electricity is coming from wind or nuclear, the heat pump is about as good as you can get.

And that's a valid point. The one glimmer of hope, as it pertains to the United States, is that coal's contribution to the generation mix is steadily falling -- from 52.1 per cent in 1996 to 44.6 per cent in 2009 -- whilst that of natural gas during this same period has risen from 13.2 per cent to 23.3 per cent (source: In addition, the heat rate for the latest generation of natural gas plants is also notably better -- as little as 5,690 BTU/kWh in the case of GE's H System combined cycle turbines (source:; under this optimum scenario, the CO2(e) advantage of a high efficiency heat pump versus a condensing boiler is approximately two to one.

In our case, I purchase 100 per cent renewable energy from Bullfrog Power ( to cover off 105% of our needs, so our CO2 emissions with respect to space heating and cooling are effectively nil.


Heat pumps are not that efficient. Ground source heat pumps are about as efficient as condensing natural gas water heaters. A cheaper form of heat storage is
'wind-furnaces' where resistance heaters store heat in rocks.

Heat storage is pretty much overrated.
Better to insulate to reduce space heating and reduce water waste and install solar collectors to slash
annual fossil fuel for domestic water by ~50%.

Heat pumps are not that efficient.

Just how do you arrive at this conclusion? The latest crop of air source heat pumps deliver 4 units of heat for each unit of electricity, hardly inefficient. They are especially effective in damp climates, as there is lots of condensation energy available from water vapour in the air. This would be all of the UK.

You can still use them in conjunction with sand/rock/brick night store heaters, to take advantage of off peak electricity rates.

No argument with insulation, but solar, in a maritime climate, is unreliable in winter, but you can bet on the wind to be blowing.

Thermal storage is fine in principle but a joke in practice if the reservoir consists of only a few cubic feet of brick or stone;a seriously sized heat reservoir is a necessity-such as a fairly large water tank or a pit filled with a few cubic yards of stone.

Heating up such a reservoir with a straight resistance electric heater could save some money if off peak pricing were in effect, but no energy.

Why anyone with a grasp of basic physics would believe such a heater is comparable in efficiency or operating costs to a heat pump is simply beyond me;if off peak pricing is in effect, it can be taken advantage of just as easily with a heat pump..

Of course in the end insulation and passive solar are the way to go;you pay only once for permanent results.


One Swiss university has some pretty big plans for seasonal heat/coolth storage (see:

And, oddly enough, we're told that too much insulation could be counter-productive in this particular case:

The possibility of heat storage in the subsoil has far-reaching consequences for building design and running costs. Project Manager Thomas Gautschi from engineering consultants Amstein and Walthert Engineering describes it in a nutshell: “Don’t insulate like idiots, network well instead.” At Science City the main emphasis is no longer on ensuring the thickest possible insulation against heat losses, as in building standards such as Minergie P for example. Instead about the focus is on delaying the flow of heat and making the excess heat in summer usable for heating in winter.

With enough ground probes, high-efficiency insulation is unnecessary, and may even be a counter-productive. In fact, the ground storage can only absorb waste heat in summer if it is “emptied” during the winter; i.e. the earth is cooled back down to its original temperature. This opens up new prospects for building developers, especially for renovations: by networking buildings they gain more freedom in dealing with the existing building shells. Areas with numerous single buildings in particular, such as the Science City Campus, harbour a far higher potential for efficiency as a total networked system than as the sum of the individual structures.


And don't forget Drake Landing in Alberta ("borehole thermal energy storage"):

An excellent example, Evan.



Just to be clear, I was talking about overnight storage only. I lived in a house in NZ years ago that had electric resistance night store heaters in each room, and they worked fine, could easily do that job with heat pumps. Better yet, for night storage, is heating up up the concrete slab of the house itself. My family's farmhouse in Australia had zoned hydronic in floor heating, hot water from a wood fired boiler, with solar hot water panels on the roof, and an electric HW backup (all this 35 years ago).
Start out with a warm floor slab at 0700 and it keeps the room warm all day.
Smart passive solar is great (and we had it) but only limited ability to do so in dense urban housing (row housing or multi-storey apts). For these, heat pumps are ideal, if CHP is not available.

Hi Nick,

I'm impressed with your former home;presumably you got a substantial off peak night rate discount for using the heat overnight storage system.

