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Book Review: Renewable Energy Systems
Posted by Rembrandt on February 4, 2011 - 11:29am
The development of renewable energy and integration in today’s electricity systems is a complex issue. Fortunately, many scholars have given a lot of thought into the issue, one of which is Professor Henrik Lund of Aalborg University in Denmark. His recent book, Renewable Energy Systems: The Choice and Modeling of 100% Renewable Solutions, provides useful insights in barriers to technological change, the modeling of electricity systems, and case examples of energy planning. The book’s audience due to this broader setting ranges from scientists to civil servants working on energy systems, and people working in the electricity sector. Professor Henrik Lund will speak about his work at the ASPO 9 conference April 27-29 2011 in Brussels, Belgium.
The first part of the book, deals with what Lund calls choice awareness theory. The concept is introduced because often no choice is offered in case of societal decisions on energy planning. Illustrated via a number of Danish examples where power companies offered politicians and the public only a single choice, such as building a more efficient coal power plant, instead of considering a variety of alternatives. He briefly analyses the reasons behind this behavior in terms of strategy, societal structures, perception, and different power distribution between companies, government, and citizens. In his experience there is first a need to create awareness of multiple choices for society. These alternatives need to be outlined using a rigorous scientific approach using technical and economic feasibility studies, and an analysis of public regulation measures and proposals. To make this process more easy Lund proposes to use a modeling tool, one of which described in detail in the book is his freely available EnergyPlan which has been under constant development at Aalborg University since 1999.
The use of this part of the book is particularly for those not initiated that well in energy systems who still have difficulties grasping the complexity of the issue. One of the aspects that brought back memories when reading the book was that alternative systems need to be made comparable in terms of capacity and energy production. Often I have come across confusion on solar power capacity, watt-peak capacity, and actual power production in discussing energy at lecture evenings and debates in the Netherlands.
The second part of the book is more interesting for energy experts interested in technical feasibility of renewable electricity integration in the grid. The technical feasibility study of a Danish electricity system running 100% on renewable electricity is presented, developed with the EnergyPlan tool. The analysis starts with a reference scenario from the Danish Energy Authority for the electricity system in 2020. To understand the problem of renewable intermittency Lund analyses patterns of sunshine, wind, and waves in West Denmark during a number of years, shown for wind energy in figure 1.
Based on such an hourly distribution patterns a number of analyses are made and conclusions are drawn. First, excess electricity production is analyzed. This measures how much electricity from intermittent sources is produced above electricity demand on an annual basis, with as a variable the amount of renewable energy source production. The analysis shows that to meet demand it doesn’t help much to combine wind, solar, and wave electricity, shown in figure 2. The idea that the wind blows when the sun doesn’t shine is incorrect, at least for West-Denmark, as the optimal mixture of sun, wind and wave power only leads to a marginal decrease in excess production. The results show that without other measures going beyond approximately 10% of renewable electricity production in the electricity mix mainly leads to excess production not to useful electricity. The variety between years on this point are only marginal. The conclusion of Lund on this part is similar to that from Hannes Kunz and Stephen Balogh in their fake fire brigade analysis on electricity.
Next, the variability per hour is modeled and how intermittency on an hourly basis can be overcome for various renewable electricity shares. Professor Lund analyses a number of solutions:
- To regulate CHP stations to address fluctuations in wind power next to heat demand. In this system CHP stations would be partially replaced by boiler heat production when excess electricity is produced. The consequences is lower fuel efficiency of CHP systems
- Investing in heat pumps and heat storage capacity equal to approximately 1000 MW of electric power in 2030 and one day of heat consumption storage. These can be used instead of boilers to restore fuel efficiency while also decreasing excess electricity production.
- Grid stabilization via CHP and wind power which has traditionally only been done via large power stations.
- Integrating the electricity sector and the transport sector by introducing electric vehicles which can deliver a battery discharge to the grid when in stationary mode at the parking lot.
A combination of these options and their effects on excess electricity production are modeled using excess wind electricity, of which a few are shown in figure 3. In that figure S0 refers to the reference scenario, S1 refers to (de)-activating small and medium-sized CHP stations along wind electricity production using boilers as a replacement, S2 refers to adding heat pumps instead of using boilers, S3 refers to adding electric vehicle batteries to the system which replace 20% of oil consumption.
In modeling electric vehicles in the scenario of figure 3 it was assumed that in 2030 in West Denmark about 3.2 TWh of electricity had substituted 9.8 TWh of oil via electric and hydrogen fuel cell vehicles. Based on a national level assumed electricity to oil substitution of about 20.8 TWh of oil consumption, which is 40% of all transport fuel used in 2030 in the reference scenario. This would be replaced by 7.3 TWh of electricity used in electric and hydrogen fuel cell vehicles. The much lower consumption level in terms of energy comes from the higher efficiency of these vehicles types. Further assumptions are that electric vehicles load during the night where they reduce excess electricity, and that hydrogen electrolyzers operate 4000 hours per year at hydrogen electrolyzer stations. More detailed analyses are available in the book on a specific chapter on transport integration of the electricity grid, where other options such as intelligent battery electric vehicles which charge after signals from the grid when excess electricity is available.
To end this part the costs of electricity and different storage options are discussed. The cost aspects is a comparison of the costs of wind investments versus the money earnings of selling wind power on the Nordic Nord Pool electricity market. The time period is based on a 7 year historical period where the average price on the market is taken to smooth out variability in hydro-power availability. The analysis shows that without investments in flexibility of the system such as heat pumps, the benefits of wind power quickly drop below the costs as too much excess electricity is produced, at around a 7% wind electricity share of electricity demand. That can be extended using heat pumps according to Lund. I found the description of this part to be too brief to be very insightful however, as many of the involved factors such as investment costs and fuel costs are not described quantitatively, and only the outcomes of the analysis is displayed.
Finally, the book ends with a number of case examples of renewable electricity implementation and renewable energy scenarios including Los Angeles, Denmark, Thailand, and Germany. These are helpful to illustrate the ideas and theory with real life examples, to get an idea where things can go right and wrong in terms of energy planning. Overall I found the book very helpful in describing approaches to analyze electricity systems, and getting more insights into the technical feasibility of large renewable electricity shares. I am not convinced, however, about the economic possibilities of large shares of renewable electricity systems. Especially because the focus in the book lies on Denmark which has a favorable situation of hydro-power and interconnectedness between other countries.
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"Renewable" energy:
Is it fair to misleadingly keep calling it that?
________________________________
From a thermodynamic viewpoint, no energy is a "renewable" kind.
Most of our energy originates in the fusion fires of the Sun.
It then flows like an ever widening river towards the cold sink hole of outer space.
A small part of the rivers runs through it, through out little rock hurtling about the Sun. But none of that energy is "renewable". When it leaves our rock and heads to the sky to join its buddies, it is gone forever. (Goodbye and thanks for the fish.)
@Step Back
I agree with what you are saying about the thermodynamic perspective, however on a human time scale renewable energy is renewable energy as we can consider the lifespan of the sun eternal for human purposes. Hence it makes sense to talk about renewable energy (flow) versus fossil energy (stock).
Rembrandt
Thank you first for the information about the next ASPO conference in Brussels, Belgium!
I know now where to go for my Eastern vacations!
The book seems to be very interesting and reading the article led naturally to Energy Plan:
http://energy.plan.aau.dk/introduction.php
We have here all the work of Pr H Lund, and free software “The EnergyPLAN model” for download! The EnergyPLAN model is a computer model designed for energy systems analysis
I also had a look at a study made for Greenpeace around “Battle for the Grid” in Europe
http://www.greenpeace.org/raw/content/eu-unit/press-centre/policy-papers...
@Patarol,
Thanks for sharing the greenpeace study, it's one of their better studies so far and shows the improvement in thinking about these issues.
What I have problems with is the aggregate figures that are shared publicly in terms of cost, and what this means for the cost of electricity. There is no breakdown on how they derive these figures, and there is no information in the 'low grid' scenario on the cost of these electricity sources. That's a comment that I have with many studies that people really need to detail what it is that they are modelling, what the model is and the results at a dissagregate level. Similar problem that occurs as well with the World Energy Outlook of the IEA or the International Annual Energy Outlook of the EIA.
For the case studies it is too bad that they only look at one day, as demonstrated in the fake fire brigade post it is necessary to look at storage/intermittency issues over a longer time duration perspective.
Rembrandt
I agree with your final thoughts on this book--it is very difficult to see how this type of system will ever be viable on any large scale.
I disagree, it's actually very easy!
http://www.commutebybike.com/2011/01/14/commute-by-velomobile/
The reason you can't see it because you're looking at it the wrong way you're still trying to find a way to maintain
BAU. And that as we all know by now is thermodynamically impossible! You need to mentally enter an
alternative reality where alternative energy is the only way to go. Otherwise it will never make sense.
Shouting through the megaphone: "BACK AWAY FROM THAT PARADIGM AND NOBODY WILL
GET HURT, PUT IT DOWN, AND PUT YOUR HANDS UP IN THE AIR, GET YOURSELF FREE!!"
@FMagyar,
Can you also give a constructive response to what this "aternative non-BAU" reality would look like?
Yes, though probably not in the space of a comment on TOD. You could start by looking at the picture and the velomobile link I provided. Obviously it goes way beyond that. However the point I'm trying to make is that we need to change the way we think about alternatives and the simple fact that our current paradigm is not sustainable.
I actually work with low voltage solar powered off grid LED lighting installations. The biggest challenge I face is setting proper expectations as to what can realistically be achieved with those systems. The most common objection I face is people telling me that these systems don't really work. That is a patently false statement, the problem is most people resist change and want to continue doing things as they have been until now. My job is to help the scales fall from their eyes and to see things differently. I'll be the first to admit I have been trying to tweak my message and approach for a long time with limited success.
BTW there are plenty of people out there who have been putting their versions of what the "aternative non-BAU" reality will look like out there and have done a much better job that I ever could. An amalgam of the views of people like Richard Heinberg, John Michael Greer, Jeff Rubin, Howard Kunstler, Dimitri Orlov to name a few, have all contributed to painting in a few pixels of that reality. I don't subscribe to any particular version of what the "aternative non-BAU" reality will look like.
At the end of the day I'm just trying to suggest that a big part of our problem is poorly set expectations.
Cheers!
Edit: Ouch! I just watched this:
http://www.thenation.com/video/157985/dmitry-orlov-peak-oil-lessons-sovi...
Now there's a guy who sure knows how to set expectations....
"I don't subscribe to any particular version.."
Here, here.. the point today is to let go of this one.. don't cling ONTO the sinking ship, even if you're still standing on it.. just free your thoughts and perception up enough to be looking around at that dependency in terms of '..what parts of it could still float? What are my options?'
That's the trick with the BB's.. they might be born of BAU, but aren't permanently tied to it. Diversify..
Letting go can be a pretty tall order. It can be hard enough to keep ones sanity intact when one tries to navigate between the views of Orlov and the incessant bombardment from the propagandists of BAU.
http://finance.yahoo.com/family-home/article/112001/the-super-bowl-economy
Wonder what the Super Bowl costs in terms of energy?
Emphasis mine.
Hi Fred,
Talk about difficult navigation: in your first post, I was almost giddy with delight over seeing all those brightly colored velomobiles. And then, I followed your Orlov link and began to wonder if I should revise my estimate regarding the length of my retirement.
I follow the stock market somewhat and catch some of the prognostications of the wall street gurus. It seems that the USA has once again demonstrated its exceptional-ism and proved its mastery of the universe with the new version of the IPhone, the innovation of Facebook, smart roads, nanotechnology and the like. Growth may be a bit slower than we would like, but basically the future is bright and we just need to focus on new technologies to make everything "more better". Of course, if we could just get the government off of our collective backs we could greatly accelerate growth in everything. (note tongue pressed hard into cheek)
We really are starting to see a fairly bright line here: either most of the folks that comment on TOD are delusional or the rest of the world is very misguided. Not much middle ground.
