Leave Your Solar Panel Installation Work in Kunitachi City, Tokyo to Kakeru Koumuten Co., Ltd.!
For solar panel and battery installation in
Kunitachi City, Tokyo,
Kakeru Koumuten is at your service!
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 battery installation considering roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Kunitachi City”
“Costs for Solar Panel and 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 a satisfactory 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
- Possible Subsidies and Grants Available 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’re Looking for a Solar Panel Installer in Kunitachi City, Contact Kakeru Koumuten
- Characteristics of Kunitachi City, Tokyo and Key Points for Solar Installation
- Service Area in Kunitachi City, Tokyo
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Kunitachi City, Tokyo
Regarding why we are entrusted with solar panel installation by customers in Kunitachi City, Tokyo,
one reason is that “Kakeru Koumuten serves Kanagawa Prefecture and Tokyo”,
but we also have “strengths in solar panel installation that cannot be imitated by other companies”, which have received high praise 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 multiple estimates!
1. We Also Handle Exterior Renovations Besides Solar Panel Installation!
Issues 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 you are knowledgeable about solar panels, there may be cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have expertise in roofing to avoid maintenance and trouble 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 issues after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has prepared the following warehouses and material storage areas to provide low-cost, high-quality solar work and exterior renovations.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding based on the construction conditions, allowing us to assemble scaffolding in-house.
By not outsourcing scaffolding work and using our own scaffolding team, we can also cut costs for scaffolding work.
We own scaffolding materials for approximately 50 single-family homes!
In Kokubunji City, our in-house scaffolding team will plan the scaffolding according to the site conditions.
Storage of Materials in Our Large In-house Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we canrespond quickly in emergencies!
In-house sorting and transportation of waste materials
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 down on waste disposal costs.
Exterior renovation dedicated showroom
In the showroom, not only can we hold meetings, but you can also
check the actual foundation brackets for solar panels and see how they are attached to the roofing materials!
We can also provide simulations of the potential earnings 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 handle 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 assist you from the estimate to the completion of the work.
Since the same person handles everything, including sales and construction management, smooth communication is possible.
We can provide consistent in-house construction from temporary scaffolding installation, exterior wall painting, to roof renovations!
4. Various Permits and Skilled Workers
We have obtained construction industry licenses and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal and painting specialists on staff, and we are confident in our construction techniques.
We can handle large-scale roofing projects, such as those for factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation work, we also provide our own construction warranty (leakage warranty)!
(The construction 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 a roof renovation is performed. The construction warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty details.)
Aftercare is available every year, and we send out notification DM each 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.
Even if you cannot access the roof at high altitudes, we can utilize drones to assist you!
During leak investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of your solar panels decreases due to dirt or other factors, we can provide cleaning with a specialized brush.
We will respond according to your 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.
We compile easy-to-understand materials that include points to consider and disadvantages for customers who may not be familiar with solar installations!
We encourage you to obtain comparative estimates and compare them with other companies’ plans!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 to 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 (roof 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 fixing strength of the fittings 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, will affect the power generation. We will create a layout diagram from the drawings and the site, and you can check it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels that can be installed (installation capacity) is determined by the shape and size of the roof. Since the number of panels that can be installed varies depending on the size of the panels, we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will confirm whether the method involves drilling holes in the roofing material for fixing or using fittings to grip and secure the roofing material. The fixing method varies by construction method, so please check the waterproofing treatment method for the fixing 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 capacity, switching to lighter roofing materials may also be an option if necessary. |
| 7. Installation Location of Equipment and Wiring | We will check 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. |
Fixing 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 of fixed parts, cracks and 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 fix 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 the removal and reinstallation of 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
Potential Subsidies 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 application period, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| System | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Tokyo Metropolitan Government “Reiwa 8 Year Household Solar Power Generation Promotion Project” (Cool Net Tokyo) | New installation of certified solar modules in residential properties or their premises in Tokyo, with a system capacity of less than 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 frames, waterproofing work, 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 Metropolitan Government “Reiwa 8 Year Household Storage Battery Installation Promotion Project” (Cool Net Tokyo) | New installation of storage batteries in residential properties in Tokyo, and must be SII registered equipment. 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) Expansion of storage battery units: 60,000 JPY/kWh (maximum 720,000 JPY per household) (Additional incentives for participation 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 residential property being installed (or have consent from all owners), and be able to cooperate with the city’s survey. Application after installation completion is required, 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 utilized for DR (demand response) with registered products. | Calculated based on a standard amount of 34,500 JPY per initial effective capacity of 1kWh (subsidy rate within 3/10; maximum 600,000 JPY per application). | The budget was reached on May 29, 2026, and the public recruitment has ended. (Applications are currently not possible.) |
| 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 of windows (openings) and structures; applications cannot be made for storage battery installation 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 site for 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 completion, 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 system. Procedures differ by system, so please confirm before contracting and starting construction.
