The Future Shape of Concentrating Solar Power (CSP) 24 comments
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Parabolic Troughs have dominated Concentrating Solar Power [CSP] until recently, but several companies are vying to replace them. Will the upstarts succeed, or will incumbency and improvements to trough technology ward off the competition?
Dr. Arnold Leitner, CEO of Skyfuel, Inc., thinks the battle for dominance of CSP will be "winner-take-all."
The technology which can deliver power when it is needed at a reasonable price should triumph. Photovoltaic [PV] technologies are rapidly producing price reductions, and can be used almost anywhere, but only produce power when the sun is shining. In contrast, CSP which is still cheaper than PV enables inexpensive thermal storage, with the promise of dispatchable power to compensate for the variability of other renewable power sources and demand. Dispatchability assures CSP with storage a place in the eventual energy mix.
Heat Transfer Fluids
The ability and efficiency of a technology to accommodate thermal storage (and provide dispatchability) is a function of the heat transfer fluid and working temperature.
Three heat transfer fluids have been demonstrated to date: Steam (in power towers and troughs) mineral oil (in most parabolic trough plants,) and molten nitrate salts (in power towers.) The working temperature for steam is limited by the potential for corrosion. Molten salts and oil break down at high temperatures, with molten salt and steam capable of achieving the highest temperatures (about 565° C for nitrate salts.)
Companies such as BrightSource and eSolar are currently working to commercialize supercritical steam in power towers.
Lower temperature steam is also the working fluid for Ausra, a company working to commercialize the Compact Linear Fresnel Reflector (CLFR) geometry. CLFR breaks up a trough into a series of narrow, nearly flat, reflectors saving on the high cost of carefully focused troughs. Ausra recently announced that they were refocusing on becoming a technology and materials provider, rather than building solar farms on their own. An industry observer who prefers to remain anonymous thinks that this will mean the end of the company for practical purposes, since the process heat market is very difficult to sell into, and few companies are willing to back expensive, untried technology, especially from a third party vendor.
Oil is commonly used as the heat transfer fluid in parabolic trough systems because it does not freeze at night (nitrate salts freeze at 220° C) and operates at lower pressure than steam. According to Bill Gould, Chief Technical Officer of Solar Reserve, such systems have peak operating temperatures of 375°C. Solar Reserve is working to commercialize the nitrate salt/power tower combination which was demonstrated at DOE's Solar Two in the late 1990s, for which Bill Gould was the project manager.
Nitrate Salt | |
Composition | 60% NaNO3 and 40% KNO3 by weight. |
Melting Point | 221 °C |
Boiling Point | Has very low vapor pressure, but begins to decompose around 600 °C |
Cost | $90-$160/kWe (trough); $30-$55/kWe (tower) |
Other uses | Fertilizer |
Thermal Storage
The best established thermal storage system is two-tank molten salt, according to Greg Glatzmaier, a Senior Engineer II on the National Renewable Energy Laboratory's (NREL) CSP research team. Pressurized steam or oil have also been used, but at higher cost per kWh. Pressurized steam is only practical for short term buffer storage, according to Greg Kolb, a Distinguished Member of Technical Staff National Solar Thermal Test Facility.
Commercial projects using oil as a heat transfer fluid and molten salt for thermal storage include Nevada Solar One and Solar Millennium's (SMLNF.PK) Andesol parabolic trough plants. Solar Millennium is currently the only pure-play publicly traded CSP company I'm aware of.)
According to Gould and Glatzmaier, the thermal storage systems systems at the Andesol plants suffer 7%-10% round-trip energy losses in heat exchange. If molten salt is also used as the heat transfer fluid, then there is no need for heat exchangers, and no such heat loss. The lower working temperature of these plants also requires much more salt and larger tanks to effectively store the same amount of electricity as for a power tower, once the lower temperatures and efficiency losses are taken into account..
Gould calculates that a trough plant will require three times as much molten salt (along with larger tanks to store it) as a power tower to store an equivalent amount of energy. With additional information from Glatzmaier, I calculate that, to store the equivalent of 1 kWh of electricity at a trough plant requires approximately $90-160 of capital cost, compared to about $30-$55 at a tower, with the variability arising from the commodity price of salt, which is mainly used as fertilizer.
