Solar Panel Installation Japan: Costs and Subsidies 2026

Solar panel installation in Japan has grown quickly as more homeowners look to lower electricity bills, reduce their carbon footprint, and gain energy independence from the grid. A typical solar energy system converts direct sunlight into direct current electricity through photovoltaic panels, then uses a solar inverter to convert it into the alternating current your home actually uses, whether the system is a rooftop installation, a flat roof mount, or a ground-mounted array.

New Tokyo regulations, effective April 2025, require large-scale home builders to meet a portfolio-wide solar generation quota across the new houses they supply as part of the city's push toward net zero CO2 emissions. This obligation falls on major home suppliers rather than individual homeowners, and it does not apply to existing homes. If you're building through a smaller local builder below Tokyo's supply threshold, you may not be personally required to install solar panels at all, though many builders choose to include them anyway given the available incentives covered below.

If you're planning to get a new house or are considering getting solar panels, this guide covers the full solar panel installation process in Japan: how many solar panels you're likely to need, what a solar panel installation guide should cover step by step, current government subsidies, realistic cost savings, and how to choose between solar companies offering financing, solar loans, or a simple cash purchase.

👉 Read also: Will Japan Pay You to Move There?

Overview of solar panels

Solar panels, or photovoltaic (PV) modules, convert sunlight into electricity. A PV cell generates direct current (DC) electricity, which is then converted to alternating current (AC) via a power conditioner (inverter) for use in homes or businesses. Solar panels are a key technology in reducing reliance on fossil fuels and promoting renewable energy.

Benefits of solar panels include:

• Reduction in electricity bills

• Lower carbon footprint

• Energy independence

• Eligibility for government subsidies and tax incentives

Why are solar panels necessary in Japan?

As the world moves towards a net zero CO2 emission goal by 2050, the Tokyo Metropolitan Government (TMG) formed The Carbon Half Plan to halve greenhouse gas emissions by 2030. Part of this initiative involves solar panels to promote renewable energy.

Do I need solar panels in Japan?

Large-scale home builders supplying new detached houses in Tokyo after April 2025 must meet a solar generation quota across their portfolio, though the requirement is structured around the builder's total supply rather than mandating a solar panel installation on every individual house.

However, if you are purchasing a property in a different part of Japan, it's possible that solar panels may not be mandated in the region.

Consult with an English-speaking real estate agent or your local municipality about whether the city or prefecture in question has incentives for solar installations.

Many regions offer subsidies, tax incentives, and rebate programs to help defray the cost of solar installation.

What type of solar panels are there in Japan?

There are two types of solar panel systems in Japan:

• Domestic Systems (under 10kW): Uses the electricity that was generated and sells the excess.

• Commercial Systems (over 10kW): All generated electricity is sold and can not be used for personal consumption.

Many houses will use the domestic system, while businesses will use the commercial solar panel system.

How do I install solar panels for my house in Japan?

Installing a solar panel is fairly simple once you have the needed information.

While people's personal experience varies, here are some general steps to help you with the solar panel installation process.

Step 1: Research local regulations and incentives

Check local building codes and zoning laws about the rules for installing solar panels on your property.

We recommend contacting your local ward office for detailed information regarding incentives and tax breaks when installing solar panels.

Step 2: Obtain quotes and choose a contractor

There are many solar panel installation companies in Japan. The most popular solar companies are the following:

• QCELLS

• Canadian Solar (カナディアン・ソーラー)

• Next Energy (ネクストエナジー)

Get quotes from different companies to compare the prices and their services.

Step 3: Financing the system

Many solar panel companies offer financing options, including loans, leases, or power purchase agreements (PPAs).

Calculate the long-term savings and payback period to understand the financial burden and future benefits.

Step 4: System design and installation

There are four types of roof shapes in Japan:

• 切妻 (kiri dzuma)

• 寄棟 (yose mune)

• 入母屋 (iri moya)

• 片流れ屋根 (katanagare yane)

Each roof will need a unique panel design that the contractor will draw up for your home's needs.

Before installation day, your contractor will typically set up scaffolding around the work area for safety, a standard step that can add a day on either end of the actual installation. The mounting structure itself is designed to keep each panel securely oriented and stable against wind and weather, since a loose or poorly angled mount reduces both safety and how much energy the system generates over its lifetime. Electrical wiring between panels typically uses MC4 connectors, an industry-standard connector type built to handle outdoor conditions safely over the system's lifespan.

