Solar
Renewable energy generation
Solar panels, or 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, clean electricity to power your appliances. You can sell extra electricity to the grid or store it for later use.
There are over 1.3 million installations on homes across the UK – see where the UK solar panel hotspots are.
Let’s look at how they work and whether they’re suitable for your home.
The average solar panel system is around 3.5 kilowatt peak (kWp). The kWp is the maximum amount of power the system can generate in ideal conditions.
A 3.5kWp system typically covers between 10 to 20m2 of roof surface area, using between six and 12 panels.
An unshaded, south-facing roof is ideal for maximum performance. East or west facing roofs still work, but we don’t recommend installing solar panels on a north facing roof.
A system facing east or west tends to get around 15-20% less energy than one facing directly south.
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, but sometimes shading is unavoidable. Some solar panel systems can minimise the impact of shading using ‘optimisers’.
Solar optimisers help improve the overall performance of your solar panel system. So, if one panel is shaded, it doesn’t impact how much electricity the other panels can generate.
If your roof doesn’t have shading, optimisers won’t help you generate more electricity. But having an optimiser gives you extra opportunities to monitor your system’s performance.
Solar panels on houses are considered ‘permitted development’ and don’t usually need planning permission. But there are exceptions so it’s best to check with your local planning office for guidance. For example, there may be extra restrictions if you live in a:
listed building
conservation area
national park
If you’re planning to install a solar panel system in your home, you must register it with your Distribution Network Operator (DNO). The DNO is the company responsible for bringing electricity to your home. Usually, your installer will register the device with the DNO for you.
In Northern Ireland, your installer will register your system with NIE Networks.
The ideal place to install solar panels is on a sloping roof, as the panels work best when angled towards the sun. But if you can’t do that, there are a few other options available to you:
Yes, it’s okay to install panels on flat roofs. Panels on flat roofs are normally tilted up to help maximise energy production.
It’s important that the panels don’t disturb 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 from leaks.
Sometimes it might be recommended to renew the roof covering so that your roof remains in good condition while the solar panels are attached to it Even though it may add to the cost, the overall solution will be cheaper in the long run.
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 be as south-facing as possible
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.
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 dioxide emissions
Solar electricity is a clean, renewable energy source. 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.
Sell extra energy to the grid
Export the electricity you can’t use yourself and get paid for it. The Smart Export Guarantee lets you sell extra electricity to the grid.
Installing a solar diverter
Instead of sending surplus electricity to the grid, a solar 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 solar 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 solar 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.
How much do solar panels cost to install?
Generally, domestic solar panel systems are around 3.5 kWp and cost around £7,000. The cost depends on:
- the size of system
- any difficulty accessing your roof
- whether you choose panels or tiles
- whether you integrate the panels into the building
- whether you need to renew the roof covering
You can lower the cost of installation costs 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
How much will I save with a solar panel system?
The amount you could save using a solar panel system depends on:
- How much of the solar electricity you’re able to use yourself.
- Whether you sign up for export payments like the Smart Export Guarantee.
- Where in the UK you live, as areas further south get more direct sunlight.
How do I maintain a solar panel system?
You don’t need to do much to keep your solar panel system running well. The main thing is to keep nearby trees well-trimmed to minimise shading 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 make to ensure everything is working properly. This should include details of the main inverter fault signals and key troubleshooting guidance.
Ideally, your installer should show this to you after installing the system. Speak to your installer for how much maintenance the panels need before you commit to installing anything.
How do I get solar panels?
- Use our solar panel calculator to get an idea of what size system is right for you.
- Get 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. It’s also worth getting quotes for a solar battery.
- Agree a quote with an installer and book an installation date.
- The installer will install scaffolding before adding the mounts, panels and battery.
- The inverter is connected to your home so you can start using the electricity generated.
- The installer should test the system and talk you through how it all works.