CPV solar panels designed to float on water: Sun and surf pilot array constructed - Photovoltaics World
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CPV solar panels designed to float on water: Sun and surf pilot array constructed

February 14, 2011 - Xinhua General News Service -- Israeli solar-energy firm Solaris Synergy is promoting floating concentrating photovoltaic (F-CPV) to reduce the cost of photovoltaic cells and cut down on the amount of land that an energy farm requires.

Solaris Synergy says why not exploit lakes, reservoirs, canals, and close offshore bodies of water, an untapped area where nothing is built or grown, and one that even provides its own cooling for the delicate electronics.

"If it's possible to capture the sun rays that fall upon the water, one can produce a lot of energy by exploiting the surface area," company co-founder Yossi Fisher told Xinhua.

Additionally, the system would serve to limit the evaporation and growth of algae on the bodies of water "both unwanted results of solar heating," Fisher said.

Solaris' Floating Concentrating Photovoltaic (F-CPV) collectors are made up of modular connecting panels on which the curved solar arrays are mounted.

The Jerusalem-based company came in first-place at an international clean tech competition held at Tel Aviv University last year, that sought entrepreneurs who could come up with the best ideas for dealing with energy and economic problems faced worldwide.

Since there's no friction or heavy weights involved in turning the floating array, the assembly requires only a small motor and related computerized gear to rotate the curved panels to track the sun's path across the sky.

Fisher also said their arrays require less silicon than other designs, both due to the unique design that aims the sun's rays at a more tightly focused point, and due to the cooling system that has an unlimited amount of water on hand.

"The moment you have the sun focused on the arrays, the temperature can go as high as 70-80°C, which lowers the efficiency by upwards of 30%," Fisher said.

The electrical output of F-CPV arrays is measured in kilowatt-hours. Solaris says they have the only "cold silicon" in the world, which they claim increases efficiency by 25%. Each of the floating fiberglass and plastic segments produces 200 kw/hr, and can interlock with each other enabling practically any size, shape and electrical output required, according to the company.

"You needs about 10 dunams (2.5 acre) of area per megawatt, and each reservoir can produce about five megawatts apiece," Fisher said.

According to Fisher, if Solaris power grids were installed over the country's hundreds of recycled waste water reservoirs, Israel would be able to generate 10 to 20% of its power needs energy from renewable sources by 2020.

As well, since only most of the water used in cooling the solar energy arrays evaporates and only a small quantity is returned to its source, the body of water beneath the arrays isn't heated, Fisher said.

After two years of operation, Solaris' eight-member team have constructed a small working prototype at the facility. Another prototype, located at Kibbutz Ketura in the Negev Desert close to Eilat, will be on display at the 4th annual Eilat-Eilot Renewable Energy International Conference and Exhibition, beginning February 24.

The organizers say thousands of participants from Israel and abroad have attended the event, and Solaris hopes to garner major exposure prior to expanding their trials into the real world later this year.

Israel's water authority Mekorot, which runs many of the country's more than 400 reservoirs, has agreed to allow Solaris to install a pilot array at a reservoir near Jerusalem, a move that would open the company to the local market, according to Fisher.

But Fisher has a bigger goal in sight overseas. Solaris will also install a similar setup at a reservoir near Marseilles, under the auspices of Electricite de France, among the world's largest utility companies. The Israel-European R&D Eureka project is partially funding the French installation.

Copyright 2011 Xinhua News Agency

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