Orientation matters as much as the mounting itself. Since Japan sits entirely in the Northern Hemisphere, panels generally perform best facing south, though east or west facing roofs can still work with a modest reduction in output. Optimal tilt angle also varies by region: roughly 20 to 26 degrees in Okinawa, 28 to 32 degrees in the Kanto and Kansai regions, and 30 to 40 degrees in Hokkaido and northern Japan, with south-facing at around 30 degrees serving as the commonly cited national rule of thumb. Your contractor's site assessment, which includes checking your roof's condition, shading from nearby buildings or trees, and your household's power bills, determines the actual design for your specific property rather than relying on these regional averages alone.

If your system includes battery storage set up as an off-grid or backup configuration rather than a standard grid-tied system, a charge controller is used to prevent the battery from overcharging, though most residential solar installations in Japan are grid-tied and sell or use excess energy in real time rather than relying on a charge controller.

The contractor will handle the permits from local authorities. Depending on the system's size, complexity, and how many solar panels your system will require—installation will take from a few days to a couple of weeks.

Step 5: Inspection, connection, and activation

Once the installation is done, the local authorities will inspect it to ensure it complies with the electrical codes. If the system is connected to the grid, the process may include installing a device to measure the electrical flow in and out of your house.

Once approved, your contractor will activate the system, which will begin generating electricity.

Step 6: Maintenance

Solar panels require minimal maintenance overall, since a solar panel system has no moving parts to wear down the way mechanical equipment does. That said, routine care still affects how much energy your system actually generates over time.

Panels do need occasional cleaning to clear dust, pollen, or bird droppings that block direct sunlight and reduce output, ideally during the cooler parts of the day to avoid thermal stress on the glass. In Japan specifically, climbing onto your own roof to clean panels is not recommended given the steeper pitch of many traditional roof shapes and the safety risks involved, so most homeowners have this done by their installer or a professional maintenance service instead.

Japan's Photovoltaic Energy Association (JPEA) recommends a professional inspection of solar systems one year after installation, then every 4 years afterward. For most residential systems under 10kW enrolled in Japan's Feed-in Tariff program, this periodic inspection isn't just a recommendation, it's a requirement under the amended FIT Act, and skipping it can put your FIT certification at risk.

Some solar companies include maintenance as part of your total cost or offer it as an additional service, so it's worth confirming what's covered before signing a contract.

What does a solar panel system involve?

A breakdown of a solar panel system

A complete solar system installation includes:

• Solar panels (solar cell module): generate electricity when sunlight hits it

• Frame: contains the solar panels

• Power conditioner: adjusts the voltage for home use

• Power monitor: displays power status and usage

• Dedicated cables: for the solar panel systems

How much does a solar panel cost in Japan?

Three major factors affect the cost of solar panels:

1. Manufacturer: Different companies sell solar panels with varying amounts of kilowatts (kW).

2. The roof: the price increases proportionately to the number of solar panels you purchase and the type of roof and subsequent mounting structure required. Additionally, the shape, size, and material will also affect the overall costs of installing solar panels.

3. Subsidies: The third and final factor is subsidies. The government encourages new detached houses to install solar panels, and subsidies greatly help reduce the costs of installing solar panels.

Currently, the average price for a solar panel in Japan ranges from 200,000 to 400,000 yen per kilowatt (kW).

Are there subsidies for installing solar panels in Japan?

The Tokyo Metropolitan Government is actively promoting the adoption of solar power generation through various incentives to support residents and builders in transitioning to a decarbonized society.

These incentives are designed to reduce greenhouse gas emissions and increase energy efficiency across the city.

Here's an outline of the key governmental incentives available for the installation of solar panels:

1. Subsidy expansions for zero-emission houses

To help create zero-emission houses, both national and local governments have made solar panel subsidies to encourage the installation of solar panel systems.

a) National subsidies for solar panels in Japan

Japan's national subsidy programs for residential solar installation and battery storage are reorganized on a near-annual basis, so program names from even a year ago are often already retired.

As of fiscal year 2026, the main national framework is the Mirai Eco Housing 2026 Project (みらいエコ住宅2026事業), one of four programs under the Ministry of Land, Infrastructure, Transport and Tourism's "Housing Energy Conservation 2026 Campaign" (住宅省エネ2026キャンペーン), alongside separate programs for water heater efficiency, window renovation, and rental multi-unit water heaters.

Unlike its predecessor, the Kosodate Green Housing Support Project, which prioritized household attributes like having young children, the current program prioritizes the housing's actual energy performance, meaning GX-oriented and ZEH-level new housing can qualify regardless of family composition. Subsidy amounts for GX-oriented new housing currently reach up to 1.6 million yen per unit, though eligibility depends on meeting the program's energy performance requirements at the design stage, not adding solar panels after the fact.