I apologize if you thought my remarks about understanding the efficieny of heat pumps were directed at you;I assure you, they were not.

We have been working to improve the energy efficiency of our own home but since the house is old and we won't be around too many more years we can't afford really major upgrades.

We have added vinyl siding over extra styro foam type insulation and double glazed glass with argon, plus a reflective metal roof.We have also added strategically placed decidious shade trees, and a glassed sunroom which is not much used in the hot months but is a real delight from October till May, and solar domestic hot water is in the works-it will have electrical backup of course.

We heat with wood cut on the place, backed up by a a couple of externally vented high efficiency kerosene fueled mini furnances.Our kerosene consumption averages about fifty to seventy five gallons per year but we could get by with a lot less by paying more attention to the wood stove in the wee hours during really cold weather.

A heat pump would be really nice but since the wood is free and we need the exercise and have ample time to cut it we will probably never get one.

Our air conditioning expenses run only thirty dollars a month or so since we use ac sparingly.We are outside a lot and ac only the rooms in actual use, usually no more than one or two at any given hour.

I realize that my strategy is not optimal for helping my utility with peak load, but we use powerful window units capable of cooling a hot room in just a few minutes, and I turn them off and on just like the lights.

It may be of interest to some readers that we often sleep on an open porch equipped with cieling fans if the weather is really hot;we can see the moon and stars and the nearby mountians, and enjoy listening to the night noises of the deep country.We stay inside if the night time temperature doesn't drop to eighty or so, depending on the humidity.

This is a delightful way to spend the night, almost like camping and better in some respects.Any one who is in a position to do so should give it a try.

Up until a few days ago there was a very fat and contented toad that emerged from the grass and sat under the night light enjoying some very fine dining while expending very little effort.

I think the new coon dog ate it, even though he is well fed; most dogs won't touch a toad unless they are starving, but this particular dog is ALL HOUND to the very bottom of his sorry soul..I think maybe he is also an egg robber...if I catch him at that he will get a new home in town someplace if anybody will take him-otherwise it's the death penalty.

Very impressive, and we should use wind wherever it helps.

But this somewhat detailed peek into the construction should lead to a sobering thought for any reader of TOD: how do we build the next wind farm with 10% less oil? And the one after that with 10% again less. And so forth, to the obvious conclusion.

Building wind farms from wind farms would really be something to write home about.

ric merritt:
That is why wind farms ought to be developped ASAP, where suitable. There is a danger that we will run out of energy before we can build enough energy infrastructure of the renewable type.
Artificial lagoons could be build around to store the energy when supply of wind is great, and demand low.
On this, as in many things, the USA ought to move on, because its blessing from heavens of free abundant energy is now disappearing.

..but of course, there is the opportunity to build these next windfarms from multiple sources, not JUST from other windfarms.

As Jerome answered me above, the oil consumed in O&M isn't much compared to the energy output given by the farms. Maybe we can use some of the oil that we've chosen not to use making and shipping One-use plastic containers for food all over the world?

As it stands, the power that is immediately available at a windfarm should be able to support the operations in the field, unless there is simply some irrevocably unworkable reason against running electricity from the Transformer stations onto crane-ships, etc.. and what would be so unusual about the windpower on the grid running (in part) the factories that are making the Turbine pieces? I'm sure they already do.

With less of other fuels available, but this wind, hydro and solar still online, do you think we won't be figuring out how to use the power when we've got it? (and for Transportation.. see Electric Rail) I'm not promising perfection and utopia.. but it's not perfect now, either.


Maybe we can use some of the oil that we've chosen not to use making and shipping One-use plastic containers for food all over the world?

Or maybe some of the oil used to commute a banker in a F-150 80 miles a day or maybe some of the oil used to heat a house with bad insulation?

It seems to me that the wind system will be useful as long as we can keep the whole interconnected system operational (including electric grid system and gas or hydro backup generating power, and production and transport of replacement parts needed for wind, grid, and backup generation.) We really don't know how long that will be. If we can keep the whole system operational for 30 or 40 years, then the cost per kWh will not be too bad. If we discover after 10 years, we can't things going, the cost will be much higher.

Jerome, what is the lifetime of these turbines that you have built into your cost estimates?

