We had a non Heartland, 30 amp unit the last two years when I kept track. Last year in Topeka, where it was decent for two weeks then blistering low 100's for the last two weeks used 900 KWH, Avg. 31.03448275862/day. Dallas, May of last year, temperatures averaged 80's every day and used 828.9 kwH, Avg. 29.60357142857/day. June of 2011, it was really hot in Oklahoma City, used 984 KWH, Avg. 33.93103448276/avg day which was our highest so far. These are all monthly rates, except Dallas, where we stayed 5 weeks. Paid anywhere from $0.12 to $0.15 KwH. Hope that helps.