Wednesday, November 24, 2004

Improving Solar Technology: Solar Energy Dish Farms

A Sandia National Laboratories project in New Mexico will test whether a farm of solar dishes can compete with conventional fuels for electricity generation.

The initiative calls for the installation of six dishes by the end of the year, which should create enough electricity to power 150 kilowatts of grid-ready electricity--enough to supply 40 homes.

The dishes, which have 82 individual mirrors in them, can automatically move to capture the most sun during the course of the day and then shut down at sunset. The system, which can be monitored via the Internet, requires minimal maintenance, according to Stirling Energy.

Sandia's solar dishes direct the sun's rays onto a receiver that transfers the heat to an engine filled with hydrogen. As the hydrogen is heated and then cools, the pressure on the engine changes. That changing pressure drives the pistons, which in turn power an electrical generator.

Stirling Energy researchers believe that large formations of these dishes are viable--and pollution-free--energy sources for utility companies in the southwest, where there is a lot of sun, or potentially remote areas, such as the Navajo reservation.

The Stirling system dishes are more efficient than commonly used photovoltaic solar cells at converting the sun's heat to electricity, Liden said. The net solar-to-electricity conversion is 30 percent, which is substantially higher than what photovoltaic cells are capable of.

CNet News Article on New Mexico Solar Farm Project