At Kakeru Koumuten Co., Ltd., we will guide you on eligibility after confirming the conditions for each system.
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 cell modules installed newly in residential homes or on their premises, with a capacity of less than 50 kW. A pre-application before installation is required.
For existing homes, the subsidy amount is 150,000 JPY/kW for up to 3.75 kW (maximum 450,000 JPY), and 120,000 JPY/kW for exceeding 3.75 kW. 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 subsidy and performance report is from June 30, 2026, to March 30, 2029. For details on eligible equipment and conditions, as well as the 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 60,000 JPY per kWh for additional storage battery units (maximum 720,000 JPY/unit), with additional amounts for participation in DR demonstrations.
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 project is intended for simultaneous installation with solar power, but applications can also be made for storage batteries alone. The application for subsidy and performance report 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 Residential Use”
Kunitachi City is implementing subsidies for those who install smart energy-related systems in residential homes within the city. For the fiscal year Reiwa 8, the subsidy amounts are 25,000 yen/kW for solar power in new homes (up to 125,000 yen), and 20,000 yen/kW for existing homes (up to 100,000 yen). Battery storage systems are also listed as eligible equipment, so please check the official page for the subsidy amounts. Eligibility includes 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 consent from all owners), and cooperate with the city’s survey.
Applications are accepted via post-installation application, and 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 upon reaching the application limit. Individuals can apply for up to two types per fiscal year. Please check the status of applications on the city’s official page or at the service counter.
👉 Here is the official page of Kunitachi City (Subsidy for installation of smart energy-related systems for residential use)
National Subsidy “DR Household Battery Project (Support Project for the Introduction of Household Battery Systems for DR Resources)”
The national government has been implementing the “DR Household Battery Project” to support the installation of household batteries.
This program targets those who are newly introducing registered battery systems that can be utilized for demand response (DR), and for the fiscal year Reiwa 7 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 also conditions such as excluding contracts or orders made before the grant decision.
However, the supplementary budget for Reiwa 7 reached its budget limit on May 29, 2026, and the public offering has ended (the previous year’s supplementary budget for Reiwa 6 also ended on July 2, 2025). Currently, applications cannot be made, so 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 from the national government.
👉 Here is the official site for the DR Household Battery Project
Solar Panel Installation & Battery Installation Price List
⇧Service Menu | Click here for costs related to Solar Panel Removal and Hot Water Heater Dismantling
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and storage batteries should be checked separately as “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.
Considerations for Installation Capacity (kW) and Storage 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). Storage batteries are compared based on the amount of electricity they can store, represented 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 panel costs 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 rough estimates and may vary based on wiring length, scaffolding area, existing roofing materials, panel layout, etc.)
▶ Service Menu | Click here for costs related to Solar Panel Installation and Storage Battery Installation
Items to Check in the Estimate (Cost Verification)
When comparing estimates, it is common to compare different capacities and equipment just by looking at the amounts. 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, total installation capacity (kW) are listed. |
| 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 a storage battery. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range usable during a power outage (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of the hardware suitable for the roofing material and the method of securing it (whether it is a method that drills holes or a method that clamps and secures). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, presence of a monitor to check power generation. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at the fixed parts, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | Extent of support for applications to the power company, certification applications for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If roofing work and exterior painting are done simultaneously, confirm 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 it is tax-inclusive or tax-exclusive, conditions under which additional costs may arise, details and duration of manufacturer warranty and workmanship warranty. |
If the capacity differs, both the price and power generation will change. Kakeru Koumuten Co., Ltd. warmly welcomes comparative estimates, so if you bring estimates from other companies, we will explain the differences by item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can obtain an approximate estimate and a profit 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 approximate estimate and profit simulation!
