We use cookies to allow us and selected partners to improve your experience and our advertising. By continuing to browse you consent to our use of cookies. You can understand more and change your cookies preferences here.

Coronavirus Read our latest advice
Reviews based on facts
Our rigorous tests find the facts, and our impartial reviews tell you the truth about how products perform. First month £5, then £9.99 per month, cancel anytime.
Try Which?
1 October 2020

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 to buy solar panels. 
Solar panels 7 446487
Sarah Ingrams

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 the best and worst solar panel brands.

Solar panel cost by system size
System size Average cost
1kWp  Join Which? to reveal
2kWp  Join Which? to reveal
3kWp  Join Which? to reveal
4kWp  Join Which? to reveal
5kWp  Join Which? to reveal
Data from RICS and correct at September 2019.

The more electricity the system can generate, the higher the savings on your energy bill will be – but the bigger the initial cost is.

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 survey of Which? members who have solar panels in May 2019.

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)  Join Which? to reveal
Medium (3,500kWh)  Join Which? to reveal
High (5,000kWh)  Join Which? to reveal
Data from RICS and correct at September 2019.
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.

Because these prices are averages, you should get quotes from solar panel companies. Three quotes will allow you to compare their latest prices for your specific system and home.

Solar tiles, which are part of the roof rather than fitted on top of it, are becoming more popular. These are more expensive than conventional solar panels. Find out more about how does solar PV work?

Are solar panels getting cheaper?

Solar panel prices have dropped since 2011, but become more consistent over the past couple of years.

Before 2015, the average paid for a 3.6-4kWp solar panel system was more than £9,000, according to our survey of Which? members. Between 2015-2018, the average cost was closer to £6,600.

But statistics published by the government's Department for Business, Energy and Industrial Strategy in May 2019 show the cost per kilowatt of solar PV installed stayed fairly consistent between April 2017 and March 2019. It fell by around £200 between 2014 and 2016.

The government’s Feed-in Tariff (FIT) scheme incentivised people to buy solar panels by paying them for the electricity they generated and any excess they exported to the grid. As the cost of buying solar panels dropped, so did the rates paid by the FIT.

The FIT scheme closed to new applicants in March 2019. By the end of 2019, big energy companies will have to offer a Smart Export Guarantee (SEG) tariff instead. But, so far, very few companies are offering one.

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. Or find out about the new Smart Export Guarantee.

Solar panel cost calculations

To calculate the 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.

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

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