Tokyo's decarbonization subsidies for households can, by combining solar panels, storage batteries, and V2H, target up to about ¥2.6 million from the metropolitan programs alone (example: 5 kW solar panels on an existing home + 10 kWh storage battery + V2H). At the same time, there is a pitfall: receiving multiple subsidies in the same year can be taxed as "temporary income." This article covers everything from amounts and application periods to the tax points to watch.
The big picture: the metropolis's 3 programs stack with national subsidies
Tokyo's household subsidies are provided under the "Project to Expand Insulated, Solar-Equipped Housing that is Both Disaster-Resilient and Health-Promoting" (administered by Cool Net Tokyo). The three pillars are ① solar power generation, ② home storage batteries, and ③ V2H (vehicle-to-home, charge/discharge equipment linking an EV and the home). They can also be combined with national subsidies, and the more you stack, the lower your out-of-pocket cost[Cool Net Tokyo (in Japanese)].
| Program | Subsidy guide | Cap |
|---|---|---|
| ① Solar power generation | Existing homes: up to ¥150,000/kW | ¥450,000 for 3.75 kW or less (above that, ¥120,000/kW) |
| ② Home storage battery | New install ¥100,000/kWh | ¥1.2 million/household (not in DR) |
| ③ V2H | Full installation cost with solar panels + EV | ¥1 million |
① Solar power generation
The unit price changes depending on whether the home is newly built or existing, and a distinctive feature is that existing homes (retrofit installation) get more generous support[Cool Net Tokyo FY2026 (in Japanese)].
| Category | Capacity | Subsidy unit price | Cap |
|---|---|---|---|
| Existing home | 3.75 kW or less | ¥150,000/kW | ¥450,000 |
| Above 3.75 kW | ¥120,000/kW | Eligible costs (under 50 kW) | |
| New home | 3.6 kW or less | ¥120,000/kW | ¥360,000 |
| Above 3.6 kW | ¥100,000/kW | Eligible costs (under 50 kW) |
5 kW × ¥120,000/kW (the unit price above 3.75 kW)
= ¥600,000 subsidy
② Home storage battery
Generous support is provided according to capacity. The cap and add-ons change depending on whether you take part in the demand response (DR) demonstration[Cool Net Tokyo FY2026 (in Japanese)].
| Category | Unit price / add-on | Cap |
|---|---|---|
| New install (storage battery package) | ¥100,000/kWh | ¥1.2 million/household (not in DR) |
| Expansion (storage battery unit) | ¥60,000/kWh | ¥720,000/household (not in DR) |
| Participate in the DR demonstration | +¥100,000/unit add-on | The per-household cap is lifted, up to the eligible subsidized costs |
| DR participation + energy management equipment installed | Add-on increased to +¥150,000/unit | Same as above |
To receive the DR demonstration's add-on and higher cap, you must conclude the DR demonstration contract before the combined grant application and results report. Get the order wrong and you cannot receive the add-on.
10 kWh × ¥100,000/kWh (within the ¥1.2 million cap)
= ¥1 million subsidy
③ V2H (charge/discharge equipment linking an EV/PHV and the home)
For V2H, the subsidy rate changes greatly depending on whether you also own solar panels and an EV/PHV. This is where the combination with the Tokyo EV purchase subsidy pays off[Cool Net Tokyo FY2026 (in Japanese)].
| Condition | Subsidy rate | Cap |
|---|---|---|
| Have both solar panels and an EV/PHV | Full installation cost (10/10) | ¥1 million |
| Only one of the two | 1/2 of the installation cost | ¥500,000 |
If you are about to buy an EV, considering it together with the Tokyo EV purchase subsidy makes V2H eligible for a full subsidy, which greatly increases the effect. On June 24, 2026 the metropolis announced it would raise the cap on EV vehicle purchase subsidies to up to ¥1.3 million, and combined with the national CEV subsidy this reaches a scale of up to ¥2.6 million. For details, see the Tokyo EV Purchase Subsidy Guide.
Model case: combining the metropolis's 3 programs
Here is a guide for the case of installing solar panels, a storage battery, and V2H together on an existing home while also owning an EV.
Stack the national subsidies (discussed below) on top of this and you can add even more.
Combining with national subsidies
Tokyo's subsidies can be combined with national and municipal subsidies (but note that you cannot receive subsidies that in total exceed the installation cost).
- Storage battery: It could be combined with the national "DR Home Storage Battery Project" (FY2025 supplementary budget, up to ¥600,000), but it closed on May 29, 2026 when its budget was reached[SII official (in Japanese)]. SII has clearly stated it will not reopen applications for this project, and a successor project under the next supplementary budget is undecided
- V2H: The national charging-infrastructure subsidy (FY2025 supplementary budget) has a slot for V2H charge/discharge equipment and can be combined. For private homes, the equipment cap is ¥750,000 plus a construction-cost cap of ¥550,000, and applications are expected to open July–September 2026 = right now is the time to move. In parallel with the metropolitan preliminary application, be sure to check when acceptance opens[Next Generation Vehicle Promotion Center (in Japanese)]
- National subsidies typically run out of budget within a few months of opening. A realistic approach is to build your funding plan around the metropolitan subsidy and treat the national portion as "a top-up if it is still open"
Application periods and common stumbles
▶ Preliminary applications are made from each program page of Cool Net Tokyo: Solar panels / Storage battery / V2H
| Procedure | Timing (FY2026) |
|---|---|
| Preliminary application | From May 29, 2026 (now accepting) |
| Grant application | June 30, 2026 – March 31, 2027 (V2H, etc.) |
The following three are the typical failure patterns.
