For a winning combination, you can use combined thermal/solar panels and then drive a heat pump with the electricity on the pre-warmed water. But that adds comp

For a winning combination, you can use combined thermal/solar panels and then drive a heat pump with the electricity on the pre-warmed water. But that adds complexity. The primary reason we use electricity as intermediary is that it’s comparatively easy to transport even for longer distances and can be used to drive almost any that needs energy - produce heat, cold, mechanical work, computers, …