The Shape of Things to Come
In terms of configuration, many experts see long term advantages in power towers. Nate Blair, a Senior Analyst at NREL says the underlying efficiency advantage of towers arising from higher working temperatures will lead to more power from a similar investment in hardware. A Rankin cycle turbine will operate at about 37% efficiency for troughs, or 41% for a tower, meaning a tower can produce approximately 8% more electricity from the same amount of heat.
The combination of energy storage using molten salt, no heat transfer losses, and the thermal efficiency of power towers, point to power towers with molten salts as the working fluid as the long-term favorite.
There are challenges. Only parabolic troughs are a proven, bankable technology. Dr. Leitner estimates that it will cost between $500-$700 million to commercialize a new technology. Solar Reserve plans to overcome this barrier with a performance guarantee from United Technologies (NYSE:UTX) up to the value of the contract, or $200 million, but in the current financial climate financing remains difficult.
SkyFuel has plans to use the innovative reflective film ReflecTech in a hybrid of parabolic trough and CLFR configuration called a Linear Power Tower [LPT]. By increasing the diameter of the receiver they hope to reduce heat loss and allow the salt to stay molten for longer periods. ReflecTech enables relatively inexpensive, large parabolic mirrors to be used in the CLFR configuration, with 10 mirrors, each about 3 meters wide focused on each receiver. This should achieve 85x magnification, sufficient to reach temperatures comparable to those in a power tower.
SkyFuel hopes to commercialize the LPT incrementally, by first testing it as part of existing parabolic trough plants using oil as the heat transfer fluid. Might the parabolic trough triumph by incorporating the advantages of power towers?
DISCLOSURE: The author has a long position in UTX.
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This article has 24 comments:
Those who are only interested in the technical problems, please skip the rest of my comment.
We have been suffering, ever since the Industrial Revolution, from increasing concentration of capital-intensive projects, where increasingly large swathes of our lives are controlled by centralized powers--be they corporate or governmental. Railroads, oil cartels, and large utilities all fit this mold.
Solar energy--that is, photovoltaics--was born in the revolutionary idea that we could decentralize the source of our electricity; everyone can have their own power plant, and reduce dependence on a centrally-controlled grid. The evolution of the internet has trended along these lines, as well, and helped reinforce our understanding of how we can each take more responsibility for what we consume.
CSP is a throwback to the old, centralized power model. Now, I know we are not ready to leap into a world of no grid, and perhaps CSP is the best way to power the grid in some places. So please don't read this as an attack on the technology. My only problem is that now we have an ambiguity in the term "solar power," where in one context it suggests local generation with photovoltaics, and in another it refers to centralized, capital-intensive CSP.
Because these are contradictory models of how our economic resources are used and controlled, we now have a tension that arises whenever the term "solar power" is mentioned.
Most people, perhaps, are not so sensitive to this tension. But most people pay only marginal attention to renewable energy issues, and there's no way to tell how many of them may get a sense of discomfort about solar energy without ever recognizing why. When marketing a product or idea that calls for broad public support (or participation), language matters.
I don't have a solution to this, or even a concrete complaint. Just an idea that perhaps need to considered further.
www.altenergystocks.co...
On Apr 16 07:55 PM Alan Young wrote:
> Perhaps a socio-economic comment is out-of-place vis-a-vis your fine
> technical discussion, but I'm somewhat distressed by the whole concept
> of CSP.
> Those who are only interested in the technical problems, please skip
> the rest of my comment.
>
> We have been suffering, ever since the Industrial Revolution, from
> increasing concentration of capital-intensive projects, where increasingly
> large swathes of our lives are controlled by centralized powers--be
> they corporate or governmental. Railroads, oil cartels, and large
> utilities all fit this mold.
>
> Solar energy--that is, photovoltaics--was born in the revolutionary
> idea that we could decentralize the source of our electricity; everyone
> can have their own power plant, and reduce dependence on a centrally-controlled
> grid. The evolution of the internet has trended along these lines,
> as well, and helped reinforce our understanding of how we can each
> take more responsibility for what we consume.
>
> CSP is a throwback to the old, centralized power model. Now, I know
> we are not ready to leap into a world of no grid, and perhaps CSP
> is the best way to power the grid in some places. So please don't
> read this as an attack on the technology. My only problem is that
> now we have an ambiguity in the term "solar power," where in one
> context it suggests local generation with photovoltaics, and in another
> it refers to centralized, capital-intensive CSP.
>
> Because these are contradictory models of how our economic resources
> are used and controlled, we now have a tension that arises whenever
> the term "solar power" is mentioned.
