Leave Your Solar Panel Installation Work in Adachi Ward, Tokyo to Kakeru Koumuten Co., Ltd.!
For solar panel and battery installation in
Adachi, Tokyo,
Kakeru Koumuten is at your service!
Kakeru Koumuten is a company specializing in exterior renovations.
As a strong player in roofing work, we are entrusted withsolar panel and battery installation that considers roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Adachi, Tokyo”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Adachi, Tokyo”
We will also explain the above three points!
Installing solar panels carries risks such as“the occurrence of leaks” and other troubles.
To ensure a satisfactory solar panel installation, we recommend obtainingthree estimates!
Table of Contents (tap to open/close)
- Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Adachi-ku, Tokyo
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Adachi-ku, Tokyo
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installer in Adachi-ku, Tokyo
- Benefits of Introducing Solar Equipment
- Points to Note When Introducing Solar Power Generation
- How to Choose Solar Panels
- Frequently Asked Questions about Solar and Storage Battery Installation in Adachi-ku, Tokyo
- If You’re Looking for a Solar Panel Installer in Adachi-ku, Tokyo, Contact Kakeru Koumuten
- Characteristics of Adachi-ku, Tokyo and Key Points for Solar Installation
- Service Area in Adachi-ku, Tokyo
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Adachi-ku, Tokyo
Regarding why our company is entrusted with solar panel installation by customers in Adachi-ku, Tokyo,
“Our unique strengths in solar panel installation that cannot be imitated by other companies”
have received positive feedback from many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We Also Handle Exterior Renovations Besides Solar Panel Installation!
Problems such as leaks that occur during solar panel installation may be caused by insufficient verification of the roof and waterproofing at the installation site.
Even if one is knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside their expertise, so caution is necessary.
It is reassuring to have expertise in roofing to avoid maintenance issues and troubles after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent troubles after solar panel installation!
2.Specialized Equipment for Exterior Renovation
Kakeru Koumuten Co., Ltd. has prepared the following warehouses and material storage areas to provide solar work and exterior renovations at low cost and high quality.
We have established five bases for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding depending on the construction conditions and can assemble the scaffolding in-house.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also reduce the cost of scaffolding work.
We own scaffolding materials for approximately 50 single-family homes!
Even if there is a height difference on the site, our in-house scaffolding team will plan the scaffolding according to the local conditions.
Storage of Materials in Our Large Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, we canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, allowing us torespond quickly in emergencies!
Sorting and Transporting Waste Materials In-House
The installation of solar panels often involves roofing work, generating various waste materials such as paints, wood, and metals.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior Renovation Dedicated Showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on roofing materials!
We can also provide simulations of the revenue and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also have samples of roofing materials and models that explain the structure, allowing for detailed explanations!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is its complete in-house construction.
By having Kakeru Koumuten manage everything from inquiries to project completion in a consistent manner, we can keep costs down while providing high-quality roof renovations.
Additionally, one representative will handle everything from the estimate to project completion.
Since the person in charge does not change, whether it’s the sales representative or the construction management representative, smooth communication is possible.
We can provide consistent in-house construction from temporary scaffolding installation, exterior wall painting, to roof renovations!
4. Various Permits Obtained & Skilled Workers on Staff
We have obtained construction industry licenses and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal workers and painting specialists on staff, and we are confident in our construction techniques.
We can also handle large-scale roofing projects such as those for factories!
5. Warranty and Aftercare Maintenance
In addition to the manufacturer’s warranty for solar panel installation work, our own construction warranty (leakage warranty) is also included!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, it may not be possible to provide a warranty unless a roof renovation is performed. The construction warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary depending on the warranty content.)
Aftercare maintenance is available annually, and we send out notification DM every year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
If you cannot access the roof due to height, we can utilize a drone to assist!
During leak investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of the solar panels decreases due to dirt, we can perform cleaning with a specialized brush.
We will respond according to the customer’s wishes.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training so that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
Kakeru Koumuten provides not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar installation guidebook” and a “profit and loss simulation” that takes into account loan interest rates and electricity costs.
The profit and loss simulation can be created for projected cumulative profits and losses over 20 to 30 years.
Even customers who are not familiar with solar installations will receive materials that clearly summarize important points and disadvantages!
We encourage you to obtain comparative estimates and review plans from other companies!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 or 30 years.
