Leave Your Solar Panel Installation Work in Kunitachi City, Tokyo to Kakeru Koumuten Co., Ltd.!
For solar panel and storage battery installation in
Kunitachi City, Tokyo,
trust Kakeru Koumuten!
Kakeru Koumuten is a specialized exterior renovation company headquartered in Aoba Ward, Yokohama City.
As a company strong in roofing work, we are entrusted with solar panel and storage battery installation considering roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Kunitachi City”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Kunitachi City”
We will also explain the above three points!
Installing solar panels carries risks such as “the occurrence of leaks” and other troubles.
To ensure you have no regrets about your solar panel installation, we recommend obtaining estimates from about three companies!
Table of Contents (tap to open/close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Kunitachi City, Tokyo
- Roof Inspection Before Installing Solar Panels
- Subsidies and Grants That May Be Applicable in Kunitachi City
- 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 Kunitachi City, 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 Kunitachi City
- If You Are Looking for a Solar Panel Installer in Kunitachi City, Contact Kakeru Koumuten
- Characteristics of Kunitachi City, Tokyo and Points for Solar Installation
- Service Area in Kunitachi City, Tokyo
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Kunitachi City, Tokyo
The reasons why our company is entrusted with solar panel installation by customers in Kunitachi City, Tokyo include
one reason being that “Kakeru Koumuten covers Kanagawa Prefecture and Tokyo as its service area”,
and we have “strengths in solar panel installation that cannot be imitated by other companies”, which 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 Can Also Handle Exterior Renovations Other Than Solar Panel Installation!
Troubles such as leaks that occur during solar panel installation may be caused by insufficient checks on 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 knowledge about the roof to avoid maintenance 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.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide low-cost, high-quality solar and exterior renovation work.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the necessary scaffolding materials for temporary scaffolding based on construction conditions and can assemble scaffolding ourselves.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also cut costs for scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
In Kokuritsu City, our own scaffolding team will plan the scaffolding according to the site 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 canprocure materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we canrespond 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 paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Showroom dedicated to exterior renovations
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 the roofing materials!
Simulations for potential earnings and installation costs when introducing solar panels are also available!
Since roofing and exterior wall work often accompany each other, we also provide samples of roofing materials and models that illustrate the structure, allowing for detailed explanations!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is our all work performed by our own team.
By maintaining a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof remodeling at reduced costs.
Additionally, one representative will handle everything from the estimate to project completion.
Since the same person will manage sales and construction, smooth communication is ensured.
We can perform consistent in-house work from temporary scaffolding setup to exterior wall painting and roof remodeling!
4. Obtaining Various Permits and Skilled Workers
We have obtained construction industry permits and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal and painting technicians on staff, giving us confidence in our construction techniques.
We are capable of handling large-scale roofing projects for factories and other facilities!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty, our solar panel installation work comes with our own workmanship warranty (leakage warranty)!
(The workmanship warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof remodeling is performed. The workmanship warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty details.)
Aftercare maintenance is available annually, and we send out notification DM each year.
If you have any questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roof troubles and situations.
Even if access to the roof is not possible, we can utilize a drone for inspections!
During leakage investigations, we can also conduct surveys using a thermal imaging camera.
If the power generation of the solar panels decreases due to dirt, we can also 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 Clear Materials and Simulations
At Kakeru Koumuten Co., Ltd., we provide not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar installation guidebook” and a “financial simulation” that takes into account loan interest rates and electricity costs.
The financial simulation can project cumulative income and expenses over 20 to 30 years.
Even customers who are not familiar with solar installations will find our materials easy to understand, including important points and potential drawbacks!
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 to 30 years.
It is crucial to confirm before installation whether it is safe to place them directly on the current roof, as this is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, specializing in roofing work, has summarized the items to check before installation.
