DOE Finally Begins Support of CSP

The U.S. Department of Energy’s Solar Energy Technologies Program has released a Funding Opportunity Announcement (FOA) for companies to develop storage solutions, manufacturing approaches, and new system concepts for large-scale concentrating solar power (CSP) plants. The collaborative public-private partnerships aims to reduce the nominal levelized cost of energy (LCOE) of CSP power plants from 13-17 ¢/kWh in 2007 to a target of 7-10¢/kWh by 2015 and 5-7¢/kWh by 2020. DOE estimates that satisfaction of these cost targets could lead to installation of 16,000 to 35,000 MW of new generating capacity by 2030. This would result in a savings of 36-80 million tons of CO2 emitted to the atmosphere each year relative to coal plants of similar capacity.

The FOA anticipates three phases of effort: concept feasibility, prototype development, and field validation with a “go/no-go” decision at the end of each phase. DOE is providing $5M toward the FOA in FY07 with an additional $5M planned for FY08. These funds will be sufficient to cover all of Phase 1, and will allow several successful projects to begin Phase 2 activities.

DOE has found that Nevada, New Mexico, California, Arizona, Utah and Texas have enough combined potential project sites to provide up to 6800 MW of generating capacity – roughly equivalent to seven times the country’s current electricity generating capacity. CSP technology is the least expensive solar technology for providing large quantities of electrical power, and with sufficient storage, it can deliver baseload power.

Worldwide, CSP is currently being developed for utility-scale, central power generation markets in the U.S., Spain, North Africa, and Israel. Spain is the most active in CSP development. Four tower and three trough plants, totaling 180MW are currently under construction/development, and three of the plants are slated to have between six and sixteen hours of thermal storage. Interest continues to rise, and the national electric utilities planning on developing as many as one dozen 50MW trough plants.In the U.S., nine CSP power plants totaling 354 MW have been operating reliably in California for over 16 years, and CSP seems poised to grow significantly in the state. Each of the three major California utilities (Southern California Edison, San Diego Gas and Electric, and Pacific Gas and Electric) have signed power purchase agreements for a CSP project or have indicated an intent of doing so. In August 2005, Southern California Edison (SCE) signed a power purchase agreement for 500 MW of CSP dish-engine systems on a 4,500 acre site near Victorville, CA, with an option to expand the project to 850 MW. In September 2005, San Diego Gas & Electric (SDG&E) signed a power purchase agreement for a 300 MW dish-engine project in California’s Imperial Valley, with an option of expanding the project to 900 MW. In August 2006, the Pacific Gas and Electric Company initiated plans with Luz II, LLC, to purchase at least 500 MW of solar energy beginning in the spring of 2010.

The state of Nevada has put in place tax credits enabling construction of a 64 MW CSP project near Las Vegas which will be dedicated this summer. Nevada Power will purchase the power from the plant. A 1 MW CSP system, completed in 2006, is operating in Arizona for Arizona Public Service. In addition, several other utilities, under the leadership of Arizona Public Service, are investigating the potential of forming a consortium that would buy power from a 250 MW CSP plant built in Arizona.

This funding opportunity appears to be about five years later than it should have been, since there has been considerable commercial activity during this time.  By the time these projects are complete, PV solar may well be beating their price goals. Whether these projects will speed up technology development or not is questionable, but any way we can get solar more competitive is good. CSP does have the advantage of not using any materials that are likely to be in short supply, unlike PV solar which is likely to have continuing supply problems with materials used to make the cells, as material suppliers continue to struggle to keep up with demand.  This scenario is likely to happen even to thin film suppliers when their production volumes reach several gigawatts per year, maybe a relatively happy problem that will occur with sucess.

Comments

[Susan K]

"CSP does have the advantage of not using any materials that are likely to be in short supply,

unlike PV solar which is likely to have continuing supply problems with materials used to make the cells, as material suppliers continue to struggle to keep up with demand.

This scenario is likely to happen even to thin film suppliers when their production volumes reach several gigawatts per year..."

Could you elaborate?
What are the materials that thinfilm solar will run short of? I thought thinfilm was shortage-proof.
What exactly are the materials used in CSP that won't run short?

[eric]

This all should have happened 10 years ago. Guess I shouldn't complain though - better late than never.