Confirming “Is it okay to install them directly on the current roof?” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, which specializes in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing materials such as slate, tiles, metal roofs, and flat roofs (rooftop waterproofing). If the remaining lifespan of the roofing material is short, we may suggest roof renovation first. |
| 2. Condition of Substrate and Waterproof Sheet | If the sheathing boards or roofing (waterproof sheet) under the roofing material are damaged, it will affect the fastening strength and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, Slope, and Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, can affect the power generation. We will create a layout diagram from the drawings and the site, and you can confirm it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The shape and size of the roof determine the number of panels that can be installed (installation capacity). The number of panels that can be installed varies depending on the panel size, so we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will check whether the method involves drilling holes in the roofing material for fastening or using brackets to secure the roofing material. The fixing method varies by technique, so please confirm the waterproofing treatment method for the fixed parts during the estimate. |
| 6. Weight of the Roof | The roof will become heavier due to the panels being added. After investigating the existing roof, substrate, and load-bearing capacity, switching to lighter roofing materials may also be an option if necessary. |
| 7. Installation Location of Equipment and Wiring | We will confirm the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect the cost. |
| 8. Ease of Scaffolding Setup and Delivery Routes | If there are elevation differences on the site, planning for scaffolding and the delivery route for equipment and materials may require some ingenuity. The width of the front road and any steps on the site will also be checked during the site survey. |
Fixing Methods and Confirmation Points by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproof treatment of fixing parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suitable for the type of tile (even methods that do not drill holes in the tiles will secure to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lighter roofing materials before installation. |
| Metal Roof (Horizontal/Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a framework | Type and deterioration status of the waterproof layer, waterproofing around the framework. Consider in conjunction with the timing of waterproofing work. |
If you plan to renovate the roof 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the roof is deteriorating, it may be more cost-effective in the long run to renovate to a highly durable roofing material before installation.
Kakeru Koumuten Co., Ltd. specializes in roofing work and can also handle the removal and reinstallation of solar panels, so please consult us according to the condition of your roof!
▶ Click here for roof renovation in Adachi Ward, Tokyo
Possible Subsidies and Grants in Adachi Ward, Tokyo
If you are introducing solar panels or storage batteries in Adachi Ward, Tokyo, there is a possibility that the systems from the “National Government,” “Tokyo Metropolitan Government,” and your local “Adachi Ward” may apply.
The following information is based on the official pages of each system as of October 6, 2026. The application status may change based on the budget, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Tokyo “Home Solar Power Generation Promotion Project” | Individuals, corporations, or management associations installing a new unused solar power system (output less than 50kW, JET certification, etc.) in residential properties within Tokyo. The generated power must be used in the residential part. Pre-application is required | Existing homes: 15,000 JPY per kW for 3.75kW or less (maximum 450,000 JPY), 12,000 JPY per kW for over 3.75kW and under 50kW New homes: 12,000 JPY per kW for 3.6kW or less (maximum 360,000 JPY), 10,000 JPY per kW for over 3.6kW |
For the 2026 fiscal year, pre-applications are being accepted from May 29 (will end once the budget is reached). From the pre-application for the 2026 fiscal year, submission of a certificate issued by a financial institution during the performance report is mandatory |
| Tokyo “Home Storage Battery Promotion Project” | Owners of eligible equipment (storage batteries registered with SII, excluding national and local governments). Must be installed between April 1, 2026, and March 30, 2027. If pre-applying after October 1, 2026, only products registered with the national SII for the 2026 fiscal year are eligible | Storage battery package: 100,000 JPY per kWh (maximum 1,200,000 JPY per household) Additional for participating in DR demonstration (100,000 JPY per unit; 150,000 JPY per unit if energy management equipment is installed) Expansion of storage battery unit: 60,000 JPY per kWh (maximum 720,000 JPY per household) |
For the 2026 fiscal year, pre-applications are being accepted from May 29. Grant application and performance report will start from June 30 |
| Adachi Ward “Subsidy for Solar Power Generation Systems and Storage Battery Installation (Post-Installation Application)” | Individuals or corporations that newly install an unused solar power system or storage battery in residential properties within the ward. A surplus power purchase agreement with the power company is required for solar power. Applications must be made within 12 months from the payment completion date of the equipment (loan contract date in case of a loan) | Solar power generation: maximum 240,000 JPY (maximum 288,000 JPY if using a contractor within Adachi Ward) Storage battery: maximum 50,000 JPY (maximum 60,000 JPY if using a contractor within Adachi Ward) |
