BY SYSTEM SIZE GUIDE
10kW Solar System 2026: Cost, Output & What to Expect
A 10kW solar system costs £9,000 to £14,000 fully installed in 2026 and generates roughly 8,500 to 9,500 kWh a year in the UK.
A 10kW solar system costs £9,000 to £14,000 fully installed in 2026 and generates roughly 8,500 to 9,500 kWh a year in the UK.
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A 10kW solar system costs £9,000 to £14,000 fully installed in 2026 and generates roughly 8,500 to 9,500 kWh a year in the UK. It needs around 50 to 60 square metres of unshaded roof and around 22 to 26 panels. There's no direct grant for solar, but 0% VAT runs until March 2027 and the Smart Export Guarantee pays you for surplus electricity. Payback typically lands at 8 to 11 years.
A 10kW system can run a large family home, a small business, or a home with an EV and a heat pump. That's the headline. The fuller picture is more interesting.
In UK conditions, a 10kW array produces around 8,500 to 9,500 kWh per year, depending on roof orientation, pitch, and where you live. A south-facing roof in Cornwall will outperform a south-east facing roof in Aberdeen by maybe 15%. The average UK home uses around 2,700 kWh of electricity a year, so a 10kW system generates roughly three to four times that.
Which means most homes don't actually need 10kW. We'll come back to that.
Where 10kW makes genuine sense:
If you're a couple in a three-bed semi with a gas boiler and one car, a 10kW system is almost certainly oversized. See our guide on small businesses, farms, or workshop operations for more detail. A 4kW or 5kW system will serve you better and cost less.
Expect to pay £9,000 to £14,000 fully installed, with most quotes landing around £11,000 to £12,500.
Here's how that breaks down for a typical install:
| Component | Typical cost |
|---|---|
| Panels (22 to 26 x 400-450W) | £3,500 to £5,500 |
| Inverter (10kW string or hybrid) | £900 to £1,800 |
| Mounting, cabling, DC isolators | £600 to £1,000 |
| Labour and scaffolding | £2,500 to £4,000 |
| DNO application, commissioning, MCS certification | £400 to £700 |
| Battery storage (optional, 10kWh) | £4,500 to £7,000 |
A few things drive the spread. Tier-1 panel brands like REC, LG, or Sunpower add £1,000 to £2,000 over budget options like Trina or Jinko. A hybrid inverter (which lets you add a battery later) costs around £400 more than a basic string inverter, and we think it's nearly always worth it. Scaffolding for a complex roof, or an installation that needs a DNO (Distribution Network Operator) approval for export over 3.68kW per phase, can push the bill up.
One genuinely good news bit: 0% VAT on domestic solar installations runs until 31 March 2027. On a £12,000 system that's a saving of around £2,000 versus pre-2022 pricing. If your installer charges you 20% VAT on a residential install before that date, challenge it.
Battery costs have come down sharply since 2023, but a 10kWh battery still adds £4,500 to £7,000. Whether it's worth it depends entirely on your usage pattern, which is the topic of another article. See our guide on 10kWh battery still adds significant cost for more detail.
Probably not, if you're a typical UK household. Here's the honest bit.
Around 70% of domestic solar installs in the UK are between 3kW and 6kW. The 10kW bracket is dominated by larger properties, commercial sites, and homes with significant electrification (heat pump, EV, or both).
The rule of thumb we use:
A 10kW array also needs serious roof space. Around 50 to 60 square metres of unshaded south, south-east, or south-west facing roof. That's typically the entire main roof slope on a four-bed detached. If you've got a chimney, a velux window, or a TV aerial in the way, you might struggle to fit the panels.
The other consideration is your DNO. Most UK domestic supplies are single-phase, which caps inverter export at 3.68kW without DNO approval. A 10kW system will almost always need DNO sign-off for higher export, which is fine but adds two to six weeks to your install timeline. Three-phase properties (more common in rural areas and businesses) avoid this bottleneck.
