Key figures 4kW system: £5,500-£7,000 installed Annual saving: £680-£960 Payback: 6-9 years All prices include 0% VAT

Solar panel prices in the UK have dropped significantly over the last five years. A typical 4kW system (the most common size for UK homes) now costs between £5,000 and £7,000 fully installed, including 0% VAT. That is roughly 20% less than in 2022.

With electricity prices still well above pre-2021 levels, the payback period for solar panels in the UK is now shorter than ever. In this guide, we break down the real costs, savings, and payback periods for solar panel installations in 2026.

Prices checked: July 2026.

Solar Panel Prices by System Size

System Size Number of Panels Typical Annual Generation Installed Price (0% VAT)
3kW 7-8 panels 2,550 kWh £4,500-£5,500
4kW 10-11 panels 3,400 kWh £5,500-£7,000
5kW 13-14 panels 4,250 kWh £7,000-£8,500
6kW 15-16 panels 5,100 kWh £8,500-£10,500
8kW 20-22 panels 6,800 kWh £11,000-£14,000

Generation estimates assume a south-facing roof in southern England with no shading. Prices include 0% VAT. Updated July 2026.

What Is Included in the Installed Price

  • Solar panels (typically 420W-450W each in 2026)
  • String inverter (or microinverters for premium installs)
  • Roof mounting system
  • Cabling and isolation switches
  • Scaffolding
  • Installation labour
  • VAT at 0%
  • MCS certification paperwork
  • DNO notification

What Is Extra

  • Battery storage: £2,500 to £9,000 extra depending on size
  • Bird-proofing (mesh around panel edges): £200-£400
  • EV charger: £800-£1,500
  • Complex roof scaffolding (tile, slate, high pitch): £300-£600

Solar Panel Prices by Brand

Panel Brand Panel Wattage Price per Panel Typical 4kW System Cost
JA Solar 430W-450W £120-£160 £5,500-£6,500
Longi 430W-450W £110-£150 £5,500-£6,500
Trina Solar 430W-450W £130-£170 £5,800-£6,800
Canadian Solar 430W-450W £130-£180 £5,800-£7,000
SunPower 420W-440W £250-£350 £7,500-£9,000
REC 420W-440W £200-£300 £7,000-£8,500

Premium panels (SunPower, REC) are more efficient per square metre and come with longer warranties (25-40 years), but cost significantly more. For most UK homes, mid-range panels from JA Solar, Longi, or Trina offer the best value.

Inverter Types and Costs

Inverter Type Typical Cost Pros Cons
String inverter £500-£1,200 Cheapest option, simple Single point of failure, shading affects whole string
Microinverters £1,500-£2,500 Panel-level optimisation, no single failure point More expensive, more components
Hybrid inverter £1,200-£2,000 Works with solar + battery, future-proof More expensive than string inverter alone
Optimisers £400-£800 Added to string inverter for shading mitigation Mid-range cost, improves string inverter performance

If you plan to add a battery later, a hybrid inverter now saves you replacing the inverter later. If you have shading on part of your roof, microinverters or optimisers prevent the shaded panel from dragging down the whole array.

Savings and Payback

Estimated Annual Savings

System Size Annual Generation Saving on Bills (50% self-use) SEG Export Income (at 15p/kWh) Total Annual Value
3kW 2,550 kWh £320 £190 £510
4kW 3,400 kWh £425 £255 £680
5kW 4,250 kWh £530 £320 £850
6kW 5,100 kWh £640 £380 £1,020

Calculated at 25p/kWh electricity (current GB price cap rate) and 15p/kWh SEG export. Savings assume you are home during the day or have a battery to store excess generation.

Payback Period

System Size Installed Price Annual Value Payback Period
3kW £5,000 £510 ~10 years
4kW £6,000 £680 ~9 years
5kW £7,500 £850 ~9 years
6kW £9,500 £1,020 ~9 years

Solar panels are warrantied for 25-30 years and typically last longer. Even with a 9-10 year payback, you get 15-20 years of free electricity.

Battery Storage With Solar

Adding a battery roughly doubles the usable solar energy. Without a battery, you use about 30-40% of your solar generation directly. With a battery, that figure rises to 70-80%.

Setup Installed Price Annual Value Payback
4kW solar only £6,000 £680 ~9 years
4kW solar + 5kWh battery £9,000 £850 ~10.5 years
4kW solar + 10kWh battery £12,000 £950 ~12.5 years

See our battery storage guides for detailed pricing on specific battery sizes and brands.

Solar Panel Grants and Support

  • 0% VAT on solar panel installations (automatic, no application needed)
  • Smart Export Guarantee (SEG) — your supplier pays you for exported electricity (rates vary from 5p to 15p per kWh)
  • ECO4 — fully funded solar panels (and sometimes batteries) for low-income households
  • Home Upgrade Grant (HUG) — for off-gas-grid homes in England

There is no direct government grant for solar panels for the average homeowner in 2026, though 0% VAT saves you roughly £1,200 on a typical 4kW installation.

Frequently asked questions

For most UK homes with a south-facing or east/west roof, yes. Payback is typically 8-12 years and panels last 25-30 years. With current electricity prices, a 4kW system saves roughly £680 per year.

A 3-bedroom house typically installs a 3.5kW to 4kW system, costing £5,500 to £7,000 fully installed. This covers roughly 50-60% of the home's annual electricity usage.

Solar panels are permitted development in most of the UK. You do not need planning permission unless your home is listed or in a conservation area. Always check with your local council.

Solar panels typically produce 80-85% of their original output after 25 years. Most manufacturers offer a 25-year performance warranty. The inverter typically needs replacing after 10-15 years at a cost of £500 to £1,500.

The ECO4 scheme can fully fund solar panels for low-income households receiving certain benefits. For most homeowners, there is no "free solar" scheme — ignore companies offering "free solar panels" as they typically involve a lease or PPA agreement.

A typical 4kW system saves £50 to £70 per month on electricity bills, plus £20-£30 per month from SEG export payments, for total savings of roughly £70-£100 per month.

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