250 watts would be 1 Kw hour every 4 hours and 400 would be 1 Kw hour every 2.5 hours so if you figure mean PGE rate of ~ 20 cents per Kw hour as an average you're looking at an xtra 60 plus cents a day with the 250 for 12 hours and $1 buck a day xtra for the 400 watter
250 watts would be 1 Kw hour every 4 hours and 400 would be 1 Kw hour every 2.5 hours so if you figure mean PGE rate of ~ 20 cents per Kw hour as an average you're looking at an xtra 60 plus cents a day with the 250 for 12 hours and $1 buck a day xtra for the 400 watter