Tools / 01Plug-in Solar
Plug-in Solar
Savings Calculator
Plug-in (balcony) kits connect through a normal socket. Proposed UK rules allow up to 800W.
Rule-dependent · last updated 11 Oct 2026
Your inputs
800W
300W800W limit
Which way does it face?
The direction the panels point
How is it mounted?
Upright panels on a balcony catch less summer sun.
Where in the UK?
Sunshine varies north to south.
Is anyone home in the day?
Power you don’t use goes to the grid unpaid.
Estimated saving per year
£94
Likely worth it. Pays back well inside the panel’s life.
Generation
547kWh
Used at home
70%
Payback
5.9yrs
Generation by month · kWh
Assumptions
- Regional yield
- 950 kWh per kW/yr
- Direction factor
- × 1
- Mounting factor
- × 0.72
- Share used at home
- 70%
- Export payment
- None
How this is calculated
- 1Generation = kit size (kW) × regional yield × direction factor × mounting factor.
- 2Saving = generation × share used at home × your unit rate. Exported power is not paid for on most plug-in setups.
- 3Payback = kit cost ÷ annual saving. No panel degradation or price changes.
The rules, in one line each
- 800W thresholdThe proposed maximum output for a kit you plug in yourself.
- DESNZ consultationThe government review deciding how plug-in solar is allowed in the UK.
- BS 7671 Amendment 4The update to UK wiring regulations that covers plug-in generators.