UK Irradiation and Solar Electricity Generation Potential

UK Irradiation Map

Optimally-inclined photovoltaic modules

Solar photovoltaic systems need only daylight to operate and can therefore work in most locations. As the output from photovoltaic cells changes based upon the amount of daylight available, they will always be more efficient when placed in unshaded areas, orientated in a southerly direction for maximum potential; though any direction in the southerly arc between East and West will work (typically at no less than 85% efficiency). Output is dependent on the strength of the sunlight, not on the outside air temperature.

Solar PV systems can be supplied in virtually any size, and their output will be related to the area of the solar panels. An area of one square metre typically produces 100 to 180 watts peak of PV capacity. The productivity of solar PV does not vary greatly across the UK with typical levels between 1100 kWh per square metre in the South West, to 800 in the Scottish Highlands. This is shown in the colour coded irradiation map on the right.

Solar panel direction

Panel Orientation

Panels should be angled between 30 and 45. The diagram illustrates the best orientation for a solar panel. A value of 100 being the optimum position and angle to the sun.