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Renewable Baseload Energy

Posted on 27 November 2010 by dana1981

A common argument against investing in renewable energy technology is that it cannot provide baseload power - that is, the ability to provide energy at all times on all days.  This raises two questions - (i) are there renewable energy sources that can provide baseload power, and (ii) do we even need renewable baseload energy?

Does Renewable Energy Need to Provide Baseload Power?

A common myth is that because some types of renewable energy do not provide baseload power, they require an equivalent amount of backup power provided by fossil fuel plants.  However, this is simply untrue.  As wind production fluctuates, it can be supplemented if necessary by a form of baseload power which can start up or whose output can be changed in a relatively short period of time.  Hydroelectric and natural gas plants are common choices for this type of reserve power (AWEA 2008). Although a fossil fuel, combustion of natural gas emits only 45% as much carbon dioxide as combustion of coal, and hydroelectric is of course a very low-carbon energy source.

The current energy production structure consists primarily of coal and nuclear energy providing baseload power, while natural gas and hydroelectric power generally provide the variable reserves to meet peak demand. Coal is cheap, dirty, and the plant output cannot be varied easily.  It also has high initial investment cost and a long return on investment time.  Hydroelectric power is also cheap, clean, and good for both baseload and meeting peak demand, but limited by available natural sources.  Natural gas is less dirty than coal, more expensive and used for peak demand.  Nuclear power is a low-carbon power source, but with an extremely high investment cost and long return on investment time.

Renewable energy can be used to replace some higher-carbon sources of energy in the power grid and achieve a reduction in total greenhouse gas emissions from power generation, even if not used to provide baseload power.  Intermittent renewables can provide 10-20% of our electricity, with hydroelectric and other baseload renewable sources (see below) on top of that. Even if the rapid growth in wind and other intermittent renewable sources continues, it will be over a decade before storage of the intermittent sources becomes a necessity.

Renewable Baseload Energy Sources

Of course in an ideal world, renewable sources would meet all of our energy needs.  And there are several means by which renewable energy can indeed provide baseload power. 

Concentrated Solar Thermal

One of the more promising renewable energy technologies is concentrated solar thermal, which uses a system of mirrors or lenses to focus solar radiation on a collector.  This type of system can collect and store energy in pressurized steam, molten salt, phase change materials, or purified graphite.  

The first test of a large-scale thermal solar power tower plant was Solar One in the California Mojave Desert, constructed in 1981.  The project produced 10 megawatts (MW) of electricity using 1,818 mirrors, concentrating solar radiation onto a tower which used high-temperature heat transfer fluid to carry the energy to a boiler on the ground, where the steam was used to spin a series of turbines.  Water was used as an energy storage medium for Solar One.  The system was redesigned in 1995 and renamed Solar Two, which used molten salt as an energy storage medium.  In this type of system, molten salt at 290ºC is pumped from a cold storage tank through the receiver where it is heated to about 565ºC. The heated salt then moves on to the hot storage tank (Figure 1).  When power is needed from the plant, the hot salt is pumped to a generator that produces steam, which activates a turbine/generator system that creates electricity (NREL 2001).

 

Figure 1:  Solar Two Power Tower System Diagram (NREL 2001)

The Solar Two molten salt system was capable of storing enough energy to produce power three hours after the Sun had set.  By using thermal storage, power tower plants can potentially operate for 65 percent of the year without the need for a back-up fuel source. The first commercial concentrated solar thermal plant with molten salt storage - Andasol 1 - was completed in Spain in 2009.  Andasol 1 produces 50 MW of power and the molten salt storage can continue to power the plant for approximately 7.5 hours.

Abengoa Solar is building a 280 MW solar thermal plant in Arizona (the Solana Generating Station), scheduled to begin operation in 2013.  This plant will also have a molten salt system with up to 6 hours worth of storage.  The electrical utility Arizona Public Service has contracted to purchase the power from Solana station for approximately 14 cents per kilawatt-hour. 

Italian utility Enel recently unveiled "Archimede", the first concentrated solar thermal plant to use molten salts for both heat storage and heat transfer.  Molten salts can operate at higher temperatures than oils, which gives Archimede higher efficiency and power output.  With the higher temperature heat storage allowed by the direct use of salts, Archimede can extend its operating hours further than an oil-operated solar thermal plant with molten salt storage.  Archimede is a 5 MW plant with 8 hours of storage capacity.

The National Renewable Energy Laboratory provides a long list of concentrated solar thermal plants in operation, under construction, and in development, many of which have energy storage systems.  In short, solar thermal molten salt power storage is already a reality, and a growing resource.

Geothermal

Geothermal systems extract energy from water exposed to hot rock deep beneath the earth's surface, and thus do not face the intermittency problems of other renewable energy sources like wind and solar.  An expert panel concluded that geothermal sources could produce approximately 100 gigawatts (GW) of baseload power to the USA by mid-century, which is approximately 10% of current US generating capacity (MIT 2006).  The panel also concluded that a research and development investment of less than $1 billion would make geothermal energy economically viable.

The MIT-led report focuses on a technology called enhanced or engineered geothermal systems (EGS), which doesn't require ideal subsurface conditions and could theoretically work anywhere.   installing an EGS plant typically involves drilling a 10- to 12-inch-wide, three- to four-kilometer-deep hole, expanding existing fractures in the rock at the bottom of the hole by pumping down water under high pressure, and drilling a second hole into those fractures.  Water pumped down one hole courses through the gaps in the rock, heats up, and flows back to the surface through the second hole. Finally, a plant harvests the heat and circulates the cooled water back down into the cracks (MIT 2007).

Currently there are 10.7 GW of geothermal power online globally, with a 20% increase in geothermal power online capacity since 2005.  The USA leads the world in geothermal production with 3.1 GW of installed capacity from 77 power plants (GEA 2010).