| 1. Type of roofing material and age | The method of securing the panels varies depending on the roofing material, such as slate, tiles, metal roofs, or flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of the substrate and waterproof sheet | If the sheathing or roofing (waterproof sheet) beneath the roofing material is damaged, it can affect the fastening strength and waterproofing. We also check for any signs of leaks. |
| 3. Orientation, slope, and shading of the roof | The orientation and slope of the roof surface, as well as shading from neighboring houses, trees, or utility poles, can affect power generation. We create a layout diagram based on the drawings and the site, and you can verify it through power generation simulations. |
| 4. Shape of the roof and available installation area | The number of panels that can be installed (installation capacity) is determined by the shape and size of the roof. The number of panels that can be installed varies depending on their size, so we compare based on the total output of the roof. |
| 5. Method of securing and waterproofing details | We check whether the method involves drilling holes in the roofing material to secure it or using brackets to hold the roofing material in place. The method of securing varies by technique, so please confirm the waterproofing treatment of the secured areas during the estimate. |
| 6. Weight of the roof | With the addition of panels, the roof will become heavier. After investigating the existing roof, substrate, and load-bearing capacity, switching to lighter roofing materials may be an option if necessary. |
| 7. Location of equipment installation and wiring | We confirm the installation locations for the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring also affects costs. |
Securing Methods and Checkpoints 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) | Waterproofing treatment of fixed 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 lightweight roofing materials before installation. |
| Metal Roof (Horizontal and 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 frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you perform roof renovations 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the roof is deteriorating, renovating to a highly durable roofing material before installation may help reduce costs in the long run.
Kakeru Koumuten Co., Ltd. specializes in roofing work and can also handle the removal and reinstallation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Kunitachi City, Tokyo
PossibleSubsidies and Grants in Kunitachi City, Tokyo
If you are introducing solar panels or storage batteries in Kunitachi City, Tokyo, there is a possibility that you may be eligible for programs from the “National Government, Tokyo Metropolitan Government, and Kunitachi City”.
The following information is based on the official pages of each program as of October 7, 2026. The application status may change depending on the budget and recruitment period, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Period for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Tokyo “Reiwa 8 Year Household Solar Power Introduction Promotion Project” (Cool Net Tokyo) | New installation of certified solar modules on residential properties in Tokyo, with systems under 50kW. Pre-application before installation is required. | Existing homes: 150,000 JPY/kW for 3.75kW or less (maximum 450,000 JPY), 120,000 JPY/kW for over 3.75kW New homes: 120,000 JPY/kW for 3.6kW or less (maximum 360,000 JPY), 100,000 JPY/kW for over 3.6kW (Additional costs for mounting, waterproofing, and renovation defect insurance, etc.) |
Pre-application: From May 29, 2026 Grant application and performance report: From June 30, 2026 to March 30, 2029 |
| Tokyo “Reiwa 8 Year Household Storage Battery Introduction Promotion Project” (Cool Net Tokyo) | New installation of storage batteries in residential properties in Tokyo, with SII registered devices. This project is intended for simultaneous installation with solar power, but applications can be made for storage batteries alone. Pre-applications after October 1, 2026 will only be eligible for SII registered products for Reiwa 8. | Storage battery package: 100,000 JPY/kWh (maximum 1,200,000 JPY per household) Storage battery unit expansion: 60,000 JPY/kWh (maximum 720,000 JPY per household) (Additional incentives for participating in DR demonstrations, etc.) |
Pre-application: From May 29, 2026 Grant application and performance report: From June 30, 2026 |
| Kunitachi City “Subsidy for Installation of Residential Smart Energy Related Systems” Reiwa 8 Year | Must reside in the city, own the equipment, have paid all city taxes, be the owner of the installation property (or have consent from all owners), and be able to cooperate with the city’s survey. Applications must be made after installation is completed, and those who complete installation within the application year are eligible. Individuals can apply for up to two types per year. | Solar power generation (new construction): 25,000 JPY/kW (maximum 125,000 JPY) Solar power generation (existing): 20,000 JPY/kW (maximum 100,000 JPY) Storage battery systems are also listed as eligible equipment (please check the official page for subsidy amounts). |
Application acceptance: From April 1, 2026 to March 31, 2027 (first-come, first-served basis) Applications will close once the budget is exhausted. Please check the city’s official page or window for application status. |
| National “DR Household Storage Battery Project” (Reiwa 7 Year Supplement) | New installation of household storage systems that can be used for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 1kWh at 34,500 JPY (subsidy rate within 3/10; maximum 600,000 JPY per application). | As of May 29, 2026, the budget has been reached, and applications are now closed. (Currently, applications cannot be made.) |
| 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 renovations for windows (openings) and structures; applications cannot be made for the installation of storage batteries alone. Solar panels are not included in the eligible equipment | Storage battery: 96,000 JPY/unit | Ends as soon as the budget limit is reached. Please check the official website for the application status |
In Tokyo, a pre-application before installation is required for subsidies, and starting construction beforehand may result in ineligibility. In Kunitachi City, the subsidy is a post-application after installation is complete, and applications are accepted on a first-come, first-served basis, so once the budget is exhausted, acceptance will end. In both cases, it is necessary to meet the eligible equipment and conditions, and applying does not guarantee approval. For combined use with national and Tokyo subsidies, please check the official pages of each program. Procedures differ by program, so please confirm before contracting and starting construction.
