I don't know much about electric safety covers other than that they are covers that deploy at the touch of a switch.

We just came home from a 5-day jaunt to Banff for a friend's wedding. (It rained most of the time). I left my solar panels turned off, but my solar cover on--today the pool was 96 degrees! That's in North-Central New Jersey, with a 20,000 gallon pool, using a cheaper blue cover. It had been in the mid-80's when we left.

Covers insulate AND prevent evaporation-based heat loss.