For the 2026 fiscal year, the 3rd phase (October 1 to December 28) is currently accepting applications. The 4th phase will be from January 4, 2027, to February 26, 2027. Will end once the budget is reached |
| National “DR Home Storage Battery Project” (2025 Fiscal Year Supplement) | Newly introducing home storage systems that can be utilized for DR (demand response) with registered products | Calculated based on an initial effective capacity of 34,500 JPY per kWh (subsidy rate within 30% and maximum 600,000 JPY per application) | The budget was reached on May 29, 2026, and the public offering has ended (there is no plan to reopen the public offering as stated on the official website, and applications cannot be made at this time) |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but they must be combined with essential works such as insulation renovation of windows (openings) and the structure; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities | Storage battery: 96,000 JPY per household | The program will end once the budget limit is reached. As of October 5, 2026, the application amount for renovations is displayed as 8% of the budget on the official website. Please check the reception status on the official site. |
The Tokyo solar power and storage battery subsidy program requires prior application. For storage batteries applied for after October 1, 2026, only products registered with the national SII will be eligible, and the equipment requirements will change. The subsidy in Adachi Ward is a post-installation application system, requiring applications to be submitted within 12 months from the payment completion date of the equipment (or loan contract date in the case of loans). Eligibility conditions, application procedures, and the possibility of combining different programs vary, and applying does not guarantee funding, so please confirm before contracting or starting work.
Kakeru Koumuten will guide you on eligibility conditions and application periods for each program after confirming them.
National Subsidy “DR Home Storage Battery Project (Support Project for the Introduction of Home Storage Systems for DR Resource Implementation)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those introducing new storage systems that can be utilized for demand response (DR) with registered products. In the fiscal year 2025 supplementary budget, the subsidy amount was determined based on a standard amount of 34,500 yen per initial effective capacity of 1 kWh, with a subsidy rate of up to 30% and a maximum of 600,000 yen per application. There are conditions such as that contracts or orders made before the grant decision are not eligible.
However, the fiscal year 2025 supplementary budget reached its application amount on May 29, 2026, and the public offering has ended. The official site also states that there are no plans to reopen the public offering, and applications are currently not possible. Please check the official site for future public offerings.
Additionally, there are currently no subsidies confirmed for the installation of solar panels on existing homes.
👉 Here is the official site for the DR Home Storage Battery Project
Tokyo “Promotion Project for the Introduction of Solar Power Generation in Homes”
This subsidy is for those installing unused solar power generation systems in residential homes in Tokyo. The simultaneous installation of storage batteries is not a requirement.
● Existing homes: For systems below 3.75 kW, 150,000 yen per kW (maximum 450,000 yen); for systems over 3.75 kW and below 50 kW, 120,000 yen per kW.
● New homes: For systems below 3.6 kW, 120,000 yen per kW (maximum 360,000 yen); for systems over 3.6 kW and below 50 kW, 100,000 yen per kW.
● Additional amounts for the installation of rooftop frames and waterproofing work are also available.
The target is to install unused panels with a capacity of less than 50 kW that have obtained JET certification, used in residential areas. The process involves making a prior application and then submitting a grant application after installation. From the fiscal year 2026 prior application, it has become mandatory to submit certificates issued by financial institutions at the time of performance reporting.
According to the official page of Tokyo, prior applications are being accepted from May 29, 2026. The program will end once the budget is reached, so please check the official page for the reception status.
👉 Here is the official page of Tokyo (Cool Network Tokyo)
Tokyo “Household Battery Installation Promotion Project”
This is a subsidy for the installation costs of battery systems aimed at increasing self-consumption of electricity generated by solar power and improving energy independence during emergencies.
●Battery Package: 100,000 JPY per kWh (up to 1,200,000 JPY per household)
●Additional for DR Demonstration Participation: 100,000 JPY per unit (150,000 JPY per unit if energy management equipment is installed)
●Battery Unit Expansion: 60,000 JPY per kWh (up to 720,000 JPY per household)
Eligible applicants are owners of the subsidized equipment (excluding national and local governments), and installation must be completed between April 1, 2026, and March 30, 2027. If applying in advance after October 1, 2026, only products registered in the national SII for the fiscal year 2026 are eligible.
The official Tokyo page states that advance applications are being accepted from May 29, 2026. For detailed information, including conditions for combining with solar power generation, please check the official page.