Wind Compressed Air Energy Storage (CAES)

Various methods of storing wind energy have been explored, including pumped hydroelectric storage, batteries, superconducting magnets, flywheels, regenerative fuel cells, and CAES.  CAES has been identified as the most promising technology for utility-scale bulk wind energy storage due to relatively low costs, environmental impacts, and high reliability (Cavallo 2005).  CAES plants are currently operational in Huntorf, Germany (290 MW, since 1978) and Macintosh, Alabama (110 MW, since 1991).  Recently this type of system has been considered to solve the intermittency difficulties associated with wind turbines.  It is estimated that more than 80% of the U.S. territory has geology suitable for such underground storage (Gardner and Haynes 2007).

The Iowa Stored Energy Park has been proposed to store air in an underground geologic structure during time periods of low customer electric demand and high wind.  The project is hoping to store a 20 week supply of compressed air and have approximately 270 MW of generating capacity.  The project is anticipated to be operational in 2015. 

A similar system has been proposed to create a wind turbine-air compressor.  Instead of generating electricity, each wind turbine will pump air into CAES. This approach has the potential for saving money and improving overall efficiency by eliminating the intermediate and unnecessary electrical generation between the turbine and the air compressor  (Gardner and Haynes 2007).

Pumped Heat Energy Storage

Another promising energy storage technology involves pumping heat between tanks containing hot and cold insulated gravel.  Electrical power is input to the system, which compresses/expands air to approximately 500°C on the hot side and -150°C on the cold side. The air is passed through the two piles of gravel where it gives up its heat/cold to the gravel. In order to regenerate the electricity, the cycle is simply reversed.  The benefits of this type of system are that it would take up relatively little space, the round-trip efficiency is approximately 75%, and gravel is a very cheap and abundant material.

Spent Electric Vehicle (EV) Battery Storage

As plug-in hybrids and electric vehicles become more commonplace, the possibility exists to utilize the spent EV batteries for power grid storage after their automotive life, at which point they will still have significant storage capacity.  General Motors has been examining this possibility, for example.  If a sufficiently large number of former EV batteries could be hooked up to the power grid, they could provide storage capacity for intermittent renewable energy sources.

Summary

To sum up, there are several types of renewable energy which can provide baseload power.  Additionally, intermittent renewable energy can replace dirty energy sources like coal, although it currently requires a backup source such as natural gas which must be factored into the cost of intermittent sources.  It will be over a decade before we can produce sufficient intermittent renewable energy to require high levels of storage, and there are several promising energy storage technologies.  One study found that the UK power grid could accommodate approximately 10-20% of energy from intermittent renewable sources without a "significant issue" (Carbon Trust and DTI 2003).  By the time renewable energy sources begin to displace a significant part of hydrocarbon generation, there may even be new storage technologies coming into play.  The US Department of Energy has made large-scale energy storage one if its research priorities, recently awarding $24.7 million in research grants for Grid-Scale Rampable Intermittent Dispatchable Storage.

This post is the Intermediate version (written by Dana Nuccitelli [dana1981]) of the skeptic argument "Renewables can't provide baseload power". 

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Comments 1 to 50 out of 102:

  1. That 14 cents a kw sounds a bit pricey for Arizona. It will cost the consumer much more than 14 cents. Right now the consumer pays approx 11 cents per kw at the retail level. I hope it doesn't end up like Minnesota. Rates are going through the roof because of the contracts for purchase of wind power.
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  2. Camburn, when coal power was new, the power cost about US$3.00/kw-h (in 1990, inflation adjusted terms) & its only been in the last 60 years that electricity from coal-fired power fell below the US$0.20/kw-h (again, in 1990 inflation adjusted terms)-& that required much more tax-payer assistance than solar or wind has ever received. So as a new technology, I'd say that solar thermal is off to a very good start. Obviously as economies of scale are achieved, the price will fall below then $0.10c/kw-h range. Also, your claims about Minnesota don't really stack up too well either. According to the EIA, electricity prices in Minnesota have only risen by 0.1c/kw-h (barely a 1% rise), & are still below the average US rate of 11.53c/kw-h. So it seems that, on all counts, your claims just aren't backed up by the facts!
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  3. BTW, Dana, you forgot to mention Vanadium Flow Batteries. There is strong evidence to suggest that this could be an ideal way to store wind power for release when wind is not available. King Island Wind Farm-for example-is able to provide 50% of the communities power needs from Wind alone because of the batteries. It would probably only be 1/3rd that amount if they relied on the wind power *only* when the wind was available.
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  4. In order for renewable sources to provide baseload power, the system has to have extra capacity to collect and store energy, over and above it's rated output, and just how much extra energy it can capture on any given day is likely to be highly variable subject to prevailing weather conditions. I am wondering if there are any advantages to be had by running output below capacity in order to store energy, especially when there will be no advanced knowledge whether the system will accumulate energy for one hours output or six hours output on any given day, over putting all the output into the grid as it is being generated. I can understand that storage would be necessary for a stand alone unit, but isn't it just unnecessarily increasing costs and lowering efficiencies if such systems were made part of a national grid?
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  5. Unavailability of wind and solar power cannot cancel together even at the national scale. If we want to hedge it at a national grid, it requires huge energy storage capacity. I think there must be local implementation of energy storage. Actually I am not optimistic about fulfilling energy demands of modern societies by renewable sources. I think we should try to redesign local energy demands to match local energy availability in space and time.
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  6. Marcus: Renewable costs in Minn: http://minnesota.publicradio.org/display/web/2010/11/23/wind-power-electricity-rates/
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  7. Kooiti Masuda@5: I agree. We should be building thorium reactors. Known tech, deff baseload power, low co2 footprint. I live in a state that has tremendous wind resources. The problem is, when the wind stops, it stops over a very wide area. And it does stop, and stops at times for over 48 hrs. During that lull, there still has to be energy delivered from a base facility.
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  8. What Dana has not talked about is the smart grid to control loads, HVDC lines for more efficient transmission of power. North Dakota has plans to sell wind power to Chicago over HVDC lines. Today we have the equivalent of the dumb grid. There is very little control over peak loads. Being able to shut down loads intermittently would be able to reduce power by about 20%. Also tieing the grids together in a national grid would bring the cost of power due to the ability to have more competition. With a cap and trade program or some funding source, we would be able to modernize our power lines to handle our energy needs more intelligently.
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  9. @ Marcus I'm intersted in the rise of coal power as a dominant player. Where did you source those figures from?
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  10. I am resentful this article was posted, as it is a bunch of half-truths at best, which damage the stellar reputability of this blog. Here is my list of objections: 1. All the "baseload renewable energy" schemes mentioned in the article are extremely expensive and therefore unrealistic as a solution. The fundamental reason for this is the same as why these energy sources were abandoned by our ancestors some 200 years ago: low energy density and finicky energy flows related to these sources. And please keep in mind that there were 1/6th of population o the planet then with 1/10 - 1/100th of per capita energy use. Even then it was not enough. Renewable energy advocates have been posting wishful thinking along these lines for well over two decades, and the complacency generated in thinking public did a lot of harm as an impediment to the necessity of actually facing the dire reality. I should say these energy sources are great in specific niches, however thinking we can build a backbone of industrial society using these sources is delusional wishful thinking, which I object to. What follows are specific objections to the mentioned energy generation schemes. 2. Concentrated Solar Thermal - great some places, untenable in others. Not every place has sunshine as regular as southern California or Spain. Few hours of energy storage do not qualify as "baseload", even in these places. Using CST as baseload in northern Europe or Canada does not add up, when there are cloudy and rainy days and weeks with little sunshine. Even in the most sunny places CST is still prohibitively expensive despite centuries of development. 3. Geothermal - great but limited to places with appropriate geology - a heat source close to the surface. Even then, some such suitable places developed earthquakes and the projects had to be abandoned (such as close to Basel in Switzerland), or the heavy metal pollution brought up from the GT wells is prohibitive (such as mercury pollution which closed GT plants in Italy). Most of the places with suitable geology are already used, or are not available for exploration. Who of the environmentalists want to convert Yellowstone National Park to a GT plant, which would supply few percent of US electricity at best? Therefore GT does not scale up to be much more useful then it already is. 4. Compressed Air Energy Storage - CAES does not compress and reuse compressed air, as the article suggests. The expanded air drops in temperature (pV = nRT), and would freeze & destroy the turbine. CAES indeed use the compressed air to aid compression stage in a gas fired turbine. In another words, CAES plant is a gas plant with efficiency improvements. We should keep in ming that there is less energy available in natgas reserves than in oil (according to BP2010 statistics), so unless we want to go with all-out fracking, which has its own dire environmental consequences, any scheme which relies on natural gas is doomed to fail, as is clearly neither renewable nor sustainable. 5. Pumped heat storage - there is no heat storage which was demonstrated to scale. 6. EV battery storage - the largest component the variable cost of running an EV is not the cost of electricity, but the battery amortization with use. In another words, cycling the battery is more expensive than the electricity it stores. Unless there is some great break-through in battery storage which would reduce battery amortization by at least an order fo magnitude, this scheme is a wishful thinking. 7. This article does not mention hydro electricity, by far the largest non-nuclear clean and sustainable source of dispatchable energy. Pumped hydro is by far the largest storage we actually have on the grid. It has issues similar to most of the above, namely it does not scale anymore, as most of the suitable locations are utilized. 8. To summarize, none of these sources can realistically replace coal as a baseload source. On the other hand, we do have a baseload energy source which readily replaces baseload coal at lower costs (in most places), and which is steady, controllable, scalable, and clean (or as clean as wind/solar in life cycle emissions) - nuclear energy. This is not to say that nuclear energy is a kind of fairy dust which does not have its issues, it is just to say that nuclear is the best of all realistic alternatives. Time we spent wishing that there was fairy dust solution to our problems is a time wasted in daydreaming.