Look at the experience of the Utsira wind/hydrogen experiment.

An output limited 300kw Enercon wind turbine(143 kw max) with a 100kva voltage controller, 50kw electrolyser, 50 kwh battery and 55 kw hydrogen IC kept 10 homes, 29kw average demand was satistied 65% of the time(NordskHydro estimates 50% long term).
A simulation shows that going from 55kw hydrogen ICE to larger fuel cells, more hydrogen storage and a more efficient electrolyser would be capable of 100% pure wind operation.

It is probable that improved fuel cells and electrolysers will come along in time. Fuel cells cost 2.5 times hydrogen ICEs but that difference isn't prohibitive.

Gail, if you don't think there will be a grid, than all of this is irrelevant. You won't have a civilisation and we won't need oil either.

Offshore foundations are built to last 50 years, the turbines at least 25 years and they will most likely be repowered or improved continually (better blades, or components) along the way. Manufacturers manage to wring out a couple % more of their turbines each year, on the same site.

" long as we can keep the whole interconnected system operational (including electric grid system and gas or hydro backup generating power, and production and transport of replacement parts needed for wind, grid, and backup generation..."

I think that demand is a little excessive. The 'Grid' is of course a number of interconnected grids, with multiple generating sources on it.. Yes, we've seen a major section collapse in a cascade of failures.. and yet we also commonly see the result of wind damage or a big storm where wires are down and customers are out, but most other sections are still up and functioning.. or where a power plant goes down for repairs or maintenance, and this doesn't crush the 'Whole Interconnected System' ..

While it is very complex, our electricity supply is not a single chain of links all depending on ALL the other links to keep functioning. It is often paralleled and duplicated, for just this reason.

Oh no! Not again? An under sea cable has broken and is leaking electrons at a furious rate. An hydraulic ram meant to cut the cable failed due to dead batteries. The Coast Guard is rushing to deploy floating insulation to prevent the electrons from soaking into nearby beaches and marshes. British Power otherwise known as BP claims only a few hundred coulombs per day are leaking but independent observers say the leak could be as high as 70,000 coulombs per day. BP intends to inject electron dispersants but environmentalists claim the mix of electrons and untested dispersants could make this disaster even worse. It may be weeks before a relief cable could be lain and the leak finally stopped. There are rumors of lighting balls washing up on nearby beaches. BP has hired local people to collect these balls but has required them to sign liability waivers if anyone is electrocuted. Tourists are canceling reservations to nearby beach resorts and the hotels are threatening to sue BP.

Thanks Thomas. I got a good laugh from that. Collecting lightning balls is just too good!

I am mostly concerned with all of the electric eels and stingrays which may be permanently jobless as a result. It is all too easy to ignore the plight of the "low-voltage" guys during a catastrophe of this sort


Is there a simple "here's how many acres of wind farms" or "here's how many wind turbines" would be required to supply 100% of current US energy needs? This has been done for solar, yielding a 100 mile x 100 mile swath of Nevada.

I have read that wind density is too low and there just aren't enough locations. Perhaps someone would claim wind will be suitable based on cutting electricity usage, but that's cheating IMO.]

Also, what do you say about the recent report that 6500+ birds are killed by wind farms in WA and OR alone each year?

I can't find what is the levelized cost of wind WITHOUT feed in tariffs or tax credits- do you know what it is?

Lastly- if the CO2-AWG meme is killed after CERN reports its CLOUD results end of August, and coal- without sequestration- becomes politically correct again, and the tax subsidies, feed-in tariffs, and quotas go away- will the current wind farms be able to stay in operation?

There are no wind farms in my neck of the woods but housecats kill birds by the thousands about everywhere, including locally.We used to have an old sow cat that brought home an offering of fresh dead bird as often as three times in a single week;she would climb right up on my chest when I was stretched out resting and purr and was more than ready to share her catch.

Unless the birds under consideration are endangered, only a person seriously uninformed in respect to the overall environmental situation would consider the loss of five or ten thousand scattered over a large state to be of any consequence, in relation to the larger environmental benefits of getting away fron coal and natural gas.

More birds than that live within a few miles of my mountian home;my personal very conservative estimate is that there are at least five hundred birds per square mile here, on a year around basis.The actual number is probably much higher,especially during the summer.

