There is a cool project ongoing outside of Stockholm, Sweden. The goal of the project is to create a house that can manage it´s own energy needs using renewable energy. This is done using 68 solar cells and a windmill. The house has been adapted to primarily use DC power, some local appliances are however not available in DC so there is a converter installed to feed these with AC.
Due to the hostile winters in Sweden (We don´t have a lot of sunlight during the winter) there will be a Stirling motor installed to manage the heating and electricity production during this season. The Stirling motor will be energized by pellet fuel at the first go but since a Stirling motor can be actuated using any heat source, a future solution can be hydrogen.
The company that is working on this project is projecting that the house requires 7-8 kWh per year but will produce 18 kWh!
I read about this in the swedish magazine NyTeknik.