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Home Solar and Batteries in Japan: FIT, After the FIT, Subsidies and Quotes
Rules to know and points to check in quotes (checked 2026-11-01).
1. Feed-in tariff (FIT)
Since the second half of FY2025, residential systems under 10 kW use the "initial investment support scheme": ¥24/kWh for the first 4 years and ¥8.3/kWh for years 5–10. The same applies to FY2026 and FY2027 approvals. After 10 years you sell under a contract with a retailer.
2. Renewable energy surcharge
The FY2026 surcharge is ¥4.18/kWh (meter readings from May 2026 to April 2027). It is charged on electricity you buy, so self-consumption also saves the surcharge.
3. Typical costs
- Solar: ¥289,000/kW on average for new homes installed in 2025 (Procurement Price Calculation Committee). Retrofits cost more because of scaffolding and other work.
- Batteries: METI data show household battery costs fell from ¥187,000/kWh (FY2019) to ¥121,000/kWh (FY2023). The national target is ¥70,000/kWh by 2030.
- Maintenance: according to the industry association (same committee), an inspection every 3–5 years costs about ¥38,000, and the inverter is replaced once in 20 years for about ¥384,000 (5 kW system). The simulator defaults are based on this.
4. Subsidies
The national government (e.g. demand-response battery subsidies), prefectures and municipalities may offer subsidies. Eligible equipment, amounts and timing (often before signing a contract) change every year, so check official pages. Since April 2025, Tokyo requires large home builders to install solar on new houses.
5. What to check in quotes
- The output assumptions (radiation data, losses, shading). Ask why if they differ a lot from this site.
- The battery's usable capacity (less than rated), power (kW), and whether it backs up the whole house.
- Warranties for panel output, equipment and workmanship or leaks.
- The total price including scaffolding and paperwork, and how subsidies are applied.
6. Door-to-door sales
Be careful with pitches like "only today" or "your bill will be zero". Contracts signed in door-to-door sales can be cancelled within 8 days of receiving the contract document (cooling-off). The consumer hotline is 188 (National Consumer Affairs Center).
Primary sources (Japanese): METI FY2026 prices and surcharge / ANRE FIT prices / Committee materials (110th) / METI battery costs / ANRE after the FIT