UK Solar PV Irradiation Levels - Annually

Solar PV systems are driven by light, not heat, from the sun.

This light is described as  'irradiation' and is calculated in the map below as the likely 'Kilowatt hours' generated per 1kw (peak) array per annum.

The key point to note here is that the Standard Assessment Process (SAP) Verulam Electrics is obliged to use is based on the solar yield in Sheffield.

Here in St Albans, Hertfordshire, we benefit from much better yields than we can specify in our Return on Investment statements. It makes Solar PV an even better investment than it looks on paper.