⚡ Cu ρ (75°C): 0.0214 Ω·mm²/m 🔌 NEC / IEC Standards: NFPA 70 & IEC 60364 🇺🇸 US Grid Avg: $0.175/kWh 🇩🇪 DE Grid Avg: €0.345/kWh 🇸🇪 SE Elpris: 1.54 SEK/kWh 🇳🇴 NO Strøm: 1.17 NOK/kWh 🔩 Copper Ref: $9,650/t (2026-10-25)
☀️ Solar PV Array · 440W N-Type TOPCon · LiFePO4 Battery Storage

Solar System & Battery Sizing for 1,425 kWh/Month in Cologne (NRW), Germany

Complete photovoltaic engineering breakdown for a 1,425 kWh/month (47.5 kWh/day) electricity profile in Cologne (NRW), Germany (3.3 Peak Sun Hours/day).

Recommended Solar Array18.04 kWp41× 440W Solar Panels
LiFePO4 Battery Bank36.4 kWh30.9 kWh Usable + 16.1 kW Inverter
Annual Solar Generation17,383 kWhRoof Area: 84.0 m² (904 ft²)
Estimated Annual Savings€6,084/yrPayback: ~4.9 yrs · 7.3t CO₂

Technical Specification Table — 1,425 kWh/Month Solar System (Cologne (NRW), Germany)

Monthly / Daily Electricity Consumption1,425 kWh/month (47.5 kWh/day)
Location Peak Sun Hours (PSH)3.3 hours/day (Cologne (NRW), Germany)
Required PV System Size (80% Performance Ratio)18.04 kWp DC
Number of Solar Panels (440W N-Type Bifacial)41 panels
Roof Area Required84.0 m² (904 sq ft)
Recommended Hybrid Inverter Rating16.1 kW AC
Recommended LiFePO4 Battery Storage (85% DoD)36.4 kWh Nominal (30.9 kWh Usable)
Estimated Annual Output17,383 kWh/year (~1,449 kWh/month)
Estimated System Turnkey Cost (Before Tax Credits)€29,766
Annual Electricity Bill Savings (@ €0.35/kWh)€6,084/year (€507/month)

Frequently Asked Questions

How many solar panels are needed for 1,425 kWh per month in Cologne (NRW), Germany?

With an average of 3.3 Peak Sun Hours per day in Cologne (NRW), Germany and an 80% system performance ratio, a monthly usage of 1,425 kWh (47.5 kWh/day) requires a 18.04 kWp solar array, which equals 41 standard 440W N-Type solar panels occupying 84.0 m² (904 sq ft) of roof space.

What size solar battery bank do I need for 1,425 kWh/month?

To cover evening and overnight loads (65% of daily consumption at 85% LiFePO4 depth of discharge), a 36.4 kWh nominal (30.9 kWh usable) LiFePO4 battery bank paired with a 16.1 kW hybrid inverter is recommended.

How much money will a 18.04 kW solar system save in Cologne (NRW), Germany?

Generating approximately 17,383 kWh per year at an average local tariff of €0.35/kWh, the system saves €6,084 per year (€507/month) with an estimated payback period of 4.9 years.