Solar System & Battery Sizing for 1,225 kWh/Month in London, United Kingdom
Complete photovoltaic engineering breakdown for a 1,225 kWh/month (40.8 kWh/day) electricity profile in London, United Kingdom (3.4 Peak Sun Hours/day).
Technical Specification Table — 1,225 kWh/Month Solar System (London, United Kingdom)
| Monthly / Daily Electricity Consumption | 1,225 kWh/month (40.8 kWh/day) |
| Location Peak Sun Hours (PSH) | 3.4 hours/day (London, United Kingdom) |
| Required PV System Size (80% Performance Ratio) | 15.4 kWp DC |
| Number of Solar Panels (440W N-Type Bifacial) | 35 panels |
| Roof Area Required | 71.8 m² (773 sq ft) |
| Recommended Hybrid Inverter Rating | 13.7 kW AC |
| Recommended LiFePO4 Battery Storage (85% DoD) | 31.2 kWh Nominal (26.5 kWh Usable) |
| Estimated Annual Output | 15,289 kWh/year (~1,274 kWh/month) |
| Estimated System Turnkey Cost (Before Tax Credits) | £28,490 |
| Annual Electricity Bill Savings (@ £0.28/kWh) | £4,281/year (£357/month) |
Frequently Asked Questions
How many solar panels are needed for 1,225 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 1,225 kWh (40.8 kWh/day) requires a 15.4 kWp solar array, which equals 35 standard 440W N-Type solar panels occupying 71.8 m² (773 sq ft) of roof space.
What size solar battery bank do I need for 1,225 kWh/month?
To cover evening and overnight loads (65% of daily consumption at 85% LiFePO4 depth of discharge), a 31.2 kWh nominal (26.5 kWh usable) LiFePO4 battery bank paired with a 13.7 kW hybrid inverter is recommended.
How much money will a 15.4 kW solar system save in London, United Kingdom?
Generating approximately 15,289 kWh per year at an average local tariff of £0.28/kWh, the system saves £4,281 per year (£357/month) with an estimated payback period of 6.7 years.