Solar Thermal Towers And How They Work

A Solar Thermal Tower runs on the thermal law that hot air rises. Basically the way a thermal tower works is very similar to what would happen if you combined a convection oven with a chimney. A solar thermal tower has three main parts. The tower, the collector, and the turbine. The more prominent is the tower itself. The tower is almost like an exhaust. Around the tower is a huge collection area. The collection area is usually a covering of very thin film polymer sheeting, glass, plexiglass or lexan. The sun hits the collection material, heating the area underneath. As this air gets warmed up to around 100 deg, the air looks for an escape route. The heated air can reach speeds of up to 35 mph when exiting out of the thermal tower. If you put wind turbines inside the tower so that the heated, escaping air is making them spin, the heated air can be used to generate electricity.

This type of power plant also works at night. With no modification, the sun not only heats up the air in the collector area, but it also heats up the ground, so at night when the sun goes down, the ground releases its heat which still produces the air current to make the turbines generate electricity. Because of the obvious absence of heat, the power output won’t be quite as much as during daylight hours. However if water is piped through the collection area, it will hold and transfer more heat with greater efficiency when the sun goes down.

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