How do solar panels work?

Solar PV consists of many cells made from layers of semi-conducting material, most commonly silicon. When light shines on this material, a flow of electricity is created. The cells don’t need direct sunlight to work and can even work on cloudy days. However, the stronger the sunshine, the more electricity generated.  Because the electricity used for household appliances is alternating current (AC), an inverter is installed along with the system to convert DC electricity to AC. This electricity can be used throughout your home, or exported to the grid.

Do you have enough space?

Space is a key consideration. The average system size is around 4.2kWp and this will typically take up around 25m2 roof area. An unshaded, South facing roof is ideal for maximum electrical output. East or West facing roofs could still be considered, but North facing roofs are not recommended. A system facing East or West will yield around 15-20% less energy than one facing directly South.

What about if there is parts of my roof which will be shaded?

Any nearby buildings, trees or chimneys could shade your roof and have a negative impact on the performance of your system. Finding an unshaded spot is best, however sometimes shading is unavoidable. Some solar PV systems can minimise the impact of shading using ‘optimisers’. If you don’t have shading, the use of optimisers is not necessary or beneficial, other than the increased monitoring opportunities they offer – they won’t generate more energy.

Do I need permission to install a solar PV system?

Solar PV panels are considered ‘permitted developments’ and often don’t require planning permission. However, exceptions apply and it’s best to check with your local planning office for guidance. If you live in a listed building, conservation area or national park, additional restrictions may apply.

Reduce your electricity use

During daylight hours, you’ll be generating electricity even on cloudy days, but if you’re using more power around your home than your panels are generating, or during the evening when your panels are not generating any electricity, you’ll be supplementing this by importing electricity from the grid. Reducing your electricity use can help lower your bills and reduce your carbon footprint. If you’re claiming a Smart Export Guarantee tariff, you’ll receive a payment for every unit of electricity you export. Remember to turn devices off and avoid standby.

Maintenance of solar panels

Solar PV systems need little maintenance. Keep an eye on nearby trees to ensure they don’t begin to overshadow your system. In the UK, panels that are tilted at 15 degrees or more benefit from being cleaned by rainfall, which helps to ensure optimal performance. If you live in an area with more dust in the air. In these cases, you might need to have the panels cleaned occasionally. 

We also recommend the fitting of Bird Protection around the panels to prevent Pigeons and other birds from roosting underneath.