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UK balcony solar — cost & payback in 2026

Quick answer: A compliant UK 800W balcony solar install costs roughly £300–£1,000 all-in (kit + electrician + G98), produces ~600–900 kWh/year, and saves £130–£200/year at the current ~27p/kWh price cap through self-consumption. Payback lands at 3–5 years for the bare-panel install, or 5–7 years if you add a battery. SEG income is generally not available for plug-in installs.

What you actually pay

ItemTypical UK costNotes
Microinverter (APsystems EZ1-M / Hoymiles HMS-800)£107–£120800W AC, anti-islanding, EN-certified
One 400–500W panel£80–£150Bifacial or monocrystalline
Two-panel kit (most common)£200–£350Includes mounts, cables
Premium brand (EcoFlow STREAM, Anker SOLIX)£500–£1,000Polished app, brand support
Electrician hardwire + G98£200–£400CPS-registered, 1–2 hour job
Optional battery (1–2 kWh)+£500–£1,000Solarbank / SolarFlow / STREAM Ultra

Realistic total all-in (no battery): £300 budget DIY-microinverter route, £500 typical 2-panel kit + electrician, £1,000 premium brand + electrician.

Realistic total with battery: £1,200–£2,000.

What you save

UK insolation gives roughly 0.7–1.1 kWh per watt of installed AC capacity per year, depending on orientation and shading. For an 800W system:

  • Shaded or strong-east/west balcony: ~560–640 kWh/year
  • South-facing balcony, modest shade: ~720–800 kWh/year
  • Tilted, unshaded, south-facing: ~840–880 kWh/year

At ~27p/kWh (UK price cap, mid-2026), that translates to:

  • Shaded: £150–£170/year
  • Typical south-facing: £195–£215/year
  • Best-case unshaded tilted: £225–£240/year

These assume ~100% self-consumption. In practice some daytime production goes unused if your household is empty — haircut the savings by 10–25% to be honest with yourself. A battery brings self-consumption back near 90% and adds ~£30–£60/year.

Realistic payback

SetupTotal costYearly savingPayback
Budget DIY-style 800W + electrician£500£180~2.8 years
Typical 2-panel kit + electrician£700£195~3.6 years
Premium brand (EcoFlow STREAM)£1,000£200~5 years
Premium + battery (STREAM Ultra)£1,500£235~6.4 years

SEG (Smart Export Guarantee) — usually not available

SEG pays UK households for electricity exported to the grid (typically 5–15p/kWh). To qualify you need an MCS-certified installer and a smart meter exporting on the SEG channel. Plug-in balcony installs almost never meet MCS, so SEG income is generally zero for this category. We don’t model it in our payback numbers, and you shouldn’t either.

Want to model your specific flat? The UK savings calculator lets you adjust rate, kit price and per-watt yield.