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  11. @ Camburn. If Thorium were so amazing, then why is it still not in commercial development? Perhaps because of the fact that its incredibly expensive, largely untested & has a number of key engineering issues which are nowhere near being solved. Fact is, all I'm reading in the above posts is the usual Denialist Clap-trap about how "useless" renewable energy technologies are. In truth, they've had a far, far more rapid rate of development-in terms of efficiency, cost & reliability-than coal or nuclear power-& with only a fraction of the Research & Development Budget. Contrary to the above claims, the strongest winds are at night-when the sun doesn't shine-& the majority of solar energy systems currently in existence don't require direct sunlight to work. Rapid developments in storage technologies over the last decade are making cheap high density storage a reality. Of course, the great advantage of renewable energy systems (& I'm including gas in there too-given that methane can be easily sourced from nature) is that they can be more easily "tuned" to meet demand, whereas coal & nuclear power produce almost as much electricity at night as they do during the day-resulting in a massive *glut* in off-peak electricity. Not only that, but renewable energy systems can be built small & close to the source of demand-thus reducing the roughly 10% loss of electricity that occurs during wide-spread transmission & distribution of electricity. Overall, coupled with the lack of an ongoing fuel requirement, most renewable energy systems will leave coal & nuclear power for dead-which is exactly what has the owners of these technologies so scared-& why they & their MSM allies run such a concerted fear campaign against them!
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  12. 70rn, I got my information from a book called "The Big Switch", by Gavin Gilchrist, & he sourced his information from a man called C. Weinberg. The information is from 1993, which is why I used 1990 Inflation adjusted dollars.
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  13. @ Camburn-you'll have to do better than some pathetic MSM propaganda piece. They're trying to blame renewable energy for rising electricity prices here in Australia too-even though there is no causal link between renewable energy investment & change in tariffs between the various states. Fact is, the retail cost of your electricity is 10.22c/kw-h. If Minnkota is buying Wind-Power for 4.5c/kw-h, then I don't see how his company can be losing money. For the record, the cheapest price wholesale price I've seen for base-load electricity (coal or nuclear) is around 4c/kw-h. Here in Australia, the wholesale price for coal-fired electricity is actually closer to 5c-6c/kw-h. Of course that doesn't stop the retailers charging us more than 20c/kw-h for electricity during peak times. So please tell us *why* you believe this obviously self-serving Utility CEO? Can't you tell when someone is trying to invent excuses to rip off their customers?
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  14. tt23-ah, the old "nuclear energy will save the day" speech-though you took a while to get around to it. Face facts, nuclear power is a pipe dream. 60 years of R&D & government subsidies, & its still one of the most expensive forms of electricity around. Even PV's are threatening to provide cheaper electricity over the next 5-10 years. However, unlike nuclear power, PV's don't generate large quantities of long-lived nuclear waste, don't use up precious water & don't generate large quantities of surplus electricity during off-peak periods. Also, what happens when those 80 years worth of uranium reserves run dry? The reality is that, with proper storage technologies, most of the currently available renewable energy technologies are already capable of producing close to base-load power. Developments over the next decade will probably bring them up to base-load capacity-assuming they get the public funding they deserve, but have for so long been denied. Of course, then you have tidal streams-which are already capable of producing reliable power. Then you have bio-gas from landfill, sewerage plants, forest plantations & farms. They're already in the process of generating electricity using osmotic potential-so it probably won't be long before Osmosis plants will be generating base-load electricity. As I said above, the potential of renewable energy has only just been tapped, which has the mainstream energy suppliers scared out of their minds!
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  15. @ marcus Thanks for that. And I agree with you re - nuclear, there seems little point replacing one finite source with another. Quite apart from that issue there is a huge political hot potatoe to handle with the siting of such facilities, the nimby crowd is likely to start weighing in pretty rapidly with any new reactor developments, regardless (in some respects unfortunately) of whether or not it's actually a good idea.
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  16. I can't say nuclear is a perfect technology, and I would hope that several decades down the track both coal and nuclear end up as obsolete alternatives to renewables. But between coal and nuclear - the two traditionally dominant baseload sources, the answer is crystal clear. On the other hand, there's also room for adaptation to intermittent supply on the demand side with smarter grids, metering, and appliances.
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  17. The problem we have at the moment is that whilst renewable power (particularly onshore wind) is getting close to the levelised costs of other sources of power (gas/coal), we haven't properly communicated the extra costs associated with it in terms of distribution, storage and smart grid tech. This gives renewables an reliably rosy impression. But the amount and cost of the storage depends on how much you rely on renewables. I think dana did a pretty good job, although the 'renewables are still decades away from providing most power in most countries' maybe should have been hammered a bit harder. We need nuclear and CCS for steep CO2 cuts.
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  18. Dana, i'll add two UK projects to your energy storage list: Isentropic energy storage: http://www.isentropic.co.uk/ Another CAES idea, Seamus Garvey's compressed air underwater energy bags: http://news.bbc.co.uk/1/hi/england/nottinghamshire/8500075.stm
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  19. I actually question whether a 'big' baseload capacity is required for a future where we need to cut the number of gadgets used, consume less per capita etc. Another issue is the massive inefficient use of energy in the US, partly because energy prices are low. Although probably no one wants really expensive energy, when prices are to low, there is a significant amount of waste, it's natural for people not to worry so much about what they use, if it is cheap. Some of the ideas Dana has posted about aren't really 'baseload' providers, the point being is that the nature of electricity generation will change since the 'load' is intelligent and adjusts it's consumption based on monitoring the grid. eg. we are talking about smart grid concepts. Finally it should be pointed out that current large scale generation is a quirk of consumerist history. Electricity generation companies, engineers etc, had developed the method for generating electricity from coal and oil, which needed a big consumer market to soak up the capacity (because that generation technology had to be running all the time to be efficient, stop start operation wasn't practical). This resulted in electricity companies desperately selling vacuum cleaners, washing machines etc in the 1950s, 60s so that they had a market to sell their electricity to. Now we have generations of people that don't know how to live without it. But the current grid technology had to be invented years ago to get what we have now. So it isn't unreasonable to expect changes in the way we use electricity in the future, with microprocessor controllers in fridges, freezers, cars etc, deciding how much energy can be drawn from the grid. Indesit are testing a fridge in the UK that does this and a smart grid test project is being set up to test different technologies.