👉 Click here for the official Tokyo (Cool Net Tokyo) page
Adachi Ward “Subsidy for Solar Power Generation System and Battery Installation Costs (Post-Installation Application)”
This is a subsidy for those who newly install unused solar power generation systems or batteries in residential areas within the ward. The application process occurs after installation, not before the construction.
●Solar Power Generation: Up to 240,000 JPY (up to 288,000 JPY if using a contractor within Adachi Ward)
●Battery: Up to 50,000 JPY (up to 60,000 JPY if using a contractor within Adachi Ward)
Eligible applicants include individuals, owners of multi-unit residences, managers of condominiums, small to medium-sized businesses, and those listed on the ward’s official page. If installing solar power, a surplus power purchase agreement with the electric company is required. The application condition is that 12 months have not passed since the payment completion date of the equipment (or loan contract date in the case of a loan). It is possible to combine this with Tokyo’s subsidy projects, but if the total amount exceeds the eligible expenses, adjustments will be made.
The official Adachi Ward page states that for fiscal year 2026, the 3rd phase (October 1 to December 28) is currently accepting applications (the 4th phase will be from January 4 to February 26, 2027). Applications will close once the budget is reached, so please check the official page for the application status.
👉 Click here for the official Adachi Ward page
Solar Panel Installation & Battery Installation Price List
⇧Service Menu | For Costs Related to Solar Panel and Battery Installation, Click Here
⇧Service Menu | For Costs Related to Solar Panel Removal and Water Heater Removal, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and batteries should be checked by separating them into “Equipment Costs (Device Costs)” and “Construction Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary greatly depending on the installation capacity, equipment grade, and roof condition.
Considerations for Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatts). Batteries are compared in terms of the amount of electricity they can store, expressed in kWh (kilowatt-hours).
The amount of kW that can be placed on the roof varies for each house based on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panels as approximately 800,000 JPY to 1,200,000 JPY for 3 to 5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6 to 10 kW. (These are just approximate amounts and may vary depending on the length of wiring, the scope of scaffolding, existing roofing materials, and the layout of the panels.)
▶ Installation Menu | Costs for Solar Panel Installation and Battery Installation
Items to Check in the Estimate (Cost Verification)
When comparing estimates, it’s common to compare different capacities and equipment. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, and total installation capacity (kW) are specified. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls in conjunction with the battery. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range of use during power outages (entire house or specific circuits), and installation location. |
| 4. Mounting Frame and Hardware | Name of the hardware suitable for the roofing material and the method of securing it (whether it involves drilling holes or clamping). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, and whether there is a monitor to check the power generation amount. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at the fixing points, and whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | How much support is included for applications to the power company, certification for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If it is simultaneous with roofing work or exterior painting, check that the same scope and quantity are not double-counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters or old panels, and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether prices are tax-inclusive or tax-exclusive, conditions under which additional costs may arise, and details and duration of manufacturer and workmanship warranties. |
If the capacities differ, both the price and power generation will change. Kakeru Koumuten Co., Ltd. welcome comparisons, so if you bring estimates from other companies, we can explain the differences item by item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can get an estimated quote and a financial simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can obtain an estimated quote and financial simulation!
*The simulation results are estimates. Actual financial results may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection and replacement.
Customer Feedback
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installations
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh |
| Base Mounting Hardware Used |
| Niigata Manufacturing/Aluminum Catch-Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed using catch-type hardware gripping the horizontal metal roof (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Expected recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| About 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the introduction of solar panels and storage batteries. I heard that grants are available, and I would like to know how much will be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of the grant, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Adachi City, Tokyo
There are many solar panel installation contractors available in Adachi Ward, Tokyo, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and battery storage installation work, let’s check the following 4 points.
● Knowledge of roofs as well as solar panels
● Confirm the presence of warranties and aftercare services
● Obtain estimates from multiple contractors (3 companies as a guideline)
● Check if they provide support for subsidy applications
By confirming the above 4 points, you will be able to choose a reliable contractor.
