Here are examples of some of our solar PV arrays for both domestic and commercial customers now enjoying free electricity and receiving the feed in tariff, which is set at 41.3p per kWh until 01/04/12 for installations up to 4kWp and is guaranteed for 25 years. A typical solar installation should have a payback period of 8-10 years and an annual return of between 5% - 8% on the investment, although this can be higher or lower depending on the location, solar array size, aspect, shading and weather conditions.