If you install solar panels, a home battery, or V2H equipment in Saitama Prefecture, where does the money come from and how much? For the 2026 fiscal year (Reiwa 8), the answer is: the prefecture pays up to ¥450,000 for solar plus a battery — but you cannot combine it with a national subsidy for the same equipment, a restriction you do not see in neighbouring prefectures. On top of that, V2H is not covered by the prefecture at all; you have to pick it up from municipalities such as Saitama City (¥100,000) and Kumagaya City (¥50,000), plus the national programme. This article organises the three layers — prefecture, municipality, and national — from primary sources, along with the tax treatment of the money you receive.
Three layers, and one trap unique to Saitama
Up to ¥450,000 for solar + battery
¥70,000/kW for solar (capped at ¥350,000) plus ¥100,000 per battery. Solar requires a battery to be installed at the same time. V2H is not eligible.
Where V2H lives
Saitama City pays ¥100,000 for V2H; Kumagaya City up to ¥50,000. For solar and batteries, Kawaguchi City goes up to ¥160,000 — availability varies enormously by city.
V2H up to about ¥1.3 million
The charging infrastructure subsidy covers V2H for private homes: up to ¥750,000 for the unit plus up to ¥550,000 for installation. The national DR home-battery subsidy closed in May 2026.
Saitama's requirements state explicitly that the project must "not be combined with a national subsidy programme, or with a municipal subsidy programme funded by national treasury disbursements, covering the same eligible equipment." The Tokyo-style approach of stacking prefectural money on top of national money simply does not work here. For a given piece of equipment, it is either the prefecture or the nation — not both. Municipal subsidies funded by national treasury disbursements are also excluded.
The prefectural programme: Household Energy-Saving and Renewable Equipment Subsidy
| Eligible equipment | Amount | Cap |
|---|---|---|
| Solar PV | ¥70,000/kW | ¥350,000 (i.e. 5kW worth) |
| Storage battery | ¥100,000 per unit | Flat amount |
| Ene-Farm (residential fuel cell) | ¥50,000 per unit | Flat amount |
| Solar thermal system (forced circulation) | Two-thirds of eligible costs | ¥200,000 |
| V2H charging/discharging equipment | Not eligible (use municipal and national programmes) | |
Solar: 5kW × ¥70,000/kW = ¥350,000 (exactly at the cap)
Battery: ¥100,000
= ¥450,000 in total from the prefecture
Five requirements that will block your application if missed
- Solar requires a battery installed at the same time. You cannot apply for solar alone (a requirement introduced for the 2026 fiscal year)
- An existing home in the prefecture that you live in yourself. New builds are not eligible
- A contract with a certified "Saitama Prefecture Energy-Saving and Renewable Equipment Anshin Contractor." Use a non-certified installer and you get nothing, even if the equipment and amounts qualify
- The contract date must be on or after 1 April 2026, and work must start after the grant decision. Starting work before the decision disqualifies you
- Solar must not be certified under the FIT scheme, and at least 30% of generation must be self-consumed (grid connection is also required)
The application window runs from 18 May 2026 to 29 January 2027, on a first-come, first-served basis. Around 3,100 subsidies are planned across all eligible equipment combined, so the programme can close before the deadline. Check remaining capacity before signing a construction contract.
The key decision: prefecture or nation?
The prefecture is usually the better bet
The national home-battery subsidy (the DR home battery programme under the FY2025 supplementary budget, capped at ¥600,000) closed on 29 May 2026 when the budget was exhausted, and SII has stated it will not reopen applications. In practice, for the 2026 fiscal year there is no direct national subsidy for solar or batteries — so going for the prefecture's ¥450,000 is the straightforward choice.
When the national route wins
If you are building new and using a ZEH-type national subsidy, or if the same equipment is covered by one of the Housing Energy-Saving 2026 Campaign programmes, you cannot also take the prefectural subsidy. Choose the national route when its amount is larger. Note that the prefectural subsidy is limited to existing homes, so new builds are outside its scope from the start.
Saitama Prefecture warns that solar-equipment subsidies run by Chichibu, Tokorozawa, Kasukabe, Iruma, Niiza, Kuki, and Shiraoka may be funded by national treasury disbursements. If you live in one of these cities and take the municipal subsidy, you may lose access to the prefectural subsidy for the same equipment. Check with both offices before applying and compare which is larger.
V2H: zero from the prefecture, so combine municipal and national
Saitama's household programme does not cover V2H. The prefecture's separate EV subsidy scheme, which used to include V2H, is not scheduled to run in the 2026 fiscal year. That leaves two sources.