[Eduardo Pereira]

It is very importanto to evidence that CSP as more rigid than photovoltaic. Or is it not true, that CSP is not cost effectiveness under 50 Mwp compared with flate plate crystalline. Thereby it is non sense to compare CSP with thin film, which will be focused on BIPV application. Finally it will be crucial to present different potential between CSP technologies. Why? Because only CPV (photovoltaic) has the futur advantages to obtain larger economie of scales in the futur and not be so dependent from other resources as the water use neither turbines efficiency.

[eric]

There is a typo in the article above. It says:

...Nevada, New Mexico, California, Arizona, Utah and Texas have enough combined potential project sites to provide up to 6800 MW....

but I think it should probably be 6800 GW instead.

[Gerry Wolff]

With heat storage in melted salts and the use of gas as a backup source of heat, CSP plants can deliver any combination of base load, intermediate load or peaking power.

Waste heat from CSP plants can be used for desalination of sea water.

Further information about CSP may be found at:

http://www.trecers.net/index.html

and

http://www.trec-uk.org.uk/index.htm

[Jim from The Energy Blog]

For the short to medium term thin-film solar may be not be short of any materials. Silicon solar, is suffering from a supply shortage of silicon, not due to a shortage of the raw materials for silicon (sand), but due to a shortage of manufacturing capacity. There very well could also be a supply shortages of materials like Indium and Gallium, which are not as widely used as silicon, due to manufacturing capacity, not necessarily due to a shortage of raw materials, although this is a possibility if CIGS solar becomes the leading technology. It is not necessarily the amount of raw material that is in the ground, but rather whether it can be mined economically.

CSP plants are defined by DOE as thermal concentrating solar plants using mirrors to concentrate the solar energy,not using any solar cells. Concentrating PV solar is considered another category.

CSP plants are largely made from steel, aluminium and glass and the quantity consumed, compared to the respective industries capacities is small, so it is unlikely that shortages will occur.

As far as thin-film PV plants being compared to CSP plants, a 40 MW thin-film solar plant is being built in Leipzig, Germany with First Solar cells. Larger plants are sure to be built in the future as prices go down.

eric is right that the 6800 MW figure used in the DOE press release should be 6800 GW. The U.S has over 1,000 GW of generating capacity.

[Dr. Hussain Alrobaei]

Renewable forms of energy are the only energy sources that become cheaper with time. Due to research and development and to the effects of mass production and larger unit scales, the cost of most renewable forms of energy is reduced by 10 to 20 % each time the installed capacity doubles. Wind, biomass and Concentrating Solar thermal Power (CSP) plants are already today competitive with fuel oil at 50 $/barrel, and heading for competitiveness with natural gas and coal. A major advantage of CSP plants is their capability for thermal energy storage and hybrid operation with fossil or bio-fuels, allowing them to provide firm power capacity on demand. Further, due to a higher solar irradiance, the cost of CSP is usually lower in the Middle East and North Africa (MENA) than in Europe. Therefore, there will be a significant market for producing solar electricity under the ideal meteorological conditions in the sunbelt countries of the MENA and transferring part of this electricity to Europe. As proposed recently by the Trans-Mediterranean Renewable Energy Cooperation, concentrating solar thermal power stations in MENA could be used for export electricity to Europe as well as for providing regional freshwater from combined thermal desalination of sea water [1,2]. The electricity produced in CSP plants can be used for domestic needs and export, as well as for additional desalination of sea water through reverse osmosis (RO), if required. The design of such combined solar power and desalination plants can be flexibly adapted to any required size and need. CSP plants can be designed from 5 MW to several 100 MW capacity [3]. Therefore, in the future European mix of energy sources for power generation, CSP can serve to cover base load, intermediate load or peaking load and even to compensate the fluctuations of PV and wind power.

1. Hussain Alrobaei , 2007, Novel Integrated Gas Turbine Solar Cogeneration Power Plant/DEC, Halkidiki, Greece ,22–25 April 2007.
2. Hussain Alrobaei , 2006 , Repowering and Modification of Grid Connected Reverse Osmosis Desalination Plants/CIERTA 2006 , Exposiciones y Congresos - Roquetas de Mar (Almería).
3. Hussain Alrobaei,2006, Integrated Gas Turbine Solar Power Plant/ The Energy Central Network/energycentral.com/centers/knowledge/whitepapers.