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  20. tt23: "The fundamental reason for this is the same as why these energy sources were abandoned by our ancestors some 200 years ago: low energy density and finicky energy flows related to these sources." There are so many assumptions and things wrong with that statement, it's hard to know where to start! 1. Today isn't the same as 200, 300 or 1000 years ago. I don't think Tudor Britain had access to microprocessors or the ability to store significant amounts of energy and use it where ever they wanted it. They also didn't know about global warming. 2. Although coal has a high energy density, if you work out the figures and include losses, more energy is used to operate a coal power station than it produces. It's only when you ignore the fact that a large chunk of a lump of coals energy is lost, that it becomes rational to use it. Energy density works in 'theory' but is usually lost in practical engineering. 3. In the past they couldn't distribute the information to manage the 'finicky' energy sources. It would have been impractical to send a man on a horse from the windmill to homes 100 miles away to tell them to use less wind energy for their wooden washing machine, because the wind died by a few metres per second. Today that information can be transmitted through the grid or down existing communications networks in seconds. Basically, you seem to have little imagination and not only misunderstand the past, but also the future!
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  21. tt23: "Renewable energy advocates have been posting wishful thinking along these lines for well over two decades...however thinking we can build a backbone of industrial society using these sources is delusional wishful thinking, which I object to." Status Quo advocates have been posting fantasies about maintaining the current way of life for decades. Such delusional thinking misses the point, which is we need sustainable systems that complement our environment. Building a backbone for a sustainable society is the goal, not a crash and burn 'industrial society'.
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  22. As many have mentioned, there is lots of waste in our (U.S.) cheap energy market. To help define and eliminate waste the power prices can be set in ways that provide the greatest incentive to match the availability of renewable power. It is easy to envision a few dollars of computer and network hardware in each appliance and around the grid to save a lot on both generation and transmission costs. Such a system could easily handle variations in wind or partly cloudy solar days, for example. (BU Engineering magazine has the Fall issue devoted to smart solutions where I found a reference to this article) http://www.bu.edu/pcms/caramanis/TaborsParkerCaramanisIEEEPaperSmart%20Grid%20HICSS%2005-01-03.pdf
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  23. Dana, Excellent post. I'm wondering in a country like the USA, which is large and has large wind resources, how much does having big wind farms in North Dakota and Texas (and in between) counter the issue of low winds. How often is it windless over the entire center of the US? I understand that Australia is smaller and might have more windless days over the entire country, how often does that happen? What about Europe?
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  24. michael sweet: The wind corridor is vast, but when it slows down it does slow down over a wide area. http://minnkota.com/ Look at Astabula and Langdon as these are two large wind farms. They are approx 140 miles apart as the crow flies. I have talked with Minnkota as to wind variability. I had no idea that when the wind dies at one station, it dies over SD, Iowa, Minn, ND etc. I do not know if the wind dies in Texas at the same time as it does in the upper midwest. When examining baseload, one has to look at all users. Commercial/residential etc. You can not run a business with intermitent power. And in ND, Minn, SD etc, you can't decide not to heat your home for several hours without consequences. Solar is not an option at the northern latitudes. Not only do we have less sun, we have more clouds. Fact of life. On any grid that goes great distances, there is loss of power. One of the main stumbling blocks to ND selling wind energy to Chicago has been that loss. People are demanding efficiency, which should be done. I wish it was simple in scope. That wind/solar etc could supply the energy needs of the US on a cost basis similiar to what we currently have.
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  25. @Marcus at 17:57 PM on 27 November, 2010 Thorium was not developed for several reasons: it was not chosen in the early days due to the problem of making thorium derived fissile into a warhead due to U232 contamination which decay chains produce strong gamma radiation which will kill your workers, screw your weapon's electronics and chemical explosives, and tell everyone where it is, in short. Later after a brief investigation and two operational test reactors it fell out of favor compared to uranium/plutonium route due to several turns of history, mainly the large investment into the U/Pu route, which was found good enough; and personal politics within the AEC. It is similar to why we use PWRs now: they were developed by the Navy and found to be good enough. Anyway, the political/societal priorities had changed dramatically since the 1970s, so it makes a good sense to give thorium a second look. I would recommend brief primer here: http://www.youtube.com/watch?v=WWUeBSoEnRk Also your statement is not entirely accurate, India has developed their own way of using thorium commercially. They already have small test reactor successfully up and running in Kalpakkam, and several large scale (500MWe) reactors are already under construction. The first one should turn on next year. It is really a shame that US decided to get left behind in this crucial technology, and wishful thinking about renewables certainly did the job of cementing in our coal and gas based infrastructure.
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  26. Thank you tt23@25. Thorium is a very viable alternative which the US has bountiful supplies of. While the rest of the world races ahead with nuclear tech, the US lags behind further and further.
