Photovoltaic Cells | Solar Stirling Engines | Solar Chimneys
Passive Heating

Solar Chimneys are sometimes also called Solar Towers. They operate on the principle that "hot air rises". The systems are surprisingly low tech, consisting of a large solar collection area under a thin, transparent membrane, and a chimney. The air under the membrane heats up, like a greenhouse, when exposed to the Sun. This hot air then tries to rise and its only way up is to rise up the chimney. Large turbines intercept the rising air flow to rotate large generators to produce electricity.

The first working prototype, pictured above, was built and tested for 7 years, in Spain during the 1980's. It worked much better than expected. Recently, a number of projects are moving forward to build much larger units.