Power of sun

Published: Saturday 31 May 1997

A prototype solar device that produces enough hot air from the sun's rays to drive the turbines of a 50 kw power station has brought the prospect of cheap, solar-generated electricity a step closer. The solar energy collector has been successfully tested by Israeli researchers at the Weizmann Institute of Science, Jerusalem. Many modern power stations use hot gas to drive the turbines that produce electricity. The gas must be between 1,200 and 1,350 c and must reach pressures of between 10 and 30 bar. Existing solar collectors, which focus the sun's rays on tubes of air, cannot do this. The new device focuses the sun's rays through a quartz window to heat ceramic pins around which air flows. The array of pins --- which researchers have nicknamed the 'porcupine' -- absorbs solar energy and transfers it to the air. As the ceramic pins have a large surface area they transfer heat to the surrounding air very efficently.

Subscribe to Weekly Newsletter :

Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.