RE: Delusions
Dave,
Yeah, I told a neighbor yesterday pretty much how I felt about oil and energy and to 'some degree' what that meant for us, for this culture. I basically said it in terms like 'The conversation is about to completely change..' Reminding him just of how much our food supply is Long-distance Truck borne, and what can happen to the prices. He didn't seem to disagree, but his eyes definitely widened a bit as I got into it. (I apologized after- for the amount I dumped onto him.. as I said to him 'Sometimes it just has to come bubbling out..')
I mentioned how this is just off people's radar screens.. and he said "It's off mine, I don't know anything about this.." and I told him that I didn't even drag my wife into much of these thoughts, since it would probably shut her down.. she can barely deal with how extreme the mainstream news has gotten, much less the implications of what we're talking about around energy.. and of course, I hold off a bit just in case we are being delusional.
Knock Wood!
Bob
I just stopped by here for a second, but saw this and feel the need to vote with Fred. I have been very busy recently doing what I have hoped to do for decades- take a serious shot at solar thermal by way of stirling engines. Things are going great. The only real competition we see is triple junction PV, which is also going great, but, for reasons I still do not understand, is still thought by the money powers, to be in the final analysis "a bit more expensive than stirlings".
So. I repeat my old song, which I have never heard refuted except by whiny statements like "politically impossible".
1) Solar is super abundant
2) We know how to do it, now, not later. And are getting smarter at it by the minute.
3) we HAVE to get off carbon, no choice here at all.
4) "too expensive" is bullshit. Think of the fraction of GDP we spent right now on utterly frivolous stuff that does nobody any good at all, in comparison to what we are putting on sustainable energy. If we get real, we will have PLENTY of everything we need to do the job. And do it fast.
Yep, yep. I do know that "getting real" is the real problem. OK, so we are doomed?
Now, back to the fun part. Doing it.
Thanks, Fred.
Wimbi, do you have anything you can show us with regards the work you are doing with stirlings? I for one would love to hear more about it. Years back I saw this TED talk by Bill Gross from Idea Labs on new energy.
http://www.ted.com/talks/bill_gross_on_new_energy.html
What I found fascinating was the control system that he built to focus the mirrors with what was cheap off the shelf technology back then in 2003. Obviously what he built must not have been economically viable on a larger scale when competing with fossil fuels at the time and it didn't get off the ground. However that doesn't negate the technology or mean that it can't or won't work if the economics change.
Right, Fred. Gross had, and still has, a lot of good ideas. My understanding is that he started off thinking of a stirling at his focal point, but couldn't find one, then went to PV, and then steam.
I thought it a cute trick to instruct his field of mirrors to spell out CAL TECH (rah rah), just to show how much control he had.
Anyhow, there has been a lot of crazy work on stirlings that any competent machine designer would flunk at first sight, and they have got a deserved bad rep. as a result. But we are gonna change that real quick,-- tune in next year.
And how many times have you heard that? -- followed by a long, long, dead, silence.
So here's my little bet. In a year you will see a living, running solar thermal machine that in a bright desert (certainly not here in these gloomy eastern hills) will cost maybe a few hundred dollars per kilowatt, and beat all comers in a field trial of dollars per kW hr. And run just fine on nat. gas, when the sun don't shine.
PS, You are so right on the economics. But we both know there's phony economics, an exercise in global self-delusion, and real economics that counts all the cost. It says solar costs less.
Well I've been starting to look around the world to see where I might want to have my final hurrah, so to speak, and have been narrowing it down to somewhere along the north eastern Brazilian coastline. Dry, sunny, no hurricanes, laid back etc... I think it is a great area for solar in general and I suspect there may be a niche for stirlings. So I will be on the look out to see what develops.
Thanks for the review
Does Pr Lund discuss how they would use the heat pumps ?
Can you elaborate a little further on this point (if possible)
I am guessing he doesnt do any analysis of solar thermal + heat storage (being Denmark) in his examples ?
yes he is, go to his site:
http://energy.plan.aau.dk/introduction.php
@Energy for all
The case on the website given by Patarol is also given in the book which include some solar thermal on rooftops. There is no detailed discussion about the specific combination of solar thermal + heat storage in the book. In case you are referring to CSP that is not covered in the book.
Regarding heat pumps they would be used in combination with CHP power plants. "First, using heat pumps can decrease excess electricity production. Second, by replacing CHP heat production by heat pumps, the flexibility of the CHP stations is increased as long as the capacity is maintained. Third, by adding heat storage capacity to the system, the flexibility is further increased. (Lund, page 91)."
The following flexible energy system has been analyzed using the energyPlan model:
"The CHP units int he energy system are supplemented by heat pumps equal to approximately 1000 MW of electric power in 2030 and heat storage capacity equal to the heat consumption of approximately 1 day."
"CHP units and heat pumps are operated according to a strategy of meeting the difference between demand and wind power production."
"All CHP units and wind turbines built after 2005 are involved in securing grid stability."
The book shows a number of charts including electricity demand over a period of 200 hours and how these factors balance electricity demand versus production.
Many Thanks - that answers my questions
I will have a look at his site in some more detail from Patarol's link
Denmark, as already has been remarked, has some unusual features. Denmark put in a lot of District Heating using coal fueled CHP in the 70s/80s in response to oil shocks. This electricity production was not directly controlled by the grid and it is interesting to note that since 2005 in order to manage wind integration, they required new plant to be involved in securing grid stability.
I think perhaps there are 2 different issues with regard to the grid and balancing generation from different sources. I understand that Grid stability in the face of variable, only partly controlled input requires continuous balancing, with for example synchronous gas turbine generators, to match varying demand. Ramping up and down production on the supply side using controlled sources (or on the demand side by directing the use of electricity) to follow diurnal demand is a separate matter (?) and is the one I presume is referred to below,
Denmark is somewhat atypical due to its tiny geographic extent. I wrote this about 41/2 years ago:
The primary problem usually raised by wind opponents is intermittent availability with significant daily, monthly, and seasonal variations. Probably the first person to address this issue systematically was Gregor Czisch for Western Europe. He analyzed 3 hr. interval recorded wind speed (at 10 m average height above ground) for all areas that could provide =>1500 full load hours (FLH)/yr, i.e. minimum 17% full load factor. His analysis shows that:
• 5 minute correlation is near zero at 20 km
• 12 hour correlation is near zero at < 1000 km
• 24 hour correlation is near zero at 1800 km
• monthly correlation is near zero at 2500 km.
Of course at the 80 m hub height of a 1.5 MW turbine the FLH and correlation distances would improve significantly. Archer and Jacobson (A&J)1,2 found that for a small area only 500 by 700 km centered in Kansas, averaged over 8 wind-farm locations, the incidence of zero power wind was zero. One turbine might be expected to produce 30% of rated kWh during a year. Using the 8 wind farm curve of average windspeed vs % of time available, and assuming the ratings of the NEG/Micon NM82/150 turbine (nominal windspeed of 12 m/s, cut in windspeed of 3 m/s and cut out windspeed of 18 m/s) the 8 wind-farms produce 85.5% of nominal annual output and operate at or above nominal 38% of the time. However this estimate understates probable performance for 3 reasons:
1. A&J used measured wind speed increase from 10 m to 80 m on a few sites, generated a formula to be applied to all other sites where measurements at 80 m were not available, and generated their curve using the estimated 80 m windspeed. Because wind speed increase is not linear with height, and because power is proportional to the cube of windspeed, the upper half of the swept circle has more weight than the lower half. The “virtual” windspeed at the hub is higher than the estimated.
2. Turbine manufacturers specify performance parameters conservatively.
3. Measured upper level wind speeds tend to be slightly higher then estimated.
Therefore, as a conservative adjustment, to better reflect expected performance, the A&J 8 wind-farm curve was shifted right by 1 m/s and performance recalculated. With this adjustment, for the selected turbines, the 8 wind-farms can be expected to produce 111% of nominal energy in a year, and would be at =>100% of nominal output 48% of the time.
1 http://www.stanford.edu/group/efmh/winds/winds_jgr.pdf
2 http://fluid.stanford.edu/~lozej/winds/winds.html
This idea could be extended over a greater area with smart grid ties to improve performance further, and then if excess energy were used to generate hydrogen, and hydrogen driven turbines used to generate electricity during wind lulls, only about 15% standby capacity would give 100% of nominal near 90% of the time, better than the average coal fired plant.
This is really good stuff from Murray. In my opinion, we haven't even scratched the surface as to how to do serious calculations and how to optimize entropic sources of energy. I would classify these systems as "predictably unpredictable". Certain laws of physics and probability apply as invariants and allow us to reason about how to go forward. The smart grid technology hasn't considered these factors to any depth so they can obviously get smarter.
Murray
The wind farms in the UK are spread over an area of over 1000km, with the modern turbines they fail to produce the energy these theoretical papers say they should.
http://www.bmreports.com/bsp/bsp.php
The total metered capacity is 2662MW, for every day I have seen over 2000MW I have seen 5 under 300.
From what I have seen it is vital that any wind power is matched with some form of storage system.
I guess one of the cheapest ways to do this is hot water cylinders in houses triggered to come on with mobile signal. Like an alarm can be. But we have to work out these things along the way.
Just sticking up wind farms without dealing with the hard bit will just fail.
Don't know if this is helpful,but in my area the utility offers a heating system which is intended to power up during off peak hours and store the heat in ceramic blocks which provide enough heat to cover the whole day. Program it to power up when wind, for example, is in excess, and this might be part of a solution. This uses resistance heating, so it is not optimum, but I don't believe heat pumps are feasible in this area with temps going down as far as 30 below. It was over 26 below a few days ago.
Direct electric heating is an incredible waste of the most precious (? - maybe oil is also a contender?) form of energy we have (electricity). In Switzerland, new buildings are not allowed to have direct electric heating any more. Air-based heat pumps are inefficient at low outside temperatures, but geothermal versions (? not sure about the correct english expression for this) are just fine, delivering a higher COP (heat out / electricity in) than air-based heat pumps. Unfortunately, they are more expensive, and a lot of people buy the less efficient air-based versions, because the upfront costs are lower. In the long run, ground-based heat pumps are preferable, because they will pay back the higher investment in the long run, and allow us to move to a lower energy society.
There are a lot of "ifs, ands & buts".
Ground loop heat pumps are not always more efficient. The Fujitsu air source heat pumps have 26 SEER in cooling mode (better than ANY ground source unit) and COP 3.5 at +7 C.
Far better than ground source heat pumps in my area (New Orleans) where cooling demands dominate. The parasitic losses of pumping the liquid solution through the ground (plus maintenance) and the problems of installation, make high efficiency air source heat pumps the best solution, coupled with natural gas heat for colder days.
Best Hopes for Evaulating Alternatives for each area,
Alan
Just tossing in a thought I've had, as the topic has arisen.. but when You and Paul in Halifax and others talk about Air Source Heat Pumps, I've been driven to think about a hybrid I'd be interested in exploring.
The house my family built in Maine around 1980 employed a 'Cool Tube', a very low tech Geothermal setup that brought the home's air supply in from a long underground tube that supplied fresh air to the house at 40-50 degrees F year round.. for winter it was essentially a preheater of the outdoor air, before the Masonry Stove did its part.
Just wondering about supplying an Air Source Heat Pump with the pre-moderated air coming to it like this from underground? Anybody know about the volume of outside air that an Air Source pump uses? That would be an issue, as the cool tube uses a fairly low volume of air, giving it time to do the thermal transfer against the pipe walls. But it seems to me that the ASHP effectiveness could be boosted by doing this, in any case.
PS As far as FIERZ comments, I think it makes sense to have Resistive heating available in case there's no other place to 'Put' excess electricity.. storing it in Heated homes, Water Tanks or conversely in Overcooled Freezers seems to make sense. But It also makes me wonder if it isn't possible to make a Hot Water Heater more efficient using Microwaves? I'd likely keep that simplicity of a resistive heating element as the 'simple' backup.. but it's a thought.
