Why not just get a solar PV system and a variable speed pump? On top of that, you can get a solar blanket to keep the heat in. That seems to be a better option, since the solar PV system also provide power to the rest of your house instead of just your pool pump. A variable speed pump will help drastically reduce the energy usage. A solar blanket will help keep the heat in the pool and to keep the pool ~5 degrees warmer normally, which will reduce the amount of gas needed to bring the pool temp up.