

Stirling Engine
Spring 2011 ToysThis securely packaged kit contains a Stirling engine module, an 11-inch parabolic mirror, a base with a voltmeter, a charging cable, an alcohol burner, an electric car, and replacement glass and steel wool for the engine. The excellent 33-page instruction manual includes abundant illustrations/photographs and complete explanations of the function and operation of each component. It provides the science and history of the Stirling engine (it was developed almost 200 years ago) and current and future use of this technology as we continue to rely more on renewable energy resources. Maintenance and cleaning procedures for the engine are also provided.
To use the kit, the Stirling engine is attached to a sturdy base and is affixed with a parabolic mirror. Adjustments are made to focus the sun's rays onto the sealed glass cylinder using a ratcheted housing and sighting rod. When the air in the cylinder heats up (to up to 482 degrees Fahrenheit), it expands and pushes a piston that operates a generator that generates electricity that charges a rechargeable battery in the electric car. Heat can also be generated by heating the glass cylinder with the alcohol burner included with the kit.
At first, we could not get the engine to run outside in the sun and no volts were generated. But, after giving the hand crank a bit of a nudge, the engine started right up. Voltage readings were around 2 volts even with thin clouds and minor tree cover. During operation, the engine sounded like, and vibrated much like a sewing machine. According to the manual, 2-3 hours of charging time results in 5 minutes of run time on the car. This would also involve constant adjustments to the mirror to maintain the orientation to the sun.
We enjoyed creating this kit and look forward to continued use as we learn how to operate it optimally