Bob
Hi Bob,
I'm not qualified to provide you with a proper answer, but I suspect a cool tube would have no positive affect on performance. Air flow over the coils is considerable (stand in front of the exhaust and you'll quickly get a sense of this for yourself). In fact, a restricted air flow would degrade performance and potentially damage the compressor. Most certainly, any modification made to your system will void its warranty. Best to keep things as is.
Cheers,
Paul
The Fujitsu air source heat pumps have 26 SEER in cooling mode (better than ANY ground source unit) and COP 3.5 at +7 C.
The Heliotherm HP10L-WEB air source heat pump has a COP of 4.2 at +2 C and a COP of 3.4 at -7 C:
https://institute.ntb.ch/fileadmin/Institute/IES/pdf/Pr%C3%BCfResLW10101...
With respect to heating performance, Alan's numbers may be a bit conservative. According to the Fujitsu service manual, at 47°F/8.3°C the 12RLS draws 1.2 kW and supplies 4.68 kW of heat, which translates to be a COP of 3.9. At this same temperature, its small brother, the 9RLS, consumes 0.80 kW and provides 3.51 kW of heat, for a COP of 4.39.
Source: http://www.e-comfortusa.com/PDF_files/Fujitsu/9RLS/Fujitsu_ASU9RLS-AOU9R...
I've always maintained that air source heat pumps offer greater overall value in most single family residential applications. Ductless heat pumps in particular are relatively inexpensive (e.g., the installed cost of a 12RLS can be as little as $2,500.00), easy to install, safe, reliable and virtually maintenance free; in moderate to moderately cold climates, they're likely to be a better option.
For argument sake, let's assume a home has a space heating requirement of 20,000 kWh a year and that the cost per kWh is $0.135. Heated by electric resistance, the annual cost is $2,700.00. To be conservative, let's assume the seasonal COP of our air source heat pump is 2.5, in which case our space heating demand falls to 8,000 kWh, for a net savings of $1,620.00/year. If the seasonal COP of our ground source system is 3.5, say, then we're now down to 5,714 kWh/year. Thus, in this example, our marginal savings in moving from a COP of 2.5 to 3.5 is 2,286 kWh or $308.61/year. Much better, so it would seem, to take the extra dollars that would have been spent on a ground source heat pump and use them to improve the thermal efficiency of the home, to install a solar DHW or PV system, or to simply pay down debt.
FWIW, I should also note that Dr. John Straube of the University of Waterloo has done extensive field testing of GSHPs in this country and has concluded that their COPs are often overstated:
Source: http://www.buildingscience.com/documents/digests/bsd-113-ground-source-h...
Cheers,
Paul
Much better, so it would seem, to take the extra dollars that would have been spent on a ground source heat pump and use them to improve the thermal efficiency of the home, to install a solar DHW or PV system, or to simply pay down debt.
Good point. What is also often overlooked that one can increase COP by reducing the heating temperature (new houses around here have a heating temperature of +28C ). This can be accomplished with insulation and increasing the heating surface area (if the floor and walls are also heated then the room/air temperature can be lowered without feeling any colder due to the higher IR radiation around ones body (e.g. 19C feel like 21C)).
No question, proper insulation and air sealing with a particular emphasis on enhancing personal comfort should be priority one. A high efficiency heat pump in a cold and drafty home is not likely to improve comfort in any material way and, moreover, it's a waste of dollars if the system has to be oversized to meet the needs of the building.
To expand on your point: my home office faces north and has three exposed walls and a good amount of glass. The walls and ceiling are well insulated, but the windows are clearly problematic (0.3 U-value). I sit less than half a metre from the glass and no matter how warmly I bundle up, I feel the cold. When temperatures dip below -15°C I might turn up the in-floor electric heat to 30 or 35°C and that helps considerably, but I can still feel the heat being sucked out of my hands, arms and upper torso. Simply moving my desk a metre or so away from the windows or possibly adding heavy drapes would make a world of difference but neither option is in the cards.
Cheers,
Paul
Try translucent double honeycomb cell blinds that fit tightly inside the window frame.
Adds R-4 roughly.
Alan
Try adding a layer of laminated glass.
We put 12.5mm lami on our fixed windows, and 9mm lami on the movable glass, and now we don't need heat until the temperatures go well below 0 C.
More efficient for heating, but useless for cooling, since it is an air to water heat pump.
It might be useful for commercial water heating though.
Alan
There are a couple of ways to use geothermal heat pumps in cold climes but the up front cost is substantial. Closed loops using vertical holes work--enough loop has be buried deep enough (usually 100-400 feet depending on the geology and heat needs) to harvest the constant 55-58 F earth that lies below the seasonally fluctuating surface.
The discontinuous permafrost in interior Alaska can make the vertical design interesting. There might not be permafrost, or there might be 100-150 vertical feet of it starting anywhere from a few to forty feet from the surface. And in some spots conditions vary that much in an area that could be covered by less than a city block.
Another way is being tried just north of Fairbanks, AK. During the long days of the short summer, roof mounted solar thermal panels heat fluid that goes to polyethylene loops buried horizontally about a dozen feet under the soil. A heat pump then spends the long winter harvesting that heat from the soil through the same loops. The pilot project just the other side of hill from my home just became operational about month ago. Data will be forthcoming.
1000 km is a distance, not an area. The example used was 800 km long, just in Kansas. I don't know what is meant by "metered capacity". If you mean nameplate, we know that wind turbines run at nameplate capacity roughly 25 to 30% of the time, and this has to be taken into account in designing the whole system. In the USA % of time at nameplate capacity has grown steadily due to better siting, better turbines, and better load matching. I expect near 40% of the time will be available some time in the future.
Maybe you picked 6 mostly bad days :>). Your statistib needs a lot of fleshing out to be meaningful.
Murray
Have you got a site which actually shows electricity produced by wind each day?
Too many people when talking about wind talk about average, this hides the too much and too little power that wind produces 90% of the time.
There is nothing hidden in the website I linked, anyone can look on a daily basis and see exactly how much gas or coal you would have to burn to make up for the wind power changing.
I will record this data and publish it on this website in a few weeks, do not be suprised if nameplate is reached only about 5% of the time.
Detailed production numbers have been obtained for years in the Netherlands and they show 26% nameplate capacity for land based turbines and 36% capacity for sites at sea. The numbers are accurate and registered using calibrated meters. There are a few cooporations that exploit their own turbines and put the production numbers online (not daily numbers unfortunately, but for capacity calculations this isn't necessary).
See also e.g. De Windvogel (Dutch cooporation, use google translation. Click on the turbine image to see it's production numbers). Take for example De Amstelvogel, it produced at 25.3% of nameplate capacity in 2007.
So your expectations for 5% is way too low or that particular site is really bad.
jaz was talking about the percentage of time generation occurs at nameplate capacity, which is not the same as the capacity factor.
Thanks, jaggedben, head and brick wall spring to mind.
That sounds like a normal distribution curve. The real questions are, "What is the average, what is the standard deviation, and it it a left or right skewed normal distribution curve?" The biggest question is, "How often does it fail to meet demand?"
I suspect the answers will not make the wind proponents very happy, especially the last. It will probably fail to meet demand far too often.
This is not necessarily a problem if the country has sufficient hydroelectric capacity or gas peaking units to fill the gaps, but I think in many cases they have not thought about the issue very hard, and the result will be frequent rolling blackouts and/or very high electricity prices.
It's not a matter of making the "wind proponents very happy", its a matter of doing the science correctly!
Wind speeds do not follow a Normal distribution, they heuristically follow what is called a Weibull distribution and one can derive from maximum entropy principles that it should match the Rayleigh distribution (which is in the family of Weibull distributions with coefficient=2). In reality, the measurements match closely to Rayleigh.
Most natural phenomena that show some amount of disorder, randomness, or variability follow the principles of maximum entropy. These are immutable laws and it should neither make wind proponents happy or sad. We all have to learn how to adapt to the laws of nature and deal with it. I just don't find that it helps to make assertions without doing the slightest bit of research on the topic.
I have a whole section in the book The Oil ConunDrum devoted to deriving the statistical wind distribution profile.
Read the section and you can see how to answer these kinds of questions.
The Weibull distribution does somewhat resemble a normal distribution. However I don't think it will make the proponents of wind power particularly happy:
My point is that many wind power proponents haven't really thought about this issue - that the energy comes in short bursts - at all. They need to have the conventional power capacity to cover the periods when the wind doesn't blow. The Danes can rely on the Norwegians and Swedes to cover their periods of no wind, at considerable cost to Danish consumers, but what if all Europe is dependent on wind power?
but what if all Europe is dependent on wind power?
If they are dependent of wind for 20% of the total MWh. no big deal except the Swiss get rich(er). Build more pumped storage (12 GW is Switzerland), more turbines in hydropower plants for better peaking, more HV DC transmission (the co-relation between Ukrainian wind, Icelandic wind and Spanish wind is probably not all that high).
Add some solar PV and a major reduction in FF will occur. Add nukes and even less CO2.
Alan
Actually, 20% is reasonably feasible if it's backed up by sufficient peaking capacity (e.g. hydro or natural gas). The Swiss, the Norwegians, and a few others should do well from that. Beyond that it starts to get tenuous.
My concern is people who are saying we can replace ALL our generating capacity with wind and solar - i.e. shut down the nukes, shut down the fossil fuel plants, and build no additional hydro capacity. That sounds rather tenuous.
The biggest concern is Britain, who's economy will be in dire straits (as if it is not already) if it doesn't do something soon to offset the decline in North Sea oil and gas production. Wind power is not likely going to be enough.
The issue in the UK is fuel, not generating capacity. The quickest way to save fuel is conservation and new wind power (solar PV perhaps in "sunny" South England) whilst the first few EPRs are built.
Four EPRs (6.4 GW) on-line in England & Wales by 2021-22 is about the best that can be reasonably hoped for. Wind turbines installed in 2012 will be ready for scrap by the time the UK gets a surplus of nuclear power.
Best Hopes for Conservation, Wind and Nukes,
Alan
Building out pumped storage is not the only option. I got a bit excited by the mention of heat pumps in The Fine Article. This is why:
http://www.isentropic.co.uk/index.php?page=storage
A heat pump takes mechanical input and divides the ambient temperature into a heat source and a heat sink. This heat pump is fully reversible ... it is also a heat engine, which takes the temperature differential it has created and turns it back into mechanical power. Using silos of gravel bathed in an inert gas for heat transfer fluid, this becomes a very efficient electrical energy store for stationary applications.
Now relying on something unproven like this might be unwise, but it is definitely something to watch very closely.
It may have been mentioned on TOD before but I think it's worth bringing up every time someone talks about expanding hydro or pumped storage, to increase awareness. After all, you can put a couple of silos of gravel anywhere.
Disclaimer : I am not an investor in this technology. I wish I was.
The Danes can rely on the Norwegians and Swedes to cover their periods of no wind, at considerable cost to Danish consumers,
Not true. Besides the fact that Denmark exports over 90% of its wind turbines - not only generating Danish jobs but also Danish tax income:
http://www.windpower.org/download/541/DanishWindPower_Export_and_Cost.pdf
but what if all Europe is dependent on wind power?
Besides the fact that not taking advantage from other sources such as hydro, PV, biomass and even conventional sources would be nuts:
http://www.theoildrum.com/node/7406#comment-765203
The question is: How to reduce fossil fuel consumption. The question is not and will never be: How to create a grid with 100% wind power. Keep in mind more fossil energy is burnt in heating systems than what the EU requires electric energy in total. Switzerland with a considerable amount of electric heating burns 42% more energy in fossil heating systems than what the entire country consumes electric energy: http://www.bfe.admin.ch/themen/00526/00541/00542/00631/index.html?lang=d...
Again: Combined heat and power plants which power heat pumps which replace fossil fuel furnaces reduce the fossil fuel consumption by 60%. (Figure 7)
I did all sorts of statistical analysis and came to the conclusion that the variance from the Rayleigh is minimal, and since it follows the Rayleigh this is a physical law, much like the density of air with altitude.