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  27. @Marcus at 18:05 PM on 27 November, 2010 > tt23-ah, the old "nuclear energy will save the day" speech-though you took a while to get around to it. Face facts, nuclear power is a pipe dream. Do you realize that nuclear power is the youngest source of energy? While the civilization spent thousands years developing wind energy, the fundamental physics beyond fission was only realized 60 years ago! Do you realize that nuclear in the US produces more electricity than the entire grid produces > 60 years of R&D & government subsidies, Nuclear power reactors receive NO subsidies. They actually have to pay large fees, such as the $4 000 000 / year / reactor regulatory fee. They are also the only single one energy source which has to pay for its own decommissioning, and for the treatment of spent fuel (in two separate accounts). No other energy source does that, and if any other source was held to such standards, it would perish over night. > & its still one of the most expensive forms of electricity around. Actually it is the one cheapest electricity source, you were badly misinformed: http://www.world-nuclear.org/uploadedImages/org/info/US_ElectProduction_Costs.jpg > Even PV's are threatening to provide cheaper electricity over the next 5-10 years. However, unlike nuclear power, PV's don't generate large quantities of long-lived nuclear waste, Instead of easily & safely stored small amounts of solid waste, it generates persistent pollution such as silicon tetrachloride, and results in large quantities of electronics waste which none has any idea how to treat on the scale when PV would make a visible dent in electricity production. > don't use up precious water The PV panels or mirrors need cleaning. The largest nuclear power in the US is actually in the desert, happily using only waste water from a nearest city. > & don't generate large quantities of surplus electricity during off-peak periods. Which we need for charging up electric cars. PV on the other hand is only useful for hot sunny days AC, and even then is mismatched with electricity demand curve by some 4 hours, mandating another source to back it up, not speaking about how to power civilization in the night, or in places where cloudless sunny days are exception not a norm. > Also, what happens when those 80 years worth of uranium reserves run dry? We will switch to breeders, which is tested and proved technology since the early 1050s. There is enough uranium to power civilization for several billion (10^9) years, and then there is thorium. See the calculation here: http://www-formal.stanford.edu/jmc/progress/cohen.html > The reality is that, with proper storage technologies, most of the currently available renewable energy technologies are already capable of producing close to base-load power. The reality is we do not have the "proper storage technology". Not even close. Again, the largest storage we actually have (i.e. not a pipe dream), is pumped hydro, and it was not even mentioned in the list of author's fantasies . > Developments over the next decade will probably bring them up to base-load capacity-assuming they get the public funding they deserve, but have for so long been denied. We see the disastrous results in Europe already. Despite all the R&D funding and subsidies. > Of course, then you have tidal streams-which are already capable of producing reliable power. Then you have bio-gas from landfill, sewerage plants, forest plantations & farms. They're already in the process of generating electricity using osmotic potential-so it probably won't be long before Osmosis plants will be generating base-load electricity. Sorry these are recycled hypes from 30 years ago. 25 kWe of biogas per landfill are not going to cut it. ? As I said above, the potential of renewable energy has only just been tapped, which has the mainstream energy suppliers scared out of their minds! As I said above, people knew about the potential of renewable resources since they were people around. Most civilization perished as these renewable resources proved again and again as insufficient to sustain them. Modern civilization developed after it tapped controllable and scalable energy sources with orders of magnitude higher energy density. To get out of our current dire predicament we need to step up several more orders of magnitude in energy density with a clean and sustainable energy source. Fortunately we already have one - nuclear fission.
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  28. Sorry I typed too fast, and one cannot edit the posts! The last few paragraphs get screwed beyond comprehension, so here is a better version: > As I said above, the potential of renewable energy has only just been tapped, which has the mainstream energy suppliers scared out of their minds! As I said above, people knew about the potential of renewable resources since there were people around. Most civilizations perished as these renewable resources proved again and again as insufficient to sustain them, primarily by exhaustion of wood. Modern civilization developed after it tapped controllable and scalable energy sources with orders of magnitude higher energy density than these renewable ones. To get out of our current dire predicament we need to step up several more orders of magnitude in energy density with a clean and sustainable energy source alternative, which has the crucial qualities of scalability and controllability. Fortunately we already have one - nuclear fission.
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  29. tt23: "PV...results in large quantities of electronics waste which none has any idea how to treat on the scale when PV would make a visible dent in electricity production." Urm, if you are worried about electronics waste, why promote an energy source that supports an electronics market. You are shooting your own foot again.
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  30. The mention of APS is interesting, but not surprising. After fighting renewables for decades, the company appears to be pursuing distributed energy with a vengeance. Both with solar thermal, and robust support for rooftop PV. We have so far to go with direct-to-grid renewables (ie no storage) that the lack of storage should in no way be seen as a counter to renewables. Indeed, by the time we get to this issue, we may find renewables are doing just fine. While this is a good overview - all these items in the future and utility level solutions leave me cold. Every poster here should put solar (heating first) on their roof, wind in their yard, solar PV, ground source heat pump (all of course, where practicable - but that is almost everywhere for at least one). The point is: we already know how to solve it - NOW. Yes, we can improve the solution going forward, but there is a temptation to say "well - efficiencies are going up, price coming down, let's see what the utility does...." But that ignores the key tool we have - swaying public opinion by actions. Humans response VERY STRONGLY to what the other guy does. You are the other guy - lead the way.
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  31. tt23@27 we will switch to breeders, which is tested and proved technology since the early 1050s. Then we would have to deal with the consequences of a very widespread plutonium economy. Just imagine what might happen if Iran, North Korea, Chechnya etc had easy access to tonnes of the stuff.
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  32. tt23: "As I said above, people knew about the potential of renewable resources since they were people around. Most civilization perished as these renewable resources proved again and again as insufficient to sustain them." That is totally incorrect. They were not abandoned because they couldn't sustain the population. They were abandoned because fossil fuels came along, that helped the population grow beyond what previous technologies could support. Civilization wouldn't have perished just because it continued using wind and water to power it's needs. The population would have been restricted, that isn't the same thing. And BTW repeating something that has been rebutted in a previous comment doesn't make it correct again. (re The Ville comment 20).
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  33. Camburn @24... Your entire comment here about not being able to run a business on intermittent power is totally ignoring the thrust of the entire article that Dana wrote. You are arguing as if, when the wind dies so does all the electricity. Go back and read the article again. It's all about how to smooth out the intermittency in order to deliver base load. For every weather cycle that might deliver a day or two of no wind conditions there are many more other days that deliver high winds that would outpace the demand. The point is to capture and store that over capacity for later use. The other thing everyone seems to miss in this discussion is that current energy production suffers exactly the same kinds of issues of matching demand to production. We have base load units that end up on spin reserve at night. And then we have other plants that get turned on only during peak hours and lay idle the rest of the day. People get all twisted up in their shorts over the intermittency of renewables when the intermittency of demand is as big a problem to energy efficiency as anything. Most of the solutions that Dana is presenting here work just as effectively for all forms of electricity production to smooth the production/demand cycle. Peter Sinclair has a really good Youtube video on house electric vehicles play into the mix.
