How much do solar panels cost?

Wondering whether it's worth forking out for solar panels? We've crunched the numbers to help you estimate how much solar panels will cost for your home.

Solar panels aren't cheap. But they can help reduce your electricity bills, earn money by generating electricity that you can sell back to your energy company, and help cut your carbon footprint.

Keep reading to learn more about solar panel costs. Alternatively see how much you could earn from solar PV and if solar panels are a good investment.

Solar panel prices

Before you start getting quotes for solar panels, having a good idea of how much they should cost you will help make sure you don’t pay more than you need to.

The most popular solar panel system size is between 3.6kWp and 4kWp, according to our survey of more than 1,000 solar panel owners.* This size of system generated 3,750kWh of electricity per year, on average for owners. 

For comparison, a home using a 'medium' amount of electricity gets through 2,900kWh per year on average, according to energy regulator Ofgem. A 'high' user takes 4,300kWh per year.  

The cost of a solar PV system varies depending on:

• the size of the system, including how many panels
• the type of solar panels
• the type of building they'll be fitted on
• the quality of the inverter and other components.

We’ve worked with the Royal Institution of Chartered Surveyors (RICS) to find out the average prices for various sizes of solar PV systems. The tables below reveal how much you should expect to pay for a solar PV system, including the inverter, controls and installation.

Only logged-in Which? members can view the prices. If you’re not a member, join Which? to get instant access to this, plus our solar panel brand reviews.

Solar panel costs by electricity generation

The more electricity the system can generate, the greater the savings on your electricity bill can be – but the bigger the initial cost.

It’s important that your system is sized correctly for your household’s electricity use, so that you don’t overpay. 

If you're not sure what size solar panel system is appropriate for your home, we’ve also listed prices you should expect to pay based on your annual electricity usage. You can find this on your annual energy statement or in your online account.

But keep in mind that solar panels generate most of their electricity during the day, so you may not be around to use it (unless you have a battery). In fact, our survey of solar panel owners* found that:

• 12% use less than a quarter of their solar electricity
• 34% use between a quarter and half
• 22% use between half and three quarters
• 13% use more than three quarters.

So you'll still need to buy electricity from the grid, especially on dark winter evenings. 

Battery storage lets you bank electricity generated by your solar panels until you need it, but buying a battery will mean it takes longer for your system to pay for itself. Find out more about solar panels and battery storage. The cost of a battery is not included in the prices above.

Solar panel costs by property type

Another way to get a rough estimate of solar panel costs is by looking at the most common sizes of system on different types of home. 

The costs below show the median average amounts that solar panel owners in our survey paid for their systems.

Which? members will need to log in to see the prices paid by owners. If you're not a member, join Which? to reveal the costs.

All of the prices above are averages, so you should get quotes from solar panel companies for your specific needs. Three quotes will allow you to compare prices for your specific system and home.

Use our Which? Trusted Traders search tool below to find local solar panel experts near you for quotes and installation.

Are solar panels getting cheaper?

Solar panel prices have dropped dramatically since 2011, and fallen again over the past couple of years.

The average cost for a kilowatt of solar panels fell by around £250 between 2018/19 and 2020/21, according to statistics published by the government's Department for Business, Energy and Industrial Strategy (BEIS) in May 2021.

It said that the median average cost per kilowatt of a small solar PV installation (0-4kW) was £1,429.

Back in 2013-14, the average cost was around £480 more per kW.

When are solar panels costs lowest?

Prices vary during the year. For example, between May 2020 and April 2021, prices per kW were highest in April, May and February and lowest between August and October, according to BEIS. 

This doesn't mean that solar panels are always cheaper in the summer though. Spring 2020 prices would have been impacted by Covid-19. In the previous year (2019-20), the cheapest month was November.

We recommend you get three quotes before you buy, so you have a good idea of the going rate for your installation.

Get paid for your solar panels' electricity

Some energy companies will pay you for electricity generated by your solar panels that you don't use but put into the grid instead. This is called the Smart Export Guarantee (SEG).

You won't get it automatically when you export electricity you're not using. You'll need to sign up with an energy company. 

Find out about the Smart Export Guarantee explained, including how much you could earn and which companies offer it.

The SEG replaces the government’s Feed-in Tariff (FIT) scheme, which closed in March 2019. If you're already signed up to it, read our guide to the Feed-in Tariff. 

Solar panel cost calculations

To calculate average purchase and installation costs by system size and electricity needs, the Royal Institution of Chartered Surveyors (RICS) analyses costs from a variety of sources, including surveys, online quotes and retailer pricing information. It combines these with quotes from specialist subcontractors to give the most accurate average prices.

The prices include everything necessary to carry out the installation. This includes materials, labour, preliminary work, contractor costs, VAT and profit. 

Materials costs are based on the best trade prices from a range of suppliers across the UK, which are then benchmarked to reveal the best national average. Labour rates are based on the current Building and Allied Trades Joint Industrial Council wage agreement. RICS then uses this data in a standardised model. Data copyright RICS 2020 and reproduced with permission. Prices are correct as of October 2020.

*Which? conducted an online survey in June 2021 with 1,116 Which? Connect members who have solar panels.