Knowledge of roofs as well as solar panels
Defective installation of solar panels can sometimes be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge of solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient verification of roofs and waterproofing
・Solar panels were installed on a deteriorated roof, resulting in leaks
・Solar panels were installed on a roof with a short lifespan, requiring a renovation to detach and reattach the solar panels within a few years
・Misjudgment of the type of waterproofing led to incorrect treatment and subsequent leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the presence of warranties and aftercare services
When choosing a solar installation contractor, make sure to check for warranties. It is important to confirm not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While the solar panels and battery storage units come with manufacturer warranties, also check for the presence of a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may cover the repairs within the warranty period and conditions.
Additionally, some contractors provide aftercare services separate from warranties, so be sure to check if the contractor you are considering has aftercare services.
Since abnormalities or damage on the roof may not be visible, you might not notice them yourself.
By conducting inspections during aftercare, you can detect abnormalities early, making it easier to prevent major repairs or failures!
Kakeru Koumuten Co., Ltd. offers a rain leak warranty as part of the workmanship warranty for solar panel installations. (The warranty for solar panel installations is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty unless a roof renovation is performed.)
We also conduct aftercare maintenance and send out annual DM!
If you check the DM and wish to proceed, we will visit for aftercare maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting a solar panel installation, let’s obtain estimates from multiple contractors.
Even for the same manufacturer and the same work content, costs may vary, and warranties and after-sales services may differ.
Additionally, obtaining multiple estimates makes price negotiations easier.
To request your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates,
“Check the estimate items”
“Type of solar panel”
“Warranties and after-sales services”
let’s compare in detail and make a judgment! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid judging solely based on price!
▶ Go to “Breakdown of Installation Capacity, Equipment, and Construction Costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, there is a possibility that the subsidy will not be granted.
Since there are systems like the Tokyo subsidy that require prior application, it is reassuring to have a contractor who supports the preparation of necessary documents and the flow of procedures.
Let’s complete the procedures specified for each system (for the Tokyo subsidy, prior application) before proceeding with the construction!
For the Tokyo subsidy, after installation, you will need to submit a grant application and performance report, which will be reviewed before the grant is issued! (The flow of procedures varies by system)
▶ Go to “Subsidies and Grants that May Apply in Adachi Ward, Tokyo” in this article
Benefits of Introducing Solar Equipment
The benefits of introducing solar panels are as follows!
Benefit 1: Economic Benefits
The biggest advantage of introducing solar panels is the economic benefit!
The selling price of electricity has decreased compared to ten years ago, but by consuming the electricity generated, you can reduce the amount of electricity purchased from the utility company and gain benefits!
As electricity prices rise, the ability to cover consumption with solar power becomes attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
For residential use (under 10kW), the selling price (FIT) from certifications after October 2025 is set at “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year.” The same price will apply for the 2026 fiscal year. After the fifth year, it is generally more advantageous to use it in your home (self-consumption) rather than selling it, making the combination with a storage battery a viable option.
👉 Ministry of the Environment | For purchase prices and periods, click here
Advantage 2 Subsidies can be utilized!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
Reducing the actual burden through subsidies is a significant advantage!
In Adachi Ward, you may be eligible for programs from the national government, Tokyo Metropolitan Government, and Adachi Ward (please check the application status for each program).
Advantage 3 Environmentally friendly!
Solar power generation has low carbon dioxide emissions and can reduce dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices like power conditioners do have operating noise.)
Advantage 4 Heat insulation effects are expected!!
By installing them on the roof or rooftop, the panels block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the temperature of the roof, providing a heat insulation effect!
（This does not improve the insulation performance of the building itself）
Benefit 5 Electricity can be used even during power outages!!
If a storage battery is installed, it becomes possible to use electricity even during emergencies like power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capability, you may be able to use electricity from a dedicated outlet during daytime generation.
（The devices, output, and duration that can be used during a power outage vary depending on the model and wiring method）
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1 Maintenance costs can be incurred
A particularly overlooked maintenance cost is for the roof where solar panels are installed.
If you perform roof remodeling 10 to 20 years later, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorated, it is reassuring to remodel it with durable roofing materials before installing the solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It would be reassuring to consider maintenance costs in the simulation before introducing solar panels!
Point 2 The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix hardware to the roofing material and substrate with screws, waterproofing of the fixed parts is crucial.
In methods that involve making holes in the roof, the risk of leaks inevitably arises.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, one option is to replace the roofing material with a metal roof and fix the solar panels using the catch method. (The catch method has compatibility conditions between the roofing material and hardware, and it cannot be used with all metal roofs)
Catch-type base metal fittings for horizontal metal roofs
Note 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load-bearing capacity, switching to a lighter roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their outputs and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
How to Choose 1: Compare based on total output of the roof
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and the more power generated, the better!