Kakeru Koumuten will guide you on the eligibility conditions for each program after confirming them.
Tokyo “Reiwa 8 Year Household Solar Power Generation Promotion Project”
Tokyo is providing subsidies for those installing solar power generation systems in residential homes through Cool Net Tokyo. The eligible systems are those using certified solar modules installed newly in residential homes or on their premises, with a capacity of less than 50kW. A pre-application before installation is required.
For existing homes, the subsidy amount is 150,000 JPY/kW for 3.75kW or less (maximum 450,000 JPY), and 120,000 JPY/kW for over 3.75kW. Additionally, there are extra items such as installation of mounting frames, waterproofing work, and renovation defect insurance. The pre-application period is from May 29, 2026, and the application for grants and performance reports is from June 30, 2026, to March 30, 2029. For details on eligible equipment and conditions, as well as budget status, please check the official page.
👉 Cool Net Tokyo | Official page for solar power generation is here
Tokyo “Reiwa 8 Year Household Storage Battery Promotion Project”
Tokyo is also providing subsidies for newly installed storage batteries in residential homes. The subsidy amount is 100,000 JPY per kWh for storage battery packages (maximum 1,200,000 JPY/unit), and for additional storage battery units, it is 60,000 JPY per kWh (maximum 720,000 JPY/unit), with additional amounts for participation in DR demonstrations.
The eligible equipment must be registered with SII (Environmental Collaboration Initiative). If applying for pre-application after October 1, 2026, only equipment listed in the Reiwa 8 year SII registered product list will be eligible. This program is intended for simultaneous installation with solar power, but applications can also be made for storage batteries only. The application for grants and performance reports has been accepted since June 30, 2026.
👉 Cool Net Tokyo | Official page for storage batteries is here
Kunitachi City “Subsidy for Installation of Smart Energy Related Systems for Homes”
In Kunitachi City, subsidies are available for those who install smart energy-related systems in residential homes. For the fiscal year Reiwa 8, the subsidy amounts are 25,000 yen/kW (up to 125,000 yen) for solar power in new homes, and 20,000 yen/kW (up to 100,000 yen) for existing homes. Battery storage systems are also included in the eligible equipment, so please check the official page for the subsidy amounts. Eligibility is limited to residents of the city who own the equipment, have paid all city taxes, are the owners of the home where the installation will take place (or have the consent of all owners), and cooperate with the city’s survey.
Applications are accepted via post-installation application, and only those who complete the installation within the fiscal year are eligible. Application acceptance runs from April 1, 2026, to March 31, 2027, and will end once the budget is exhausted or on a first-come, first-served basis. Individuals can apply for up to two types of subsidies per fiscal year. Please check the application status on the city’s official page or at the service counter.
👉 Here is the official Kunitachi City page (Subsidy for installation of smart energy-related systems for homes)
National Subsidy “DR Home Battery Project (Support Project for Home Battery Systems for DR Resource Introduction)”
The national government has been implementing the “DR Home Battery Project” to support the installation of home battery systems.
This program targets those who introduce new battery systems that can be utilized for demand response (DR) with registered products. In the fiscal year 2027 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 excluding contracts or orders made before the grant decision.
However, the fiscal year 2027 supplementary budget reached its application amount on May 29, 2026, and the public recruitment has ended (the previous fiscal year 2026 supplementary budget also ended on July 2, 2025). Applications are currently not being accepted, so please check the official site for future public recruitment.
Additionally, there are currently no subsidies available for the installation of solar panels in existing homes from the national government.
👉 Here is the official site for the DR Home Battery Project
Price List for Solar Panel Installation and Battery Installation
⇧Service Menu | For Costs Related to Solar Panel Installation and Battery Installation, Click Here
⇧Service Menu | For Costs Related to Solar Panel Removal and Hot Water Heater Removal, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and batteries should be confirmed by separating them into “Equipment Costs (Device Costs)” and “Construction Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.
Understanding 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 (kilowatt). Batteries are compared based on the amount of electricity they can store, expressed in kWh (kilowatt-hour).
