I get those letters too. Hey I can turn off the central air and take my daughter most likely to the doctor for asthma attack which will cost me a lot more then paying for the CA on. We were gone in the spring for vacation. Turned off everything I could think off. Even the humidifier and the letter said I used over 150% then homes around me. Something isn't right here. Another one is a employee had both kids move out of the house last year. So only him and his wife. They both still work and he gets the letter that he is using 150% more too? He is like How!