Is solar worth it in the UK in 2026?
For most UK homes with a reasonable roof and rising bills, yes. But the size of the win swings hard on one thing: how much of your own electricity you use during daylight. A retired couple at home all day might use half of what their panels make. A household out from 8 to 6 might use a quarter and export the rest. Same panels, very different payback. Here's what actually decides it.
Your roof: direction, pitch and shading
A south-facing roof at a 30 to 40 degree pitch is the textbook best case. In most of England it generates somewhere between 850 and 1,000 kWh per kWp installed each year, dropping toward 840 in Scotland and rising past 1,000 in the South West. East and west roofs split that output across the morning and evening, usually 10 to 15% less in total, but often better matched to when you're actually home.
Shading is the quiet killer. One chimney or tree throwing shadow across part of the array at midday can cut output by 10 to 30%, because many panels wired in a string drop to the level of the weakest one. Roof area sets the ceiling: a 455W panel takes about 2 m², so a typical 4 kWp system is roughly 9 panels needing around 18 to 20 m² of clear, well-oriented roof. Flats rarely work, because you need sole access to a suitable roof.
How much daytime electricity you use
This is the lever most people underestimate. A unit of solar you use yourself is worth more than one you export, and it isn't close. You avoid buying at the import rate, which sits around 25p/kWh under the current price cap, but you only earn the export rate on surplus, which runs from about 12p to 20p depending on your supplier. Use a kWh at noon and you save 25p. Export it and you might earn 15p. That 10p gap, repeated thousands of times a year, is most of the difference between a good payback and a slow one.
Working from home, charging an EV in daylight, running a heat pump, or just shifting the dishwasher and washing machine to midday all push your self-consumption up. Without a battery, most homes self-consume 30 to 50% of what they generate. A battery stores the midday surplus and releases it into the evening peak, often lifting that to 60 to 85%. Whether it pays for itself is its own question, covered in do I need a battery.
Import and export rates, and the Smart Export Guarantee
You save by not buying; you earn on what you send back. Export is paid under the Smart Export Guarantee (SEG), and the rates vary more than people expect. The best widely-available tariffs reach about 20p/kWh, the most popular sit near 15p, and several pay around 12p. Most require you to take your electricity from the same supplier, plus an MCS-certified install and an export-capable smart meter to measure what you send out.
One caveat that trips people up: standing charges are a fixed daily fee for being connected to the grid, and solar does not reduce them. Panels cut the units you buy, not the daily charge.
Cost, VAT and the headline price
Price scales with size and whether you add storage. A panels-only domestic system commonly lands somewhere between about £5,000 and £10,000, with larger arrays and a battery pushing higher. The full breakdown, and how to sanity-check a quote, is in how much solar panels cost.
There is one genuine discount worth knowing: domestic solar and battery installations carry 0% VAT in the UK until 31 March 2027, down from the 5% that applied before and the 20% on most goods. After that date the rate is set to return to 5%, so the maths is slightly better today than it may be in a few years.
Payback and the 25-year view
Payback for a well-matched system usually lands in the high-single-digit to mid-teens of years. The panels don't retire at that point. A quality panel loses about 2% of output in its first year from light-induced degradation, then around 0.5% a year after that, so at 25 years it still produces roughly 87% of what it did on day one. The figure that matters is the 25-year net benefit, after degradation and energy-price inflation, not the sticker price.
Solar isn't worth it for everyone. A heavily shaded or north-only roof, a flat without sole roof access, or a household out all day with no battery and a low export rate can all push payback past the point of interest. The honest test is to run your own numbers rather than a national average.