>
> Most people, perhaps, are not so sensitive to this tension. But most
> people pay only marginal attention to renewable energy issues, and
> there's no way to tell how many of them may get a sense of discomfort
> about solar energy without ever recognizing why. When marketing a
> product or idea that calls for broad public support (or participation),
> language matters.
>
> I don't have a solution to this, or even a concrete complaint. Just
> an idea that perhaps need to considered further.
>
>
On Apr 16 04:22 PM Freya wrote:
> CSP is alive and well in the USA, various States. With the world's
> largest such facility contracted to be built in Arizona.
>
> Abengoa Solar, ABGOF. I'm really surprised you haven't heard of it.
Reason for "I believe" is explained in our PNM proposal which is under development.
"At the final session of the electric irp Evlin Wheeler asks participants if they would like to be involved in PNM's solar project.
I reponded affirmative.
I did not receive any information about this project, so I phoned Greg Nelson on April 6, 2009 and left a message on his recorder.
Mr Nelson returned my phone call on April 8.
He told me that solar project negotiations were confidential, we would not receive any written information of the solar project, and that we may hear a public announcement in perhaps July 2009.
We feel that a feasibility study of solar electric generation technologies would help PNM, its stockholders, the presidential administration and others make the best decision possible either to invest in or purchase solar electricity generation technologies.
Chairman, President and CEO Questar Corporation Keith O. Rattie said on April 2, 2009
Why did my generation fail to develop wind and solar? Because our energy choices are ruthlessly ruled, not by political judgments, but by the immutable laws of thermodynamics. In engineer-speak, turning diffused sources of energy such as photons in sunlight or the kinetic energy in wind requires massive investment to concentrate that energy into a form that's usable on any meaningful scale.
Perhaps solar technologies have changed since Mr Rattie's generation of engineers studied choices?
Or perhaps assertions made in the post
fast neutron
Santa Fe, NM
January 12, 2009
From actual experience, wind farms produce 1.2 watts per square meter. Solar Thermal and Photovoltaic methods capture 5 to 6 watts per square meter. There is no economy of size in either technology. Dividing the watts you need by those values gives the land area in square meters needed to produce the juice. The numbers are astronomical
www.topix.net/forum/so...
are correct?
But I believe that Mr Rattie's statement "the immutable laws of thermodynamics" is likely correct and that HEAT RATE can be computed for solar electric generation.
If so, then N/A in FOIL 6 and 7 should be replaced by values.
..."
Below appeared today.
"Sempra Generation, a subsidiary of Sempra Energy (NYSE: SRE), today announced its intention to construct a new 48-megawatt (MW) expansion of its existing photovoltaic power-generation facility near Boulder City, Nev., about 40 miles southeast of Las Vegas.
The combined 58-MW installation would become the largest operational photovoltaic solar-power facility in North America.
Construction will commence after Sempra Generation contracts to sell the facility's power output. The project could be operational by late 2010.
Sempra Generation has agreed that Tempe, Ariz.-based First Solar will be the engineering, procurement and construction contractor. .."
www.google.com/search?...=
"Thursday April 16, 2009 17:33
Notice received April 16, 2009.
home.comcast.net/~bpayne37/pnmelectric...
Let's hope the stockholders don't get stung with any bad solar electric energy ideas."
> jack
I really appreciate your detailed technical discussion. Thanks.
A side question: Do you see any possible development of facilities that combine photovoltaic and thermal solar? It seems to me looking at each source separately involves wasting some of the incident energy available and also not taking full advantage of using all the peripheral facilities (and grid feeds).
Another side question: Is there any feasibility for thermal air towers using wind turbines for the rising hot air otherwise wasted? Is there any commercial work in this area?
While PV solar's role as distributed energy is important, we need both that and the centralized power of CSP. In fact, it's the dispatchability of CSP power that will help facilitate the ability to balance the other various sources like wind and PV and integrate them into the grid.
www.altenergystocks.co...
The above article discusses why CSP's dispatchable power is actually more valuable than the base load power we now get from coal and nuclear. And he argues that a grid with less base load power would actually be easier to balance.
He's criticizing Joe Romm at Climate Progress for calling CSP baseload solar, but only because he agrees with him, that it's better than baseload.
Wait; I just noticed that Tom Konrad already commented on this, and he is the author of the article.
