because you can't directly use heat for anything else other than for heating There's Stirling Engines. If the solar collection is pure thermal, and if that col

because you can't directly use heat for anything else other than for heating There's Stirling Engines. If the solar collection is pure thermal, and if that collection and the storage can be made dirt cheap, then the 37% or so efficiency of conversion to electricity stops being a problem. But what are currently problems with Stirling Engines -- Hardly any of the industrial optimization has been applied to them Re: Wright's Law. So they are quite costly! Heat pipe solar thermal could be made dirt cheap through economies of scale, and it works very well, even in climates like England's. I could envision house construction changing to include sub-basements which are just polystyrene insulated boxes filled with sand. By over-provisioning storage by 4X, houses in cold climates could have huge electrical power stores, especially in summer. (Especially if the house uses heat exchangers which can draw directly from the thermal store.)