*The simulation results are approximate. Actual profits may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection and replacement.
Customer Voices
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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
| Work 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 Arrangement |
| 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 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 |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that grants are available, and I would like to know how much can 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 when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We understood the expected amount of the grant that will be provided, so we explained it 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 confirm the following 4 points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the presence of warranties and aftercare 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 installed on a severely deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring a renovation for removal and reinstallation within a few years
・Misjudging the type of waterproofing and incorrect processing leading to 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 aftercare 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 scope of coverage, disclaimers, and cost conditions.
While the solar panels and battery storage units come with manufacturer warranties, also check for the presence of installation warranties in case leaks occur after installation!
For contractors that offer installation warranties, 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 the warranty, so be sure to check if the contractor you are considering has after-sales service.
Since changes or damages on the roof can occur in areas that are not visible, there is a possibility that customers may not notice them themselves.
By conducting inspections during after-sales maintenance, we can easily detect abnormalities early, preventing major repairs or breakdowns!
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 unless roof renovation is performed.)
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 construction content, costs may vary, as well as warranties and after-sales services.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request from your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check the following:
“Check the items in the estimate”
“Type of solar panels”
“Warranties and after-sales services”
Make sure to compare these details carefully! 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 “Installation Capacity and Breakdown of Equipment and 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 submitted 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.
Complete the procedures specified for each system (for Tokyo’s subsidy, prior application before installation is required; for the subsidy in Kunitachi City, check the application 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 be granted after a review. 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 summarized in the following five points!
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, you can gain benefits by reducing the electricity purchased from power companies by consuming the generated electricity yourself!
As electricity prices rise, the ability to cover your consumption with solar power becomes attractive!
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, with the same price applied in the 2026 fiscal year. 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 details on purchase prices and periods, visit the Agency for Natural Resources and Energy
Benefit 2: You Can Utilize Subsidies!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the requirements, 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 systems available 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 like 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 of the roof, providing expected heat insulation effects!
(Note that this does not improve the building’s insulation performance 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 are incurred
A particularly overlooked maintenance cost 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 is reassuring to be able to request a simulation that considers maintenance costs 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 when using screws or other fasteners to secure the roofing material and substrate, waterproofing of the fixed parts becomes crucial.
If the method involves making holes in the roof, there will inevitably be a risk of leaks.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and securing the solar panels using the catch method is also an option. (The catch method has compatibility conditions between the roofing material and fasteners, 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 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!
Choosing Method 1: Compare based on total output of the roof
When installing solar panels on the roof, it is important to consider how much power can be generated in a limited area, and generating more power is always better!
Solar panels come in various sizes and outputs depending on the manufacturer.
A panel with 350W output and a panel with 400W output may seem that the one with higher output is better at first glance.
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,” leading to 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.
Choosing Method 2: Compare based on 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 warranty value is a standard figure for guarantees and does not indicate the actual degradation rate or power generation itself.
By not deciding solely based on initial output and considering the degradation rate, you can choose solar panels without regrets!
Choosing Method 3: Compare based on warranty period
Solar panel warranties include various types such as “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 may only offer a 10-year warranty, so there is a wide range!
Longer warranties are better, so be sure to 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 the condition of the roof. In the above construction example (4.3kW solar panel + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines by capacity are published on the solar panel and storage battery installation pricing page. We will create a layout diagram from the drawings and on-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, Tokyo’s subsidies for solar power generation and storage batteries (Cool Net Tokyo) are accepting pre-applications. For storage batteries, only SII registered devices (registered products for Reiwa 8) are eligible from pre-applications made after October 1, 2026. Kunitachi City’s “Subsidy for Installation of Residential Smart Energy Related Systems” 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 household storage battery project has closed its public recruitment.
Since the application status may change, please check the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies after the construction is completed?
For many programs, procedures are required before construction. Tokyo’s subsidies require 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 differ by program.