Regarding the cost of heat storage for CSP, the article left out the conclusion by NREL that heat storage will not adversely effect the economics of CSP.
"Thermal storage, along with an enlarged solar field, also allows the CSP plant to operate at a higher annual capacity factor, about 40 percent with 6 hours of storage versus 28 percent for no storage. This gives the plant the ability
to generate higher revenues to off-set the additional cost of the storage system. The levelized costs in Table 6-2 reveal this, as the trough plant with 6 hours of storage and
without storage have roughly the same cost of energy ($157/MWh vs. $154/MWh)"
For what it's worth, there is another method of heat storage, which is claimed to be superior to molten salt. It uses a bed of alumina pebbles with CO2 as a heat transfer medium. It's claimed to allow much higher operating temperatures, and without the high melting point of the salts.
As a result, there is a bigger differential between the high temp and the low temp, making it more efficient.
I have no idea what others think of it, or whether NREL has done any research on it.
www.trec-uk.org.uk/res...
There is also the option of coupling CSP with natural gas.
NREL
"All of the SEGS plants (the 9 pilot plants in the Mojave, built between 1985 & 1991 ) are “hybrids,” using fossil fuel to supplement the solar output during periods of low solar
radiation. Each plant is allowed to generate 25 percent of its energy annually using fossil fuel. With the use of the fossil hybrid capability, the SEGS plants, during Southern
California Edison (SCE) on-peak hours, have exceeded 100 percent capacity factor for more than a decade, with greater than 85 percent from solar operation."
billp37
"Let's hope the stockholders don't get stung with any bad solar electric energy ideas.""
While this may not answer your question for your stockholders, it makes it clear that it is not a bad solar electric energy idea.
www.nrel.gov/csp/pdfs/...
"A comparison of the levelized cost of energy
(LCOE) revealed that the LCOE of $148 per MWh for the first CSP plants installed in 2009 is competitive with the simple cycle combustion turbine at an LCOE of $168 per
MWh, assuming that the temporary 30 percent Investment Tax Credit is extended. The LCOE for the CSP plant is higher than the $104 per MWh LCOE of the combined
cycle combustion turbine plant."
"As shown in Table ES-2, CSP plants installed in 2015 are projected to exhibit a delivered LCOE of $115/MWh, compared with $168/MWh for the simple cycle combustion turbine and $104/MWh for combined cycle plants. At a natural gas price of about $8 per MMBtu, the LCOE of CSP and the combined cycle plants at 40 percent capacity factor are equal."
and
"Investment in CSP power plants delivers greater return to California in both economic activity and employment than
corresponding investment in natural gas equipment:
- Each dollar spent on CSP contributes approximately $1.40 to California’s Gross State Product; each dollar spent
on natural gas plants contributes about $0.90 - $1.00 to Gross State Product."
"Operations period expenditures on operations and maintenance for CSP create more permanent jobs than alternative natural gas fueled generation. For each 100 MW of generating capacity, CSP was estimated to generate
94 permanent jobs compared to 56 jobs and 13 jobs for combined cycle and simple cycle plants, respectively."
The NREL states clearly that the first CSP plants will be expensive, but that the costs should fall rapidly as economy of scale and experience come into play.
I believe your number for Wind at 1.2 watts/ sq meter is for the total land area where turbines are sited. Since a 2-3 megawatt turbine has the actual footprint of about a parking space, and uses only about 2 1/2% of the land where it's sited, your number seems way off. Correct me if I'm wrong.
you might get some insight by contacting FPL[florida utility and largest USA user/provider of wind/solar[both PV snd CSP].
they are building both PV and CSP now in florida, with CSP integrated with NG[INTEGRATED CYCLE], but have not linked PV with CSP. THEY MAY ANSWER THE WIND TOWER UPDRAFT QUERRY ALSO[pardon the caps, i failed to shift in my haste].
great detail at website fplgroup.com
On Apr 17 01:24 PM John Lounsbury wrote:
> Tom - - -
>
> I really appreciate your detailed technical discussion. Thanks.<br/>
>
> A side question: Do you see any possible development of facilities
> that combine photovoltaic and thermal solar? It seems to me looking
> at each source separately involves wasting some of the incident energy
> available and also not taking full advantage of using all the peripheral
> facilities (and grid feeds).
>
> Another side question: Is there any feasibility for thermal air towers
> using wind turbines for the rising hot air otherwise wasted? Is there
> any commercial work in this area?