So what would we like to know? How about the time it takes to reach a certain level of energy in terms of a probability. This is the data from Ontario with the theory in red.
How about a different level of energy:
This is called predictable unpredictability. We redesign or rearchitect the way we use energy to accommodate natural theoretical laws. Obviously I had to change my mindset to work out these equations; it's just a matter of time that other people will start getting on board.
BTW, figures from The Oil ConunDrum
Just for clarification:
Wouldn't you apply a cumulative density function in a practical application?
(e.g. Is the probability over 90% that after 24 hours 200 MWh will have been produced?)
Yes, a CDF is also reasonable way of looking at it. The PDF describes a little better what the "most likely" time to collect an energy is. My mind switches between the two automatically, yet I acknowledge that this could confuse some people.
WHT, you may be referring to different issues, but a lot of studies have been done. See http://search.nrel.gov/query.html?qp=site%3Awww.nrel.gov+site%3Awww.sst....
Murray
The whole link didn't go through. Go to NREL and search for "wind integration studies".
@Murray
Interesting information, I looked through the stanford paper and have to dive in more detail in their extrapolation approach to see whether I trust these figures.
What I was thinking about was that zero power indication is only one out of many that is relevant. Also less than 5% at which percentage of the time, less than 25% etc.
The cost of having excess energy producing hydrogen and using that to generate electricity is a significant barrier. I don't think that's manageable.
Rembrandt
Hi Rembrandt,
I did the following computation back in 2004. It would need some serious updating to now, but I doubt if it is a significant barrier.
With wind turbine costs now at about $0.90/W installed, and amortization over 30 years at 6 % the direct cost of electricity at nominal output would be 1.91 cents/kWh. If we increased the number of turbines by 33% the cost of electricity at nominal output would go to 2.54 cents/kWh, we would be at =>nominal output 58% of the time and we would generate 147% of nominal output energy per year. If we added hydrogen fueled gas turbine backup at 40% of nominal power at a capital cost of $.60/W financed at 6 %for 30 years we would be at => nominal output 75% of the time and nominal electricity would go up to 3.14 cents/kWh. Total output would go to 157% of nominal. If the surplus energy is used to generate and store hydrogen at 75% efficiency (feasible with existing electrolysis and compression equipment), and the backup burns hydrogen to generate electricity at only 40% efficiency (greater than 50% should be possible with a CCGT), there would be at least 70% more hydrogen than needed to run the backup generator. The cost of the electrolysis, compression and storage might push the direct cost for total nominal electricity to 3.5 cents/kWh. This cost is better than coal or natural gas at 2004 prices. Now extend this approach to even more efficient 3 MW turbines and perhaps 3 times as many wind-farms spread over say 500 by 2000 km. and nominal power will be available close to 100% of the time, so the problem of intermittence can be overcome. However, to get there utility management would have to think in whole system terms and would have to cooperate over a large interstate geographic area, a couple of things they are not accustomed to doing
If the surplus energy is used to generate and store hydrogen at 75% efficiency (feasible with existing electrolysis and compression equipment)
That seems higher than I would anticipate, although higher efficiencies on the CCGT side could balance that.
Alan
The best available electrolysis equipment in 2004 was 90% efficient w/o preheat, and compression to 5000 psi is about 90% efficient. Some loss in storage and retrieval is to be expected. However, even at 70% or 65% it would be feasible. Murray
Keep also mind that a 9.5 MW combined heat power plant has already an efficiency of 48.7% running on natural gas (over 90% total efficiency):
http://ge-j920gasengine.com/
The efficiency of a natural gas engine increases with the addition of hydrogen:
http://www.greencarcongress.com/2010/05/eden-20100531.html
(Hydrogen speeds up the combustion process of methane in the combustion chamber which increases the efficiency of the Otto-cycle.)
CHP plants which power heat pumps which replace fossil fuel furnaces reduce the fossil fuel consumption by 60%. If these CHP plants run on Hythane the fossil fuel consumption is reduced by at least an other 20%. And if the heat pumps partially run on wind power and hydro power...
In a good wind site the wind is blowing about 30% of the time. The rest of the time the power is made up by burning coal or natural gas. so how green is the green energy if you never shutdown a single coal fired plant?
Renewables, like wind and solar, without storage is like buying a new Kenworth tractor trailer and having it parked at the rest stop 70 % of the time with the driver(s) having at tailgate party. Then complaining about the high cost of transportation.
The income depends not so much on the fuel used but on the time you have your equipment(capital) running.
You can hide this fact by subsidies but someone always pays.
Please provide references. "In God we trust. Others please bring data." And then note that the wind is always blowing somewhere. If you integrate the grid from Texas to Manitoba your widely dispersed Kenworth is always working. See my first comment above.
I think you would go broke driving truck.
my reference is the wind massive farm going in near my home 30 % was quote in the zoning meeting... but put in your own number.
at 50 % you still have a bunch of kenworths sitting doing NOTHING. The wind may be blowing elsewhere but that does not mean you can transmit it down the transmission line that is already maxed out. If you build all the transmission line to do that this also will be sitting around doing nothing most of the time.
That is already the case.
Transmission is built for peak demand plus a large safety margin (see Path 15 in northern California when it was not). At 3 AM there is massive underused transmission capacity everywhere.
Chose something else to worry about.
Alan
The problem is you can not schedule when the wind blows.
Yet you can predictably schedule the amount of solar energy that reaches the earth. This predictably turns into a world-wide mean kinetic energy in the form of wind and then it becomes a matter of load balancing. Its not simple but it is more dependable than waiting for the next super-giant oil reservoir.
http://www.wunderground.com/US/Region/US/2xWindSpeed.html
the time is 8:57 mountain time.
Take a look at this map. The whole country is calm tonight. Except for the one small spot that hits 20 mph, which still is pretty calm so windy. Tonight is very colds. depending on other regions to back you up will not work.
You have to have a storage system or otherwise you never shut a single fossil fueled plant down.
http://www.tva.gov/sites/raccoonmt.htm
Alan
Perhaps this type of reservoir can be built on the spent coal mountaintop removal mines in Appalachia. That, and/or wind turbine arrays.
With little plaques that say: "Mankind forfeited this mountain's natural ecosystems in the pursuit of energy" Perhaps with pics of the pre-mountaintop removal vistas.
Sad eco-snark to the side, why not? we already scalped the mountaintops...
My amateur guess at one post-FF scenario:
USA energy supply:
~20% wind
~25% solar passive structure heating, CSP and PV
~5% hydro
~5% geothermal
~5% biomass
~60% nuclear fission (Gen III, IV, Thorium, Breeders, etc) [20% overkill to compensate for wind/solar intermittent]
Combined with a ~ 30% drop in per-capita energy use and constraining U.S. population to < 400M and then slowly declining (~.5%/yer). Major lifestyle changes and investment in conservation, but not Olduvai Gorge.
This does not compute. How many "Gen III, IV, Thorium, Breeders, etc" reactors being built right now? In order to get to 60% nuke, we'd need to see a large rush to construct these plants. There is no such thing happening. On the contrary, the fleet of nukes is aging and they all stand to be decommissioned in the next few decades. It isn't clear we'll build enough to even replace the 100 or so we have now, let alone build another 600 of them.
The solar and wind contributions right now are very small, but they are on a rapid percent growth path. They have very large potential.
Also, I think you have biomass and geothermal too high. I'd guess 2 percent ea -- too much land required for 5% biomass and geothermal is highly problematic.
Looks good to me. (Hint: next time take a screenshot and save it)
BTW, Is that wind measured at 100-ft off the ground? You probably can't tell me because you don't know.
True, but renewables are really getting somewhere if they replace coal-, gas- and nuclear plants on a large scale. Not if because of wind- and solarenergy they have to construct less new FF fired powerplants (even when some of them replace only old ones).
Regarding windfarms, after having used the best places on land and near the coast, they have to go (further) offshore where there in many cases will be interference with shipping routes. All problems possible to solve but it takes many many years and by then the question is if that much extra energy will be needed, taken into account the possiblity of an economic collapse and die-off.
I think I go with what Bandits wrote further below:
http://www.windpoweringamerica.gov/images/windmaps/id_wind_potential_cha...
the note says "areas greater then 30% at 80 meters is considered to have suitable wind resources".
The "Installed Capacity" is the potential megawatts (MW) of rated capacity that could be installed on the available windy land area, and the "Annual Generation" is the estimated annual wind energy generation in gigawatt-hours (GWh) that could be produced from the installed capacity.
Unfortunately, that is not true. Statistically speaking, you can absolutely count on having days on which the wind does not blow anywhere from Texas to Manitoba.
Your widely dispersed Kenworth would be like the hundreds sitting at the side of the TransCanada Highway between Revelstoke and Banff recently. Not only were all the major passes on the TransCanada Highway closed, but so were all the passes on all the other highways in the Canadian Rockies. They just had to wait until the weather cleared and the crews got all the avalanches and snowfall off the highways - 5 days later.
Wind systems are similar. There would days when a big blocking high stalled over the middle of the continent, all the wind came to a stop, and then none of the wind turbines would turn until it decided to move on again. Weather is like that.
I would like to see some actual references to back this assertion up. Personal anecdotes and experiences are fine as it goes, but I don't know many people that are 100-foot tall and can tell me their recollections at altitude.
I honestly would like to see the definitive reference on this.
My own personal anecdote: Many a time it has felt perfectly calm but then you look at a flag flapping at 100-ft in the air and you see it straightened out.
Personal anecdotes and experiences are fine as it goes, but I don't know many people that are 100-foot tall and can tell me their recollections at altitude.
I just go by feeling. If I'm standing on the ground, and I don't feel any wind, then it's not blowing at ground level. If I'm right next to a wind farm, the wind is not blowing, and none of the turbines are moving, then I kind of assume that it's not blowing 100 feet off the ground, either. I'm the kind of person who does tours of wind farms and hydroelectric plants on my vacations, so I've seen a lot of them.
My problem is that I have driven past a lot of wind farms where none of the turbines are moving, and I have talked to some weather experts who have told me that there are times when the wind is not blowing anywhere, so I am kind of dubious about people who state it is always blowing somewhere. I would like to see, say, 30 years of studies indicating that the wind is always blowing somewhere. If a government is going to bet large amounts of tax money on it, they should have this data.
I have often seen government authorities screw up in a major way and cost their taxpayers billions because they didn't do their homework before spending a lot of money on something that didn't work. I could give examples, but then this message would get far too long.
I think there is a principal misalignment between two ways of thinking. First everything we do on Earth is a loosing battle with entropy. WHT, you are showing what we are stacked against, and suggest we have to learn to live with that, and here is more or less where your interest seems to stops. As I see it, the "rock" people (if you do not mind the term) are dealing with the nasty details of fighting the (unfortunately losing) battle and you are "squeezing", literally and figuratively, stuff out of earth's resources. There seem to be a gap between...and anybody to bridge?
CC,
No one can argue with your first sentence, taking in the big picture of time and space.
However, as long as the Sun keeps shining (and the insolation doesn't rise past the point where Earth becomes uninhabitable, perhaps by 100M Yr in the future), then we have the ability to use the sun's energy for civilization.
Sun's energy:
- wind
- hydropower
- biomass
- PV
- CSP
- Passive solar structures for residences and other uses.
We also have Earth's geological heat (left over from accretion and from radioactive decay).
Given: The stored ancient sunlight is finite and will 'run out', certainly in economically useful terms. So, NG, coal, oil are but a temporary input in these timescales.
The other energy source: Various implementations of nuclear fission. Could last for many hundreds, if not thousands, of years if breeders are implemented.
Of course, humanity's ability to live within the constraints above depend on a very substantial down-shift in energy use, both per-capita basis and through longer-term population reduction.
Actually factually speaking, you can absolutely count on not finding a single day in Germany and Spain where no wind power has been produced in both countries simultaneously:
Power production of all power plants including wind in Spain:
https://demanda.ree.es/generacion_acumulada.html
Power production of wind power plants in Germany:
http://www.transparency.eex.com/en/Statutory%20Publication%20Requirement...
