I suspect that instead of converting the sun's energy into electricity and then back again for warming up water, it might be more cost effective to use heat absorbing surfaces with a fluid running through - pipes in asphalt maybe, and then warm up a tank of water.

With the modern boilers hot water tanks have been taken out of a lot of houses, but they are still available and could soon be adapted and plumbed back into the system.

Just don't walk on the asphalt barefoot on a warm Summer afternoon if the cooling fluid isn't running through the pipes.