Solar panels come in various sizes and outputs depending on the manufacturer.
A panel with an output of 350W and a panel with an output of 400W may seem at first glance that the higher output panel is better.
However, if the size of the panel does not fit well with the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” resulting in different numbers of panels that can be installed on the same roof due to size differences.
400W×15 panels = 6kW (total output of the roof)
350W×20 panels = 7kW (total output of the roof)
As shown above, even if the output of a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual power generation (kWh) will vary depending on conditions such as roof orientation, slope, and shading.
How to Choose 2: Compare based on degradation rate of solar panels
Solar panels have a degradation rate, and their output gradually decreases over 10 years and 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or power generation itself.
Choosing solar panels while considering the degradation rate, rather than just the initial output, will lead to a regret-free selection!
How to Choose 3: Compare based on warranty period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
For output warranties, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies!
It’s always better to have a longer warranty, so let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Battery Installation in Adachi, Tokyo
We have compiled frequently asked questions from customers considering the installation of solar panels and batteries in Adachi, Tokyo. (Tap to open the answers)
How much does it cost to install solar panels and batteries in Adachi, Tokyo?
The cost varies depending on the installation capacity, equipment, and roof condition. In the above construction example (solar panel 4.3kW + battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines for different capacities are available on the solar panel and battery installation pricing page. We will create a layout diagram from the drawings and site survey and provide a free estimate!
Are there any subsidies available for solar power and battery installation in Adachi, Tokyo?
As of October 6, 2026, Tokyo’s “Promotion Project for Solar Power Generation in Households” (for existing homes, 15,000 yen per kW for systems under 3.75kW, with a maximum of 450,000 yen) and “Promotion Project for Battery Installation in Households” (100,000 yen per kWh, with a maximum of 1.2 million yen per household) are accepting pre-applications starting May 29, 2026, as posted on the official Tokyo (Cool Network Tokyo) page. Adachi Ward offers subsidies for solar power systems and battery installation (up to 240,000 yen for solar power, 288,000 yen if using a contractor within Adachi Ward; up to 50,000 yen for batteries, 60,000 yen if using a contractor within the ward), which are currently accepting applications for the third period of FY2026 (October 1 to December 28), as stated on the official Adachi Ward page. The national DR home battery project has ended its public recruitment.
Since the application status may change, please refer to the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies after the construction is completed?
This depends on the system. Tokyo’s subsidies require pre-application. Conditions such as whether you can contract and start construction before applying vary by system, so please check before signing a contract.
The order of procedures varies by system, so please confirm before contracting and starting construction.
Can solar panels be installed on a slate roof? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate. The method of securing the panels varies by construction method, and when securing brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is essential.
Kakeru Koumuten Co., Ltd. is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation. If deterioration is progressing, we can also suggest methods such as roof overlay (cover method) or complete replacement before installation.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed within 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with durable roofing materials before installation.
Please consult us on how to proceed with the installation after checking the condition of the roof through a site survey!
Is it better to install a storage battery together with solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it in your home rather than selling it.
Additionally, the subsidy for storage batteries in Tokyo (for Reiwa 8, it is 100,000 yen per kWh, with a maximum of 1.2 million yen per household) aims to increase self-consumption of electricity generated by solar power. In Adachi Ward, the installation costs for storage batteries are also included in the subsidy. You can compare “solar only” and “solar + storage battery” in a financial simulation for your consideration.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and site survey, and provide you with the installation capacity and power generation simulation.
Adachi Ward is considered to have a flat terrain with little elevation difference, but the shape and orientation of the roof, as well as the shadows cast by surrounding buildings and trees, will differ for each house. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
For the above construction example (solar panels 4.3 kW + storage battery), it took about 3 days. The duration may vary if roofing work is done simultaneously or depending on the shape of the roof and installation capacity.
Additionally, please note that there will be a separate period for applying for subsidies and to the power company, so please consult us early.
What is the current selling price (FIT) for electricity?
For residential use (less than 10 kW), the selling price for certified installations after October 2025 will be 24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year, and the same price will apply for the 2026 fiscal year.
The idea is to recover initial costs more quickly in the first 4 years and then focus on self-consumption. Kakeru Koumuten provides financial simulations that take into account loan interest rates and electricity costs.
