Having finally had a chance to sit down and do some calculations on our first year with solar power, the figures are quite interesting.
Based on our use over the previous two years our average annual electricity consumption was 4320 kWh. Our first years solar generation was 4047 kWh which is around 93.5% of our average usage. This is much better than we expected, we had hoped for 75-80%. It seems that with a bit more effort to improve efficiency and reduce waste we could get very close to 100%.
The electricity consumption figures for the first full year with solar show that we used 2720 kWh. This is around 63% of the average for the previous two years and gave us a saving of around 1600 kWh. This works out at around £190 saving on our annual electricity bill at current prices. Adding this to the income from the FIT we made a net return of around 14% on the installation cost. This means the pay back time will be just over 7 years.
Overall this is on the high side of our expectations and we are very pleased with it. Given the very indifferent summer we had in 2012 it will be interesting to see how the system performs in future years. The majority of the electricity the system generates is in the 6 months between April and September. If we have a better summer then the likelihood is that the annual generation will exceed this years figure and take us close to the 100% mark for generation vs consumption.
