Solar System & Battery Sizing for 825 kWh/Month in London, United Kingdom
Complete photovoltaic engineering breakdown for a 825 kWh/month (27.5 kWh/day) electricity profile in London, United Kingdom (3.4 Peak Sun Hours/day).
Technical Specification Table — 825 kWh/Month Solar System (London, United Kingdom)
| Monthly / Daily Electricity Consumption | 825 kWh/month (27.5 kWh/day) |
| Location Peak Sun Hours (PSH) | 3.4 hours/day (London, United Kingdom) |
| Required PV System Size (80% Performance Ratio) | 10.12 kWp DC |
| Number of Solar Panels (440W N-Type Bifacial) | 23 panels |
| Roof Area Required | 47.1 m² (507 sq ft) |
| Recommended Hybrid Inverter Rating | 9.0 kW AC |
| Recommended LiFePO4 Battery Storage (85% DoD) | 21.1 kWh Nominal (17.9 kWh Usable) |
| Estimated Annual Output | 10,047 kWh/year (~837 kWh/month) |
| Estimated System Turnkey Cost (Before Tax Credits) | £18,722 |
| Annual Electricity Bill Savings (@ £0.28/kWh) | £2,813/year (£234/month) |
Frequently Asked Questions
How many solar panels are needed for 825 kWh per month in London, United Kingdom?
With an average of 3.4 Peak Sun Hours per day in London, United Kingdom and an 80% system performance ratio, a monthly usage of 825 kWh (27.5 kWh/day) requires a 10.12 kWp solar array, which equals 23 standard 440W N-Type solar panels occupying 47.1 m² (507 sq ft) of roof space.
What size solar battery bank do I need for 825 kWh/month?
To cover evening and overnight loads (65% of daily consumption at 85% LiFePO4 depth of discharge), a 21.1 kWh nominal (17.9 kWh usable) LiFePO4 battery bank paired with a 9.0 kW hybrid inverter is recommended.
How much money will a 10.12 kW solar system save in London, United Kingdom?
Generating approximately 10,047 kWh per year at an average local tariff of £0.28/kWh, the system saves £2,813 per year (£234/month) with an estimated payback period of 6.7 years.