Stirling engines are well noted for their simplicity and efficiency. Yet, their use in power generation has never really taken off. I envision small scale Stirling engine generators powering individual homes or small communities as it seems their efficiencies are lost when they are built on too large a scale.
Because Stirling engines are able to operate at lower temperatures than other engines, a Stirling generator is able to capture energy that is often wasted in a home. Have you thought about the heat that our homes generate and then waste or vent to the outside? The hot flue gases going up your chimney or wood stove stack, the hot air exiting your clothes dryer. As long as there is a sufficient temperature differential between the heat source and the ambient temperature, the stirling engine can extract that energy.
What if you could capture those energy losses being vented by your home, add in some more energy from a solar collector or mirrored array and generate power for your home. You could power the Stirling generator with a small pellet stove or gases from a septic tank. All of these energy sources are small but the can be captured and they quickly add up.