Costs and savings

Export payments With any domestic PV system, there will be times when the electricity you generate is more than you can use or store, so the surplus will be exported to the grid to be used by somebody else.

If you want to be paid for exporting, you need to make sure you’re getting an export payment.

If you were able to claim the Feed-in Tariff (this closed to new applications at the end of March 2019), then you will be getting export payments as part of that. If not, you need to find an energy company that will pay you for this surplus.

Following the closure of the Feed-in Tariff scheme to new solar PV system applicants in March 2019, the Smart Export Guarantee (SEG) was introduced to provide financial support to small-scale renewable energy generators for the electricity they export to the grid.

The savings from solar PV with the SEG are considerably higher than without it.

In Great Britain, the Smart Export Guarantee pays you for the electricity you generate. In Northern Ireland, you can get paid for any surplus you export – usually estimated based on how much you generate. Several organisations offer this service, so if you’re interested, we recommend researching their offers to find one that works for you.

Annual savings when using the electricity you generate

Most households will use about 15-25% of the energy you generate, though this can change quite dramatically based on:

Whether you work from home.

How many people are at home during the day.

Whether you have an electric vehicle.

Whether you heat your home or hot water using a heat pump or other electrical heating.

Whether your cooking is done using electricity.

Instead of sending surplus electricity to the grid, a PV diverter switch can power the immersion heater in your hot water tank, storing hot water for you to use later.

On its own, excess solar energy is unlikely to meet all of your hot water needs, but it can help reduce your bills.

Maintenance

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.

Debris is more likely to build up if you have ground-mounted panels, or if you live in an area with more dust in the air.

In these cases, you might need to have the panels cleaned occasionally.

Once fitted, we will leave written details of any maintenance checks that you should carry out to ensure everything is working properly.

This should include details of the main inverter fault signals and key troubleshooting guidance. Ideally, your installer should demonstrate this to you once the system has been installed.

Keeping a close eye on your system and the amount of electricity it’s generating (alongside the weather conditions) will help you understand what to expect and alert you to when something might be wrong.

The panels should last 25 years or more, but the inverter is likely to need replacing sometime during this period, at a cost of about £600-1,000 (depending on system size and the manufacturer).

Good inverters have online monitoring functions and can warn you by email if the system fails.

Most inverters have warranties of five years as a minimum, which can often be extended up to 15 years.