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  34. It is taken as axiomatic that PV panels last 30 years. Why? They might suffer some degradation of output, but not that much. What is a more realistic lifetime of a PV array?
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  35. Rob@33: My point exactly. At this time, and in the foreseeable, there is no way to "store" that electricity economically. While we burn more coal/methane for energy and increase the co2 load, we have proven tech that will/could cut that co2 load. It is outright scandelous that we are not using that tech. That tech is nuclear. The rest of the world is embracing it. http://www.world-nuclear.org/info/inf17.html. We are being pound foolish to continue the path we are on.
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  36. Camburn - does the rest of the world include Germany? They are, I believe, the leaders in solar PV (and equal to the Northern US in terms of sun and clouds). Nuclear may have a transitional role. But it has so many questions and such high costs (and the amount of CO2 released for the concrete is staggering) it has to be a tier 2 solution. Also, a comment was made about no government subsidies. This is simply untrue. At a minimum the US government is supplying loan guarantees. More frightening - the US is providing liability limits to nuclear plants. As per usual - privatize profits and socialize risks. For the foreseeable future - just install the renewable technology we KNOW works - with no notable downsides, (and this is the part people keep ignoring) AS FAST AS POSSIBLE. When we get to the point of needing storage and/or baseload power - it will be a whole new world (in energy terms). Some of the pie-in-the-sky stuff will already be done, some will be ready, and some will remain "in the sky." How about we keep nuclear at 20% of US load for the next 20 years, then look around (all the while INSTALLING the known-good renewable technology). Once carbon is priced into the economy - the world will change (for the better).
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  37. A couple of years ago I came across the idea ofKiteGen, which seemed to have a lot of potential - I've heard little about it since. Does anyone know if there is anything in it? It seems to me that harnessing the more reliable high altitude winds would eliminate much of the need for baseload power. Offshore kitegen is the future, just no-one has realised this yet.
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  38. Camburn @35... Can you define "in the foreseeable" for me? Dana is presenting here technologies that are all in the works, not just pie-in-the-sky ideas. I'll tell you, I'm not anti-nuclear. I think we need to quickly pull out all the stops and get the world off fossil fuels. But I would counter that nuclear is not a simple solution therefore can not be the only solution. Rationally dealing with the issues of climate change will require solving the problems of energy usage and production on as many different levels as possible. I'm always of the opinion that it's a mistake to dismiss any solution. Ultimately the market will select the best solutions. To echo actually thoughtful, once carbon is priced into the economy that's when things will get better.
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  39. @MarkR 17 I agree that lack of cost of grid enhancement, storage, etc... assessments may paint a somewhat rosier picture than renewables actually have, but don't forget the much higher external costs (esp health) to burning coal, also not accounted for in those costs- in a recent study here it was estimated that coal's external costs exceed the direct costs: http://geology.utah.gov/sep/renewable_energy/co-benefits.htm
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  40. t23 - like The Ville, I don't even know where to start. I guess the easiest claim to debunk is that nuclear power receives no subsidies. The EIA found in 2007 nuclear power received $1.27 billion in subsidies that year alone (compared to $740 million in 1999). President Obama has also proposed to triple nuclear power loan guarantees to over $54 billion in 2011 - loans which put taxpayers at risk if the energy companies default, which often happens on nuclear projects. Nuclear power is very heavily subsidized, though not on a per-kWh basis because it's such a well-established technology (there's so much nuclear already in place). As for claiming the article is full of "half truths", those blue words are links. I suggest reading them if you don't believe what's said in the article. Every claim is supported by various studies or real-world examples. This seems to be one of those cases where people have their pre-conceived notions and are incapable of reading about the subject with an open mind. Not much I can do about that, other than suggesting that people re-read the article with their biases and pre-conceived notions in check. There was also a comment that the USA is falling behind in nuclear technology. The same comment applies to solar PV (Germany), solar thermal (Spain), wind (China), etc. Odd that people don't seem to object to the USA falling behind on these renewable technologies.
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  41. I'm on the same boat as Rob when it comes to nuclear. I have nothing against it, except that right now new nuclear power is very expensive. People argue that there are ways to make it cheaper - the same is true of renewable power. Concentrated solar thermal is expected to drop below 10 cents per kWh in the next decade as it achieves economies of scale and technology advancements, for example. I think nuclear power has its place as part of the solution, but it's no silver bullet. There are lots of obstacles, from a lack of sufficient nuclear engineers to NIMBY concerns to construction and decommissioning costs. It's *a* solution, not *the* solution. MarkR and Utahn both make good points regarding somewhat external costs that aren't usually accounted for. But this article doesn't focus on costs, it focuses on available and developing technologies. I'll also repeat Rob's comment to Camburn - all the technologies discussed in the article are in place or in development. As metioned, the Iowa wind CAES project is on track for completion in the next 4-5 years. The wind turbine air compressor just got funding from the DOE, as shown in the final link. tt23 also made a comment about geothermal not being available anywhere, which again indicates that he didn't really read the article, which specifically discusses EGS which could work basically everywhere. But now I'm just repeating what's in the article, so again I suggest that certain people look it over again and try actually reading it this time.
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  42. Heraclitus the first test installation in Italy is due to start flying in a matter of a few weeks. If succesfull, four more are already approved. The hardest part of the whole project has been burocratic, it went through several stop and go. An anecdote. In Italy the Kitegen needs a permanent flying permit from both Civil Aviation and Air Forces. For the first test flights they also needed a special permits for each flight.
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  43. Thanks for the article and comments that follow. Very informative. Some more information that overlaps with the topic of this article … An interactive article on Powering a Green Planet: http://www.scientificamerican.com/article.cfm?id=powering-a-green-planet The study summarized in the above link: http://www.stanford.edu/group/efmh/jacobson/WindWaterSun1009.pdf
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  44. An interesting approach to getting more energy out of the sun, is that being done by Zenith Solar of Israel and by Cogenra. In both cases, these are concentrating PV solar which produce both electricity and hot water. Solar cells in CPV systems need to be cooled to avoid heat damage and maintain efficiency. These two companies turn this liability into an asset. Zenith says they get an overall solar conversion efficiency of 75% Cogenra claims to capture 80% of the sun's energy. http://www.treehugger.com/files/2010/11/cogenra-hybrid-solar-system-80-percent-efficient-electricity-hot-water.php http://www.zenithsolar.com/index.html