Can you handle maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-maintenance DM notices and visits for inspections upon request from customers. We can also clean solar panels with a special brush if the power generation decreases due to dirt.
It is difficult to check areas on the roof by yourself, so please feel free to consult us if you have any concerns.
Can you also renovate roofs that already have solar panels installed?
It is possible. Kakeru Koumuten Co., Ltd. can detach and reattach solar panels in-house, allowing us to perform roof overlay (cover method) or re-roofing after removing the panels, and we will handle everything consistently until they are reinstalled. The removed panels can be stored in our own warehouse.
For costs, please refer to the solar panel detachment and water heater removal pricing page.
If you are looking for a solar panel installation contractor in Adachi-ku, Tokyo, please consult Kakeru Koumuten
Our company handles many exterior renovations, including solar panels, roof work, and exterior wall work in Adachi-ku, Tokyo.
We receive requests from many customers, including renovation companies and real estate agencies!
Kakeru Koumuten promises “high-quality renovations at low cost”, and we have received positive feedback from many customers.
We continue to update our construction achievements every year and will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay (cover method) and re-roofing but also partial roof repairs, exterior painting, and exterior wall cover methods.
We are also happy to handle small jobs like partial repairs and rain gutter cleaning!
In urgent cases like leak repairs, we may be able to provide emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult with us!
“I want to know recommended solar panels”, “I want to keep costs down as much as possible”, “I just want an estimate for now”, we will provide the best solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in the customer’s position and will propose the best construction plan!
We are confident that we will not be outdone in terms of cost, quality, and organization compared to other companies in exterior construction!
We are confident, so we welcome competitive quotes!
Estimates are completely free, and if we are found to be inferior to other companies, you are free to decline!
Characteristics of Adachi-ku, Tokyo and Points of Solar Construction
Adachi Ward is located at the northernmost point of the 23 wards of Tokyo, with a total area of 53.25 square kilometers, accounting for about 9% of the 23 wards, making it the third largest after Ota Ward and Setagaya Ward. The Sumida River flows to the south, the Arakawa River to the west, the Menagagawa River to the north, and the Nakagawa and Ayase Rivers to the east, with the Arakawa River dividing the ward from northwest to southeast. We have summarized the characteristics of the terrain in Adachi Ward, Tokyo, and points to consider when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Adachi Ward, Tokyo, and points for solar work
■ Flat terrain with little elevation difference. Check shadows and roof differences on-site
Adachi Ward is considered to be flat land with little elevation difference, gently sloping from northwest to southeast. The capacity and power generation can vary based on the shape, orientation, and slope of the roof, as well as the shadows cast by neighboring houses, trees, and utility poles, rather than the elevation difference of the site. Kakeru Koumuten Co., Ltd. creates layout diagrams from blueprints and on-site surveys, and you can confirm them through power generation simulations.
■ A ward surrounded by rivers. Check flood risk for equipment installation locations
Adachi Ward is surrounded on all sides by rivers flowing within the ward. Depending on where the power conditioner and storage batteries are installed, whether indoors or outdoors, the impact during flooding may vary. Please check the flood risk for your residence on the ward’s flood, internal water, and storm surge hazard map, and consult with us regarding the installation location and height in conjunction with the manufacturer’s installation conditions.
■ Various types of roofs and construction years for each house. Check the roof and waterproofing before installation
Even within the same ward, the types of roofs, construction years, and shapes of the sites vary from house to house. At Kakeru Koumuten Co., Ltd., we will check the type and condition of the roof and the situation of the site before installation, and propose methods for securing the installation, waterproofing details, and scaffolding plans.
■ Annual sunshine hours at the Tokyo Observatory are about 1,927 hours
According to the Japan Meteorological Agency’s average values (1991–2020), the annual sunshine hours at the Tokyo Observatory are about 1,927 hours, with January (about 193 hours) being the most and June during the rainy season (about 124 hours) being the least. (This is a reference value, not an observation value within Adachi Ward.)
The power generation in Adachi Ward can also be affected by shadows from surrounding buildings and trees, so it is important to conduct annual power generation simulations and choose the capacity of the storage battery according to the times when electricity is used the most.
Our company handles many exterior construction and solar projects in Adachi Ward, Tokyo.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacements, and leak repairs, as well as other repairs! Please feel free to consult us about any sudden troubles!
