Spanish Firms Combine To Build 50-Megawatt Solar Power Stations

A group of leading Spanish industrial companies have joined forces with electricity giant Iberdrola to invest some E 300 million over the next three years to build solar energy power stations. The plants will not rely on panels alone, but will instead use solar power to heat steam which will then drive turbines. Solar power stations work on the same principle as conventional plants, but instead of using gas or coal as their primary source of combustion, they work on clean and inexhaustible solar power.

In Andalusia and Extremadura, these firms, including ACS, Abengoa and Iberdrola, have begun building power plants of up to 50 megawatts - most new conventional power stations are around 400 megawatts - to gauge whether the sun can produce non-polluting electricity at reasonable cost. In theory, such a power station could supply the electricity needs of up to 10,000 homes, says Iberdrola.

The Institute for the Diversification and Saving of Energy (IDAE) says that the proposed plants, some of which will be in use by next year, are promising. The technology to enable more efficient use of solar power has emerged from research carried out at the Almería Solar Platform, built 25 years ago. Electricity companies for their part have been encouraged to find ways to produce cleaner energy through subsidies of up to 21 cents per kilowatt per hour produced.

The decision to expand the use of thermo-electric power stations is important, says the IDEA, but adds that their profitability could be greatly improved. According to the organization, each kilowatt of solar energy costs between €4,000 and €5,000, four times of wind energy, and only slightly cheaper than using solar panels. Among the most important projects are Andasol, a €240 million investment in the town of Aldeire in Granada. The 50 megawatt plant is based on a 350 megawatt unit in the Mojave desert in Arizona. The Solar Electric Generating System, or SGES, 160 kilometers from Los Angeles, is the biggest such project in the world, and contributes 70 percent of the world's solar electric energy.

EDIT

http://www.iht.com/getina/files/265157.html

could do this too! But all they do is talk about. The equivalent of a 15-square kilometer grid would power the whole state.

$3 a month to help them defray the costs

http://www.aps.com/my_community/Solar/Solar_29.html

As they aren't sources of pollution, they can be located closer to population centers, reducing line losses. Also, you can have several around a community, as you aren't thus "surrounding" that community with pollution sources.

Further, with many smaller stations rather than a single larger station, your energy production is less prone to total failure. You might still get brown outs, but you're less likely to get blackouts.

However, you still need a night time solution. Some wat to store a reserve of energy during peak daytime energy production hours.

These are steam thermoelectrics. They could also use heat engines. If they did that, they could heat a very large quantity of water, which would remain hot into the night, and still pass it across the heat engines. In fact, because the night air is cooler, they could get more power from the hot water at night than during the day, as long as it is well insulated.

The most efficient system ever built for utilizing solar energy was not a PV panel, but a small kinematic stirling engine that worked off sunlight reflected from a parabolic mirror array. It looked like a large solar dish. Several such units have been built. One company is here:

http://www.stirlingenergy.com/

Preliminary research into stirling engines using thermoacoustics has shown that they can acheive the same efficiencies as the kinematic stirling engines, with fewer moving parts. (In fact some may be possible where the only "moving" part is quasi-solid-state.)

Thermoacoustic stirlings can also be made into heat pumps that do not bother to change the energy into electricity and directly produce cold air when you heat the collection end.

However, most of these green energy companies tend to get wrapped up in making ever-more-efficient products rather than cheaper products. They are well past the point of diminsihing returns, at least until the industry picks up a large economy of scale. If they concentrated on making cheaper solutions, and just using more real-estate, they could probably break the wind-energy price point.

All that said, I'm a bit more interested in seeing power generation right on the premises, owned by the homeowner or apartment complex owner, rather than by energy companies. One good start would be a mass-produced product like an window-mount solar air conditioner, priced cheap, that would work during the day in conjunction with the normal air conditioner to reduce load. Such a product would have no need to store power for later use, and would take a chunk out of peak demand on the grid during the summer.

Unfortunately most green energy R&D folks follow the money, and the people that have the money are energy companies and venture capitalists, not the homeowners/landlords. So most research gets poured into creating these large installations, when in fact, the technology they use doesn't get much more efficient when you scale it up (wind does, stirling engines and mirrors do not.)