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Generating renewable electricity

Solar panels

Solar panels, also known as photovoltaics (PV), capture the sun’s energy and convert it into electricity to use in your home.

Installing solar panels lets you use free, renewable, low carbon electricity. You can sell surplus electricity to the grid or store it for later use.

According to low-carbon certification organisation MCS , there were more than 183,000 solar panel installations across the UK in 2023. This is a third higher than 2022, showing that solar is an increasingly popular renewable technology.

And, against the backdrop of unstable energy costs, it’s a good time to consider taking advantage of the free, renewable energy that solar panels provide.

How do solar panels work?

  1. When the sun shines on a solar panel, solar energy is absorbed by individual PV cells in the panel. These cells are made from layers of semi-conducting material, most commonly silicon.
  2. The PV cells produce an electrical charge as they become energised by the sunlight.
  3. This electrical charge creates a direct current (DC) of electricity.
  4. The current passes through an inverter to turn it into alternating current (AC) electricity. This is the kind of current needed for household appliances.

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

Solar panel systems tend to be made up of between six and 12 panels, with each panel generating around 400 to 450W of energy in strong sunlight.

Are solar panels right for me?

You can use our online assessment tool, Go Renewable, to find out what renewable technologies are suitable for your home.

Use Go Renewable

There are also a few things to consider before you commit to a solar panel installation:

Can I put solar panels on a flat roof?

Yes, it’s okay to install panels on flat roofs. Solar panels work best when angled towards the sun, so panels on flat roofs are normally tilted up to help maximise energy production.

It’s important that any solar panel system maintains the integrity of the roof covering to keep it watertight. For this reason, many systems are weighted down rather than fixed through the roof covering.

If you have a system that’s weighted down, the roof needs to be strong enough to deal with the added weight. If the roof isn’t strong enough, use appropriate fixings to ensure rain can’t cause any damage.

Sometimes it might be recommended to renew the roof covering so that you get the best possible roof integrity and solar panel performance. Even though it may add to the cost, the overall solution will be cheaper in the long run.

Can I install panels in my garden?

Yes, you can install panels in the garden on a suitable frame. Make sure they don’t get shaded by nearby trees and buildings, and they should face as close to south as is practical.

One advantage of mounting panels in the garden is that it’s easy to keep them clean. But you also need to be more careful about rodents and other physical damage.

Can I install panels on my shed or garage?

Yes, you can install panels on an outbuilding. It’s important to make sure that the building roof is strong enough.

If the building doesn’t have its own electricity supply already then you should factor this in when looking at the total cost of the system.

What are the benefits of solar panels?

Cut your electricity bills

Sunlight is free, so once you’ve paid for the initial installation, your electricity costs will be reduced.

Cut your carbon footprint

Solar electricity is low carbon, renewable energy. A typical home solar panel system could save around one tonne of carbon per year, depending on where you live in the UK.

That’s the equivalent of driving 3,600 miles, or from London to Bristol 30 times.

How much do solar panels cost to install?

The average domestic solar panel system is 3.5kWp and costs around £7,000.
The amount you pay is influenced by:

  • the size of solar panel system
  • any difficulty accessing your roof
  • whether you choose solar panels or tiles
  • whether you integrate the solar panels into the building

Some of the installation costs can be shared if you already have scaffolding up for roof repairs or if you’re building a new house.

The cost of ground-mounted solar panel systems is more difficult to predict, as there are more variables such as:

  • the type of mounting frame
  • how far away it is from your house

Costs can vary between installers and products, so we recommend getting quotes from at least three installers.

Make sure the installers you look at are MCS-certified, which ensures they adhere to a strict code of conduct. You can find installers on the MCS website.

Can I get a solar panel grant?

There aren’t any specific solar panel grants. But you may be able to get funding as part of other government schemes.

For England and Wales

Get in touch with your local council or energy supplier to see if they offer funding under the Energy Company Obligation (ECO) scheme.

For Scotland

Read our advice on renewable energy funding for Scottish residents.

For Northern Ireland

Get in touch with NI Energy Advice to find out what funding options are available for you.

How much will I save with a solar panel system?

The amount you could save using a solar panel system depends on a few things:

  • How much of the solar electricity you’re able to use yourself.
  • Whether you sign up for export payments like the Smart Export Guarantee (SEG).
  • Where in the UK you live, as areas further south get more direct sunlight.

Annual savings in London, South East England

Annual savings in Aberystwyth, Wales

Annual savings in Manchester, North England

Annual savings in Stirling, Scotland

Annual savings in Belfast, Northern Ireland

What are the best ways to use solar panels?

Solar panels on their own offer lower electricity bills and low carbon energy. But they’re at their best when combined with other renewable technologies.

Installing a PV diverter

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 your hot water needs, but it can help reduce your bills.

A PV diverter switch installation could add around £800 to your installation costs. You’ll need to replace your diverter after around 12 years.

If you’re interested in using PV diverter, speak with your installer. They might also suggest increasing the number of solar panels on your roof to provide more electricity for your hot water needs.
Here are the average annual savings when using a PV diverter with your solar panel system:

Annual savings with a PV diverter in London, South East England

Annual savings with a PV diverter in Aberystwyth, Wales

Annual savings with a PV diverter in Manchester, North England

Annual savings with a PV diverter in Stirling, Scotland

Annual savings with a PV diverter in Belfast, Northern Ireland

How long do solar panels last?

Your solar panels should last 25 years or more. But if you have a solar PV inverter, you need to replace this after around 12 years. This costs around £800, depending on system size and the manufacturer. Some 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 you can often extend up to 15 years. Speak to your installer about the likely lifespan and benefit of an extended warranty.

You might find that a 15-year warranty costs almost as much as a replacement inverter, so consider it carefully.

How do I maintain a solar panel system?

Solar PV systems need little maintenance. Keep an eye on nearby trees and keep them well trimmed to minimise shading of the array where possible.

In the UK, rain will clean your panels if they’re tilted at 15 degrees or more. 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.

Your solar panel installer should leave written details of any maintenance checks that you should conduct 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. Speak to your installer for exact maintenance requirements before you commit to installing a solar PV system.

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Last updated: 28 June 2024