As an FYI - Attached is a chart I created in Excel of the ratio of daily kwh usage (from electric company) to daily heating degree days (from www.degreedays.net). My system did not seem to be running properly and the electric bills were very high. Communicating this data to the installer eliminated the 'cost of electricity' issue and allowed me to focus solely on electric usage. Because the house is not occupied, almost no other electric is being used, so this data primarily represents just heat pump electrical usage. Recently, the system was fixed after it was determined that the compressor had been on lockout for an extended period of time and was running only on auxiliary heat. I will continue to update this chart to determine if the fix made a positive impact on electric usage. Sorry the image isn't too clear.