Less than two hundred miles away whole mountians are being destroyed-permanently-by coal mining.

Less than two hundred miles away whole mountians are being destroyed-permanently-by coal mining

Well put, hopefully Dirk will be able to connect the dots.

Birds are a negligible concern for wind farms (except for a couple of badly located old wind farms in California). Impact is estimated at one bird killed per turbine per year, which can be compared to the hundreds of millions o bird killed each year by buildings, cars or domestic cats.

The cost of wind I gave is a cost, ie without taking into account any support mechanisms/ 5-10c/kWh for onshore, 8-15c/kWh for offshore, roughly

Most of the wind turbine bird kills are from smaller high RPM units (sub 100KW).

Loss of habitat, buildings and communication towers are a far greater concern, especially to migratory species.

Bats seem to have about 3 times the mortality rate of birds due to wind turbine interaction.

The report noted that during a year-long study of bird and bat fatalities at the 33-turbine Crescent Ridge wind project in Bureau County, about 31 birds and 93 bats were killed after colliding with the turbines.
Under one theory, the report notes that bats may fail to detect turbines acoustically or visually.
Alternatively, according to a study of bat behavior near a West Virginia wind farm, bats may actually be attracted to wind turbines.

Still fairly low (unless you're the bat )-:

Thank you for the response. I'm not particularly concerned about the birds myself as I (well, my kids) also have housecats that are bird-killing machines- but the tip speed of those big turbines seems to be more than enough to kill a bird if it runs into it.

The two concerns I have remain the energy density of wind (which, if we are close to 2% says to me that wind could conceivably supply a significant portion of our needs, albeit with alot of towers on the horizon), and its actual cost- including storage/capacity management- without subsidies. As I was driving through Illinois today I passed a wind farm where, out of 135 turbines, appx. 10 were turning, 20 were creeping (barely moving), and the rest at a total standstill. It was 95 degrees. So with the cost of mitigating the risk of an entire power plant coming off line, I'm not sure how wind could be cost competitive with coal, natural gas, or even nuclear.

I'm not sure how wind could be cost competitive with coal, natural gas

Zero fuel cost and zero risk from carbon pricing.  Proposed systems for wind-energy storage play well with just about everything else (loads of peaking capacity which does not lose output in hot weather).

or even nuclear.

18 months from siting to switch-on versus 10 years.

Let's do some back of the envelope comparisons.

Apparently, this is the Greater Gabbard wind farm - 140 x 3.6MW = 500MW nameplate Siemens turbines. Expected load factor "better than 40%". Expected cost €1.5bn - €2bn, ~= €7,500 - €10,000 per average kW of useful (not nameplate) capacity. Allow extra for grid enhancements and backup generation.

Reckoning on approx 500 tonnes of concrete-and-steel per turbine (please correct me if this is wrong, it's based on an average by David McKay ) the whole farm will take 70,000 tons approx.

Output is not dispatchable on demand, nor can it be scheduled as baseload. Significant penetration will require a reinforced and "smart grid" with substantial variable backup capacity. For the UK this would have to be gas, adding to the nominally low wind carbon footprint to the tune of 300-odd g/kWh.

This compares with current nuclear fission plants (rough figures):

€3000/kW build cost. About a third of the above offshore wind farm.

85% load factor.

Limited dispatchability. Typically, you can back a PWR down to 80% or so, any lower and it's best to shut it down completely.

Ideal for baseload.

Approximately one seventh of the steel-and-concrete per average kW of capacity of equivalent wind.

No carbon footprint from gas backup, because it doesn't need it. IPCC estimate of total carbon footprint over lifecycle including mining, enrichment, operation, decommissioning is 40g/kWh electrical. Others calculate 60-65g/kWh for a once-through reactor assuming fossil fuel for mining.

Expected lifetime 50 years plus.

Sounds a better deal all round.

Also nukes don't get a feed-in tariff worth maybe 5c for each and every kilowatt hour they produce. This could explain the difference in build rates over the last few years.

nukes don't get a feed-in tariff

They do in the US: the next 6 nuclear plants will get the same credits as wind.

Wind in the US only gets 2 cents, and only for the first 10 years, but the US has stronger growth than Europe.

