Solar savings by home type
There's no single "what does solar save?" answer — a one-bed flat and a five-bed detached with an EV are completely different sums. Find the case closest to your home for honest numbers, and the situations where solar isn't worth it.
The pages below all use the same honest 2026 assumptions — the Ofgem price cap of 26.11p/kWh (July–September 2026), a 12p export rate (Octopus Outgoing, as at July 2026), and roughly 950 kWh of generation per kWp a year — so you can compare them like for like. What changes between them is the system size, the self-consumption pattern, and therefore the saving and the payback. Not sure which fits? Start with the free savings calculator or the straight answer on whether solar is worth it.
Small home or flat (low usage, 2–3 kWp)
Not for very low users (<1,800 kWh/yr) or homes that are empty all day with no battery — export at ~12p won't move the needle and payback drifts past 12 years.
Typically 2.5–3 kWp, ~11-year payback.
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Average 3–4 bed home (4 kWp) — the core case
Not for homes with heavy shading, a small/steep/north-only roof, or annual use below ~2,500 kWh where export dominates.
Typically 4 kWp, ~9-year payback.
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Large / high-usage detached (5–6 kWp)
Not worth over-sizing for a household that's out all day with no battery and no EV — beyond ~4 kWp of surplus you're selling at ~12p and payback lengthens.
Typically 5–6 kWp, ~8-year payback.
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Solar + battery (maximise self-consumption)
Not the fastest payback — if pure ROI is the goal, solar-only usually wins.
Typically 4–5 kWp solar + 5–10 kWh battery, ~11-year payback.
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EV owner / heat-pump home (high self-consumption)
Not for an EV driver who charges only at work or overnight and is never home in daylight — the self-consumption advantage disappears and it behaves like a plain export case.
Typically 5–6 kWp (often + battery), ~7-year payback.
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Planning to move or letting the property
Explicitly NOT recommended for owner-occupiers planning to sell within ~5 years on cost grounds, nor for landlords of bills-excluded tenancies where the tenant captures the saving.
Typically 3–4 kWp, ~10-year payback.
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How to read these pages honestly
Two homes on the same street, with the same 4kWp array, can save noticeably different amounts. The lever is self-consumption — the share of what your panels make that you actually use in the house rather than exporting for pennies. A retired couple or a hybrid home-worker who is in during the day will self-consume far more than a household that leaves at 8am, and that alone can shift a saving from the bottom of a range to the top. A battery, an EV charged in daylight, or simply moving the washing to the afternoon all push it the same way.
We show every figure as a range, confirmed at survey, because your roof's orientation, pitch and shading, your exact usage and your tariff all move the result — and no honest calculator can see those without a proper look. If your situation sits in the "not worth it" column on any of these pages, that's genuinely useful to know before you spend anything. See the full checklist of when solar is not worth it, or work out how many panels you need for your usage.
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Responds within one working day
- 1. An honest savings estimate for your roof and usage — ranges, not a sales pitch.
- 2. Matched to MCS-certified installers near you, so you can compare real quotes.
- 3. No obligation — and we'll tell you if solar isn't worth it for your home.
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