A typical UK home pays roughly £6,000 to £8,000 for a 4 kW rooftop solar system in 2026. That price includes the panels, the inverter, scaffolding, fitting and the paperwork. A battery adds several thousand pounds on top, however, so decide early whether you want one. Your own quote will depend on your roof, your electricity use and the installer.

Prices have fallen a lot in the last two years. Yet they are not the same for every house, because every roof is different. This guide explains what you pay for, what 0% VAT does, and how to compare quotes without getting confused.

What the official figures say

The best public figures come from the Department for Energy Security and Net Zero (DESNZ). It collects cost data from the MCS installation database, since every certified install gets logged there. For April 2025 to March 2026, the median price for systems up to 4 kW was £1,595 per kW, according to the DESNZ solar PV cost data published on 28 May 2026. That works out at about £6,400 for a 4 kW system. Systems of 4 to 10 kW cost a little less per kW, at £1,546.

DESNZ says that, after allowing for inflation, the median cost per kW fell by 7% for systems up to 4 kW in 2025/26, and by 9% for 4 to 10 kW systems. Which? also quotes the Energy Saving Trust, which puts a typical 4.5kWp system at around £7,600. You can read more in the Which? solar panel cost guide.

These are medians, so half of all installs cost more and half cost less. A fair range for a 4kW home system in October 2026 is about £6,000 to £8,000, but always check it against fresh quotes.

What drives the price up or down

Several things move the total, and knowing them helps you spot a quote that is out of line.

System size

Bigger systems cost more in total. They cost less per kW, because the fixed costs are shared. Scaffolding, for instance, costs about the same for 3kW as for 5kW. Our guide to how many panels you need shows how to pick a size that matches your use.

Roof type and access

A simple south-facing pitched roof is the cheapest to fit. Complex roofs, several roof faces or poor access cost more. Split east and west arrays and flat roofs need extra kit. Read about east-west and flat roof solar before you compare quotes for these.

Our roof and property suitability guide covers the checks that affect price, such as shading, pitch and roof condition.

Panels, inverter and extras

Better panels and inverters cost more, but they can also carry longer warranties. Optimisers, a battery, a diverter or an EV charger all add to the bill. Ask for each item to be priced separately, so you can see what you are paying for.

Location and installer

Labour costs differ across the UK. Larger installers often charge more than small local firms, although not always. Quote prices vary widely, which is why you need several.

What 0% VAT saves you

Installing solar panels and batteries in a home currently carries 0% VAT. The zero rate runs until 31 March 2027. It began on 1 April 2022 in Great Britain and on 1 May 2023 in Northern Ireland, according to HMRC’s VAT Notice 708/6. After that, the rate is due to revert to 5%.

On a £7,000 system, 5% would add about £350. That is not huge, yet it is real money. The relief only applies when the supplier installs the kit. If you buy panels without installation, the supply is standard-rated. Our post on 0% VAT explains the rules and the deadline in more detail.

Cost against savings

A price only means something next to what the system saves. A 4kWp system can generate around 3,400kWh a year, according to the Energy Saving Trust solar calculator. The saving depends on how much of that power you use yourself. For example, a home that is empty all day uses less, so it exports more.

The money you earn on exports is lower than the money you save on imports. Our Smart Export Guarantee guide covers rates. Still, the sums can work if the system pays back well before the end of its life. Because the answer differs for each home, work it out with your own bills.

When to buy

The VAT change is the one deadline you can see. If your install finishes before 31 March 2027, you should pay 0%. Installers are likely to get busy as that date nears, so book early rather than rush at the end. However, do not let a deadline push you into a poor deal. A rushed choice costs more than 5% VAT.

Paying for it

Most people pay cash or take a loan. First, check your own savings and your credit options. Then check what help exists. The government’s Warm Homes Loan Scheme rules (September 2026) set an initial consumer launch from September 2026, through participating lenders. Products and rates come from the lenders, so compare the total cost before you borrow. Treat any “government loan” pitch with care.

Costs people forget

Your quote should cover the main work. Check that it also includes these items.

  • Scaffolding and roof access.
  • The MCS certificate, which you need to sell power back under the Smart Export Guarantee.
  • Notifying your network operator.
  • A smart export meter, if you do not have one.
  • A warranty for the panels, the inverter and the workmanship.

Running costs are low. Panels need little care, as our guide to cleaning and maintaining solar panels explains. The inverter often needs replacing once during the life of the system, so ask what that would cost. Our maintenance and lifespan guide covers what to expect over the years.

Most homes do not need planning permission, but a few do. Check the rules in our planning permission post before you sign anything.

How to compare quotes

Get at least three quotes. Then put them side by side on the same basis.

  1. Compare cost per kW, not just the total price.
  2. Check the make and model of every panel and inverter.
  3. Ask who does the work and who handles any problems later.
  4. Confirm the installer holds MCS certification.
  5. Read the warranty terms.

Our guide to choosing a solar installer goes through each step. The questions to ask a solar installer post gives you a list to take to each visit.

Be wary of firms that push you to sign on the day. You lose nothing while you take time to compare, and you still have months before the VAT change.

Is a cheap system a good deal?

Not always, because a low quote can mean cheaper kit, less scaffolding or fewer extras. It can also mean a bargain. The way to tell is to compare like with like.

What matters in the end is the payback. A system that costs £7,000 and saves you £600 a year pays back faster than one that costs £6,000 and saves you £400. Our post on whether solar panels are worth it shows how to work this out for your own home.

Some households can get help with the cost. The grants and funding guide lists what is open in each UK nation. Be careful with adverts for “free” panels. Our explainer on free solar panel schemes separates the real schemes from the risky ones.

Overall, set your budget, get three itemised quotes, and choose on value rather than the lowest price. The costs and savings guide pulls the numbers together in one place.

Sources

Common questions

How much does a 4kW solar panel system cost in the UK?

Government data for 2025/26 puts the median at about £1,595 per kW for systems up to 4 kW, or roughly £6,400 for a 4 kW system. Energy Saving Trust gives about £7,600 for a typical 4.5 kW system. Expect most quotes in the region of £6,000 to £8,000, and ask questions about anything far outside that range.

Do I pay VAT on solar panels?

Not at the moment. Installing solar panels and batteries in a home is zero-rated for VAT until 31 March 2027. From 1 April 2027 the rate is due to go back to 5%.

Is a more expensive system always better?

No. A higher price can reflect better panels, a stronger inverter or a harder roof. It can also reflect a pushy sales team. Compare the kit, the warranty and the cost per kW, not just the total.

Can I get solar panels for free?

Some low-income households can get fully funded installations through schemes such as the Warm Homes: Local Grant in England or Nest in Wales. Most other offers of free panels come with strings attached.