This is a larger Stirling engine powered by concentrated solar is water cooled. It has a 12v DC Permanent Magnet motor operating fixed as the flywheel bearing and is powered by a large 36" Parabolic Mirror.
http://www.greenpowerscience.com/SHOPHOME.html
It produces 15 Volt max with NO LOAD. This setup as is produces about 15 watts. The heat sink is a water cooled tank that is a bit short for the displacement piston but does work. I will be adding some heat sinks soon and testing it with the 56 inch dish and a Fresnel Lens. The motor/generator has an additional pulley that the other engine I have may be tied to. The water can be fed continuously or as a tank.