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26 February 2021

How much do solar panels cost?

Find out how much solar PV panels cost, whether prices are coming down and what financial help is available for buying solar panels.
Sarah Ingrams
Solar panels 7 446487

Wondering whether solar panels will pay for themselves? We've crunched the numbers for you.

Solar panels aren't cheap. But if they can help you cut your energy bills, plus earn you money by generating electricity that you might be able to sell back to your energy company, does this mean you'll end up quids in? 

Keep reading to learn more about solar panel costs versus how much money they can save you. 

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.

Prices for solar PV systems vary depending on the size and type of the system, as well as the structure of the building on which the panels will be installed. 

So 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 below. If you’re not a member, join Which? to get instant access to this, plus our solar panel brand reviews.

Solar panel cost by system size

System size
Average cost

The more electricity the system can generate, the greater the savings on your energy bill will 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. The most common solar PV system size is 3.6-4kWp, according to our May 2019 survey of Which? members who have solar panels.

If you don’t yet know the size of the solar panel system that’s appropriate for your home, we’ve also listed prices you should expect to pay for a solar PV system based on your annual electricity usage. You can find this on your annual energy statement or in your online account.

Solar panel cost by electricity use
Annual electricity use
Average cost
Low (2,000kWh)
Medium (3,500kWh)
High (5,000kWh)
Electricity use based on Ofgem typical domestic consumption values, taking a mid-point between profile class 1 (single-rate meter) and 2 (multi-rate meter) usage.

Bear in mind that you’re unlikely to be able to meet all of your electricity needs from installing solar panels alone. They generate most electricity during the day, while many people are at work, and won’t be generating power on dark winter evenings when you’ll need to use far more electricity.

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. We haven't included the cost of a battery in the prices above.

Solar tiles, which are part of the roof rather than fitted on top of it, are becoming more popular, although they're more expensive than conventional solar panels. Find out more about how solar PV works.

The prices we've given 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. Which? Trusted Traders can help you find a reliable firm.

Are solar panels getting cheaper?

Solar panel prices have dropped since 2011, and fallen again over the past year.

The average cost for small solar PV installations fell by around £200 between 2018/19 and 2019/20, according to statistics published by the government's Department for Business, Energy and Industrial Strategy (BEIS) in May 2020.

It said that the median average cost per kilowatt of a small solar PV installation (0-4kW) was £1,458.

Back in 2013-14, the average cost was around £450 more per kW.

Prices vary during the year. For example, between May 2019 and April 2020, prices per kW were highest in July and lowest in November, according to BEIS. This doesn't mean that solar panels are always pricier in the summer though. Two years earlier (in 2017), the cheapest point in the year was July. We recommend you get three quotes before you buy, so you have a good idea of the going rate for your installation.

Get paid to generate renewable electricity with solar panels

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).

All firms with more than 150,000 customers have had to offer an SEG tariff since the beginning of 2020. Some smaller firms choose to offer SEG tariffs too. 

Find out about the Smart Export Guarantee, including how much you could earn.

The SEG replaces the government’s Feed-in Tariff (FIT) scheme. This incentivised people to buy solar panels by paying them both for the electricity they generated and any excess they exported to the grid. It closed to new applicants in March 2019.

To find out more about what the FIT was, including how much money you can make if you're already signed up, read our guide to the Feed-in Tariff

Solar panel cost calculations

To calculate average purchase and installation costs, 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. 

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

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? also conducted an online survey in May 2019 with 1,987 Which? Connect members who have solar panels.