Why where you put it matters

Plug-in solar — also called balcony solar — is a small, portable solar panel and microinverter that connects to a normal socket, giving renters and flat owners without roof access a way to generate some of their own electricity, without any structural work.

Two things decide how much a panel like this actually generates: which way it faces, and how steeply it's angled. The Energy Saving Trust — one of the UK's leading independent authorities on home energy — advises that a south-facing panel at around 30° tilt gives the best annual performance, and that installations facing north generally aren't recommended. Nearby shading from fences, walls, or overhangs matters too.

This tool uses real historical sunlight data for your exact postcode, combined with your chosen spot's facing direction, tilt, and shading, to estimate how many usable sun hours you'd actually get — and what that's worth in £ per year — before you spend anything on a kit.

Source: Energy Saving Trust, "Choosing a site and getting planning permission".

Your address

This sets your rough position and default sun angle — nothing is stored.

Postcode

map preview appears once located

Coordinates: not yet located

Where could you fit a panel?

Pick one spot to configure and estimate. Switch to another any time — your other answers stay put.

Fair use: a short wait between requests and a limit of locations per visit, to keep this free for everyone.

Your results

Estimated daily sun exposure for your selected spot.

Panel kit size: W (typical plug‑in kits run 400–800W)

What do you pay per unit? p/kWh

Don't know your rate? The UK average under the Ofgem price cap is currently around 26p/kWh (Jul–Sep 2026) — check a recent bill for your actual rate.

Real data used

Your coordinates come from a live postcode lookup (postcodes.io), shown on a real OpenStreetMap map.
Sunlight is real hourly direct + diffuse irradiance for the most recent full year at your exact location (Open-Meteo archive).
The sun's actual position — altitude and direction — is calculated for every one of those hours and combined with your chosen tilt and facing to work out how much of that light actually reaches the panel.

Simplifications and assumptions

Shading is the level you selected (none / partial / heavy) — not measured from real obstructions. A proper survey of what blocks your specific spot would give a more exact figure.
System losses are assumed at a flat 18% (cabling, inverter conversion) — real kits typically lose 10–20%.
No allowance for panels running hotter in direct sun, which slightly reduces real-world output.
This is a year-one estimate — no allowance for gradual panel output decline over time.
No inverter output cap is modelled — if your kit's inverter limits peak export, very sunny hours may in reality produce less than shown here.
Diffuse skylight and ground-reflected light use a simplified model rather than the more advanced ones professional tools use.
Estimated savings assume every unit generated directly offsets a unit you'd otherwise buy. In reality, power generated while you're out or appliances are off may not be used at the time — without a battery, that portion is worth less (or nothing) rather than the full unit rate.

Treat the ranking between your spots as reliable, and the kWh/year figure as accurate to roughly ±15–20% — good for comparing options, not for guaranteeing a bill saving.