[Eduardo Pereira]

Jim, thanks for your information about thin film project in Germany, but what I said, is that thin film , strategically speaking, will be focused on BIPV applications, due to its potential for this market. Please look at Shell strategy when sold crystalline to solar world and not thin film.This is from the books. And it is non sense to compare techonologies (CSP and Thin Film)with very different strategies (CSP focused in projects higher than 50Mwp and 100 Mwp and thin film for descentralized projects, regarding its big potential to commercial buildings and bipv applications, when green builngs in US, EU directive for energy efficiency in Buildings, and UK carbon zero emissions houses, reveal one of the major markets for PV technologies in the world, mainly for thin film. Why to establish a comparison between CSP and Thin Fim? purely non sense, strategically speaking). Finally, CPV and CSP has been promoted as an whole (remember last NREL report presented to the US congress, and I am not an US citizen) in US and in other world regions, but it is obvious that are very different. This is the reason because I note on the other post, that is necessary to establish this difference. Thanks

[david foster]

One attractive feature of CSP is the inherent storage capability achieved by keeping the molten salt (or whatever) hot. Does anyone know what the practical limits of this are? Are we talking a couple hours of storage, or a couple of days?

[Roger Bedell]

Another way to look at CSP, as a Stored Energy System that complements PV, rather than competing.

Electricity is a bit of a strange beast, kind of like the Internet, in that generating power does not need to be concentrated in one place. For example, if a big PV plant only outputs while the sun shines, some other plant, perhaps wind, gas, or stored energy hundreds of kilometers away can take up the slack when it gets dark. Since thermal storage is the main intrinsic advantage of CSP compared to PV, this geographic/power source decoupling makes many other non-obvious possibilities practical.

We all know that solar and wind have a big problem: you can't rely on them. The key to this is energy storage - store it up for when the sun goes down or the wind dies. There are lots of storage schemes, the main problem being that it is expensive to store electricity. Heat is easier.

The heat storage of CSP may be an economical storage system, in fact, why not just use them as storage systems, only generating electricity when the lower cost PV and wind systems are dark? This would entail making the molten salt storage much larger than currently planned (usually about 8 hours storage). The molten salt retains its heat for a long time, I recall seeing something like a 1 degree per day loss in a hot tank. If you make the storage big enough, it could run the turbines for days, even in the rain, making up for some of those dark PV panels and stopped wind turbines. Acting as a renewable storage scheme may make CSP much more valuable, rather than simply competing with PV.

[Roger Bedell]

David, what a coincidence - we were typing the same idea at the same time! I don't think there are any practical limits, just economic ones. The 8 hour storage was chosen because this is about how long the Spanish stay awake after the sun goes down. The molten salt (special low melting point salt) is pumped from a cold (~250C) insulated tank, heated using the oil in the solar troughs and pumped into the hot (~500C) tank. When you need electricity, you reverse the flow and heat up water for the turbine.
A dedicated "peaking" CSP with massive thermal storage like this would only generate electricity at high $ value times, and storing heat at other times for when it is needed.
I think this may be practical, but who knows? It would compete with other storage schemes like pumped hydro, CAES and flow batteries. Someone would have to run the numbers. Are you listening Flagsol/Solar Millenium?

[Calamity]

Although molten salts are receiving a lot of attention right now, there are other options which might be more cost-effective. Using high quality concrete for example. All you need is cheap concrete and pipes embedded into it. Just transfer the heating medium through the pipes to heat the concrete up. It can be durable as there are few moving parts. Such systems would require more space than molten salts which have favorable thermal properties, but space isn't much of an issue in deserts where these systems will likely be deployed.

Perhaps it's also a good idea to use Stirling engines instead of steam turbines as Stirling engines don't generate steam and therefore use up no water (can be difficult to find in deserts. Strange, isn't it?).

[Be Sargent]

Please let me know what are the comparative water usages of CSP and coal gasification per megwatt

[Orem and Provo Storage]

Hopefully the oil prospect site will turn out to be profitable out in the boonies of Utah. Then hopefully that lowers gas prices.

[fireofenergy]

I can't believe that the DOE says "up to 6,800 MW". That's nothing! I think they meant to say 6.8 terawatts. 4 TW would generate twice America's 4,000 or so terawatt hours consumed yearly. This is 20% efficiency at 25% capacity... The larger stat field would require larger heat resevoir and would raise capacity, but also prices (so that's why I stuck with the 25% capacity...)