The solar modules absorb daylight and through the photovoltaic process generate electricity. This electricity can typically reach 600 volts DC and needs to be converted by the inverter to match the power supplied to your house from the electricity grid (which is usually 230 volt AC in the UK).
The electricity generated is used on site to power your home.
A full site survey would be required to produce individual performance figures.
For more information on tariff examples please see the Ofgem website.