On Sept 10, Ausra Inc., the developer of utility-scale solar thermal power technology, announced that it has secured more than $40 million in funding from Silicon Valley venture capital firms Khosla Ventures and Kleiner, Perkins, Caufield & Byers (KPCB).
Ausra's power plants drive steam turbines with sunshine. Locally manufactured solar concentrators made of steel and glass focus sunlight to boil water, generating high-pressure steam that drives conventional turbine generators. New thermal energy storage systems using pressurized water and low cost materials will provide for on-demand generation day and night. Ausra's core technology, the Compact Linear Fresnel Reflector (CLFR) solar steam generation system, was originally conceived in the early 1990s by founder David Mills while at Sydney University. Mills later worked with Graham Morrison to develop the idea between 1995 and 2001.
Austra's innovation is that it uses commodity flat mirrors that sit low to the ground. The refectors concentrate sunlight on water-filled pipes that hang over the mirrors. As the water is heated up to 545 degrees fahrenheit (285 celsius) the resulting steam drives a standard turbine.
"We had been working on a wide range of alternatives and kept finding that simpler, cheaper approaches outperformed higher-temperature, more sophisticated designs," says Ausra Chairman David Mills.
The company claims that:
CLFR technology has significant advantages in cost, scalability and emissions profile.
Utility scale solar technology has traditionally been parabolic trough, but Ausra's less complex flat mirrors are much less costly.
Ausra's innovations in collector design dramatically reduce the cost of solar thermal generation equipment and bring solar power to prices directly competitive with fossil fuel power.
It can generate electricity for 10 cents/kWh now, under 8 cents/kWh in 3 yrs.
Ausra's zero-carbon power plants generate electricity at current market prices for fossil-fired power without the emissions caused by burning fuels. Low-cost thermal energy storage systems now under development by Ausra will allow solar electric power to be generated on demand, day and night.
Ausra's projects will include energy storage using hot water and other low-cost materials. Thermal energy storage puts the storage before the generator—heat is stored, not electric power. Storing heat is simpler, cheaper, and substantially more efficient than storing electric power. Thermal energy storage makes solar a firm, dispatchable resource.
In 2002, Mills and Morrison founded Solar Heat and Power Pty Ltd. in partnership with Ausra CEO Peter Le Lièvre, and SHP built a successful trial 1 megawatt system in 2004 for Macquarie Generation in New South Wales. A following 38 megawatt CLFR solar field is expected to be complete by 2009.
The company currently has a power project in the testing and commissioning phase in Australia, a project breaking ground this year in Portugal and a project in the permitting phase in central California. A significant number of large projects are being negotiated in other locations.
Ausra is developing a generation of plants in the 100-500 MW class.
Ausra is the successor company to Solar Heat & Power from Australia, in business since 2002.
Thanks for tip from After Gutenburg
Calamity has again drawn the wrong conclusion based on 'very simple empirical evidence'.
What is the purpose of the small amount of thermal storage? Answer: to protect the turbine (pg 8)
Is the small amount of thermal storage, physically small? Answer: No, see picture on pg 10.
What Calamity lacks is a sense of scale. Each one of those 5 MWt storage tanks is about the same size of a 4000 MWt nuclear reactor. To produce the energy to maintain the plant 24/7 would require 8 times the solar collectors, and 120 storage tanks. Multiply that whole mess by 100 to get a 1000 MWe nuke plant.
Posted by: Kit P | September 20, 2007 at 08:39 PM
Some cool pictures of sustainable energy in Spain:
http://www.panoramio.com/photo/2309290
http://www.panoramio.com/photo/2922387
http://www.panoramio.com/photo/2922015
http://www.panoramio.com/photo/2328802
http://www.panoramio.com/photo/1642983
Posted by: Kit P | September 23, 2007 at 01:37 PM
I've been wondering why CST can't be combined with CPV of 35% efficiency in at least on case, using 40.8% PV cells. The CPV is likely to become even more efficient. Electricity from the CPV could be used for grid and excess could be used to cool water in cooing tank. Cold water is easier to store than warm water because the vapor pressure is lower, as long as you don't freeze it.
There is also a patented device that uses solar heat and gas expansion to drive a piston to push refrigerant through an aperature to provide enough cool to freeze ice. i.e. the thermal expansion drives the refrigeration. It has been a while since I read about this device. Not sure if it is still being sold. Patent for it will still be on record.