I suppose those horrid offshore windfarms can buy insurance from private companies too. Those underfunded nuclear plants have to get theirs from the government. ;->

A nuclear plant requires backup in the size of its full output, should it go down (even if it's just a grid failure). It also needs back up to deal with demand variability over day, just like wind does.

I'm personally favorable to nuclea, but I don't think that it's smart to have all your eggs in the same basket, and offshore wind provided useful diversification on a scale which is meaningful and at a cost which is understood and in the same range as nuclear. The main driver of the cost of nuclear, like wind, is the cost of capital. Governments can influence that easily...

Good point Jerome (and nice photos). Part of the rationale for new, subsidized "backbone transmission" lines is to provide backup for nuclear plants (as well as transport coal-fired power long distances.)

It is often overlooked that FirstEnergy's Davis-Besse nuclear plant was out of service on a long, unplanned maintenance during August 2003. This contributed to the problems operators had in adjusting to a line disturbance.

Backup for failure is no different for nuclear than any other conventional power station on the grid. There must be enough reserve in the grid to cover the possibility any given generator could fall off it. A nuclear station with several separate reactors is obviously more flexible in this way than a large single reactor.

As far as "backup" for demand variability goes, nuclear is usually scheduled for cost-of-capital reasons as baseload. Gas is better suited to peak supply. Where wind is different is that it *also* needs cover for supply variability. A wind farm can slew irregularly from near zero to near max or max to zero in an hour or so, and another generator (gas, hydro, or pumped storage) is needed to cover this. Reserve already assigned for demand side variability cannot also cover for wind farms. Hydro and pumped are all pretty much spoken for in the UK so new reserve will be needed as these large wind farms come on line.

My thoughts exactly. This seems to be a poor allocation of scare resources.

The fact that it is pretty cool engineering/logistics doesn't alter the true cost comparisons to nuclear.

One thing about offshore windfarms. The Coast Guard or State folks would never let them go to ruin. Too much of an eyesore and public embarrassment. Any abandoned windfarms from bankruptcy, etc? Land or sea?

EDIT: OK, maybe I am wrong.
Maybe We need to create a disassembly fund that is US Govt bond invested for removal one day. You have to buy in to plant them. You just cannot outrun the state.

Not to take this too far off-topic, but I'm wondering if anybody here knows anything about generating electricity from ocean currents? What little I've found online suggests that it would work, but is hampered by the relatively low speed of currents (as compared to wind or water flowing from a dam). I would think the problem could be easily solved by creating a venturi device:

The reason why I ask: I live in Taiwan, some of our "green" government officials have been mouthing off for years that Taiwan could shut down all its nuclear reactors (we have 3, plus a 4th under construction) because we are well-situated to exploit ocean currents for electricity. The same government officials who say this have yet to provide any financing to build a prototype - just talking about ocean currents seems to be sufficient without providing any realistic plans. They are waiting for the USA or Europe to do it first, so they can copy it. Taiwan is great at copying other people's ideas, but not so great at doing anything innovative.

I actually know some of these government officials, have mentioned this to them, and they respond by asking: "Do you have a Ph.D?" I don't, and don't claim that I could build or design an ocean current generator myself. But it would be helpful if I could point to another such successful project someplace else in the world, in the hopes that it might prod our officials into putting money where their mouths are.

I thought the Koreans were working on an Inchon tidal to energy project. I will Google and edit here if I find something.

Hi TinFoilHatGuy,

Thanks for mentioning this. I did some googling and what I found are tidal energy projects:

Those are a little bit different because (I think) tides move faster than the ocean conveyor. Nevertheless, an underwater machine that could capture tidal energy would probably work in ocean currents, though it might require a larger venturi device.

Our situation in Taiwan is that we don't have powerful tides (almost no natural harbors or bays), but the strong Kuroshio Current just off our east coast. Here is a news article published in 2007 that makes it sound that Taiwan is about to build an ocean current generating system:

So what has happened in the past 3 years? Nothing. Kind of like our wind generation project - I think they put up about 10 wind towers, mainly for show. Most of them are right next to the nuclear power plants, I guess to give anti-nuke protestors the impression that they're being taken seriously. But at least the showcase wind generators are something - we don't even have that for our alleged ocean current project.

Great pics, but as I was looking at some of them I was lusting for the full-resolution versions.

