The number of solar panels you can fit on the average British roof depends on the roof size, panel size, and other factors, such as the distance from the roof’s edge. The average 3.5kWp (kilowatts peak) solar PV system in the UK consists of 10 standard 350W panels, each measuring about 1m x 2m.
To fit 14 panels on a roof, you would need a space of about twenty square metres. However, roof-mounted solar installations must be at least 30cm away from the external edge of the roof, which means you will need an even larger space to accommodate this requirement. Each solar panel usually has an area of 1.3-1.7 square metres, with around 1.6 being the most common size. The number of solar panels required depends on your energy consumption, sun hours, and roof size.
You can use the Energy Saving Trust’s Solar Energy Calculator to estimate fuel bill savings and financial payments you may receive by installing a solar photovoltaic system (solar PV) based on the information you provide.