Posted by: mds | September 24, 2007 at 12:22 PM
I've been wondering why CST can't be combined with CPV of 35% efficiency in at least on case, using 40.8% PV cells. The CPV is likely to become even more efficient. Electricity from the CPV could be used for grid and excess could be used to cool water in cooing tank. Cold water is easier to store than warm water because the vapor pressure is lower, as long as you don't freeze it.
There is also a patented device that uses solar heat and gas expansion to drive a piston to push refrigerant through an aperature to provide enough cool to freeze ice. i.e. the thermal expansion drives the refrigeration. It has been a while since I read about this device. Not sure if it is still being sold. Patent for it will still be on record.
Posted by: mds | September 24, 2007 at 12:25 PM
I've been wondering why CST can't be combined with CPV of 35% efficiency in at least on case, using 40.8% PV cells.
The cells will not operate well, or possibly even at all, at the temperature of the CST collector.
Posted by: Paul Dietz | September 24, 2007 at 01:57 PM
There is the heat engine from Deluge Inc. that could be used. I think storing cold water would be a little like going backwards, at least in the case of CST. Concentrating light on PV cells might be dangerous, if the cooling/heat collection fails you could roast them.
I think the best aproach to CST would be (if not used already) 3 stages. Steam turbine, low temperature turbine (CO2 or freon?) and maybe the heat engine at the end. The stored heat could actuate the heat engine at night.
Posted by: greg | September 24, 2007 at 02:05 PM
Sorry for the double post.
No, CPV is already an existing approach. I was suggesting using both types of collectors near each other for the benefit of cooperative energy storage. One stores hot and the other cold. Integrating both CPV and CST in one collector is another level. I don't know you can assume the CST collectors are too hot for the PV cells. How do you know this is true? There are a number of CPV companies out there. Are you sure their collectors will all fail? They are using concetrated sun light so they must have to deal with a fair amount of heat.
http://thefraserdomain.typepad.com/energy/2007/03/delta_electroni.html (Delta Electronics – 35% eff. CPV panels using 40.7% eff. Cells from Spectrolab – March 2007)
Posted by: mds | September 24, 2007 at 08:51 PM
As far as I know, PV cells become very inneficient when they get hot. If they withstand the heat, in case the cooling system fails, without sustaining damage, it could be an idea. The only problem is that the operating temperature you would want for the cells is too low to be able to take advantage of the heat removed. Unless you used some refrigerant with a heat pump. I guess I'm just repeting your idea with different words.
There could be a mechanical safety device to rotate the cells in case of overheating. The thing would be to see how far you can push the cell output and the cooling system and still be economically viable.
Posted by: greg | September 25, 2007 at 09:21 AM
Kit P said: What Calamity lacks is a sense of scale. Each one of those 5 MWt storage tanks is about the same size of a 4000 MWt nuclear reactor.
What Kit P lacks is a sense of how much near-useless desert land there is on this planet. Death Valley didn't get it's name because the region is so useful and fertile.
Kit P said: To produce the energy to maintain the plant 24/7 would require 8 times the solar collectors, and 120 storage tanks.
More like 6x the solar collectors, even less in better locations. Which would also be the locations where space is not that much of an issue; desert land is dirt cheap if you pardon the pun.
As for storage, there are many options such as cavern storage, molten salts, caloria oil, thermal concrete/ceramics, metals, or even phase change materials. You can't even come up with one fundamental, inherent reason why the first option could never work.
Now, take another look at the proposed plant's figures:
http://solarheatpower.veritel.com.au/Eurosun240CLFRFinal2.pdf
I couldn't find much wrong with them, except perhaps the low discount rate which would add a small amount to the LEC.
Posted by: Calamity | September 26, 2007 at 09:29 AM
Has anybody come up with a reflective surface like aluminum or stainless steel sheets to replace expensive mirrors? Seems to me that the cost of the glass mirrors is a big part of the cost.
A metallic sheet, even if the reflection is not as perfect as a glass mirror, can be shaped better.
Posted by: greg | September 27, 2007 at 03:16 PM
Calamity wrote: What Kit P lacks is
Please stop raping Energy Blog commenters.
Calamity wrote: how much near-useless desert land there is on this planet. Death Valley didn't get it's name because the region is so useful and fertile.
Death Valley derives its name from its reputation for killing unprepared human visitors.
