Average Cost of a Solar Panel System in 2026 (UK)
The average cost of a solar panel system in 2026 is about £6,500–£9,000 for a typical UK home — a 4–5 kWp array fully installed. Add battery storage and a typical system runs to £11,000–£16,000. Small systems start near £5,000 and larger 6 kWp+ arrays reach £12,000. With 0% VAT on domestic solar until March 2027 and payback in 7–12 years, this insight breaks down what a system really costs and what moves the price.
Solar panel system cost by size — 2026
Fully installed, 0% VAT applied. Source: BestBuilders 2026 quote data · 519 UK towns
Solar panel system cost by size (2026)
System cost scales mostly with the number of panels (the array size in kWp) and whether you add a battery. These are typical fully-installed 2026 prices with 0% VAT applied.
| System size | Panels (approx.) | Typical installed cost | With 5kWh battery |
|---|---|---|---|
| 3.5 kWp (small home) | 8–9 | £5,000–£7,000 | £7,500–£11,000 |
| 4.5 kWp (typical 3-bed) | 10–12 | £6,500–£9,000 | £9,500–£13,500 |
| 6 kWp (larger home) | 14–16 | £8,500–£12,000 | £11,500–£16,500 |
| 8 kWp+ (large / high-use) | 18–22 | £11,000–£15,000 | £14,500–£20,000 |
For a live, itemised quote on your roof, use our solar panels cost and battery storage cost pages — they carry the quote widget and up-to-date pricing for your area.
What drives the price
| Factor | Effect on cost | Notes |
|---|---|---|
| System size (kWp) | Largest single driver | More panels, more inverter capacity, more mounting and labour |
| Panel quality | £500–£2,000 | Premium mono panels and higher efficiency cost more per watt |
| Battery storage | +£2,000–£5,000 | Depends on capacity (kWh) and brand |
| Roof type & access | £300–£1,500 | Scaffolding, roof pitch, tile type, multiple facets |
| Electrical works | £200–£900 | Consumer-unit upgrade, bird protection, optimisers |
With or without a battery?
A battery is the biggest optional cost and the one most people agonise over. Panels alone are the cheaper, faster-payback option: you use what you generate during the day and export the rest for a Smart Export Guarantee (SEG) payment. A battery stores your daytime surplus for the evening, pushing self-consumption from around 35–50% up to 70–85%. That is worth most if you are out during the day, on a time-of-use tariff, or charging an EV. It adds £2,000–£5,000 and typically lengthens payback by a few years, so it is a lifestyle and tariff decision as much as a financial one. Batteries can also be retrofitted later, so it is fine to start with panels and add storage when a tariff makes it pay.
Payback and savings
A typical 4–5 kWp system saves a UK household roughly £400–£900 a year on electricity, plus SEG export income of perhaps £80–£250 a year depending on your export rate and how much you send back to the grid. That puts most systems on a 7–12 year payback. Because panels are warrantied for around 25 years and inverters for 10–12, the array keeps earning long after it has paid for itself. The single biggest lever on your return is self-consumption — the more of your own generation you use rather than export, the faster the payback. Running the dishwasher, washing machine and EV charger during daylight hours is free money.
What's included — and what isn't
A full solar quote should include the panels, inverter, mounting, cabling, scaffolding, installation, commissioning, an MCS certificate and your Building Control notification. Watch for items that are sometimes excluded or extra:
- Battery storage — often quoted as a separate line; confirm capacity in kWh, not just price.
- Scaffolding — usually included, but check for complex or high roofs.
- Consumer-unit or fuse-board upgrade — needed on some older installations.
- Bird protection — mesh around the array; cheap now, costly to add later.
- An EV charger or solar diverter — see our solar diverter guide for using surplus to heat water.
How long the install takes
A straightforward roof-mounted system is usually installed in 1–2 days once scaffolding is up, with commissioning and paperwork following shortly after. Adding a battery adds around half a day. From accepting a quote, most homeowners are generating within 4–8 weeks, the lead time driven mainly by scaffolding, the installer's diary and your Distribution Network Operator (DNO) notification for larger systems.
Planning permission and MCS
Planning: roof-mounted panels on a house are usually permitted development, provided they don't project more than 200mm from the roof plane and you are not in a conservation area or a listed building. Flats, ground-mounted arrays and some protected areas need a planning application — always confirm with your local planning authority first.
MCS matters for your money. To claim Smart Export Guarantee (SEG) payments for the electricity you export, your system must be installed by an MCS-certified installer. It's worth asking any installer to show their MCS certification and checking them on the MCS register before you sign — it's both a quality signal and a requirement for export income. Every installation must also be notified to Building Control and your DNO.
Choosing an installer: what to check
These are checks you make before hiring. BestBuilders vets the trades in our network, but confirm the following yourself:
- Ask to see MCS certification and check the installer on the MCS register — it's required for SEG payments.
- Ask for proof of public liability insurance and confirm the cover level is current.
- Get the quote to state panel and inverter make, model and wattage, plus battery capacity in kWh if included.
- Ask for a realistic generation and savings estimate based on your roof, not a best-case headline.
- Check the workmanship and product warranties in writing — panels ~25 years, inverter 10–12.
- Get three like-for-like quotes on the same system size so the numbers are comparable.
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