The amount of kW that can be installed on a roof varies for each house based on the roof’s shape, orientation, and size. 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 priced between 800,000 JPY and 1,200,000 JPY for 3-5 kW, and between 1,200,000 JPY and 1,900,000 JPY for 6-10 kW. (These are just estimated prices and may vary based on factors such as wiring length, scaffolding area, existing roofing materials, and panel layout.)
▶ Installation Menu | Costs for Solar Panel Installation and Battery Installation
Items to Confirm in the Quotation (Cost Verification)
When comparing prices in competitive quotations, it is common to compare different capacities and equipment. Please check if the following items are clearly stated in each company’s quotation!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, and total installation capacity (kW) should be specified. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, and installation location (indoor/outdoor). Also confirm if it is a type that controls the battery as a unit. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range usable 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 power generation. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at the fixed points, and whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | Extent of support for applications to the power company, certification for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If roof work and exterior painting are done simultaneously, check that the same scope and quantity are not double-counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters and old panels, as well as 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. |
Differences in capacity will affect both price and power generation. Kakeru Koumuten Co., Ltd. welcome competitive quotations, so if you bring in quotations from other companies, we will explain the differences item by item!
Self-Quotation 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 or 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 Manufactured / Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Details |
| Fixed by gripping the horizontal metal roof with catch type hardware (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the subsidy being granted, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The subsidy 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 |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that subsidies are available, and I would like to know how much will be granted. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels based on the drawings!
The layout diagram shows the arrangement of solar panels when placed 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 subsidies, so we explained this to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Kunitachi City, Tokyo
There are many solar panel installation contractors available in Kunitachi City, 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.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the presence of warranties and after-sales maintenance
● 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 about 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 about 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 severely deteriorated roof, resulting in leaks
・Solar panels were installed on a roof with a short lifespan, necessitating renovations to detach and reattach the solar panels within a few years
・Misjudging the type of waterproofing led to incorrect processing 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 unforeseen troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the presence of warranties and after-sales maintenance
When choosing a solar installation contractor, let’s confirm the presence of warranties. It is important to check not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While solar panels and battery storage units come with manufacturer warranties, it is also important to check whether there is a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may be able to respond under the warranty, provided it is within the warranty period and conditions.
Additionally, some contractors offer after-sales service separate from warranties, so be sure to check if the contractor you are considering has after-sales service.
Changes or damage on the roof may occur in areas that are not visible, so there is a possibility that customers may not notice them.
By conducting inspections during after-sales maintenance, we can easily detect abnormalities early, preventing major repairs or failures!
Kakeru Koumuten Co., Ltd. provides a 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 without performing roof renovations.)
We also conduct after-sales maintenance and send out DM every year!
Please check the DM, and if you wish, we will visit you for after-sales maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, be sure to 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 it easier to negotiate prices.
To request from your preferred contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check carefully for:
“Verification of estimate items”
“Types of solar panels”
“Warranties and after-sales services”
and make a judgment! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making decisions based solely on price!
▶ Go to “Breakdown of Installation Capacity and Equipment/Construction Costs” in this article
Check if they provide support for subsidy applications
Subsidies may be available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
There are systems that require personal applications and cannot be processed by the contractor, as well as systems that require prior application before installation, so it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Be sure to complete the procedures specified for each system (for Tokyo subsidies, prior application before installation; for Kunitachi City subsidies, check the reception status as it is first-come, first-served) before proceeding with the construction!
In the case of subsidies in Tokyo, the process involves submitting a grant application and performance report after the completion of the work, which will then be reviewed before the grant is awarded. For the subsidy in Kunitachi City, the application will be made after the completion of the work! (The procedure varies depending on the system.)
▶ Go to “Subsidies and Grants Available in Kunitachi City” within this article
Benefits of Introducing Solar Power Equipment
The benefits of introducing solar panels are as follows!
Benefit 1: Economic Advantage
The biggest advantage of introducing solar panels is the economic benefit!
Although the selling price of electricity has decreased compared to ten years ago, by consuming the electricity generated, you can reduce the amount of electricity purchased from the utility company and gain benefits!
The higher the electricity costs rise, the more attractive it becomes to cover your consumption with solar power!
If you plan to use the generated electricity at night, installing a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) will be set at “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year” for certifications after October 2025, and the same price will apply for the fiscal year 2026. After the fifth year, it tends to be more advantageous to use it at home (self-consumption), making the combination with a storage battery a viable option.
