Monday, January 14, 2008

EDIG Solar provides hybrid solution for cloudy days

Israel21c reports that Israeli company EDIG, through its subsidiary EDIG Solar, plans to make solar energy a viable power alternative through the use of low-cost hybrid generators. By using a hybrid power plant, on rainy days the company's solar turbines can switch over and run on traditional or alternative fuel.

"It's modular, meaning it can easily be increased in size, and it is flexible in terms of fuel use. It can be powered by bio-diesel, bio-gas or fossil fuels," explains the company's CTO Pinhas Doron, an engineer.

Based on the research of Prof. Jacob Karni, director of the Center for Energy Research at the Weizmann Institute in Israel, EDIG's technology attracts the sun and concentrates it by way of tiny mirrors on the ground.

The thermal energy generated by the sun drives turbines in a tower, the same turbines that can be powered by traditional fuel, the moment a cloud passes overhead, or at night when the sun sets. And in doing this, "our hybrid solution addresses the issue of intermittency of solar radiation," says Doron.

EDIG recently built a 100 kW pilot plant demonstration unit in Nanjing, China. It included a power conversion unit (a solarized gas turbine and a solar receiver), which was installed on a tower, and a field of heliostats (sun-tracking mirrors). The unit was fully operational and supplied power to the local electric grid, says Doron. "We proved our concept - we connected to the grid and operated seamlessly," he reports. The next step is building a plant in Israel's Arava Desert, which should be ready by next year.
While the company is not reinventing the "solar" wheel, its IP rests in at least two areas, says Doron. It's solar "receiver" is based on patented Weizmann technology, and the modifications on the turbine, which allows it to switch energy sources and at high temperatures, without the user noticing it, was difficult to overcome.

For more information on EDIG Solar, see the rest of this article from Israel21c.