You Can Use the Sun as a Source of Heat
Stirling engines are a type of heat engine. They convert heat into mechanical work (you can find out more about how they work here), which means that it is possible to use the sun as a source of heat to general clean power. The video below shows a working stirling engine build out of soda cans that spins up to almost a thousand RPM!
Here's a non-soda-cans stirling engine (suspended at the center of the dish) that uses a solar concentrator as a source of heat instead of candles. It's a bit more sophisticated, to say the least, but it works on the same principle.
Photo: Public domain
The Stirling engine is noted for its high efficiency (up to 40% in practice, same as the Carnot cycle in theory), quiet operation, and the ease with which it can use almost any heat source. This compatibility with alternative and renewable energy sources has become increasingly significant as the price of conventional fuels rises, and also in light of concerns such as peak oil and climate change. This engine is currently exciting interest as the core component of micro combined heat and power (CHP) units, in which it is more efficient and safer than a comparable steam engine. Stirling engines (especially free-piston types) are also being considered by NASA for use in space exploration. (source)
If you like this article, you can follow me on Twitter (@Michael_GR) and Stumbleupon (THMike). Thanks.
More on Energy
Algenol's Algae-to-Ethanol Delivers 67% to 87% Reduction in CO2
Dr. Steven Chu Answers Questions from Citizens About Energy Conservation (Video)
Should Energy Conservation be Framed in Terms of What Would be Lost?
2009 Snapshot of U.S. Energy Use by Lawrence Livermore National Laboratory