Size.Solar
550W Solar Panel Production in Tokyo
A single 550W solar panel in Tokyo is estimated to generate approximately 721 kWh of electricity per year, averaging 1.98 kWh daily. This represents the actual AC power available for your home after system conversion losses.
Your system settings
Annual bill savings
¥98,832
Save about ¥8,236 per month, capped to the 600 kWh/month use you entered.
Electricity use covered
100%
Produces 11 kWh/year above your entered use. Export credits or batteries may add value.
Annual output
7,211 kWh
Daily output
~20 kWh
System size
5.5 kW
Panels needed
10 panels*
Ready for a roof-specific design?
Turn this production estimate into a full project with roof layout, batteries, equipment, and supplier options.
Monthly production breakdown (kWh)
Project-ready estimate
Turn this result into a quote request
Start with 10 panels at 550W, about 5.5 kW, a 600 kWh/month bill target, and 14% modelled system losses. This gives suppliers the first inputs they need before roof layout, inverter limits, and battery choices are refined.
- Starter system
- ~5.5 kW
- Output per panel
- 721 kWh
- Bill value/year
- ¥9,898
- Weakest month
- Nov
10 panels for a 600 kWh/month home before roof, inverter, and battery constraints.
Estimated annual AC electricity from one 550W panel after modelled system losses.
Annual value at about ¥14/kWh, capped to the electricity use you can actually offset.
45 kWh from one 550W panel; check this month before sizing essential loads.
Roof fit
Confirm usable roof planes, shading, inverter limits, and battery needs before accepting a final layout.
Bill fit
Adjust panel count and monthly use above so savings are capped to electricity you can offset.
Quote check
Ask suppliers to show winter output, assumed losses, and any export-credit value separately.
Production evidenceShow monthly output and model assumptionsOpen this when checking winter production, irradiance, losses, or the source assumptions behind the quote handoff.
Monthly model
Monthly output and winter risk
The calculator is useful when it shows the weak months, not just a flattering annual number. Use the table to check whether winter output still supports the loads you care about.
- Best month
- Jan
- Lowest month
- Nov
- Solar resource
- 4.7 kWh/m²/day
- Model checks
- 15.0%
71 kWh from one 550W panel
45 kWh from one 550W panel
1698 kWh/m² annual irradiance
Capacity factor, 42.5% performance ratio, 758 kWh DC before conversion
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 71 kWh | 57 kWh | 70 kWh | 70 kWh | 68 kWh | 51 kWh | 61 kWh | 60 kWh | 54 kWh | 55 kWh | 45 kWh | 59 kWh |
Model basis
The model uses south-facing panels at 36° tilt, true south orientation, and 14% system loss. Typical 600 kWh/month electricity costs are ¥4,200 - ¥13,700 (typically ¥8,236) using 2025 cost data.
Solar production data provided by the PVWatts® API from NLR.