Rooftop solar in Japan typically costs about JPY 371,000 per kW installed, and household electricity is around JPY 33 per kWh. The average sunshine is about 3.6 peak sun hours a day.
As a rough example, a 5 kW home system would cost about JPY 2,134,000, make around 4,928 kWh a year, and save about JPY 162,608 a year. That is a payback of roughly 13.1 years.
Rooftop solar
For homes and businesses. Size, cost, savings and payback.
Open rooftop calculatorSolar plant
For larger projects. Project returns and break-even price.
Open plant calculatorThese are typical estimates, not quotes. Replace them with real quotes before you decide anything.
How to use the Japan calculator
- Open the rooftop or plant calculator above. It starts on Japan.
- Pick your region or search your city, so sunlight matches your area.
- Enter your monthly electricity use and replace the starting prices with your own quotes.
- Read the size, cost, savings and payback, and download the PDF report if you want to keep it.
Solar in Japan: common questions
How much does rooftop solar cost in Japan?
Rooftop solar in Japan typically costs about JPY 371,000 per kW installed. A 5 kW home system would cost roughly JPY 2,134,000. Real quotes vary by installer, roof and equipment, so use this as a starting point.
How much can I save with solar in Japan?
With electricity at around JPY 33 per kWh, a 5 kW system could make about 4,928 kWh a year and save roughly JPY 162,608 a year. Your own savings depend on how much power you use and your local price.
How long does solar take to pay for itself in Japan?
On these typical numbers, a 5 kW home system pays back in roughly 13.1 years. This is a simple estimate: system cost divided by yearly savings. It does not include subsidies, tax credits, price rises or upkeep.
How much sunshine does Japan get?
The average across the places we list for Japan is about 3.6 peak sun hours a day. Sunlight differs a lot between regions, so pick your own city in the calculator for a better figure.
Are subsidies or tax credits included?
No. The calculator does not include subsidies, tax credits or special tariffs. Rules differ by country and change often, so check current local rules before you decide.
How accurate is this solar calculator?
It gives planning estimates, not quotes. The starting prices are typical figures for Japan. Replace them with real quotes and your own electricity price to get a closer result.
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