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  45. Solar thermal and heat storage "Profit Maximization Energy storage allows the plant operator to maximize profits. During periods of low hourly power prices, the operator can forgo generation and dump heat into storage; and at times of high prices, the plant can run at full capacity even without sun. Peak Shaving Solar generating capacity with heat storage can make other capacity in the market unnecessary. With heat storage the solar plant is able to “shave “ the peak load. Reducing Intermittence The ability of thermal solar plants to use heat energy storage to keep electric output constant: (1) reduces the cost associated with uncertainty surrounding power production; and (2) relieves concerns regarding electrical interconnection fees, regulation service charges, and transmission tariffs. Increasing Plant Utilization Solar plants equipped with heat storage have the ability to increase overall annual generation levels by 'spreading out' solar radiation to better match plant capacity." http://www.nrel.gov/csp/troughnet/pdfs/owens_storage_value.pdf
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  46. johnd You asked about the extra capacity needed to store energy with renewables. With solar thermal, the steadiness of the power is quite reliable, particularly with molten salt heat storage. The location in the desert means sunshine is quite predictable and reliable. Of course for a given generating capacity, more solar collectors are needed for heat storage, but this is an incremental cost, as the central plant doesn't change. The NREL figured that the upfront cost of adding heat storage is a wash over the long run. NREL gives solar thermal power tower plants with molten salt heat storage a 70% capacity factor and 50% for parabolic solar troughs with heat storage. NREL estimates that the cost of building solar thermal plants will fall dramatically as experience is gained and economies of scale come into play. Mass production of the components would drastically reduce costs. Although they expect early CSP plants to be expensive, those costs were predicted to fall to under 10cents/kWh fairly quicly, and 4-7 cents/kWh to be achieved when the industry gets up to scale. It should also be noted that power from solar thermal with heat storage should be able to command a higher price, since it is valuable dispatchable power. It can follow the load. Can solar thermal provide large amounts of power? You bet. Nuclear advocates in Arizona tried to have nuclear classified as a renewable, in order to get the same tax credits as solar. An odd choice when you consider the following. How many nuclear plants did they plan to build in Arizona? According to NREL, Arizona has 285 GW potential for solar thermal with heat storage. I figure thats about the equivalent of 150 nuclear power plants, adjusting for capacity factors. (rough estimate) In total there is about 1,000 GW potential in the western states, mostly southwestern, from solar thermal. This is only using carefully selected areas for development, avoiding many sensitive areas, human habitation, parks national forsests, rivers lakes, etc.
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  47. Solar thermal power with heat storage makes it easier to integrate more intermittent sources, like PV solar and wind, into the grid. Another benefit of large sources of dispatchable power. While no definitively serious study, here's an interesting article on the above. It attempts to show that a grid with less baseload may not be a bad thing. "Why CSP Should Not Try To Be Coal" http://www.altenergystocks.com/archives/2009/04/why_csp_should_not_try_to_be_coal.html "Brighter than a Hundred Suns: Solar Power for the Southwest" from NREL "Even though some solar generating technologies could benefit from research and development, it was made clear that solar resources are abundant; are located where they are needed; that efficiencies from concentrating solar power (CSP) are good enough to justify deployment; and cost projections are very promising. All that solar power required, in the opinion of the experts, is an incubation period, where incentives are put in place that allow the transition of this emerging generating technology into the mainstream. It is our view that providing such an incubation period is not a leap of faith, but a proven recipe of success, as the emergence of wind generating technology in Europe has shown." "The success of an incubation period for solar power is all but guaranteed. This is because, unlike similar promises by the industry to introduce electric cars, CSP plants have already achieved a level of performance that makes them practical. They have proven their merit in over a decade of operation in the Mojave Desert, and cost-reduction projections for CSP technologies are based on the fact that they use ordinary technology in an extraordinary way." http://www.nrel.gov/csp/pdfs/33233.pdf this link is search results for "heat storage costs". Searched from NREL site. lots of articles the secret to low water use, high efficiency CSP http://climateprogress.org/2009/04/29/csp-concentrating-solar-power-heller-water-use/ In addition to Arizona's 285 GW solar thermal potential that I mentioned in a previous post, here are the numbers for some other states. New Mexico has another 220 GW, Nevada 165 GW, Utah 74 GW, California 98 GW, Colorado 38 GW, Oregon 12 GW, Kansas 6.7 GW, and West Texas has very large solar recources, for which I don't have the numbers.
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  48. Solar thermal, or CSP, can also desalinate sea water while generating power. Desertrec plans to get hot water, desalination and electric power, all from solar thermal power plants. "Skyrocketing fuel prices and the mounting reality of a peak oil future have made Desertec economically attractive for the first time since it was conceived back in 2003. ...And it doesn’t hurt that the project carries a built-in bonus: drinking water. The plan aims to use the waste heat from the solar power plants for thermal desalination to create clean water for host countries. " http://solveclimate.com/blog/20080421/solar-power-africa-best-investment-eu-can-make This could be very positive for quality of life in countries where clean water, abundant hot water, and electricity are luxuries. That, and cooperation among countries may reduce geopolitical and regional tensions. How about it Southern California? SoCal cities take water from the SF Bay area Delta via the aqueduct, the Colorado River and the Owens Valley aquifer. Combined with the massive use of irrigation water, and the needs of natural ecosystems of rivers and delta, something has to give. Impacts on fish and other creatures is severe. I'd like to see a feasability study for this. CPV can also desalinate water. "IBM Launches Solar-Powered Desalination in Saudi Arabia" ".... a concentrated solar system with an innovative cooling mechanism that will allow it to take better advantage of the desert heat and fuel the desalination process with renewable energy.......... IBM's concentrated PV system can focus 2,300 times the power of the sun onto a one square meter solar cell without causing heat damage, thanks to an indium/gallium liquid metal alloy that conducts heat away from the cell" http://solveclimate.com/blog/20100407/ibm-launches-solar-powered-desalination-saudi-arabia
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  49. Another idea, harvesting urban heat island energy: http://environmentalresearchweb.org/cws/article/news/44135
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  50. sailrick: "An interesting approach to getting more energy out of the sun, is that being done by Zenith Solar of Israel and by Cogenra. In both cases, these are concentrating PV solar which produce both electricity and hot water." There is a New Zealand company that has developed a roofing system that combines PV with solar heating. Can't remember the name of the company, although I know it is a university spin off. They get higher efficiencies from the PV part because the cells are kept cooler.
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