I am here in Alaska.
There is only one commercial scale (4.5MW) project currently operating in Alaska. It has 3each 1.5MW GE turbines set up on a mountain above the city of Kodiak. Constructed in 2009, it supplements the existing Hydro and offsets the Diesel generation. In fact the three wind turbines have cut the diesel generation in half. KEA has a good website that shows the generation to date and the energy offset. Note that the wind generation cost is less than the diesel per KWH:
And a good video about it:
This makes Kodiak area grid 89-90% renewable for power generation.
I would be interested to see other areas data of how they supplement their power with wind.

Yesterday we where lucky enough to see the first commercial vertical wind turbines in Tasmania.
The wind was too strong on Sunday so while they were on the ground they where open to the public.
There were 4 of them. Each will generate about 10kw on average up to about 30kw. They are expected to
provide about 10% of the maritime buildings power. They cost about $AUS 80k each.

You islanders are beating the heck out of us interior folk when it comes to moving to renewables. That big pipe is running at about a third of what it used to but most of our gen still comes from diesel with another sizeable chunk from coal. There is lots of wind potential close to the Healy Coal plant and a small wind farm is now in the offing.

Its all of a 29 MW plant with an expected average production of 8 MW due to intermittency. The thirty year old coal plant nearby is rated at 25 MW and managed to generate in excess of 100% of that capacity in 2005. I'm guessing almost all of our eggs will be in the fossil fuel basket around these parts for the forseeable future. Of course I'd be a fool to hold my breath for a natural gas line...Well at least we are getting a wood pellet plant up and running this year--lots of biomass generated in these parts summertime.

I note that round 3 developers have started to lobby DECC for 4 ROCs per MWh (for R3 projects only), implying significantly higher costs for these much further, deeper and more complex projects. This I believe is outwith the cost of the "Offshore Grid" which is to be socialised.

The 4 ROC lobbying implies cost assumptions (including risk adjusted investment returns) in the range of 18 - 22p/kWh, suggesting that there is limited scope to keep delivering new capacity at the price range you quoted. Could you comment please, and do you really believe that this extreme additional economic burden can be absorbed by UK energy consumers and if not, what is the future for offshore wind in the UK?

Doug Selsam has a floating turbine idea - but it seems to need large scale carbon fiber material advancement (advance in the make it cheap department)

The technology to float stuff in the ocean along with chains and anchors to hold the floating things is well developed so there is that advantage.

The idea is clever, but the effective capture area of a long, thin spine is going to be quite low compared to a HAWT of even a fraction of the height.

That is not what his numbers claim.

I'm thinking his limiting factor is material science/cost ATM. But "small wind" and "off the beaten track wind" get no love in the grant/research department. And if he DOES have something - there are people who'd be better off once the patent has expired - thus the game becomes 'run out the clock'.

If dynamically-supported wind turbines are the future, my money is on the high altitude machines.  I saw a video recently from a company proposing a biplane kite.  It would take off under power, then fly in circles at altitude (at the end of its tether, like a stunt kite) and use its propellers to generate electricity.  The higher wind speeds at altitude are one thing, but the multiplication effect from the kite's motion reduces the size and cost of the rotating machinery.  I think this is just brilliant, a big step up from gyrokites like Sky Wind Power.

Great stuff! Can I get a tour boat round the turbines from Harwich?

Looking at the layout carefully I note that the turbines are located on each side of the Galloper and Gabard sandbanks but not actually on them. Why is that? Is it to allow maintenance at all states of the tide? Or am I reading the map wrong?

Also the main supply cable is linked back to Sizewell, yet the shortest distance to the high voltage grid would be straight inland to the southern edge of Ipswich. Is this a case of more wire to get less nimbyism?

"And here is a cable laying vessel. Notice the platform on the front of the boat, which can carry several kilometers of rolled up cable (in that case, the boat was not doing any installation):"

"I advise wind farm developers on their financing needs,"

Maybe advise them that if they put that kind of weight on that helipad, they will have to buy a new one?

Innovation is the wind industry? Apart from scaling up from 30kW to 3MW in 30 years....there seems to have been limited fundamental change in configuration in the utility scale turbine over the my question is - what will kind of innovation will it take for turbines to get to a capacity factor of at least 50% over the next decade - or half the annual O+M costs?