👉 For purchase prices and periods, click here
Benefit 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 amount through subsidies is a significant advantage!
In the case of Kunitachi City, there may be applicable programs from the national government, Tokyo, and Kunitachi City.
Benefit 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 such as power conditioners may have operational noise.)
Benefit 4: Heat Insulation Effect Expected!!
By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the temperature rise of the roof, providing expected heat insulation effects!
(Note that 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 capabilities, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that 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 maintenance cost that is particularly easy to overlook is for the roof where solar panels are installed.
If you perform roof renovations 10 to 20 years later, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorating, it is reassuring to renovate it with durable roofing materials before installing 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 simulations 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 or 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, replacing the roofing material itself with a metal roof and fixing the solar panels using the catch method is also an option. (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
Installing solar panels will make the roof heavier. After investigating the existing roof, substrate, and load-bearing capacity, one option may be to replace it with a lighter roof if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output 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 by 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 generating more power is always better!
Solar panels vary in size and output depending on the manufacturer.
A panel with 350W output and a panel with 400W output may seem at first glance that the higher output panel is better.
However, if the size of the panel does not fit well on the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different installation capacities on the same roof due to the size difference.
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 one 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 amount (kWh) will vary depending on conditions such as roof orientation, slope, and shading.
How to Choose 2: Compare by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases after 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 represent the actual degradation rate or power generation amount.
Choosing solar panels considering the degradation rate, rather than just the initial output, will lead to a satisfactory decision!
How to Choose 3: Compare by 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.
Regarding the output warranty, some manufacturers offer a 30-year warranty, while others provide a 10-year warranty, so it varies widely!
Since a longer warranty is generally better, let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Kunitachi City
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Kunitachi City. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Kunitachi City, Tokyo?
The cost varies depending on the installation capacity, equipment, and roof condition. In the above construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines for different capacities are available on our solar panel and storage 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 storage battery installation in Kunitachi City?
As of October 7, 2026, the Tokyo solar power and storage battery subsidy (Cool Net Tokyo) is accepting pre-applications. For storage batteries, only SII registered devices (registered products for Reiwa 8) are eligible for pre-applications made after October 1, 2026. Kunitachi City’s “Residential Smart Energy System Installation Subsidy” is accepting applications on a first-come, first-served basis from April 1, 2026, to March 31, 2027, and will end once the budget is exhausted. The national DR home storage battery project has already closed 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 even after the construction is completed?
For many programs, procedures are required before construction. The Tokyo subsidy requires pre-application before installation, and if you install first, you will be ineligible. Kunitachi City’s subsidy allows applications after installation is complete, but it is on a first-come, first-served basis, and will end once the budget is exhausted. Procedures vary by program.
Since the order of procedures differs by program, please confirm before signing a contract 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 fixing method varies depending on the construction method, and for methods that fix 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 replacement before installation.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If 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, renovating to a highly durable roofing material before installation may help reduce total costs.
Please consult us about the installation process after confirming the condition of the roof through a site survey!
Should I install a storage battery together with the 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 Tokyo Metropolitan Government’s subsidy for storage batteries is designed for simultaneous installation with solar panels, but you can also apply for the battery alone. You can compare “solar panels only” and “solar panels + storage battery” through a financial simulation.
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 we will provide you with the installation capacity and power generation simulation.
In Kunitachi City, the shading caused by surrounding buildings and trees varies from house to 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 (4.3 kW solar panel + storage battery), it took about 3 days. The duration may vary if roof work is done simultaneously or depending on the shape of the roof and installation capacity.
Please note that there will be an additional period for applications for subsidies and power companies, so please consult us as soon as possible.
What is the current selling price (FIT)?
For residential use (under 10 kW), the price for certifications 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 a financial simulation that considers 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 notifications and visits for inspections upon request. We can also clean solar panels with a special brush if the power generation decreases due to dirt.
The roof is a place that is difficult to check 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 Kunitachi City, please consult Kakeru Koumuten
Our company handles many exterior renovations, including solar panel installation, roof work, and exterior wall work in Kunitachi City, 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 great feedback from numerous customers.
We continue to update our construction performance every year, and we 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 such as partial repairs and rain gutter cleaning!
In urgent cases like water leakage, we may be able to provide emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult us!
Whether you want to know about recommended solar panels, keep costs down, or just get an estimate, we will provide the best solutions for your specific requests.
We will never propose unnecessary work focused on profit!
