Stirling engines

Convert heat in mechanic energy?

Stirling engine!

For a general discussion: http://en.wikipedia.org/wiki/Stirling_engine
A DIY project description: http://www.emachineshop.com/engine/index.htm

• It demonstrates the principle of heat engines

• It is incredibly simple (even for heat engines)

• You can built it from scratch

Kits to experiment with Stirling Engines: http://www.newenergyshop.com/

A long list of questions and answers about Stirling Engines and their applications: here.