A solar powered world?
Arizona Public Service (APS) has announced plans to build a 280-megawatt concentrating solar power plant in the desert 70 miles southwest of Phoenix. The Solana Generating Station, if it were operating today, would be the single largest solar power plant on the planet. Solana, with its thermal energy storage, will be able to operate 24/7 providing power for 70,000 homes.
As big and impressive as it sounds itâ€™s only a tiny fraction of whatâ€™s possible: According to the Trans-Mediterranean Renewable Energy Cooperation (TREC), the energy potential from sunlight striking the worldâ€™s deserts is 700 times that of the worldâ€™s primary energy demand today. Further, solar power generated in the worldâ€™s deserts could reach 90 percent of the worldâ€™s population. Australia, Asia, Africa, North and South America all have expansive deserts. By satellite measurement there are 13,500,000 square miles (35 million square kilometers) of hot, dry, sunlit desert on the planet.
Like the APS project, solar thermal power generation is the best option for the worldâ€™s deserts. Not only is it a time-tested technology that can provide low cost power, cooling water from the plants can be used for desalinization of sea water. (Energy from clean sources is a major global need right now. So is fresh water.)
Further, made of glass and steel there are no supply constraints to solar thermal power generation equipment as with purified silicon needed for photovoltaics.
The TREC concept, known as DESERTEC, is to build solar power plants in the Middle East and North Africa (MENA) and build power lines - a Euro-Supergrid - connecting the plants to Europe.
TREC estimates that power would cost 4-6 cents per kilowatt hour to generate. Transmission costs would add another 1- 2 cents per kilowatt hour. Though solar power plants might be far from populated areas, line losses would only be about 3 percent per 620 miles (1000 kilometers) using 500 volt high voltage direct current (HVDC) lines. Total line losses from the MENA deserts to Europe would be about 10-15 percent.
The solar plants would do more than provide clean energy and water, theyâ€™d also provide jobs during construction, jobs when built and be a continual source of revenues for operators, even those nations hosting the facilities. It seems feasible that Persian Gulf nations could continue to receive revenues from the sale of energy forever after the oil is gone.
The key of course is the high voltage direct current (HVDC) lines. Bringing them in first would attract solar developers.
Like the plants conceived by TREC, the APS - Solana Generating Station project will use one of a few variations of concentrating solar technologies now being marketed. At Solana, parabolic mirrors will track the sun and focus solar energy on a heat transfer fluid. Once heated, the liquid will convert water into steam, which turns the plantâ€™s turbines to generate electricity.
Up to 1500 jobs will be created in the construction phase of Solana. Once built by 2011 the facility will have 85 skilled technicians. The company has also recently announced that it has joined a multi-state consortium of southwestern utilities that have an interest in contracting for a separate 250-MW solar power plant.
Abengoa Solar is the primary developer of the project. Abengoa Solar deploys CSP technologies across the world, including large-scale facilities under construction or development in the US, Spain, Algeria and Morocco.
The TREC initiative was founded in 2003 by The Club of Rome, the Hamburg Climate Protection Foundation and the National Energy Research Center of Jordan. The DESERTEC Concept was researched in cooperation with the German Aerospace Center (DLR). TREC is now working to make this concept a reality in cooperation with people in politics, industry and the world of finance.
If a DESERTEC for Africa, the Middle East and Europe, why not a similar project to connect the US desert southwest, perhaps Mexico too, with much of North America?
( A white paper with a full description of DESERTEC is available at the website.)