We always stand in the customer’s position and will propose the optimal 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 estimates!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Characteristics of Kunitachi City, Tokyo, and Points for Solar Construction
Kunitachi City, Tokyo, is located in the Tama region. The official page of Kunitachi City publishes hazard maps for flooding (Tama River), internal water, and landslides.
We have summarized the residential environment of Kunitachi City and points to consider when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Kunitachi City, Tokyo, and points for solar construction
■ Check the installation location of storage batteries and power converters against the hazard map assumptions
In the disaster prevention map and hazard map of Kunitachi City, flood hazard maps (assuming a total rainfall of 588mm over 48 hours in the Tama River basin), internal water hazard maps (assuming a maximum hourly rainfall of 153mm and a total rainfall of 690mm/day. Internal water refers to the phenomenon where rainwater cannot be drained through the sewer system during heavy rain, leading to flooding), and landslide hazard maps are published. When deciding on the installation location for storage batteries and power conditioners, it is advisable to check the flooding assumptions for your residence on the hazard map and consider the height and position of the installation for peace of mind.
■ Check the designation of landslide warning areas
The landslide hazard map of Kunitachi City displays landslide warning areas and special warning areas. The designation of these areas may be reviewed (for example, the warning area designation was lifted in December 2025 on the south side of Aoyagi 3-chome), so it is advisable to confirm whether your property is included in the designated area using the latest map for peace of mind.
■ Tokyo’s annual sunshine hours are approximately 1,927 hours
According to the Japan Meteorological Agency’s average values (1991-2020), Tokyo’s annual sunshine hours are approximately 1,927 hours.
Power generation varies by season, so it is important to conduct annual power generation simulations and choose the capacity of storage batteries to match the times of high electricity usage.
■ Check for shadows from surrounding buildings and trees
In places where buildings or trees are close by, the way shadows fall varies for each house depending on the roof’s orientation and height. Since solar panels generate less power when shaded, Kakeru Koumuten creates layout diagrams based on blueprints and the actual site conditions, allowing you to confirm through power generation simulations. Additionally, in areas close to trees, branches and fallen leaves may accumulate around the panels and rain gutters, so please consult us about inspections and cleaning after installation.
■ City subsidies are post-application and on a first-come, first-served basis. Tokyo requires pre-application
The subsidies from Kunitachi City are post-application after installation is complete and are on a first-come, first-served basis, so once the budget is exhausted, applications will close. On the other hand, the Tokyo subsidies (Cool Net Tokyo) require pre-application before installation. It is important to confirm the procedures and periods for each system in advance, in conjunction with the timing of the construction.
■ In narrow front road areas, plan scaffolding and equipment delivery carefully
In areas with narrow front roads or where surrounding buildings are close together, careful planning for scaffolding and equipment delivery may be necessary. Kakeru Koumuten will respond to the site conditions with our own scaffolding team and scaffolding materials.
■ Check the roof condition according to the building’s age
For buildings that have been around for a number of years, it is important to check the condition of the roofing materials and substrate before installing solar panels. Depending on the roof’s condition, installing them simultaneously with roof renovations can help reduce future costs for removing and reinstalling solar panels.
Our company serves Kanagawa Prefecture and Tokyo, and we handle many exterior construction and solar projects in Kunitachi City, Tokyo.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us about any urgent issues!
Service Area in Kunitachi City, Tokyo
Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Kunitachi City, Tokyo
Kunitachi City, Aoyagi / Kunitachi City, Ishida / Kunitachi City, Izumi / Kunitachi City, Kita / Kunitachi City, Naka / Kunitachi City, Nishi / Kunitachi City, Higashi / Kunitachi City, Fujimidai / Kunitachi City, Yakawa / Kunitachi City, Yahō
・For exterior wall painting in Kunitachi City, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・For roof renovations in Kunitachi City, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・For exterior renovations in Kunitachi City, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・Kakeru Koumuten Co., Ltd.’s construction achievements
・Kakeru Koumuten Co., Ltd.’s aftercare services
・Kakeru Koumuten Co., Ltd.’s construction menu and price list
・Kakeru Koumuten Co., Ltd.’s staff blog and announcements
・Explaining the importance of getting multiple estimates and points to compare!
・Top 12 solar power manufacturers! Features and selection tips included!
・What are the installation costs for solar power? Tips to reduce costs thoroughly explained!
・What are the best locations for solar power installation? Points for selecting installation sites included!
・Check here for solar power estimates!
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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!
