On the domestic level, there are many examples, probably the most useful is a simple solar electrical generator that stores the sun’s heat in a large black stone. This heat is then used in a basic Stirling generator that runs 24hrs a day producing a constant electrical supply. This power can then be used in house or sold on to the national grid.
The secondary benefit of this system involves using the domestic hot water system to take away the waste energy and improve the overall efficiency. This provides a neat two for one gain from a device that costs about the same as a large fridge and just sits on the roof producing electricity as it purrs away.