Service Area in Adachi Ward, Tokyo
Kakeru Koumuten Co., Ltd. accepts requests from all over Kanagawa Prefecture and Tokyo.
List of Areas in Adachi Ward, Tokyo
Adachi Ward, Aoi / Adachi Ward, Adachi / Adachi Ward, Ayase / Adachi Ward, Ikoi / Adachi Ward, Ikoi Honcho / Adachi Ward, Iriya / Adachi Ward, Iriya-machi / Adachi Ward, Umejima / Adachi Ward, Umeda / Adachi Ward, Ogi / Adachi Ward, Otanida / Adachi Ward, Koino / Adachi Ward, Odai / Adachi Ward, Kaga / Adachi Ward, Kapei / Adachi Ward, Kitakapei-machi / Adachi Ward, Kurihara / Adachi Ward, Koudou / Adachi Ward, Kohoku / Adachi Ward, Koshichiya / Adachi Ward, Koshichiya Honcho / Adachi Ward, Sano / Adachi Ward, Saranuma / Adachi Ward, Kahama / Adachi Ward, Shimane / Adachi Ward, Nitta / Adachi Ward, Shinmei / Adachi Ward, Shinmei Minami / Adachi Ward, Sekihara / Adachi Ward, Senju / Adachi Ward, Senju Akebono-cho / Adachi Ward, Senju Asahi-cho / Adachi Ward, Senju Higashi / Adachi Ward, Senju Okawamachi / Adachi Ward, Senju Kawaramachi / Adachi Ward, Senju Kotobuki-cho / Adachi Ward, Senju Sakuragi / Adachi Ward, Senju Sekiya-machi / Adachi Ward, Senju Tatsuta-machi / Adachi Ward, Senju Nakai-machi / Adachi Ward, Senju Nakacho / Adachi Ward, Senju Hashido-machi / Adachi Ward, Senju Midori-cho / Adachi Ward, Senju Miyamoto-cho / Adachi Ward, Senju Motomachi / Adachi Ward, Senju Yanagicho / Adachi Ward, Takenotsuka / Adachi Ward, Tatsunuma / Adachi Ward, Chuo Honcho / Adachi Ward, Tsubaki / Adachi Ward, Towa / Adachi Ward, Toneri / Adachi Ward, Toneri Park / Adachi Ward, Toneri-machi / Adachi Ward, Nakagawa / Adachi Ward, Nishi Ayase / Adachi Ward, Nishi Arakawa / Adachi Ward, Nishi Arakawa Sakae-cho / Adachi Ward, Nishi Arakawa Honcho / Adachi Ward, Nishi Ikoi / Adachi Ward, Nishi Ikoi-machi / Adachi Ward, Nishi Kapei / Adachi Ward, Nishi Takenotsuka / Adachi Ward, Nishi Hogikuma / Adachi Ward, Hanabatake / Adachi Ward, Higashi Ayase / Adachi Ward, Higashi Ikoi / Adachi Ward, Higashi Hogikuma / Adachi Ward, Higashi Rokugatsu-machi / Adachi Ward, Hitotsuya / Adachi Ward, Hinode-cho / Adachi Ward, Hirano / Adachi Ward, Hogikuma / Adachi Ward, Hozuka-machi / Adachi Ward, Horinouchi / Adachi Ward, Minami Hanabatake / Adachi Ward, Miyagi / Adachi Ward, Rokuki / Adachi Ward, Motoki / Adachi Ward, Motoki Higashi-machi / Adachi Ward, Motoki Nishi-machi / Adachi Ward, Motoki Minami-machi / Adachi Ward, Motoki Kita-machi / Adachi Ward, Tanzaike / Adachi Ward, Yanaka / Adachi Ward, Yanagihara / Adachi Ward, Rokugatsu / Adachi Ward, Rokumachi
・For exterior wall painting in Adachi, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・For roof renovations in Adachi, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・For exterior renovations in Adachi, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・Kakeru Koumuten Co., Ltd. project achievements
・Kakeru Koumuten Co., Ltd. aftercare services
・Kakeru Koumuten Co., Ltd. service menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of getting multiple estimates and points for comparison!
・Top 12 solar power manufacturers! Features and selection tips included!
・What are the installation costs for solar power? Tips for reducing costs explained thoroughly!
・What are the best locations for installing solar power? Points for selecting installation sites included!
・Find out more about solar power estimates here!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!
