So, just to update, I turned my Heat pump on Tuesday am with pool temp at about 62ish, by Wednesday around 1pm we were at 78. This is running the heater 24 hours a day with the solar cover on, now I have it at 82 and will leave it there through the weekend. With the solar cover it will not use a ton of electricity to maintain that. As the previous poster said, if you want to be swimming in early to mid april or in November then yeah maybe electric isn't the way to go. Here in CT if we didn't have a heater we wouldn't have the water where my wife wants it to swim in, which would be 78-80 until mid to late June on a consistent basis, so we mainly use our heater from early to Mid May through early to mid-late October. Nobody in our family wants to be swimming when the ambient temp is below 70 anyway so it really is a personal preference thing as much as anything.