Oversizing is a real risk. If you generate 9,000 kWh and only use 3,000 kWh at home, you're exporting 6,000 kWh at maybe 15p per kWh while paying retail prices of 25p per kWh for electricity in the evening. The economics work, just not as well as they would with a properly sized system.
Most 10kW system owners save £900 to £1,600 per year on bills, with another £500 to £1,000 from export income.
The maths depends on three things: how much you generate, how much you use directly during daylight hours (self-consumption), and what your supplier pays for export.
A worked example for a four-bed home with a heat pump and EV:
At a £12,000 install cost, that's a payback of roughly 7 years. Strong returns.
Now the same system on a couple's home with gas heating and no EV:
Payback closer to 8 years. Still solid, but you're effectively running an export business with your roof rather than slashing your own bills.
The big variable is export tariff. Octopus Energy pays 15p per kWh on Outgoing Fixed. British Gas pays around 12p. Some legacy suppliers offer as little as 3p. Before you sign anything, check current SEG rates and pick a supplier accordingly. We've seen homeowners stay loyal to a 4p tariff for years out of inertia, costing themselves £400+ annually.
Battery storage shifts the maths significantly. A 10kWh battery roughly doubles self-consumption (from 30% to 60%+) for most homes, which is more valuable than export income because you're displacing 27p electricity rather than earning 15p. Whether the £5,000+ battery cost is worth that uplift depends on your specific usage pattern. Honestly, this one depends on your situation and we can't give you a straight answer without seeing your half-hourly consumption data.
There's no direct grant for a 10kW solar system, but three schemes can cut the cost or improve the returns.
The first is 0% VAT. As above, this runs until 31 March 2027 and saves around £2,000 on a typical install. Not a grant, but worth flagging because some installers still quote with VAT included by mistake.
The second is the Smart Export Guarantee. Every licensed energy supplier with over 150,000 customers must offer an export tariff. You sign up with one supplier (doesn't have to be your import supplier), they install an export-capable smart meter if you don't have one, and you get paid for surplus generation. The rates are commercial and competitive, with Octopus, EDF, and E.ON leading in 2026.
The third is ECO4, and this one's quirky. ECO4 doesn't fund solar directly, but if you're eligible (means-tested benefits, EPC rating of D or below), some installers will bundle solar into a wider package alongside funded insulation and heating measures. The solar itself usually isn't free, but the combined package can be heavily subsidised. ECO4 closes 31 December 2026, so the window is narrowing.
What about the Warm Homes: Local Grant? It varies by local authority, and a few councils have started funding solar within wider home energy upgrades. Cornwall, Bristol, and several Welsh councils have run schemes that include solar. Worth checking your council's current offer before assuming there's nothing.
What you can't get: the free solar panel schemes you've seen advertised on Facebook. Those are rent-a-roof deals where a company installs panels at no cost to you but keeps the generation income for 20+ years. You pay nothing upfront, but you also save nothing meaningful. We'd avoid them.
If you're not sure what you qualify for, the eligibility checker takes two minutes and runs your details against every current scheme.
Use MCS-certified installers only. Anything else and you can't claim the Smart Export Guarantee or sell your home with confidence.
MCS (Microgeneration Certification Scheme) is the industry standard for renewable installations in the UK. An MCS install gives you a certificate, a warranty backed by a code-of-conduct body (HIES or RECC), and a 25-year performance warranty on panels and 10-year on workmanship. Without MCS, you can't register for SEG payments. Full stop.
Beyond MCS, here's what we look for:
We've also seen homeowners get burned by long warranty periods that turn out to be worthless because the installer goes bust. A 25-year warranty from a one-man-band trader isn't worth the paper it's printed on. Check Companies House, look for businesses trading for 5+ years, and read recent reviews on Trustpilot (not just the installer's own website testimonials).
One more thing. Get your roof checked before you commit. A surveyor can spot structural issues for £200 to £400, which is cheaper than discovering mid-install that your rafters won't take the load. Most installers do this as part of their pre-install survey, but make sure it's happening.
Ready to compare quotes? Start with the eligibility checker to see which grants and tariffs apply to your situation, then approach three MCS installers with that information in hand.
Common questions