And even if you were to find a few days without wind power production in both countries at the same time - which you will not:
Europe has currently a hydro storage capacity of over 300'000 GWh.
http://www.usf.uni-kassel.de/usf/archiv/dokumente/kwws/5/ew_8_hydropower...
With 7 days of zero wind-power, zero PV-power and zero conventional power, that still corresponds to 1800 GW of continuous hydro power. The average power demand in Europe however is less than 400 GW.
Needless to say there is always more wind in the winter and always more precipitation and always more PV-power in the summer:
Weather is like that.
And needless to say that Europe still burns more fossil energy for heating than what the entire continent consumes electricity. By replacing fossil furnaces with heat pumps, a gigantic amount of fossil fuel is freed up and only a small amount will be needed for flexible power production.
Combined heat and power plants which power heat pumps which replace fossil fuel furnaces reduce the fossil fuel consumption by 60%. (Figure 7)
PS: Transporting power over large distances is easy:
http://www.abb.com/industries/ap/db0003db004333/137155e51dd72f1ec125774b...
Sorry it sound anecdotal...There is a reference for it, but I do not have it on me. There is relatively high correlation for wind production in various areas in Europe, even on the span of several thousand km. I would need to dig details, but this was a real study. And it is true, that there is always some power generated in both countries, but correlation is, unfortunately, quite high.
The other is that the hydro storage is really storage for annual electricity generation, a lot (most) of it baseload. So there is not 300,000 GWh that can be harnessed as backup to wind. Look at Table 8.1 in the kassel reference in your post for total production. In most countries reservoirs get filled in the spring from spring melt, and this water "has to last".
There is relatively high correlation for wind production in various areas in Europe, even on the span of several thousand km.
No it is not. Again, just go trough the links I provided and just find one single day where both countries are close to 0% or both over 60%. Today Spain was at 4% wind capacity factor and Germany at 60% wind capacity factor:
https://demanda.ree.es/generacion_acumulada.html
http://www.transparency.eex.com/de/daten_uebertragungsnetzbetreiber/stro...
In most countries reservoirs get filled in the spring from spring melt, and this water "has to last".
Actually it's also and mostly increased precipitation during the spring, summer and fall months. Thanks to the higher water vapor content there's more precipitation in the warmer months. In Switzerland the hydro capacity peaks in September:
http://www.bfe.admin.ch/themen/00526/00541/00542/00630/index.html?lang=d...
Unfortunately there is not enough wind power in the winter to keep them from draining down to 20% until April.
So there is not 300,000 GWh that can be harnessed as backup to wind.
Currently hydro reservoirs usually peak in the fall and wind power peaks in the winter. So this wind power will actually help them draining less quickly.
And even if there were only 100,000 GWh because some of the capacity has been drained. They would still last for well over 10 days with no wind, no PV, no biomass and no conventional power on the entire continent and this has never happened (bar any gigantic meteorite impacts).
I stand corrected ..I still want to dig out the study, though. Some numbers got lost in translation about the third: The total capacity of reservoirs is 8,765 GWh according to these charts, so they have capacity to cover 15% of total Swiss consumption, so agree they can provide a really significant buffer. I got really surprised by the rainfall contributing so much to replenishment of reservoirs. Is Switzerland reluctant to go wind way? Looks ugly? There is enough nuclear + hydro to satisfy the needs?
PS. anyone - if you are Swiss - I have family in a little village in Gruyere, and spent some time there, and a little Lac de Montsalvent always looked empty. I have no idea whether there was a hydro station there, though. I would hate seeing wind turbines there, but it is a windy place.
Currently Switzerland produces more electricity than it consumes.
Unfortunately there's a big PR campaign against renewable energies. Obviously the power operators don't want to share the electricity market with anybody. Ironically, the president of the Swiss landscape preservation association (which is actively fighting any wind turbine) is also member of two associations which demand new nuclear power plants.
Here's an example of a small Swiss windfarm with 3 wind turbines.
Actually it should have been four, but the fourth couldn't be built because the artillery complained since it apparently limited their shell path options (well, I guess you never know if the USSR is ever coming back to get us).
I really don't see why ski resorts and all the power lines are considered particularly beautiful and wind turbines are considered ugly. Especially if you've ever seen brownish ski slopes in the summer.
Having said that: Switzerland is not a particularly windy place and investing in offshore windfarms may be more sensible anyway.
European Offshore wind can produce 7 times more electricity than what Europe needs: http://www.slideshare.net/Calion/offshore-report-2009-ewea
Turn the ski lift towers into wind generators. Also handy for transmission as they run in a line from the mountain to the town.
NAOM
The wind is stronger and more dependable at the summit where it gets exposed by 360 degrees of horizon. Skiers don't like wind too much, especially in an exposed chairlift. Only based on anecdotes.
Well, that is one reason for using them to carry transmission lines :) Towers above the lift lines would get more wind. Lots of towers, each with a small turbine, perhaps VAWT, several ski lifts per ski town. All adds up.
NAOM
anyone
But what do you do when you have a dry year or two in a row? water is for people to drink and farmers for their crops that people eat.
http://www.guardian.co.uk/world/2008/apr/06/spain
http://www.reuters.com/article/2007/11/21/environment-spain-water-dc-idU...
Coal and Gas? unless they were closed down, then you are in real trouble.
Nuclear does not suffer from any of these constraints and it is reliable and cheaper than wind and the backup, I and other consumers will have to pay for.
But what do you do when you have a dry year or two in a row? water is for people to drink and farmers for their crops that people eat.
Exactly, this is why you need wind farms to save hydro reserves:
http://www.reuters.com/article/2008/04/15/spain-water-idUSL1579694720080415
Nuclear does not suffer from any of these constraints and it is reliable and cheaper than wind and the backup, I and other consumers will have to pay for.
Unfortunately new nuclear is more expensive than wind and takes much more time to build:
http://www.thestar.com/comment/columnists/article/665644
http://www.weeklystandard.com/articles/nuclear-socialism_508830.html
Also, wind produces more power during winter (when there's less hydro) and doesn't require any cooling water and doesn't depend on uranium imports and costly repositories.
Wind is at $1.4/W and nuclear at $7.8/W:
http://www.nrel.gov/docs/fy07osti/41435.pdf
Coal and Gas? unless they were closed down, then you are in real trouble.
Especially if you want to save on oil and gas you need to replace fossil furnaces with heat pumps. Again: Combined heat and power plants which power heat pumps which replace fossil fuel furnaces reduce the fossil fuel consumption by 60%. (Figure 7)
The question is how to reduce the consumption of fossil fuels as fast and inexpensively as possible:
http://www.newsweek.com/2008/05/17/missing-the-market-meltdown.html
Obviously costs are different from one country to another, so each will have to do what is right for them.
Both UK governments have had independent studies done, which show offshore wind to be much more expensive than Nuclear.
http://www.decc.gov.uk/assets/decc/statistics/projections/71-uk-electric...
Page 73.
Also Nuclear does not need backup everyday so water can be saved for when it is really needed.
I am not against wind, but pumped storage, smart grid and smart appliances such as hot water cylinders are essential for it to work and that will take a long time to install in homes across UK.
Well, this study also concludes that onshore wind is cheaper than nuclear. Besides, wind is built faster and Mott MacDonald doesn't sell any nuclear power plants but Areva does.
And again the UK should first reduce its fossil fuel consumption in the heating sector (e.g. heat pumps, CHP, insulation etc.) than worrying about generating low carbon electricity:
Nuclear power is already being pumped up European mountains every night (no much difference there). And again as opposed to nuclear wind does produce more electricity in the winter when there is less hydro and generally more electricity demand in Europe. Storing nuclear power in the summer to be used in the winter is not really an option (which is why France has to turn off nuclear power plants in the summer).
I have made my own analysis of the North American electrical grid.
Some rough calculations. I basically assumed that the total economic cost of electircity would not increase. Conservation can reduce demand significantly, which allows for a corresponding increase in the cost/kWh. If conservation reduces demand by 40%, this allows for a 67% increase in the rate for = economic cost.
HV DC transmission in the 60 GW range is allowed from, say, the Wind Export Belt (Alberta-Manitoba south to Texas) both East & West, to either load centers or pumped storage. Hydro is developed to the maximum (especially in Canada, +3 GW BC, +5 Manitoba, +0.5 GW ON, +25 GW Quebec, +4 MW Newfoundland) and used in conjunction with wind & solar.
The norm for space heating is dual fuel, electric heat pumps (or resistance when too cold) or FF. Switching is made depending on wind (or solar) generation.
Air conditioning demand sees a dramatic drop due to much better insulation and more efficient a/c. Less heat to a/c away from appliances and lighting as well. So summer peak demand sees a greater drop than total MWh demand.
The best I could do, within the cost parameters, was (measured by MWh) about 34% wind, 16% solar PV and 19% hydro (lower per capita demand expands hydro % + Canada + small hydro), 2% bio-fuels and 2% geothermal (using low grade heat sources and a working fluid other than water). Matching demand geographically and temporally is difficult.
A more elegant solution is to include the other non-carbon generation - nuclear. Much less HV DC transmission is required and less FF are burned, and average costs are significantly lower.
Best Hopes,
Alan
Alan,
Thanks for sharing your analysis with us. I am heartened to know that you and some other folks are looking at the potential future NorthAm energy situation with a wide-aperture systems focus....conservation, energy efficiency, multiple interlocking yet somewhat redundant energy sources and transmission/storage technologies, and transitioning what travel remains in the future towards a greater reliance on trains vice highway vehicles.
I sincerely hope that you and folks you are working with (and other like-minded people) are gaining some traction with TPTB.
Very best hopes for your efforts.
MoI am getting more traction than I initially expected.
There is a need for viable solutions and long term goals,
Bets Hopes !
Alan
Can I add my best wishes and hope?
Thanks for swiftly putting together a summary of your calculated N American scenario. Have I got it right?
You aim to constrain your scenario such that there is a level economic overall cost/benefit from electricity; that is, your scenario will not constrain 'the economy' as a whole, and not ask 'the economy' to take the strain of electricity relatively more costly in the future than it is now? [I must admit that up to now I have considered an increase in future real cost of electricity to be inevitable in N America / EU.]
Given the attention being given to HVDC 'super-grid', here in Europe (the EU Energy Commissioner is pushing for a supergrid financed by Euro Bonds), your inclusion of nuclear is intriguing. The original proponents of the European supergrid (led by Franz Trieb, German Aerospace Centre,) who were arguing and calculating for CSP, the Desertec' project, were actively opposed to including nuclear in the generation mix. Your suggestion(?) for nuclear seems to me to offer a real 'added value' for that tricky technology, over and above its direct contribution of quantities of electricity.
more power to your hopes
phil
Let me give you an example of Florida, which would be a majority FF island, dragging down the national average w/o nuclear.
Wind potential in Florida is trivial and subject to hurricanes. The neighboring states will never have enough wind to export.
Haze pushes solar PV daily maximum to about an hour before solar noon on many days, which is not a great match with load (especially air conditioning). Afternoon thunderstorms in the summer reduce a/c demand, but also kill solar PV.
No geothermal and limited bio-mass potential. Essentially no hydroelectric and zero tidal power potential. Fairly densely populated, but verdant, so 2% bio-mass is not out of line.
Florida is ideal for solar hot water, but limited land and haze make solar thermal electrical generation non-viable.
The best solution for Florida (IMHO) is
- Enough nuclear power to supply 150% of demand at 3 to 4 AM.
- enough solar PV to generate a comparable surplus (in MW) at maximum solar insolation for an average day.
- Bio-mass is used, as much as possible, for peaking power
- Demand is pushed towards the two times/day when Florida generates a surplus (roughly 10:30 PM to 7 AM and 9:45 AM till 1 PM (varies daily with weather and daylight savings).
- A HV DC triangle, with nodes in Western Oklahoma (wind), Chattanooga TN (Pumped storage) and Orlando (with a stub towards Miami). Wind can flow directly to FL or take a longer route through Chattanooga.
