Quick answer: A typical 4kW solar panel system costs £7,000–£9,500 installed in the UK in 2026. The actual price depends on three key factors: your system size, whether you include a battery, and who installs it. We break down real prices, payback periods, and show you exactly what you'll actually pay.
Solar panel costs have become increasingly transparent in 2026, and it's now easier than ever to get a genuine installed price before speaking to a single salesman. If you're considering solar for your home, you need to understand the price breakdown — because there's a big difference between a 4kW system and a 6kW system, and an even bigger difference when you add a battery.
In this guide, we'll show you the exact prices you can expect, explain what affects the cost, and help you work out whether solar makes financial sense for your home.
Solar Panel System Prices UK 2026 — Complete Price Table
These prices are based on SolarFoundry's current verified pricing and represent genuine, installed costs including all labour, certification, and warranty:
| System Size | No. of Panels | Price Without Battery | Price With Battery |
|---|---|---|---|
| 3kW | 8 panels | £5,800 | On request |
| 4kW | 10 panels | £7,000 | £10,000 (5kWh) |
| 6kW | 14 panels | £8,500 | £11,500 (5kWh) / £13,000 (10kWh) |
| 8kW | ~20 panels | On request | £14,000 (10kWh) |
| 10kW | ~25 panels | On request | £16,500 (10kWh) |
All prices include: solar panels and inverter, full installation labour, MCS certification, DNO registration, 10-year workmanship warranty, and 25-year manufacturer warranty on panels.
These prices assume standard roof conditions. Additional costs like scaffolding are included in most professional installations — always confirm with your installer.
What Affects the Cost of Solar Panels?
1. System Size (kW)
This is the biggest cost driver. A 3kW system costs roughly 30% less than a 6kW system. Your ideal system depends on your roof space and electricity usage.
2. Battery Inclusion
Adding a 5kWh battery typically adds £3,000–£3,500. A battery isn't essential, but it dramatically increases the percentage of solar electricity you use yourself rather than exporting at the lower SEG rate.
3. Roof Type and Accessibility
A straightforward south-facing tiled roof costs less than a slate or flat roof. If scaffolding is needed, it's typically included. Roof repairs needed before installation add £500–£2,000 depending on damage.
4. Regional Labour Costs
Labour rates vary slightly across the UK. Scotland and the North can be £300–£500 cheaper than London and the South East, though MCS-certified installers maintain fairly consistent pricing.
5. Equipment Brand
Premium inverters (SMA, Fronius) may cost up to £500 more. Panel quality matters — always ask for tier-1 brands with 25-year product warranties as a minimum.
Are Solar Panels Worth It in 2026?
With Ofgem's electricity import rate at 24.5p/kWh in Q2 2026, solar makes strong financial sense for most UK homeowners. Here's a real example:
4kW system in South England, with battery:
- Annual generation: approximately 3,500 kWh
- With battery (75% self-consumed): 2,625 kWh saved from imports
- Savings on imports: 2,625 × £0.245 = £643
- Plus SEG export earnings: approximately £80–£120/year
- Total annual saving: £720–£760
- Payback period (with battery): 12–13 years
- System lifespan: 25+ years
- Profit after payback: approx. £9,000–£9,600 over remaining life
Hidden Costs to Watch For
Scaffolding: Good installers include this. Always ask: "Is scaffolding included?" Budget installers sometimes charge £300–£600 separately.
DNO Application: Required for systems over 10kW. Most MCS installers handle this as standard — confirm it's included before signing.
Roof Repairs: Missing tiles, damaged flashing, or structural issues must be fixed before installation. Budget £200–£2,000+ depending on damage.
Battery Replacement: A 5kWh battery typically lasts 10–12 years. Future replacement cost: £3,000–£4,000. Factor this into your long-term calculations.
How to Get the Best Price on Solar in 2026
Get 3+ quotes: You'll often see variations of £1,000–£2,000 on the same specification. Outliers that are significantly cheaper usually mean lower-quality equipment or missing warranty coverage.
Verify MCS Certification: You need an MCS certificate to claim SEG export payments. Always verify the installer's MCS number on the official register before signing anything.
Watch for "too cheap": Signs of a poor-quality quote include no workmanship warranty, budget unknown-brand equipment, and high-pressure sales tactics. A reputable installer won't undercut the market by more than 10–15%.
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