Since the order of procedures varies by program, please confirm before signing a contract or starting construction.
Can solar panels be installed on a slate roof? I’m worried about leaks.
Installation is possible on a slate roof, but it is necessary to check the condition of the roofing material and substrate. The method of securing varies by construction method, and when securing brackets to the roofing material or substrate, waterproofing of the secured areas is essential.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation and suggest methods such as roof overlay or replacement if deterioration is progressing.
The roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed after 10 to 20 years of installation, the cost for removing and reinstalling solar panels will be incurred separately. 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 about the installation process after confirming 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 Tokyo Metropolitan Government’s subsidy for storage batteries is designed for simultaneous installation with solar panels, but applications can also be made for storage batteries 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 based on 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?
In the above construction example (solar panels 4.3 kW + storage battery), it took about 3 days. The duration may vary depending on whether roof work is done simultaneously and the shape and installation capacity of the roof.
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 (less than 10 kW), from the certification after October 2025, the first 4 years will be 24 yen/kWh, and from the 5th to the 10th year it will be 8.3 yen/kWh, with the same prices applied in the 2026 fiscal year.
The idea is to recover initial costs quickly in the first 4 years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that takes 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-service maintenance notices via direct mail and visits customers who wish to have inspections. We can also clean solar panels using a special brush if the power generation decreases due to dirt.
It can be 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?
Yes, we can. Kakeru Koumuten can remove and reinstall solar panels in-house, allowing us to remove the panels, perform roof overlay (cover method) or re-roofing, and then reinstall them in a consistent manner. The removed panels can be stored in our own warehouse.
For information on costs, please see the solar panel removal 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 a wide range of exterior renovations, including solar panels, roofing work, and exterior wall work in Kunitachi City, Tokyo.
We have received requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received positive feedback from numerous 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 and replacement work but also partial roof repairs, exterior painting, and exterior cover methods.
We are also happy to handle small jobs such as partial repairs and rain gutter cleaning!
In case of emergencies such as leaks, we may be able to provide temporary repairs without setting up scaffolding, as long as safety can be ensured, so please consult us!
“I want to know about 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 optimal construction plan!
We are confident that we will not lose 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 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 floods (Tama River), internal water, and landslides.
Below are summarized points to be aware of regarding the residential environment in Kunitachi City and when installing solar panels and storage batteries (tap to open).
View the characteristics of Kunitachi City, Tokyo and points for solar construction
■ Check the installation locations for storage batteries and power conditioners 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 sewers 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.
■ Confirm 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 in the southern side of Aoyagi 3-chome), so it is advisable to check whether your property is included in the designated area on 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.
The amount of electricity generated varies by season, so it is important to conduct annual generation simulations and select the capacity of the storage battery according to the times when electricity usage is high.
■ Check for shadows from surrounding buildings and trees
In areas 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 electricity when shaded, Kakeru Koumuten creates layout diagrams based on the drawings and the actual site conditions, and we confirm this through 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 completed and are on a first-come, first-served basis, so once the budget is exhausted, applications will close. On the other hand, the subsidies from Tokyo Metropolitan Government (Cool Net Tokyo) require pre-application before installation. It is important to check 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, it may be necessary to devise plans for scaffolding and equipment delivery. Kakeru Koumuten will respond according to the site with our own scaffolding team and owned scaffolding materials.
■ Check the roof condition according to the age of the building
For buildings that have been around for many 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 re-installing solar panels.
Our company serves Kanagawa Prefecture and Tokyo, and we handle many exterior and solar projects in Kunitachi City, 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 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
・Trust Kakeru Koumuten for exterior wall painting in Kunitachi City, Tokyo!
・Trust Kakeru Koumuten for roof renovations in Kunitachi City, Tokyo!
・Trust Kakeru Koumuten for exterior renovations in Kunitachi City, Tokyo!
・Kakeru Koumuten Co., Ltd. construction achievements
・Kakeru Koumuten Co., Ltd. aftercare services
・Kakeru Koumuten Co., Ltd. construction menu and price list
・Kakeru Koumuten Co., Ltd. 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? Comprehensive tips to reduce costs!
・What are the best locations for solar power installation? 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!