Calamity wrote: desert land is dirt cheap
Deserts are also complex biological-ecosystems.
Introduce an ecosystem-killing technology -- such as solar-power -- into a delicate ancient ecosystem such as Death Valley, and you kill the latter.
Posted by: Nucbuddy | September 27, 2007 at 07:28 PM
Good point, even deserts have life in it. I don't think man hasn't built over any part of the world that didn't already have an eco-system and we should tread lightly. That is why it would be best if we used already existing construction (roofs) for solar power. Wouldn't it be a better world if we could do away with centralized power generation and all those ugly and costly power lines that clutter the view?
Of course that might take a while. In the mean time, I'd vote for thermal solar in areas where the impact on nature is minimum, and I think a small portion of desert used for a solar thermal plant that doesn't polute, is not going to endanger the wildlife.
Posted by: greg | September 27, 2007 at 09:13 PM
Nucbuddy, nice post except for the rape comment. I have a thick skin and can handle insults. Discussing energy with Calamity is like talking to someone on a merry-go-round, they keep coming back so dizzy they forgot what you said last time.
I have seen nuke plants, windmills, solar panels, and coal mines. Environmentalist obsess about stripping coal off of mountain tops and replanting trees. Then they call covering the tops of the same mountains with windmills sustainable.
I have my favorite spot to hike in the desert. A small springs creates a few trees for shade perfect for a few hours of solitude reading. I do understand why those who travel from LA to Las Vegas think of the desert a waste land and want solar panels to power their slot machines. They do not understand statistics or the environment.
Setting aside a certain amount of the desert to produce electricity is okay with me just spare the sustainability claims.
Posted by: Kit P | September 27, 2007 at 09:18 PM
This technology was jointly developed from the early 1990’s by both Morrison and Mills. Your article regarding the origin of this technology in Australia is quite incorrect. Why does your account fail to acknowledge the other original founder, Morrison? Mills developed the optical design of the concentrator while Morrison developed the thermal design of the absorber and system operation.
Posted by: A. Martin | December 08, 2007 at 03:18 AM
Nucbuddy is evidently a propagandist for nuclear absolutism. Small wonder Kit likes him.
A very strange bunch, they are. Seem to have lost all reason.
Back on topic, the Ausra guys have got a plant operating. 5 MWe for 15 million, that's 3000 per kWe. Going to much larger scale will result in at least a 50% increase in power generation (1.5x turbine efficiency). So that alone lowers it to 2000 per kWe. Add in the fact that larger steam cycles themselves are cheaper per kWe as well, and the fact that larger plants have lower overhead and installation costs, it looks like the capital costs can be about halved just by plant scale-up.
Posted by: Cyril R. | December 09, 2008 at 10:55 AM
Shockingly, last month Kit P announced that Ausra plant opening without any snide comments despite it being in California!
http://thefraserdomain.typepad.com/energy/2007/12/ausra-building/comments/page/3/
Posted by: A.non | December 09, 2008 at 04:11 PM
@A.non
I thought readers here would be interested in Ausra accomplishment. If you watch carefully I treat folks with respect. My snide remarks are reserved for those who make wild leaps of logic and only then when the call me a racist because I do not subscribe to their infinite wisdom. Being negative with negative people is just a sign of respect.
Making electricity with solar is interesting. Saving the world by erecting glass/metal in the desert or on the roof is absurd.
Posted by: Kit P | December 09, 2008 at 07:16 PM
There's the snide remark! Knew it was in you.
Posted by: A.non | December 10, 2008 at 04:16 AM
Dear Sirs,
We are interested in you solar power collectors.
Can you help.
Thank you.
Regards.
F.Chetcuti.
Director.
Posted by: Francis Chetcuti | March 08, 2009 at 01:38 PM
people we've got to start some where, any where!
Posted by: Tony | May 27, 2009 at 01:00 PM
a greater loss but has had the rock, lyrics miss his talent and infected us with a rage of others, wish you were his art and his talent here with us the man was alone on their own ..
Posted by: sildenafil | April 26, 2010 at 06:22 PM
Solar Energy is the most easily available and free source of energy. It is the most important out of non-conventional sources of energy too, it is non polluting, available for all and convenient source therefore helps in lessening the greenhouse effect.
Posted by: hot water heater systems | November 24, 2010 at 02:38 AM