by Angela Cotton, 8 Summerfield Gardens
There are two types of solar panel, both of which received government subsidies. Thermal panels provide hot water, and can make a significant difference to water heating bills, even in winter. Photovoltaic (PV) panels generate electricity. After around 2-3 years these will have generated enough energy to pay back that used in their manufacture, and they will continue generating for 25-30 years, after which time they can be recycled.
I am fortunate that my south-facing roof is at the back, so the panels can’t be seen from the road. My 17 panels have generated an average over 5 years of about 2590 ± 80 kWh of electricity each year, more than twice the 1100kWh we used before they were put in. Our metered usage is now around 700kWh/y, so we use on average about 15% of the solar energy and the rest goes to the grid to be used by neighbouring properties. (In winter we use nearly all our generated energy, in summer much less. We could use more if we installed a device to divert any spare solar electricity to an immersion heater to heat our water.)
While one domestic roof makes little difference to UK renewable energy generation, many roofs would. The advantages for the householder come from around 30% lower electricity bills and the (soon to be reduced) subsidy or “Feed in Tariff”. Many also become keen to reduce the amount of electricity they do have to pay for, through a combination of behaviour change and use of energy efficient device.