A separate national program, the DR subsidy (Demand Response subsidy), previously supported residential storage battery installation at a rate of 37,000 yen per kW. This program has since reached its budget cap and stopped accepting new applications as of July 2025, so it should no longer be treated as a currently available option. Always check the current status of any national subsidy program directly before relying on it for budgeting purposes, since these programs are added, renamed, and closed out on a rolling basis throughout the fiscal year.

ZEH subsidy

The following chart outlines the ZEH補助金, ZEH Subsidy tiers as most recently published:

Project	Subsidy amount
ZEH support project	550,000 yen/unit
ZEH support project ZEH+	1 million yen/unit
Next-generation ZEH+ (custom-built housing) demonstration project	1 million yen/unit
Next-generation HEMS demonstration project	1,120,000 yen/unit

Confirm current-year figures directly against METI's ZEH subsidy page before publishing, since this chart reflects the most recently available published figures at time of writing rather than a live feed.

b) Local government subsidies

Local subsidies for solar panels and storage batteries vary by municipality, and Tokyo alone currently runs several separate programs rather than one blanket subsidy. As of fiscal year 2026, Tokyo's main programs, all administered by Cool Net Tokyo, include:

• Household Solar Power Introduction Promotion Project (家庭における太陽光発電導入促進事業), for existing homes, accepting applications from June 30, 2026 through March 31, 2027.

• Tokyo Zero Emission Housing Promotion Project (東京ゼロエミ住宅普及促進事業), for new homes, accepting applications from April 1, 2026 through March 31, 2027.

• Power Conditioner Renewal Cost Subsidy (パワーコンディショナ更新費用助成事業), for replacing an aging solar inverter, accepting applications from June 30, 2026 through March 31, 2027.

• Household Storage Battery Introduction Promotion Project (家庭における蓄電池導入促進事業), starting June 30, 2026.

Most of Tokyo's own programs in this category cannot be combined with each other, so check which single program best fits your situation, whether you're installing on an existing home, a new build, replacing a solar inverter, or adding battery storage, rather than assuming you can stack them.

On top of Tokyo's metro-wide programs, individual wards and cities often run their own additional subsidies with their own budgets, deadlines, and first-come-first-served cutoffs. These change frequently enough that a specific ward's subsidy amount published even a few months ago may already be exhausted or replaced. Check your specific ward or city office's current page directly before budgeting around a local subsidy figure.

2. Tax incentives and deductions

Significant tax reductions or complete exemptions exist for those who meet the requirements as part of Tokyo's ZEH project.

These incentives include exemptions from part or all of the taxes normally due on acquiring real estate, making the initial costs of installing solar panels more affordable for property developers and home buyers.

Here is an overall summary of the deduction amount for energy-saving renovation involving solar panels.

Construction Type	Deductible Limit	Deduction Rate	Maximum Deduction Amount  (required construction + other construction total)
Energy-saving renovation work	3.5 million yen	10%	625,000 yen (675,000 yen)
Long-term quality housing (earthquake resistance or energy saving + earthquake durability)	6 million yen	10%	625,000 yen (675,000 yen)
Long-term quality housing (earthquake resistance + energy saving + durability)	3.5 million yen	10%	750,000 yen (800,000 yen)

3. Zero emission points

Tokyo extended its Zero Emission Points Program to encourage energy-efficient appliances. When Tokyo residents purchase energy-efficient home appliances, they receive points that can be exchanged for gift items.

For example, switching to a refrigerator that saves a certain amount of energy can give you points worth up to 21,000 yen.

4. Support for households without solar panel capability

The Tokyo government understands that not all buildings can install solar panels due to structural or regulatory limits.

Thus, the government is facilitating access to renewable energy through various means, such as helping to negotiate lower rates, facilitating contracts with renewable energy providers, and supporting energy distribution.

5. For housing-related organizations

The Tokyo government is looking for ways to partner with housing-related organizations, such as residential apartments, to promote energy efficiency and renewable energy as part of the broader housing industry, making it more feasible for Tokyo residents to install solar panels in apartment buildings (i.e., buildings that aren't a detached house).

Energy savings with solar panels

The amount of electricity a solar system can generate directly affects how much energy and money a household can save. Several factors influence total savings, including system size, roof orientation, shading, and local electricity rates.

Estimated annual generation

System Size	Estimated Annual Output	Notes
3 kW	3,300–3,600 kWh	Small homes or limited roof space
5 kW	5,500–6,000 kWh	Average Japanese detached house
10 kW	11,000–12,000 kWh	Large homes or small businesses

A standard 5 kW residential solar system in Japan can cover most of a household’s electricity needs, providing approximately 7,000–8,000 JPY monthly savings, reducing CO₂ emissions, and increasing energy independence.

