Are solar panels worth it in 2026?

The worked example

Take the median case: a 4kWp system on a south-facing roof, installed for an estimated £7,000, generating around 3,400kWh a year (at ~850kWh/kWp, estimate). The household uses 50% of it directly and exports the rest. At the October–December 2026 price cap — electricity 26.32p/kWh, SEG at 5p — that’s roughly £447 of avoided imports plus £85 of export income: about £530 a year, a simple payback of around 13 years on flat prices, or nearer 11 if prices rise at 3% a year. Add a battery (£3,000–£4,500, lifting self-consumption to ~70%) and the annual figure rises to roughly £660 — payback a little over 12 years on the higher £10,500–£11,500 outlay. Either way: money back well inside the 25-year panel warranty, then a decade-plus of gravy. Run your own version in the payback calculator.

When it’s clearly worth it

• South, south-east or south-west roof, little shade — the yield assumption holds.
• Someone home in the day, an EV, or a heat pump — self-consumption climbs, and with it the value of every unit.
• You’re staying put 10+ years — payback is a tenancy-length bet.
• High electricity use — home working, electric heating top-ups, big appliances.
• Installing before 31 March 2027 — the 0% VAT rate is worth real money versus whatever follows it.

When we’d say keep your money

• North-facing or heavily shaded roofs — at ~60% yield the payback stretches past 15 years and the numbers stop forgiving.
• Moving within five years — you may recover value in the sale price, but it isn’t guaranteed; don’t bank on it.
• Very low electricity use — a 1,500kWh household exports most of what it generates at 3–6p. A smaller system may work; a 4kWp one probably doesn’t.
• A roof due for replacement — re-roof first, panels second, or pay for scaffolding twice.

The verdict

At October 2026 prices, solar in the UK is a solid, unglamorous investment for the right roof: an estimated 10–15 year payback (nearer 10 with a battery), then cheap electricity for another decade or more, plus a better EPC band. It is not a get-rich scheme and it is not for every roof — and the installers worth using will tell you the same. Get the numbers for your home from the panels calculator and savings estimator, then hold every quote up against them.