Scale
In general, solar PV needs 7 to 8m2 per kW of installed capacity. Typical system sizes for domestic panels range from 1 to 4 kW so 7 to 32m2. Commercial arrays have the potential to be much larger and are limited only by roof space available.
Solar PV in the south west is estimated to have a capacity factor of around 0.1.
A 2.2 kW domestic polycrystalline PV system will produce an average of around 1900kWh of energy per year, equivalent to around 40 per cent of the average domestic electricity consumption. A system of this size would be approximately 5.5 m x 3.6 m.
A 50 kW array will produce an average of around 43,800 kWh of energy per year, equivalent to the average electricity consumption of 9.3 homes. A roof mounted array of this size would need approximately 400 square meters.