At the Zenith of Solar Energy

Saturday, March 29th, 2008

Neal Sandler of BusinessWeek writes about an Israeli solar-thermal firm, in At the Zenith of Solar Energy:

Rooftops all over Israel look strikingly similar: More than 1 million households in the nation of 7.1 million people have solar panels that produce hot water — a relatively simple technology that gained popularity after the 1973 Arab-Israeli war, when oil prices shot up sharply. As of the early 1990s, all new residential buildings were required by the government to install solar water-heating systems.

Yet despite Israel’s sunny climate and early lead in solar heating, it has been slow in adopting more sophisticated solar technologies that produce electricity from sunlight. Now, with oil hovering near $100 a barrel, a local startup hopes to build on the country’s early embrace of sun power to carve out a new clean-energy business.

Sandler evidently thinks that Zenith’s solar-thermal technology is “a new type of solar energy” — but the article is not clear about what exactly the new element is:

Zenith bought the rights to the solar technology from Ben-Gurion University and Germany’s Fraunhofer Institute. A joint Israeli-German research team from the two organizations designed a working prototype, which consists of a 10-sq.-meter (107.6-sq.-ft.) dish lined with curved mirrors made from composite materials. The mirrors focus the sun’s radiation onto a 100-sq.-centimeter (15.5-sq.-in.) “generator” that converts light to electricity. The generator also gives off intense heat, which is captured via a water-cooling system for residential or industry hot-water uses.

One big advantage of solar-thermal is that its manufacturing scales without facing a raw-materials constraint:

One of the biggest advantages of Zenith Solar’s approach, especially in today’s market, is its limited use of polysilicon. Skyrocketing global demand for traditional photovoltaic panels has led to a worldwide shortage of the material and lifted prices tenfold in the past four years.

“Photovoltaic material accounts for 80% of the cost of standard systems,” says David Faiman, chief scientific officer at Zenith, and a 30-year solar-energy veteran who was part of the development team. “Our technology succeeds in reducing this to less than 10%, while at the same time obtaining very high efficiency.”

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