A Stirling Engine is an extremely efficient device at extracting energy from heat differences (i.e. one side hot and one side cold) and it can be run from any fuel or energy source from the sun, to a candle, or from burning wood to the heat from your hand. Best of all, it is surprisingly simple to make a working model stirling engine from readily accessible free or cheaply available parts and without expensive tools. Below are a list of links to some of the better free stirling engine plans available online.
Stirling Engine Plans
SFA Stirling Engine Project
Easy to Build Stirling Engine
Build a Can Stirling Engine
For a selection of different types of stirling engine click here to visit the Scrap to Power website. Here you will find detailed photo-illustrated plans for making coke can stirling engines, Pringles tube stirling engines, walking beam engines, thermoelectric generators (TEG) and much more – all easy to build using bits and pieces of scrap.