- Pumped Storage in 12 GW and 125 GWh range
- OK wind would be connected to HV DC spine from Canada to Texas to shift wind generation to loads
- Limited hydrolysis to make hydrogen (and then > ammonia for farm use & transportation) when generation is in excess of demand and HV DC to pumped storage
- Natural gas (in CCGT) and charcoal generation when nuke + solar PV + imported wind (when available) + pumped storage + demand management + bio-mass cannot make supply = demand.
Western Oklahoma is also connected to California (4 hour delta in demand vs. FL) and Midwest (seasonal delta in demand vs. FL & CA). Pumped storage around Great Lakes and Rocky Mts. This design allows direct supply of wind, when available directly to load as often as possible, but also gives a pumped storage home much of the rest of the time.
Surplus goes to hydrogen > ammonia > farms & transportation
Florida needs more power than nukes + solar can generate twice/day. On average from 7 till 9:45 AM and from 1:15 till 10:30 PM. If Oklahoma has wind then, just import that. Second choice pumped storage, taking stored nuke, solar and wind. Third choice bio-mass that can be stored and fourth choice is efficient natural gas generation.
I would argue for a few large high efficiency coal fired plants in mothballs in case natural gas supplies become a problem. The fifth choice.
Forecasting should allow optimal scheduling and in state generation "can keep the lights on" if HV DC transmission is lost.
Florida can see a greater than average conservation reduction. Near universal solar hot water (with heat pump hot water as a secondary option) is efficient and possible in Florida.
A/c demand is a high % of Florida demand and it can be cut at two levels. Better insulation and shading (and white roofs) combined with much more efficient equipment.
Best Hopes,
Alan
Alan seems to have very accurately described both the present situation and what would make sense to be implemented in Florida. I am personally not generally a fan of Nuclear but have to agree that in Florida it needs to be one of the sources for energy generation.
As a resident of Florida I would actually like to see passive solar hot water be mandated by law. There is no reason not to use it and it would add to a significant energy savings over all statewide. Which brings up the fact that one of the most important part of the Florida State energy picture would be negawatts in the form of conservation, most forms of which Alan has already addressed. I would also emphasize low voltage LED lighting wherever possible. Some of which should be off grid and solar powered. ...Yes, that would benefit me personally >;^)
Regarding white roofs and insulation I would also add large scale implementation of solar powered attic fans, possibly also mandated by law
I would like to see more tax breaks and financial incentives for these measures from both the State and the Federal governments, the sooner the better!
Let's use the renewable energy we have to best of our abilities and conserve like hell! Maybe we could create some kind of statewide competition for the most energy efficient homes and businesses. The winners could receive cash prizes and more incentives and tax breaks.
and...
It is true that FL is not good for solar thermal elec. Basically, this works in the desert. However, FL is quite good for PV. The payback might not look good for a while. But PV costs are dropping dramatically, and will continue to drop. We saw $4 to 5 per watt for good commercial installations last year, and we may see some go down as low as $3 this year. Roof-top PV will start to look okay for FL, but it is really the larger commercial applications that are going to be money-makers.
In general, if the US goes for renewables in a big way (which I believe we must), we will need to move a lot of energy from west to east. I guess that a solar-powered US would have at least 60% of its energy produced in the west... perhaps 70%. All of the solar thermal elec potential is in the southwest ... esp California, Nevada, Arizona, New Mexico, and Colorado..,. some Texas.... and there is very large potential there. With thermal storage, these plants could operate 24/7 300 days a year.
Shipping even 10% of our peak demand between regions will require a massive transmission system. I thunk 10% is just barely doable, more adds too much expense, complexity (environmental impacts, resources, expense) to be very workable).
My plan for Florida has, in a normal day, two periods of electricity exports and two periods of electricity imports. Export surplus nuclear power late at night and excess solar PV from mid-morning to an hour or three past solar noon. Import wind power when it is available and pumped storage when it is not. Burn bio-fuels that can be stored if pumped storage runs low.
This daily In & Out + In & Out maximizes the utility of pumped storage and raises the maximum solar PV and nuclear that can be installed in Florida. Both require much less transmission than imported power.
Nuclear power slices a broad swath off the bottom of the daily demand curve, for all 24 hours. And makes the rest doable.
And the wind in western Oklahoma has three potential markets to export to plus local demand. California, Florida and the Midwest. California solar PV is about 4 to 5 hours later than Florida (4 hours clock, 1 hour due to haze in Florida), so the solar surplus in Florida should be ending about the time that solar self sufficiency starts in California. OK wind could power breakfast in California while Florida takes care of itself. and about the time that solar PV in California ends the need for imported power, Florida solar PV would be declining and in need of a small amount of imported power. Any surplus wind above FL, CA and Midwest demands ends up in pumped storage. And if pumped storage is full, it is used for electrolysis or other low value energy dump.
Weather and seasonal changes will adjust the flows of electricity, but such a system should be able to largely cope with such variations, with NG CCGT filling in the gaps as they develop.
Best Hopes for Non-carbon generation,
Alan
Well ... so ... what?
Post-FF US economy is going to look very different. Massive transmission investment is just part of the ticket cost.
Assuming no collapse, US will spend $40 trillion on energy in the next 20 years. Transmission system investments are a pretty small percentage of the overall investment required.
Alan, the 25 GW figure for Quebec is on the high side.
True, Quebec has an undeveloped hydro potential of around 44 GW, but so far they've commited to develop only 4,500 MW by 2035, as was announced in the so-called (and still a bit nebulous) 2008 Plan Nord of the ruling Liberal Party.
As far as finance, manpower and equipment goes (hydropower projects are basically civil engineering gigs), state-owned Hydro-Québec can probably sustain the development of 2 large project (1,000 MW +), refurbish older facilities while building the necessary upgrades to the main 735 kV grid and HVDC interties (Quebec, like most of Texas is not synchronized with the eastern interconnexion) with the neighboring networks (Ontario, New York, New England, New Brunswick).
HQ could probably scale up, but so far, here's what they have publicly released for the next 25 years: Eastmain-1-A Sarcelle: 918 MW, 2011-2012), Romaine (1250 MW, 2014-2020), Manic-2 and -3, SM-3 (extra turbines), Tabaret (900 MW, ca 2015), Petit-Mécatina (1200 MW, 2023-2026) Magpie (800 MW, 2030-2033). Other projects may be in the works, but they're not talking about it in public... But it is safe to assume that most projects would require extensive deals with First Nations.
Thank you for the list. I was aware of most of it, but not all. The 25 GW came from a HQ engineer at a conference, plus I believe that I read it as well.
I doubt that there will be another James Bay. None-the-less, HQ development is limited by export demand as much as resources.
And the rape of Newfoundland @ Churchill Falls finally ends in 2041. The profits from that deal have essentially paid for much of the HQ expansions since 1976.
Best Hopes for HydroQuebec development,
Alan
Alan,
It would seem most likely that Canada will greatly increase capacity on existing dams by adding more turbines and increasing transmission capacity, using hydro for the more valuable Eastern USA peak demand, rather than baseload. A logical development would be a lot more wind capacity built in northern Canada close to the hydro infrastructure.
I am aware of that. The capacity factor of Canadian hydro is 59%, US hydro 42%.
However, no provision was made for extra turbines in the average design. Replacing turbines and generators with higher capacity units of the same size is often the choice, but that upgrade is limited.
IMHO, new dams should be built with more MW than before for a given water flow.
A detail I failed to mention.
Best Hopes,
Alan
As far as HQ is concerned, its preferred strategy to increase load factors is to partially divert rivers upstream to increase water volumes. That's exactly what they did with the Rupert river back in 2009. The diversion increased the output of Robert-Bourassa, LG-2-A and LG-1 plants by 5.3 TWh/year. This solution has many advantages over building extra wind capacity: rock-filled dams are relatively cheap, they last longer than wind turbines and they are low maintenance (a big plus when the nearest town is hundred of miles away).
But meeting energy demand is only half the equation as Texas painfully discovered last Wednesday. As you can see in the following graphs, demand for energy (first graph) is not expected to rise as fast as loads in winter conditions (second graph). Meeting peak demand has always been an issue on Quebec's grid since the 80s due to the massive conversion to electricity in the residential space and water heating sector which currently accounts for nearly 13,000 MW at peak times, such as the one experienced two weeks ago (38,289 MW on January 24 at 7:38 a.m.). Summer peak is much lower at around 21,000 MW.
Turbine additions at Manic-2, -3 and SM-3 in the coming years should be seen in that context.
Regarding the use of wind, a pair of retired Hydro-Québec engineers recently published a book pitching what Neil1947 describes in his post. Stressing that Quebec has a 100 GW wind potential within 40 km of the transmission grid, they advocate the construction of up to 10,000 MW of wind near the large reservoirs in Quebec's north to maximize water outflows, adding that it could be built for less than 6¢/kWh.
So far, HQ does not seem to be interested in the concept while getting ready to integrate 3,000 MW of wind in the southern part of the province by 2015. Part of the reason is the lower rate of return of wind compared to hydro but risk aversion is probably a factor.
Anyway, scaling up renewable generation in Quebec in the coming years for export purposes will hinge on the success of interconnection projects currently before regulatory authorities in the US. While the underwater Champlain Hudson Power Express (1,000 MW to NYC) seems to sail along fine before the New York State DPS, the Northern Pass project through New Hampshire (1,200 MW to Franklin, NH) has already triggered some hostile reactions in Coos County and among independent power generators in New England.
A number of thoughts.
It may well be cheaper to subsidize better insulation than new hydropower plants.
Southern wind has several advantages. No transmission losses, minimal risk of transmission line failure and lower costs to install and maintain.
And yes, diverting additional water to existing hydropower plants is a good strategy.
Best Hopes,
Alan
It would seem that hydro using storage dams complements wind because wind output varies over a period of hours to days as weather systems cross the continent, while dams usually have months or even years of storage. Thus to store excess wind energy hydro can be reduced saving water for periods of low wind. In most cases adding new turbines is a much lower cost alternative than building new dams.
China's massive hydro(150GW) is used at about 30% capacity factor, saving hydro for peak demand, similarly mainland Australia runs its hydro at about 25% capacity factor, but this is partly due to the relatively large amount of short term pumped storage.
If N America was to derive >50% of its electricity from wind energy the grid could be stabilized by greatly expanding lake Erie/lake Ontario hydro to > 100GW capacity but only using it to back-up low wind periods, with much smaller capacity off-peak pumping back to lake Erie. This could allow all coal fired generation to be mothballed or only used for a few weeks per year, and gas fired power to be used at a much lower capacity factor(mainly exceptional demand peaks).
Wind power is already saving hydro reserves in Spain:
http://www.reuters.com/article/2008/04/15/spain-water-idUSL1579694720080415
Keep also in mind that at least for Europe there is always significantly more wind power produced during winter time when there is always less precipitation.
I have also looked at managing the fall of the Great Lakes from their spring high to their winter low.
If one stays within the natural boundaries, over 2 GW of spring energy cam be diverted to summer generation. In addition, within broad limits, generation can be maximized during weekday peak and shoulder demand.
I would like to see a renegotiation of the amount of water "wasted" on tourists. Perhaps create a spectacular Niagara waterfall when the wind is blowing well and a much more modest one when electrical demand is higher. The current treaty requires the following volumes of water over the falls.
no less than 100,000 cubic feet of water per second (cf/s) From April 1st to September 15th (inclusive) between 8 a.m. and 10 p.m.
no less than 100,000 cubic feet of water per second (cf/s) from September 16th to October 31st (inclusive) between 8 a.m. and 8 p.m.
no less than 50,000 cubic feet of water per second (cf/s) from November 1st to March 31st (inclusive)
Energy to support tourism. IMO, these numbers should be re-evaluated.
Best Hopes,
Alan
Neil1947 wrote;
similarly mainland Australia runs its hydro at about 25% capacity factor, but this is partly due to the relatively large amount of short term pumped storage.
