For this particular situation, we looked at a potential available roof area of 15 square meters. PV panels of this area will typically produce 1.5 kWp (kilo-watt peak) which equates to an annual production of around 1125 units (kilo-watt hours). A system this size would cost around
£6,135.00 to install, plus VAT at only 5%, would produce an income from FITs of £464.63 per annum, and a benefit from using your own electricity of £168.75 giving an effective net annual ‘income’ of £633.38. Again, in very round numbers, this would pay off your capital investment in 10 years leaving a subsequent on-going return of 10% per annum on your initial investment.