The coal industry is mounting a media attack on altenergy through ABEC.
Truth appears to be that coal has the INPUT BTUs - 8,800 to about 13,000 per pound.
Altenergy appears to have INPUT BTU problems which it is trying to combat with Peterson and Konrad posts.
Peterson and Konrad focus on OUTPUT BTUs.
Billions of dollars are at stake so we must expect, and are getting, a hard media fight.
Do not fear the enemy, for your enemy can only take your life. It is far better that you fear the media, for they will steal your HONOR. That awful power, the public opinion of a nation, is created in America by a horde of ignorant, self-complacent simpletons who failed at ditching and shoemaking and fetched up in journalism on their way to the poorhouse.
Mark Twain
www.prosefights.org/co...
Keep a good sense of humor.
Coal's BTUs involve massive environmental damage, blowing the tops off thousands of mountains, contaminating streams and rivers, amassing billions of gallons of toxic fly ash sludge, spewing mercury, arsenic etc and requiring about 25% of our rail freight capacity to deliver.
At this next link you will learn how oil and coal industry money is funneled through different foundations to bury the money trail, and "wipe the oil" off of it.
They set up organizations like Policy Communications, The Western Business Roundtable, Partnership for America, and Americans for American Energy, to make it seem like there is this groundswell of grassroots organizations opposing the scientific theory of man made climate change and opposing the move to sustainable energy. These are actually all the same people from the fossil fuel industry and mining industry. They are all staffed by the same executives.
"It's called 'astroturfing' - the setting up of fake grassroots organizations and it's one of the oldest tricks in the books.
Policy Communications
An energy industry-backed astro-turf network concocted by a single PR/Lobbying firm that is working to undermine the efforts of environmental groups and organizations like the Western Climate Initiative (WCI). that are pushing for solutions to climate change."
www.desmogblog.com/pol...
ABEC
"Formed in 2000 to develop astroturf support for coal-based electricity, Americans for Balanced Energy Choices (ABEC) promotes the interests of mining companies, coal transporters, and electricity producers. A domain name search reveals that ABEC's website is registered to the coal industry trade organization Center for Energy and Economic Development. (ABEC originally used the balancedenergy.org domain but later switched to a website titled America's Power)." Sourcewatch
from the ABEC website:
"Because they recognize the essential role that electricity from coal plays in protecting the environment while providing over half of the electricity used each day in the U.S., America's coal-based electricity industry (producers, transporters, and electricity generators) have provided the primary initial funding for this worthwhile project."
"..the essential role that electricity from coal plays in protecting the environment... "
And I though coal was dirty. Silly me
"These organizations purport to represent one agenda while in reality they serve some other party or interest whose sponsorship is hidden or rarely mentioned. For example, the Center for Consumer Freedom (CCF), which has a lengthy entry in SourceWatch, claims its mission is to defend the rights of consumers to choose to eat, drink and smoke as they please. In reality, CCF is a front group for agribusiness and the tobacco, restaurant, and alcoholic beverage industries, which provide most of its funding. "
"This sort of manipulation doesn't necessarily entail outright lies of commission, but it typically entails lies of omission that disguise the identity of the message's sponsor. The use of the third party technique tends to corrupt journalism, science and the other institutions that it touches. Moreover, using lies of omission rather than commission enables the people who participate in front groups to rationalize that they aren't really doing anything wrong. The logic of the third party technique implies that when PR firms set out to manufacture news, they often want to keep their clients (and themselves) out of the story." Sourcewatch
And they choose names and make statements that make it sound like they're just looking out for all our best interest.
Like "..the essential role that electricity from coal plays in protecting the environment..."
" Do you see any possible development of facilities that combine photovoltaic and thermal solar? It seems to me looking at each source separately involves wasting some of the incident energy available and also not taking full advantage of using all the peripheral facilities (and grid feeds)."
Israili company Zenith Solar is doing something akin to what you are asking about. Concetrating PV solar cells get too hot and need to be cooled, otherwise they lose efficiency and can be damaged. Zenith turns this into an asset by collecting the heated cooling water, thus providing electricity and hot water from CPV.
from their website:
"In conventional CPV systems, the excess heat generated in the solar cell needs to be removed to avoid damaging the cell and to maintain high efficiency of electricity conversion. ZenithSolar utilizes the heat generated at the solar cell receiver to provide usable hot water heating, improving overall solar power conversion efficiency to 75% ."
and
"An ordinary photovoltaic cell, which is 10 by 10 centimeters, normally produces one watt of electricity. We managed to extract more than a thousand times more - 1,500 watts. In this way, the cost of a cell is 1,500 less, becoming almost nothing."
www.businessweek.com/g...