This is not quite true. The capacity factor is indeed around 25%, but that is simply because of a lack of water, not from pumped storage. The only real pumped storage is Tumut 3 power station, at 1500MW, Australia largest hydro station, (out of a national total of about 7500MW). There is some pumped storage at Kangaroo Valley, south of Sydney, but that is only about 150MW.
The real reason for the low capacity factor is that Australia is a dry place, and even the mountain areas don't get that much precipitation, compared to Europe/N America. So when they were building the hydro schemes they knew they had only so much water to play with, and decided, correctly, to build larger plants to augment peak demand, than build smaller baseload plants.
Even absent the few pumped storage stations, the capacity factor would not be much different. It's hard to do lots of hydro without lots of water.
Paul Nash,
Mainland Australia has about 5,000MW of hydro capacity, including 500MW pumped storage outside Brisbane, 1500MW at Tumut 3(600MW pumping) and 240MW at Sholhaven(150MW? pumping), so in fact about 45% of total hydro capacity comes from pumped storage that can be re-used daily to provide peak power, and recharged at a slower rate during off-peak periods. Tasmania has 2,200MW hydro capacity but only 1500MW demand the surplus capacity is exported(up to 500MW) during peak periods while power is imported during off-peak periods and local hydro is reduced to save water.
It is true that Australia doesnt get much precipitation but the storage dams have a very large capacity, the Snowy system (8,000GWh) and Tasmania 16,000GWh or about 6months if run at full capacity, and more than 2 years supply at normal use.
The lesson is that even in a very dry continent, a lot of energy can be stored in dams and used flexibly for peak demand. Australia uses about 600GWh/day so in theory these existing storage reservoirs could back-up 100% wind and/or solar for >30 days IF additional turbines and transmission infrastructure was installed. Since low solar or low wind output is usually only for a few days, hydro is more than adequate to back-up these renewable energy resources.
The lesson is that even in a very dry continent, a lot of energy can be stored in dams and used flexibly for peak demand.
Yes, this is quite true. But all the big river sites in Australia have no been built out - so for new pumped storage, you will have to build new pairs of storages, or, at best, a new storage above or below an existing one. And this not to create any new energy, but just back up wind.
When you add the cost of a new dedicated dam, the penstock, turbines, transmission lines to the cost of wind turbines, it starts to become very expensive. Given that turbines are only just economic at present (wholesale power prices in Aust are 2-4c/kWh) add in the cost of storage for shaping to peak conditions (4-6c/kWh) and it looks very uneconomical - that is why there is no new pumped storage being built - it's much cheap[er just to do another coal station.
Australia uses about 600GWh/day so in theory these existing storage reservoirs could back-up 100% wind and/or solar for >30 days IF additional turbines and transmission infrastructure was installed. Since low solar or low wind output is usually only for a few days, hydro is more than adequate to back-up these renewable energy resources.
It is not quite that simple. The dams, especially the Snowy ones, are used to regulate river flow and distribute water to irrigators. Running the power stations at full output for extended periods, outside of the spring freshet, can have disastrous effects on the rivers, fish, etc, and, at certain times of year, like winter, would represent a collossal waste of irrigation water, as it cannot effectively be stored further downstream.
The Murray-Darling system is almost as over allocated as the Colorado river system and there is a huge debate going on at present about who gets what water (cities, irrigators, environmental flows). Releasing huge amounts of water at random intervals to satisfy big city demand because the wind is not blowing is not going to fly with any of the parties in the Murray basin.
If the wind operators want to built their own dedicated, off river, pumped storages, power to them - there are plenty of places to do that.. They should not expect others to make sacrifices for their benefit.
I love most of what you say. However, I am not as enamored of dams as you and some others. We can't forget that dams destroy thousands of acres of habitat, recreational area and river ecosystems. In addition, in California and I expect elsewhere there are major drought events many times a century, and the impact of these on generation lasts not hours or days, but months and years. Talk about intermittency. If we lose a large percent of our total hydro capacity for 2-3 years we are in big trouble, and more dams won't really help this. Also, predictions are that GW will result in less release of water from snow into our dams during the summer when it is needed. California needs to turn to wind and solar more, possibly add nuclear although the politics may be impossible.
The Climate Change models suggest drought from Kansas to California but an increase in rainfall in Eastern Canada.
On the larger issue, regions and nations that depend on hydroelectric generation should have a combination of loads that can be idled (such as aluminum production) and FF back-ups (with adequate fuel supplies).
Please note that my last resort for a mainly renewable grid is mothballed coal fired plants.
Alan
I don't want to get boring (or sound like I've joined TOD after waiting a month for new account creation to be re-enabled solely so I can repeatedly plug a single promising technology) but
The principal virtue of hydro power is that a head of water in a dam represents stored energy.
Grid energy storage, usually described in terms of hydro and batteries and compressed air and capacitors and flywheels, can also be done with heat engines. Not just stored concentrated solar heat at solar thermal power stations; heat can be stored from a heat pump meaning that the Carnot [in]efficiency of turning it back into mechanical and electric energy is cancelled out by the Coefficient of Performance of the heat pump. Of course both processes can be done with the same machine.
Isentropic Ltd of Cambridge, UK are developing a highly efficient heat pump and heat exchangers for use in this application. If successful (and there is no thermodynamic reason why they shouldn't be), then anywhere you can stick a couple of insulated, pressurised silos is a potential site for new power storage comparable to pumped hydro storage that would inundate many square kilometres of wild land.
Such thermal storage is time limited and I suspect that cycle efficiency will not be that great.
But any new option is quite good, provided it works.
Alan
A logical development would be a lot more wind capacity built in northern Canada close to the hydro infrastructure.
The problem with that is that, due to global air circulation patterns, wind speeds tend to peak at about 45 degrees north latitude, and rainfall at about 60 degrees north latitude.
There tends to be not a lot of consistent wind in northern Canada where the hydro capacity is, and not a lot of consistent rainfall in the more southerly areas where wind farms are more practical.
HI Alan
How is your book coming along?
Do you have a link to your work and/or work in progress?
Transportation bicycling well along. I finally got through to Copenhagen traffic planning to better understand their deliberate policy and results. 2015 goal is half modal share by bicycles. Add subway, walking, commuter trains and city buses and they are prepared for post-Peak Oil.
Best Hopes for the Agony of Writing !
Alan
"if" and "can"
If demand decreases 40% will the utilities shrug it off?
What happens to businesses and those that cannot "conserve"? One thing it means is those that do, must "conserve" more to make up the difference, substantially more. Maybe you mean that households can conserve and businesses can continue with their growth aims....BAU.
What do investors base their information and ROI when it comes to investing in renewable infrastructure and energy?
One thing I do know and that is if one business has reduced profits and production due to their conservation, it simply means Joe's business down the road will take up the slack.
The world at present is invested in growth. A collapse in demand of 40% electricity will have wide ramifications you need to illustrate and iterate.
HereinHalifax constantly gives real world examples of higher energy efficiency in businesses.
We have 10x the shopping space/capita that we had in 1950, and open for longer hours. Much more than EU & Japan as well.
Just cut that space by 80% and commercial energy demand will drop.
Alan
While reading David MacKay's book, I came across what sounded like a sensible idea -- the idea of having two grids. The first is a high quality, expensive grid that never goes down, and the second is a sloppy one that you use to charge your electric vehicles, which goes down all the time. The idea is to capture intermittent wind, etc. power with distributed storage (as opposed to centralized storage like pumped hydro). In the winter, you could imagine locally pumping/storing heat as well.
Any comments on this idea from people who know better? At first glance, this seems like it might be easier and more acceptable than pumping current back into a high quality grid via extra discharge cycles from stationary electric vehicles.
That's a lot of extra expense in wires and power poles that will only be in use perhaps 30% of the time.
If you are thinking along those line you need large loads which the power company and turn off at will. Perhaps your electric car. But then you may be late for getting to work.
Marty,
An interesting suggestion - but you would not actually require two physical grids.
Appliances and equipment which function perfectly happily on "sloppy power" would only be switched on when there was an excess of windpower (or other renewable) available. The switching would be automatic, controlled electronically. For example, a windpower company with excess power available could use web or even cell-phone SMS methods to cue up extra loads to match its generation capacity.
The key to it is energy storage, either as electricity in a battery system, hydrogen in an electrolysis cell or as heat.
Resistance storage heaters were devised in the 1960s as a convenient load balancer for the excess off-peak or night-time nuclear power plant. They had a fixed on time - usually 7 hours from midnight, and this was their main problem, that the heat was available too early in the working day and dissipated by the early evening. If these could be turned on by wireless signal (internet or powerline signal) when there was an excess of power available, then they would help reduce the excess electricity - and in winter, turn it into a useful additional heatsource which would offset natural gas or oil heating.
The same could be said for heatpumps which return a better efficiency than pure resistive heating, and in summer, air-conditioning when cooling is required.
Refrigerators could also benefit from sloppy power. If there was excess electricity available, a deep freeze could keep its compressor on for longer, and chill the food to a few degrees lower. Provided that this was within sensible limits (for food safety -18C to -23C) then it would not matter if your food was taken to -25C, meaning that the freezer could maintain safe temperature for longer before needing to turn on the compressor. The energy is stored as "excess cold" in the refrigerator, plus as additional heat, released to the room from the condensor coils on the back of the freezer.
Some interesting further information on this principle on the Dynamic Demand website
Many houses have low baseload electricity requirements. Currently, I am using just 104W, as I sit at my laptop, under a CFL low energy bulb, with just a few other items plugged in. Most of these devices are electronic and can work from low voltage dc power. A battery storage system, which could supply 24hrs worth of baseload dc power to these devices would be not much bigger than an old desk-top tower PC. It could be charged opportunistically when there was an excess of sloppy power. LED and low energy lighting systems are also key candidates for dc power.
Low voltage dc supplies are less inefficient in terms of resistance losses than might have otherwise been assumed, and the ability to transform efficiently from one dc voltage to another, or back to ac power and the prevailance of electronic and low wattage goods which need dc could make these dc systems attractive in terms of energy efficiency.
Electronic goods will benefit most from dc power. It would eliminate the requirement for an inefficient ac power supply stage, and instead use a dc converter which can be up to 98% efficient. A 42" flat screen TV only needs 140W of power, just under 6amps if you use a 24V supply. All of the audio-visual entertainments system, PC, printer/copier/fax, mobile phone, wireless router, burglar alarm could all be powered from low voltage dc, much more efficiently than ac.
There are few appliances under 1200W, which could not be powered from low voltage dc systems. Worktop kitchen appliances, blenders, mixers, coffee makers and even slow cookers (<200W) will work on dc power. A slow cooker will cook a meal in 6 to 8 hours, whilst you may be out of the house for 12 hours. It could "buy-in" to sloppy grid power at a cheaper rate to ensure that the meal was cooked by home-time. In the bathroom the improved safety aspects of low voltage dc for electric toothbrushes, shavers, straightening/curling tongs would be appreciable. Most of these devices could have their own battery storage. In the workshop/garage many power tools are battery opeerated, again recharging from a universal low voltage dc bus would be more energy efficient.
The introduction of electricity storage capacity will take time and money. Rather than persuade 2% of the population to invest in an electric vehicle with a 20kWh battery costing $30,000, it might be possible to achieve the same amount of dc battery storage from domestic sized stores - say with 2kWh battery, and an uptake of 20% of householders.
The household energy store could also be supplied from photovoltaic panels. Few might have the roofspace, or finance available to install a full sized 3kWp system. However with a couple of panels costing say $1000, and mounted on the wall or window sill, and rated at 300Wp would be more than sufficient to run the dc-grid, and make perhaps a 10% renewable contribution to the householder's electricity bill. These figures are based on an average European domestic usage which is close to 3000kWh per annum. It would be an attractive option for those living in appartments or smaller property where roofspace is just not an option.
The second grid, which functions on sloppy, cheap rate power, may well be a dc ring-main and battery storage system installed within the average household. It may take a long time for the smartgrid to evolve from what we have already, but within the home, there is a lot of scope for using power, smarter.