Monthly Savings Example (Tokyo)

• Average electricity rate: ~27 JPY/kWh

• 5 kW system: 5,800 kWh/year → ~15.9 kWh/day → ~7,700 JPY/month savings

• Savings vary seasonally: higher in summer due to longer daylight, lower in winter.

Additional Considerations

1. Storage batteries: Storing excess energy allows households to use solar power at night or during cloudy days, further reducing reliance on the grid.

2. Selling excess electricity: Under Japan’s Feed-in Tariff (FIT) program, surplus energy can be sold back to the grid, generating additional income.

3. Energy efficiency: Pairing solar panels with energy-efficient appliances maximizes financial and environmental benefits.

Energy savings with solar panels

The amount of electricity a solar system can generate directly affects how much energy and money a household can save. Several factors influence total savings, including system size, roof orientation, shading, and local electricity rates.

Estimated annual generation

System Size	Estimated Annual Output	Notes
3 kW	3,300–3,600 kWh	Small homes or limited roof space
5 kW	5,500–6,000 kWh	Average Japanese detached house
10 kW	11,000–12,000 kWh	Large homes or small businesses

A standard 5 kW residential solar system in Japan can cover most of a household’s electricity needs, providing approximately 7,000–8,000 JPY monthly savings, reducing CO₂ emissions, and increasing energy independence.

Monthly Savings Example (Tokyo)

• Average electricity rate: ~27 JPY/kWh

• 5 kW system: 5,800 kWh/year → ~15.9 kWh/day → ~7,700 JPY/month savings

• Savings vary seasonally: higher in summer due to longer daylight, lower in winter.

Additional Considerations

1. Storage batteries: Storing excess energy allows households to use solar power at night or during cloudy days, further reducing reliance on the grid.

2. Selling excess electricity: Under Japan’s Feed-in Tariff (FIT) program, surplus energy can be sold back to the grid, generating additional income.

3. Energy efficiency: Pairing solar panels with energy-efficient appliances maximizes financial and environmental benefits.

Frequently asked questions

How many solar panels do I need for my home?

Most Japanese households install a system between 3kW and 5kW, which typically means somewhere around 8 to 14 standard solar panels depending on each panel's wattage and your roof's available space. A 5kW solar panel system is the national average and covers most of an average household's energy needs, while the practical maximum for most residential systems is around 10kW. The right system size depends on your roof orientation, whether you have a flat roof or a sloped one, how much direct sunlight your roof gets through the day, and your household's actual energy usage.

Do I need a solar battery with my solar panels?

A solar battery is not required, but it's highly recommended if you want to use more of the energy your system generates. Solar panels only produce electricity while there's direct sunlight, and without battery storage, any excess energy your system generates during the day either gets used immediately or sold back to the grid rather than saved for use at night. Adding battery storage increases upfront costs but improves energy independence and can meaningfully reduce how much you rely on grid input after dark.

Are solar panels actually worth it in Japan?

For most homeowners, yes, over the long term. The Tokyo Metropolitan Environment Bureau estimates installing a solar power system can save around 7,700 yen a month on electricity bills in Tokyo, and combined with current subsidies and tax credits, payback periods can shrink significantly compared to an unsubsidized installation. Whether it's worth it for a specific property still depends on roof orientation, local electricity rates, and how much of the upfront cost subsidies offset.

Can I install solar panels on a rental property?

Direct installation is usually not possible on a rental property without the landlord's or homeowners association's approval, since it involves permanent changes to the building's roof tiles, electrical wiring, and electrical connections. Some renters instead use shared rooftop solar programs or virtual net metering arrangements, which let you benefit from renewable energy and cost savings without physically installing panels on the building you live in.

How long do solar panels last?

Most photovoltaic panels last 25 to 30 years, with efficiency degrading by roughly 0.5 percent per year, meaning a panel installed today will still generate the large majority of its original output decades from now. The solar inverter typically needs replacement well before the panels themselves, often after 10 to 15 years, which is why Tokyo now offers a dedicated subsidy specifically for power conditioner replacement rather than only for new installations.

How much electricity can I save per year with a solar power system?

A typical 5kW residential system in Japan generates approximately 5,500 to 6,000 kWh per year, enough to cover most of an average household's energy needs and save around 7,700 yen a month in Tokyo. Smaller or larger systems scale roughly in proportion, though actual savings always depend on your roof's direct sunlight exposure, local electricity rates, and how much of your usage happens while the system is actively generating power.

Do I need planning permission to install solar panels in Japan?

Most residential solar panel installations don't require special planning permission beyond standard local building code compliance, which your contractor typically handles as part of the installation process. However, local authorities do inspect the completed installation to confirm it meets electrical codes before the system can be connected to the grid, and homeowners in a shared building or those with a homeowners association may need separate approval before installation day.

In closing

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