Key takeaways
- • Plug-in solar in Great Britain is limited to a maximum output of 800W.
- • Savings depend heavily on how much electricity you use during daylight hours.
- • Permission may be required if you rent, lease or live in a managed building.
An 800W system produces up to 800W at any instant in bright sun, and roughly 500-750 kWh over a UK year. Understanding both figures tells you what it can realistically run.
Instantaneous loads it can cover
- Fridge freezer: 100-200W while the compressor runs
- Router, hub and standby loads: 30-80W continuously
- Laptop and monitor: 60-120W
- LED lighting for a whole flat: 50-100W
- Small dehumidifier: 200-300W
On a sunny afternoon an 800W system covers all of those simultaneously.
Loads it cannot cover alone
Kettles (2,500-3,000W), ovens, electric showers and tumble dryers far exceed 800W. Your system still contributes, reducing what you draw from the grid, but it will not run them by itself.
Over a year
650 kWh is roughly a fifth to a quarter of a low-use flat's annual electricity, or about a tenth of an average house at 2,700 kWh. Framed differently: enough for a fridge freezer, all lighting and all standby loads for a year.
Getting the most from it
Run heavy shiftable appliances at midday, charge devices in daylight, and if you have a battery station, bank the surplus for the evening peak.
Frequently asked questions
Sources
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