How Much Do Solar Panels Cost

How Much Do Solar Panels Cost?

According to InstantCost.co.uk's 2026 UK pricing data, a 4kW solar system, the most common size installed in British homes, costs £5,500 to £7,500 fitted. Smaller 3kW systems run £4,500 to £6,000, and larger 5 to 6kW systems £7,000 to £10,000. There's no VAT on domestic solar installations in the UK, so those figures are what you actually pay rather than a pre-tax starting point.

What those headline numbers don't show is where the money goes, and that breakdown is genuinely useful when you're comparing quotes.

Cost by System Size

Where the Money Actually Goes

On a typical installation, InstantCost's component breakdown looks like this:

Two things stand out here. The panels themselves account for well under half the total on most systems, which is why comparing quotes purely on panel brand misses most of the picture. And the inverter, at £588 to £865, is a substantial component that also happens to be the part most likely to need replacing before the panels do, since panels are typically warranted for 25 years while inverters generally aren't.

Battery Storage Costs

Batteries are the single biggest add-on decision, and they change the economics in both directions, which is covered properly below.

What You Actually Save

A 4kW system generates roughly 3,400 kWh a year in UK conditions. If you use about half of that in the home and export the rest, you save around £550 to £750 a year at 2026 prices, giving a payback of roughly 9 to 12 years.

Add a battery and annual savings rise to around £850 to £1,100, because you're using around 75% of what you generate rather than 50%. But payback stretches to 11 to 14 years, because the battery cost is added to the total. More savings, longer to break even.

These figures assume 27p per kWh import, 15p per kWh export under the Smart Export Guarantee, a south-facing unshaded roof, and those self-consumption rates. Change any of those and the numbers move, which is worth remembering when comparing any installer's projection.

Is a Battery Worth It?

The honest answer depends entirely on when you use electricity. If you're home in the evenings or on a time-of-use tariff, a battery converts electricity you'd have exported at 15p into electricity you use at 27p, and the numbers work reasonably. If you're out all day and use little after dark, the battery costs £2,500 to £7,000 to solve a problem you don't really have, and it drags payback without proportionate benefit.

Worth deciding on usage patterns rather than assuming a battery is simply the better version of a solar installation.

What Moves the Price

Roof direction affects output more than cost. South-facing is the benchmark, east or west loses roughly 15% of generation, and north-facing rarely pays at all.

Roof material affects cost rather than output. Slate and flat roofs are more expensive to work on than plain tile.

Scaffolding at £500 to £1,000 is almost always required on two-storey homes, and is a genuine line item worth confirming is included rather than added later.

Property size and system size obviously scale together, but the more useful question is matching system size to your actual electricity consumption rather than to available roof space.

Regional Variation

InstantCost's calculator example for Manchester and Liverpool puts a full system at £4,903 to £7,210 including battery, which gives a useful sense of how a real regional quote breaks down against the national ranges. As with most trades, London and the South East typically sit at the higher end.

Can You Get Solar for Free?

Some low-income households qualify for funded solar under ECO4, which runs to 31 December 2026. Everyone else pays privately, though the absence of VAT on domestic solar is a meaningful built-in saving.

ECO4 sits alongside several other UK energy support schemes that are frequently confused with each other, and it's worth understanding which is which before assuming you don't qualify for anything. Our related guide covers the Warm Home Discount Scheme and how it differs from the Warm Homes Plan, since the two have genuinely different eligibility criteria, application routes, and levels of support despite the similar names.

Planning Permission

Roof-mounted panels are permitted development on most UK homes, so no planning permission is needed. Listed buildings and conservation areas are the main exceptions, worth checking with your local authority before committing.

Common Mistakes and What to Do Instead

Mistake: comparing quotes on panel brand alone. Panels are under half the total cost on most systems. The inverter, scaffolding, and installation labour together often exceed the panel cost.

Mistake: adding a battery without checking your usage pattern. It raises annual savings but extends payback by two to three years. Only worth it if your consumption is genuinely evening-weighted.

Mistake: sizing to roof space rather than electricity usage. Generating more than you can use or store means the surplus earns 15p rather than saving you 27p.

Mistake: not confirming scaffolding is included. At £500 to £1,000 on most two-storey homes, this is a substantial cost that's sometimes quoted separately.

Mistake: accepting a savings projection without its assumptions. A figure assuming 75% self-consumption on a household that's out all day isn't a forecast, it's a best case. Ask what import, export, and self-consumption rates were used.

Mistake: budgeting as a one-off cost. Panels last around 25 years, inverters typically don't. Factor a replacement inverter into long-term projections.

Getting a Fair Quote

Ask for a component-level breakdown rather than a single figure, since that's the only way to see whether a cheaper quote reflects better value or a smaller inverter and thinner installation scope. Confirm the inverter model and its warranty length specifically. Check whether scaffolding is included. Ask what self-consumption rate underpins any savings figure you're shown. And get three quotes, since the spread on identically-specified systems can be substantial.

What It Costs in the UK: Quick Reference

All figures based on InstantCost.co.uk's 2026 UK solar pricing data. Savings assume 27p per kWh import, 15p per kWh export under SEG, a south-facing unshaded roof, and 50% self-consumption without a battery or 75% with one.

Staying Safe

Use an MCS-certified installer rather than a general builder. This matters practically as well as for safety, since Smart Export Guarantee payments generally require an MCS-certified installation, so using an uncertified installer can cost you the export income that forms part of your payback calculation.

Solar installation combines working at height with electrical work connecting to your consumer unit, both of which warrant proper certification. Never attempt roof-level maintenance or cleaning yourself from a ladder.

Grant eligibility and export tariff rates change periodically, so confirm current ECO4 criteria and SEG rates before building them into your financial planning.

FAQ

How much do solar panels cost in the UK in 2026? A 4kW system, the most common size, costs £5,500 to £7,500 fitted. A 3kW system costs £4,500 to £6,000 and a 5 to 6kW system £7,000 to £10,000, with no VAT on domestic installations.

How much does adding battery storage cost? A 5kWh battery adds £2,500 to £4,000 and a 10kWh battery £4,500 to £7,000 installed. It raises annual savings but extends payback by roughly two to three years.

How long until solar panels pay for themselves? Around 9 to 12 years for panels alone, or 11 to 14 years with a battery, based on 27p per kWh import and 15p export. Panels are typically warranted for 25 years.

What's the biggest single cost in a solar installation? The panels, at £2,059 to £3,028 on a typical system, though they still account for under half the total once the inverter, scaffolding, and installation labour are included.

Can I get solar panels for free in the UK? Some low-income households qualify under ECO4, which runs to 31 December 2026. Everyone else pays privately, though there's no VAT on domestic solar installations.

Do I need scaffolding, and is it included in quotes? Two-storey homes almost always need it, adding £500 to £1,000. It's sometimes quoted separately, so confirm specifically whether your quote includes it.