- Contracting first is a no-go: In principle, a preliminary application before the equipment installation contract is required. "Order the work and then look for a subsidy" can put you out of scope
- First-come, budget-limited: Even within the period, acceptance ends once the budget is reached. Once you decide to install, file the preliminary application early
- Results-report deadline: If you miss the reporting deadline after the grant decision (in principle within one year, etc., as set by each program), you cannot receive it. Always check the guide
Be sure to grasp this before applying | Tax treatment of subsidies
This is the point we at "Minna no Zeikin" most want to convey. A subsidy received for your own home is "temporary income," and depending on the annual total it can be taxed.
A subsidy an individual receives for their own home is classified as temporary income, with an annual special deduction of ¥500,000. If the total temporary income received that year exceeds ¥500,000, one-half of the excess becomes taxable. Installing solar panels, a storage battery, and V2H together in the same year can bring the subsidy total to the ¥1 million–¥2 million range, in which case a tax return is required[National Tax Agency No.1490].
Temporary income revenue: ¥1.5 million
Special deduction: −¥500,000
(¥1.5 million − ¥500,000) × 1/2 = ¥500,000 is taxed by aggregating with other income
* In a year with other temporary income, such as a maturity payment from life insurance, it is aggregated.
In fact, when you acquire a fixed asset (equipment such as solar panels, a storage battery, or V2H) with a subsidy from the national or a local government, attaching the "Statement concerning the exclusion of national subsidies, etc. from gross revenue" at the time of the tax return means the subsidy used to acquire the equipment is not included in gross revenue and can be made non-taxable (Article 42 of the Income Tax Act; not only businesses but also individuals for their own home are covered). In a year you received subsidies exceeding ¥500,000, not forgetting to attach this statement is the best measure (note that residence tax has no equivalent system).
Splitting up the years of receipt — solar panels this year, the storage battery and V2H next year — makes it easier to stay within each year's ¥500,000 deduction (within the range of your construction and application schedule).
② When a sole proprietor or corporation installs for business use
- Sole proprietor (business use): included in the gross revenue of business income (miscellaneous revenue). Tax can be deferred or excluded via the reduction entry or the special provision excluding it from gross revenue (Article 42 of the Income Tax Act; a statement must be attached)
- Corporation (business use): included in gross profit. Tax can be deferred via the reduction entry for national subsidies, etc.
③ Treatment of fixed asset tax and electricity-sales income
- Solar panels under 10 kW placed on your home's roof (residential use) are, in principle, outside the scope of fixed asset tax (depreciable assets)
- Income from selling surplus electricity is miscellaneous income. For a salary earner, if it is ¥200,000 or less per year together with other side income, there are cases where no filing is needed (calculated separately from the temporary income of the subsidy)
Summary
FAQ
How much are Tokyo's solar panel, storage battery, and V2H subsidies?
In FY2026, solar panels on an existing home are ¥150,000/kW (3.75 kW or less, capped at ¥450,000; above that, ¥120,000/kW), a storage battery is ¥100,000/kWh for a new install (capped at ¥1.2 million/household when not in DR), and V2H covers the full installation cost (capped at ¥1 million) if you have both solar panels and an EV. Since unit prices and caps change from year to year, check the latest in Cool Net Tokyo's guidelines before applying.
Can they be combined with national subsidies?
They can (you cannot receive more than the installation cost in total). However, the national DR home storage battery subsidy (up to ¥600,000) closed on May 29, 2026 when its budget was reached. For the national V2H subsidy (charging-infrastructure subsidy), check the acceptance status on the official site.
Is the subsidy you receive taxed?
A subsidy an individual receives for their own home is, in principle, temporary income, but if you attach the "Statement concerning the exclusion of national subsidies, etc. from gross revenue" to your tax return, the subsidy used to acquire the equipment can be made non-taxable (Article 42 of the Income Tax Act). In a year the total exceeds ¥500,000, consider using this special provision. Business-use subsidies are recorded as miscellaneous revenue or gross profit and can be deferred via the reduction entry, etc.
Can renters use it? What is the timing of the application?
Eligibility has requirements such as installation on a home within Tokyo, and in principle a preliminary application before the equipment installation contract is required. Since acceptance ends once the budget cap is reached even within the period, check the acceptance status on the official site early.
Reference links (sources)
This article is based on the following materials from public bodies (neutral, primary sources). Subsidy unit prices, caps, and periods change with the year and budget status. Always check the official sites and guidelines before applying.
- Cool Net Tokyo (Tokyo Metropolitan Center for Climate Change Actions) — list of subsidies (in Japanese)
- Cool Net Tokyo FY2026 — Household Solar Power Introduction Promotion Project (in Japanese)
- Cool Net Tokyo FY2026 — Household Storage Battery Introduction Promotion Project (in Japanese)
- Cool Net Tokyo FY2026 — V2H Promotion Project for Detached Homes (in Japanese)
- Tokyo Metropolitan Government Bureau of Environment — Project to Expand Insulated, Solar-Equipped Housing (in Japanese)
- SII — FY2025 Supplementary DR Home Storage Battery Project (closed) (in Japanese)
- Ministry of Economy, Trade and Industry — CEV subsidy (FY2025 supplementary, vehicles) (in Japanese)
- Ministry of Economy, Trade and Industry — Subsidy to Promote Charging/Refueling Equipment (FY2025 supplementary, includes V2H) (in Japanese)
- National Tax Agency No.1490 Temporary income (in Japanese)
- National Tax Agency No.5763 Reduction entry for assets acquired with national subsidies, etc. (in Japanese)
* This article is for informational purposes and is not tax or application advice. Subsidy unit prices, caps, and periods change with the year and budget status. Before applying, confirm each subsidy's official site and guidelines, and for tax treatment confirm with a tax office or a tax accountant.