The short answer
For most UK homes with a decent south-ish roof, solar is worth it in 2026 — payback lands around 7–10 years and the panels keep going for 25+. Add a battery and you'll use far more of your own power, but you'll stretch the payback, so a battery is worth it for some people and not others. The honest version of this answer depends on three things: your roof, your tariff, and how much electricity you use during the day. Let's do the actual maths instead of the brochure version.
What solar actually costs in 2026
Real installed prices this year, MCS-certified, including the 0% VAT relief that's still running:
| System | Fitted cost (2026) |
|---|---|
| Typical 4kW system | ~£6,500–£8,500 |
| Smaller 3kW | from ~£5,500 |
| Larger 6kW | up to ~£11,500 |
| Add a battery (4–5kWh) | +£3,000–£5,000 |
A solar-plus-battery system commonly lands £8,000–£14,000+. The 0% VAT scheme is quietly worth £1,000–£3,000 of that — a genuine discount, not a gimmick, and it won't necessarily last forever, which nudges the timing argument toward "sooner".
A note on quotes: solar pricing is messier than it should be, and the spread between a fair quote and a rip-off is wide. Get three quotes, and be suspicious of anyone selling on pressure and "today only" discounts.
The savings — and why they vary so much
A 4kW system generates roughly 3,400–4,200 kWh a year depending where you are. What that's worth to you depends entirely on two things:
- How much you use while the sun's up (self-consumption). Every unit you use yourself saves the full ~25p+ you'd have paid the grid. Every unit you export earns you far less.
- Your export rate (the Smart Export Guarantee). Exported units typically earn somewhere in the 5–15p/kWh range depending on tariff — useful, but much less than self-consumed units.
Typical annual savings for a 4kW system land around £500–£700, and you can push the top of that range by shifting usage (dishwasher, washing machine, EV charging, hot water) into daylight hours. Solar rewards you for changing when you use power, not just for generating it.
Payback: the honest, regional version
Independent means giving you the unflattering numbers too. Payback isn't one figure — it depends heavily on where your roof is:
| Location / roof | Payback |
|---|---|
| South of England, good roof | ~7–9 years |
| Midlands / average | ~9–11 years |
| Scotland / north / shaded | ~11–14 years |
Against a 25-year-plus panel lifespan, even the slow cases come out ahead. But if someone promises you a 5-year payback in Aberdeen, they're selling, not calculating.
The battery question — where it gets interesting
This is the decision most people get wrong in both directions, so here's the straight version. A battery doesn't generate anything. What it does is store your cheap or self-generated electricity to use later, so you buy less expensive grid power at peak times. It's worth it when:
- You're out during the day, so without a battery most of your solar would be exported cheaply rather than used.
- You're on (or willing to move to) a smart tariff with cheap overnight rates — then a battery earns its keep even in winter by charging up cheap at night and discharging at peak.
- You have an EV or a heat pump, which makes time-shifting much more valuable.
It's not worth it if you're home all day using power as you generate it, you're on a flat tariff, and you're chasing the fastest possible payback — a battery will add £3–5k and extend your payback by a few years.
When solar is NOT worth it (yet)
- Your roof faces mostly north, or is heavily shaded. Output drops too far to justify the spend. (Though with microinverters a north-ish roof is far from pointless — more on that in our case study.)
- You're moving within a couple of years. Solar can add value to a sale, but not reliably enough to bank on for payback.
- Your roof needs replacing soon. Do the roof first — you don't want to pay to remove and refit panels in three years. (Better still, do both at once.)
- You use almost no electricity during daylight and won't shift any. Without self-consumption or a battery + smart tariff, the savings thin out.
How to actually maximise the return
If you go ahead, these are the levers that move the numbers — in order of impact:
- Buy well. Three quotes, MCS-certified, ignore pressure selling. The install price is the biggest single variable in your payback.
- Shift your usage into daylight. Free savings, no extra kit — timers and a bit of habit change.
- Get on the right tariff. Export rate and smart import rates change the maths materially.
- Only add a battery if your usage pattern justifies it — and size it properly rather than buying the biggest one offered.
So, should you do it?
Quick self-test: roof facing roughly south/east/west and not badly shaded? Staying put 7+ years? Willing to shift some usage to daytime, or add a battery + smart tariff?
Three ticks: solar is very likely worth it in 2026, and the 0% VAT window makes the timing favourable. If the battery question is the one you're stuck on, that's usually about your daily routine and tariff, not the panels — so decide the panels first, then run the battery numbers separately.
What I'd tell a friend, in one line
Get the panels if your roof and time horizon stack up — they almost certainly will. Treat the battery as a separate decision that lives or dies on your tariff and your daily routine, not on hype.