⚡ 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 1,400 kWh/Month in Tokyo, Japan

Complete photovoltaic engineering breakdown for a 1,400 kWh/month (46.7 kWh/day) electricity profile in Tokyo, Japan (3.9 Peak Sun Hours/day).

Recommended Solar Array14.96 kWp34× 440W Solar Panels
LiFePO4 Battery Bank35.6 kWh30.3 kWh Usable + 13.4 kW Inverter
Annual Solar Generation17,036 kWhRoof Area: 69.7 m² (750 ft²)
Estimated Annual Savings¥579,224/yrPayback: ~6.2 yrs · 7.16t CO₂

Technical Specification Table — 1,400 kWh/Month Solar System (Tokyo, Japan)

Monthly / Daily Electricity Consumption1,400 kWh/month (46.7 kWh/day)
Location Peak Sun Hours (PSH)3.9 hours/day (Tokyo, Japan)
Required PV System Size (80% Performance Ratio)14.96 kWp DC
Number of Solar Panels (440W N-Type Bifacial)34 panels
Roof Area Required69.7 m² (750 sq ft)
Recommended Hybrid Inverter Rating13.4 kW AC
Recommended LiFePO4 Battery Storage (85% DoD)35.6 kWh Nominal (30.3 kWh Usable)
Estimated Annual Output17,036 kWh/year (~1,420 kWh/month)
Estimated System Turnkey Cost (Before Tax Credits)¥3,590,400
Annual Electricity Bill Savings (@ ¥34.0/kWh)¥579,224/year (¥48,269/month)

Frequently Asked Questions

How many solar panels are needed for 1,400 kWh per month in Tokyo, Japan?

With an average of 3.9 Peak Sun Hours per day in Tokyo, Japan and an 80% system performance ratio, a monthly usage of 1,400 kWh (46.7 kWh/day) requires a 14.96 kWp solar array, which equals 34 standard 440W N-Type solar panels occupying 69.7 m² (750 sq ft) of roof space.

What size solar battery bank do I need for 1,400 kWh/month?

To cover evening and overnight loads (65% of daily consumption at 85% LiFePO4 depth of discharge), a 35.6 kWh nominal (30.3 kWh usable) LiFePO4 battery bank paired with a 13.4 kW hybrid inverter is recommended.

How much money will a 14.96 kW solar system save in Tokyo, Japan?

Generating approximately 17,036 kWh per year at an average local tariff of ¥34.0/kWh, the system saves ¥579,224 per year (¥48,269/month) with an estimated payback period of 6.2 years.