| Source | Amount | Points to note |
|---|---|---|
| National: charging infrastructure subsidy (V2H) | Up to ¥750,000 for the unit plus up to ¥550,000 for installation | Around ¥1.3 million at most for a private home. Grant applications are expected to be accepted from July to September 2026. Conditions include agreeing to provide installation data to national and local government and to cooperate if asked to help during a disaster |
| Saitama City: EV promotion subsidy | ¥100,000 for V2H equipment | For homes and business premises in the city that you occupy. Completion between 1 April 2026 and 19 March 2027. Used equipment is excluded. Applications run 1 June 2026 to 19 March 2027, first-come, first-served (total budget ¥21.1 million) |
| Kumagaya City: V2H installation subsidy | 5% of eligible costs, capped at ¥50,000 | Paid in the local electronic money "KumaPAY." Installation between 1 April 2026 and 31 March 2027. You must use the equipment for at least six years and have no unpaid local taxes. One payment per household |
Municipalities: solar and battery top-ups vary widely
Saitama has unusually large differences between municipalities. Saitama City, the largest in the prefecture, has no solar or battery subsidy for residents at all, while Kawaguchi City goes as high as ¥160,000.
| City | Solar / battery | V2H / EV |
|---|---|---|
| Saitama City | No subsidy for residents (instead a group-purchasing scheme lowers prices) | V2H ¥100,000; EV ¥50,000 (standard) / ¥30,000 (mini); FCV ¥500,000 |
| Kawaguchi City | Half of installation cost for both solar and battery. Cap of ¥160,000 each with a city-based contractor, ¥80,000 with an outside contractor | EV up to ¥50,000 (PHV excluded). V2H is not on the list of eligible equipment |
| Kumagaya City | — | V2H: 5% of eligible costs, capped at ¥50,000 (paid in KumaPAY) |
Kawaguchi City's global-warming support payment increases when you use a contractor based in the city (EVs and FCVs excluded). The gap between ¥80,000 and ¥160,000 is worth having a local contractor in your quote comparison. Applications run 11 May 2026 to 15 March 2027, first-come, first-served. Against an initial budget of ¥61.18 million, ¥45.93 million (75.1%) remained as of 31 July 2026.
Is the subsidy taxable?
A subsidy an individual receives for their own home is treated as occasional income (ichiji shotoku). There is an annual special deduction of ¥500,000; if your total occasional income for the year exceeds that, half of the excess is added to your other income and taxed. The prefecture's ¥450,000 alone fits inside the deduction, but adding municipal and national V2H money in the same year usually pushes you over.
If you acquire a fixed asset (solar panels, a battery, V2H equipment, and so on) using a national or local government subsidy, attaching the "Statement Concerning Exclusion of National Treasury Subsidies from Gross Revenue" to your tax return keeps the subsidy used to acquire the asset out of gross revenue. This applies to private individuals, not only businesses. In any year your subsidies exceed ¥500,000, remember this form.
- Spreading receipts across years (solar and battery this year, V2H next year) also helps you stay within each year's ¥500,000 deduction
- Sole proprietors installing for business use record it as miscellaneous revenue in business income; corporations record it as taxable income. Consider compressed entry (asset write-down accounting) to defer tax
- Residential solar under 10kW on your own roof is generally outside fixed asset tax (depreciable asset tax)
- Income from selling surplus electricity is miscellaneous income; salaried workers may not need to file if it and other side income total ¥200,000 or less a year (calculated separately from the subsidy)
Frequently asked questions
Q. How much is Saitama Prefecture's solar and battery subsidy?
A. For the 2026 fiscal year, solar is ¥70,000/kW (capped at ¥350,000) and a battery is ¥100,000 per unit. Solar requires a battery installed at the same time, so 5kW of solar plus a battery comes to ¥450,000. Ene-Farm is ¥50,000 and a solar thermal system is two-thirds of eligible costs, capped at ¥200,000.
Q. Can the prefectural subsidy be combined with a national one?
A. No. Saitama requires that the project not be combined with a national subsidy programme, or with a municipal programme funded by national treasury disbursements, covering the same eligible equipment. For a given piece of equipment it is one or the other. Different equipment (for example, prefecture for solar and battery, nation for V2H) does not conflict.
Q. Is there a V2H subsidy in Saitama Prefecture?
A. Not from the prefecture. Its household programme excludes V2H, and the prefectural EV subsidy scheme that used to include it is not scheduled for the 2026 fiscal year. Use municipal programmes — ¥100,000 in Saitama City, 5% of costs capped at ¥50,000 in Kumagaya City — together with the national charging infrastructure subsidy (up to ¥750,000 for the unit plus ¥550,000 for installation for a private home).
Q. Can I use the prefectural subsidy on a new build?
A. No. It is limited to an existing home in the prefecture that you live in yourself. For a new build, look at national programmes such as the Housing Energy-Saving 2026 Campaign or ZEH-type subsidies.
Q. Is the subsidy taxable?
A. A subsidy received by an individual for their own home is occasional income, with an annual special deduction of ¥500,000. However, if you attach the "Statement Concerning Exclusion of National Treasury Subsidies from Gross Revenue" to your tax return, the subsidy used to acquire the equipment is excluded from gross revenue (Income Tax Act, Article 42). Consider this in any year your total exceeds ¥500,000.
Sources
This article is based on the following public sources. Amounts, caps, and application status change with the fiscal year and budget consumption. Always check the official sites and guidelines before applying.
*This article is for information only and is not tax or application advice. Amounts, requirements, and application status are as of August 2026 and programmes may close early once budgets are exhausted. Confirm individual cases with the relevant subsidy office, a tax office, or a licensed tax accountant.