Israeli energy startup Zenith Solar is pioneering a "concentrated solar power" method that is up to five times more efficient than standard technology
by Neal Sandler
Busines Week: Energy & Environment March 26, 2008, 1:20PM EST
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.
Zenith Solar, based in Nes Ziona near Tel Aviv, is a pioneer in a new type of solar energy that uses mirrors and lenses to focus and intensify the sun's light, producing far more electricity at lower cost. Compared with traditional flat photovoltaic panels made of silicon, this so-called "concentrated solar power" technology has proved in tests to be up to five times more efficient. That puts it on the verge of being competitive with oil and natural gas, even without government subsidies.
A Boost to Israel's Energy Supply
"Our goal is to utilize every suitable roof, backyard, and open space in Israel to turn households, hotels, and factories into net producers of electricity and thermal heat," says Roy Segev, the founder and chief executive of Zenith Solar. Founded in 2006, the startup has raised $5 million from a handful of private investors in Israel and the U.S. Now it's trying to raise an additional $10 million to $15 million to cover the cost of commercializing its technology.
The opportunity is compelling. Israel's National Infrastructure Ministry estimates solar panels for water-heating already satisfy 4% of the country's total energy demand. With technology like Zenith Solar's widely installed, the figure could jump to more than 16%—a big boost for a country now almost totally dependent on imported energy.
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.
Tested over the past few years at Israel's National Solar Center in the Negev desert, the prototype achieved astounding results: A concentration of solar energy that was more than 1,000 times greater than standard flat panels.
Avoiding Costly Panels
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."
After further refining the technology, Zenith plans in the coming months to take its first major steps toward commercialization. Two large-scale test installations are planned for this summer at a kibbutz and a factory. The company will put 86 of its 7-meter-high dishes on an acre of land at Kibbutz Yavne to provide the community of 250 families with more than a quarter of their energy needs. The second project will replace fuel oil used to produce heat at a large chemical plant in central Israel.