Pilio holds weather data from August 2007, therefore you can import meter readings from this date to and receive the weather-efficiency analysis. However, unless you have a complete set of past weekly or monthly records for all your energy meters we recommend that you start fresh in Pilio, taking new readings each week.

Using old bills as a source of historic meter readings can be a problem as most energy bills use estimated readings. These estimated readings are not helpful as Pilio is based on actual energy use in order to give accurate feedback.

If you enter actual readings that are backdated, Pilio will estimate readings for those weeks where you have missing data so this will give you a reasonable picture of your energy usage over time even if you have an incomplete set of readings.