2020
I do not like the word sloppy because many things will not run on it that could be intermittent. You still want clean power just intermittent. Refrigerator compressors comes to mind.
There is also thermal energy storage(TES) in the form of phase change materials.
http://www.pcmproducts.net/Solar_Heat_Storage_Recovery.htm
If you add these rubber balls filled with PCM inside your hot water tank the capacity is increased. If your hot water heater is insulated the water will stay warm.
2020Vision, thanks for all the useful info!
It made me feel better about the advent of human thought.
Those battery costs are falling ...
Electric cars are evolving quickly. Although he refuses to reveal figures, Mr Ghosn says the cost per kilowatt-hour (kWh) of battery capacity for Renault-Nissan cars has fallen by half in four years. Earlier this year Boston Consulting Group estimated that electric cars will not be fully competitive until costs fall to about $200 per kwh. That would substantially reduce the cost of the 24 kwh battery used by the Nissan Leaf. According to industry rumours, Renault-Nissan has got its costs down to below $400 per kwh, so if it can continue this progress its cars will become much more competitive.
Anyone know whatever happened to the final post of the false fire brigade series--why it hasn't been published?
As a first step towards realizing the Chinese dream of energy self sufficiency and independence, China is embarking on a wholly owned development of cheap and clean nuclear energy. The Chinese Academy of Sciences (CAS) has launched plans of developing a thorium-fueled molten-salt nuclear breeder reactor, which when functional will be a precious alternative safe and inexhaustible fuel source. As Richard Martin writes in Wired magazine, "Designing a thorium-based molten-salt reactor could place China at the forefront of the race to build environmentally safe, cost-effective and politically palatable reactors."
This speaks to the necessity for nations making smart energy development and fielding choices if they want to survive over the long term.
From The Texas Trubune
What happened yesterday to cause the rolling power blackouts across Texas?
State Sen. Troy Fraser, R-Horseshoe Bay, in a phone call with the Tribune today, stressed that conclusions are still tentative but said a chain reaction of problems involving the state's coal and gas plants appeared to be the cause — and wind plants were having trouble, too. So far no blackouts have been ordered today.
Electricity demand spiked in Texas yesterday as the cold weather struck, setting a wintertime record for usage. Summer usage is higher, but winter also can bring strong demand because about two-thirds of Texas homes are heated with electricity.
Initially, it appears, some coal plants went offline due to cold-weather problems, taking a large chunk of electricity out of the grid. Luminant, a major power-generation company, confirmed that its two coal units at the Oak Grove plant in Robertson County failed, as did two units at a coal plant in Milam County. "We are in various stages of start-up and operation for that group," Allan Koenig, a Luminant spokesman, said via e-mail. Three of these four units only began operating in the last few years; Fraser, who chairs the Senate Committee on Natural Resources, noted that they had new emissions-control technologies, and said one question was how those technologies had handled the cold.
Dave Knox, a spokesman for NRG, another power company, said that a cold-weather problem also caused a shut-down of its Limestone coal plant near Jewitt, Texas. The problem occurred yesterday, albeit after the early-morning crisis, and the plant returned to operating early this morning.
Natural gas plants were hastily turned on to make up for the coal-plant failures. But, Fraser said, some power cuts affected some stations for compressing natural gas — so without power they couldn't pump gas, causing some gas power plants to go offline. In addition, rules regarding "curtailment" of natural gas — who gets first dibs on gas when gas supplies are tight — were last revised in 1972, Fraser said, leaving some power plants at risk of losing out on supplies. A large minority of Texans heat their homes with gas, in addition to the needs of the power plants, so there was extremely high demand for gas during the freezing weather.
"We didn't have enough available gas," Fraser said. An affidavit filed yesterday with the Railroad Commission by Trip Doggett, the head of the Eletric Reliability Council of Texas, the state's grid operator, said that "certain gas suppliers may be curtailing natural gas to electric utilities or electric generation customers." Koenig, of Luminant, confirmed that "one of our gas plants has been curtailed due natural gas supply restrictions."
Wind generators also appeared to be having problems, said Fraser; he had received reports of some turbines shutting down because of issues with ice on the blades. "The wind was blowing yesterday, but I'm not sure wind generation was available because they had problems with ice," he said. (At an Iberdrola wind farm near Corpus Christi that the Trib visited yesterday, most turbines were spinning steadily, in response to the grid operator's call for maximum production. But the plant's operator, Daniel Pitts, said that a few machines were having issues because the cold air had affected the nitrogen in the hydraulic system that helps run the turbines.) Dottie Roark, a spokeswoman for ERCOT, said that yesterday morning between 5 a.m. and 8 a.m., about 3,500 to 4,000 megawatts of wind was available (the state has about 10,000 megawatts of wind installed).
Is the problem solved? "We think we're probably going to be okay today, and obviously it's going to warm up from there," said Fraser.
In the next couple of weeks, after the crisis passes, Fraser said he would call a hearing on the blackouts to figure out what happened and how to fix it. He noted that there were "a lot of unusual circumstances" to this storm, and that while Texas was well-prepared for spiking electricity usage in the summer, "to my knowledge we've never been tested for an event during the winter." But it's clearly imperative to fix the system, he said. The Public Utility Commission, which oversees ERCOT, met this morning and is also investigating the cause of the power-plant problems, spokesman Terry Hadley said.
ERCOT said this morning that 3,000 megawatts — the equivalent of nearly twice the output of the Oak Grove coal plant — remained offline this morning. But Roark, the ERCOT spokeswoman, said that the grid operator was unable to say which plants remained offline today "because this is considered protected information under market rules in a competitive market."
From the Nuclear Energy Institute:
As Texas copes with rolling electricity blackouts and its coldest temperatures in decades, you should be aware that the state’s four nuclear power plants – which have a combined electric generating capacity of 4,800 megawatts – are operating at 100 percent capacity.
And how much worse would the Texas blackouts have been without the 3,500 to 4,000 MW of "unreliable" wind generation ?
Answer, 4,000 MW of "firm load" (homes, shops mainly) was shed at the maximum. Double the peak load shed, but also add many hours on either side of the load shedding w/o wind.
The total MWh required to be shed would have been several times worse w/o wind. Natural gas supplies, which were curtailed to electric generators, would have been MUCH shorter without wind reducing NG demand all winter long.
OTOH, twice as much wind installed in Texas would have meant no load shedding of firm load and no natural gas curtailments.
Alan
Wow just look at how much gas we would (not) have burned if it wasn't for the fantastic performance of the "renewable" fuel ethanol.
In fact without ethanol the American and quite possibly the economies of the world would have been crippled years ago.
That does not mean ramping up ethanol will save the day. It has meant we have ramped up our consumption of oil and other fossil fuels because ethanol provided the means to sustain an unsustainable economy. We continued the exploration and exploitation of reserves which otherwise would have remained reserves.
Much worse than that, with the continuance of BAU which ethanol and other renewables are providing we have passed the point of no return with global warming.
Sustainable renewable energy is for a time and place without the encumbrance of over population and world destroying fossil fuels.
It's all due to people and corporations invested in the promotion of BAU.
While we continue to stretch the elastic band of modern civilization, populations continue to increase and the devastation of flora, fauna, oceans, rivers, lakes and forests continue at an ever increasing pace. That devastation will escalate until finally the realization takes hold that our world and lifestyle is and always was a charade.
Simply explained, self preservation along with procreation are the two dominant human traits.
We have (in the foreseeable future) stabilized somewhat the procreation part while we maintain the means, but fornication continues unabated providing a bomb requiring a spark. Self preservation is another matter, that will ultimately destroy everything because the world is grossly over populated.
The time for "doing something", "being positive" passed fifty years ago.
What is now criminal is the promotion of BAU and false hopes and dreams.
People are in the main clever and inventive. If the faucets which feed BAU are turned off, initial turmoil and human construction destruction is inevitable. In the end though there will be something to salvage.
Continuing on our present path ensures there will be nothing to salvage. No one is going to give up and die. We will all fight to the end, that is the human condition but championing the means to continue our destructive lifestyle is the worst crime in human existence.
I disagree that speeding the collapse of industrial civilization, with the resultant die-off, is the best option available.
Alan
Alan, who agreed ? The only people that are working on this consciously are people like suicide bombers. Most others want BAU because they consider that necessary for a healthy economy. That is the tragic trap that human race is in.
The critique appeared to call for ending any semblance of BAU, calling efforts to preserve it and preventing a massive die-off the greatest crime.
I doubt that the writer is doing anything actively to end any semblance of BAU, other than posting occasionally on the internet.
Some have called my medium term vision BAU Lite. I see growing elements of sustainability, with reduced impacts, evolving within the current systems.
With enormous luck, I can help make things a little bit better than what they would otherwise be.
Best Hopes,
Alan
BTW, most rail infrastructure will likely survive a massive die-off.
As someone who grew up in Texas, I can tell you if the wall/ceiling insulation and windows in the average Texan home had been up to standard, the peak heating load and airconditing load would fall about 20-30%. This reported ERCOT incident would likely not happen. Texans are conditioned to expect very low energy prices, so there is no point in paying for increased energy efficiency up front. OPEX from energy use is simply an insignificant component in the lifecycle cost analysis. This applies to home building standards in particular.
For the past century (give or take) societies have moved from living with storable and intermittent sources of energy to centralized and relatively constant energy sources. Wood, coal, whale oil, etc. were stockpiled and managed by families, communities, tribes. Expecting folks in these times of outsourced, on-demand energy to return to this way of managing their energy needs may seem naive, but since my view of the future is more Archdruidish, Orlovian perhaps, this is what I foresee: people and communities taking more responsibility for their energy needs. Producing as much energy locally, utilizing intermittant sources when they can, including unreliable grid power, and finding ways to store and time-shift what they need will add resiliance not found with increasingly complex central solutions.
Thermal storage on a small to medium scale, batteries perhaps, stored backup such as bottled gas and wood for specific purposes, all add resiliance. Most folks these days are utterly reliant on centralized sources of energy that will become increasingly unreliable. Flip-the-switch-and-hope will be their future. Expectations will change.
A trillion euros for a massive nuclear buildout?! Large scale investments in renewables? Smart grids? Are these attempts to prevent a collapse, or mitigation of one that is already occuring?
Overall I found the book very helpful in describing approaches to analyze electricity systems, and getting more insights into the technical feasibility of large renewable electricity shares. I am not convinced, however, about the economic possibilities of large shares of renewable electricity systems.
Which is contrary to the facts:
http://www.windpower.org/download/541/DanishWindPower_Export_and_Cost.pdf
And Denmark is currently at 22.1% of wind power share.
And this is besides the fact that Denmark exports over 90% of its wind turbines - not only generating Danish jobs but also Danish tax income.
Investing in heat pumps and heat storage capacity equal to approximately 1000 MW of electric power in 2030 and one day of heat consumption storage.
An electric hot water system with a power demand of 5 kW already provides 1000 MW of electric power with only 200,000 systems. And the insulated tank keeps the heat for one day (only one water tank per 22 Danes).
http://www.eitherm.ch/site/boiler-speicher-puffer?page=shop.product_deta...
These systems are already run at night (during low demand), to have warm water during the entire day.
In addition, a modern house (insulated according to central Europe standards) doesn't need additional heat storage. The heat capacity of the house alone is sufficient and the insulation prevents it from cooling down quickly.
Besides even a stainless steel heat storage tank which can store heat energy over several weeks can last over 100 years is still cheaper than a Ford F-150 or a Chevrolet Silverado the two best selling cars in the US and definitely neither cars are needed (most people simply don't need to tow big boats over high mountains with dirt roads) nor lasting 100 years:
http://www.jenni.ch/pdf/Energie_fuers_Leben.pdf
And of course, future homes will have to be heated with heat pumps instead of fossil furnaces. It simply doesn't make sense to keep on burning more fossil energy in heating systems than what the entire continent requires electric energy.
The question is: How to reduce fossil fuel consumption. The question is not how to create a renewable grid.