Although not quite what you are asking about, it's conceivable that wind and PV solar could co-exist on the same land, since the wind turbines have so much space between them. This could make better use of the transmission lines. Of course wind farms may co-exist with agriculture too.
CSP can also be combined heat and power, or used for desalinization exclusively or combined with power generation. I've been wondering if this might be used to alleviate the water shortages in Southern California.
I'm guessing that it would depend on the logistics of pumping sea water to the solar plants, and fresh water back to LA and San Diego. Whether that's practical or feasable, I'm not sure. There's little doubt that Southern California will need desalinization.
Another interesting idea is to use wave action and buoys to drive pumps that force sea water through a reverse osmosis membrane for desalinization. There is one company working on this.
On Apr 17 10:14 AM Road Runner wrote:
> Too bad for Ausra. They seemed to have a promising technology.
I had this same thought, and asked a panel at a CSP/CPV investing conference. With current technology there seems to be little chance of combining CSP and CPV... CSP needs to be very hot, while CPV works best when cool.
On Apr 17 01:24 PM John Lounsbury wrote:
> Tom - - -
>
> I really appreciate your detailed technical discussion. Thanks.<br/>
>
> A side question: Do you see any possible development of facilities
> that combine photovoltaic and thermal solar? It seems to me looking
> at each source separately involves wasting some of the incident energy
> available and also not taking full advantage of using all the peripheral
> facilities (and grid feeds).
>
> Another side question: Is there any feasibility for thermal air towers
> using wind turbines for the rising hot air otherwise wasted? Is there
> any commercial work in this area?
Thanks for addressing my question. I will follow up on information you provided.
Although there are several configurations for CSP, and CSP with heat storage, it would seem that at least some of them could be retrofitted for heat storage at a later date.
When the news came out recently that Brightsource had signed a deal to build 1300 MW of their power tower CSP in the Mojave, I was a little disapointed that it didn't include heat storage, but mostly gladdened that such a big project was approved.
The inventor of the alumina pebble and CO2 heat storage method, that I referenced in the first comment, mentions the possiblility of retrofitting for heat storage. He also had the idea of using a small power tower system with his storage method, to increase the temperature of the heat transfer medium of a larger parabolic trough system, to improve it's efficiency.
The dish type CSP systems like, Stirling and Infinia make, can be used as distributed energy, siting them near the end user, like a factory.
There is even a company selling rooftop trough CSP systems. Sopogy calls it MicroCSP.
www.sopogy.com/
I included them in my 10 Clean energy Gambles for 2009
www.altenergystocks.co...
On Apr 20 05:42 AM jimp wrote:
> Does anyone like what Emcore (seekingalpha.com/symbo...)
> is bringing to the table regarding CSP?
I think the brightsource deal did not include storage because their working fluid is high temperature steam, which means that, even though it is a tower, they would have to use heat exchangers in order to incorporate storage.
On Apr 19 11:24 PM frflyer wrote:
>
> Although there are several configurations for CSP, and CSP with heat
> storage, it would seem that at least some of them could be retrofitted
> for heat storage at a later date.
>
> When the news came out recently that Brightsource had signed a deal
> to build 1300 MW of their power tower CSP in the Mojave, I was a
> little disapointed that it didn't include heat storage, but mostly
> gladdened that such a big project was approved.
>
> The inventor of the alumina pebble and CO2 heat storage method, that
> I referenced in the first comment, mentions the possiblility of retrofitting
> for heat storage. He also had the idea of using a small power tower
> system with his storage method, to increase the temperature of the
> heat transfer medium of a larger parabolic trough system, to improve
> it's efficiency.
>
> The dish type CSP systems like, Stirling and Infinia make, can be
> used as distributed energy, siting them near the end user, like a
> factory.
> There is even a company selling rooftop trough CSP systems. Sopogy
> calls it MicroCSP.
> www.sopogy.com//
>
>
>
>
A "bird in the hand", as it were. Besides, ABGOF trades.
Abengoa Solar, ABGOF. I'm really surprised you haven't heard of it.