An item by Toni Feder titled “Scientists help make deserts into solar-energy hubs” (PHYSICS TODAY, July 2011, page 21) refers to upcoming implementations of concentrated solar power (CSP) technology as pilot projects. However, nearly 100 years ago, Philadelphia scientist Frank Shuman applied the CSP concept to a system he built in Meadi, Egypt. He used reflective troughs to power a steam engine that operated a pump to bring irrigation water to the desert. Along with his pilot project, “by 1914, Shuman was talking of building 20 000 square miles of collector in the Sahara”1 for producing energy from the Sun. Although CSP components have improved since then, old photographs of Shuman’s facility in Egypt look remarkably like the one on the July 2011 cover of PHYSICS TODAY.
Since there are conflicting views on the job-creating potential of renewable energy, scientists promoting solar-energy hubs in the desert might want to review the findings of reference 2, which makes the following claim:
Europe’s current policy and strategy for supporting the so-called “green jobs” or renewable energy dates back to 1997, and has become one of the principal justifications for U.S. “green jobs” proposals. Yet an examination of Europe’s experience reveals these policies to be terribly economically counterproductive.
But then review the follow-up report by Eric Lantz and Suzanne Tegen, which claims that the methodology used by Gabriel Calzada Álvarez and colleagues “does not reflect an employment impact analysis.”3
Attention should also be paid to the termination of large CSP projects. For example, a proposed 290-megawatt CSP plant for Arizona Public Service was terminated in 2009 because Lockheed Martin Corp “decided not to go forward with the project due to the size and the final risk profile of the EPC [engineering, procurement, and construction] contract, among other factors.”4
Are water supplies in the desert adequate for the operation of CSP? Can the deserts provide—locally or through importation—the water resources needed to sustain CSP plants without denying desert inhabitants the water they need for survival? To reduce water usage for CSP, we could use dry-cooling instead of wet-cooling towers, but even with dry cooling, will the water resources be sufficient for the total steam cycle and for cleaning mirrors?
Gerhard Knies’s hopes for CSP in deserts, like Shuman’s a century ago, are admirable. But Knies’s prophecy that “the transfer from fossil fuel to renewable energy will become the biggest business of the future” is reminiscent of other grossly inaccurate energy-related predictions. For example, Lewis Strauss claimed more than 50 years ago that atomic power was the answer to energy problems and that it would make “electricity too cheap to meter.”5 History shows that such claims should be made with considerable caution.
Frank Shuman's solar collector, built in 1908 in Meadi, Egypt. (Courtesy of Tacony Historical Society.)
Frank Shuman's solar collector, built in 1908 in Meadi, Egypt. (Courtesy of Tacony Historical Society.)
