Leave the installation of solar panels in Komae City, Tokyo to Kakeru Koumuten Co., Ltd.!
For Solar Panel and Battery Installation in
Komae City, Tokyo,
Kakeru Koumuten is at your service!
Kakeru Koumuten is a company specializing in exterior renovations.
As a company strong in roofing work, we are entrusted withsolar panel installations and battery installations considering roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Komae City, Tokyo”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Komae City, Tokyo”
We will also explain the above three points!
Installing solar panels carries risks such as“the occurrence of leaks” and other troubles.
To ensure a satisfactory solar panel installation, we recommend obtainingestimates from about three companies!
Table of Contents (Tap to Open/Close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Komae City, Tokyo
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Komae City, Tokyo
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installation Contractor in Komae City, Tokyo
- Benefits of Introducing Solar Equipment
- Points to Consider When Introducing Solar Power Generation
- How to Choose Solar Panels
- Frequently Asked Questions About Solar and Storage Battery Installation in Komae City, Tokyo
- If You Are Looking for a Solar Panel Installation Contractor in Komae City, Tokyo, Contact Kakeru Koumuten
- Characteristics of Komae City, Tokyo and Key Points for Solar Installation
- Service Area in Komae City, Tokyo
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Komae City, Tokyo
Regarding why our company is entrusted with solar panel installation by customers in Komae City, Tokyo,
“Our Unique Strengths in Solar Panel Installation That Cannot Be Imitated by Other Companies”
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 estimates from any number of companies!
1. We Also Handle Exterior Renovations Aside from Solar Panel Installation!
Issues such as leaks that occur with solar panel installations 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 expertise in roofing to avoid maintenance and issues 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 for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding based on construction conditions and can assemble scaffolding in-house.
By not outsourcing scaffolding work and using our own scaffolding team, we can also reduce the costs of scaffolding work.
We own scaffolding materials for approximately 50 single-family homes!
Even if there are height differences on the site, our in-house scaffolding team will plan the scaffolding according to the local conditions.
Storage of Materials in Our Large Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials available, allowing us torespond quickly in emergencies!
Sorting and Transporting Waste Materials In-House
The installation of solar panels often involves roofing work, generating various types of waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior Remodeling Dedicated Showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on roofing materials!
We can also provide simulations of potential earnings and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany projects, 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 a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof renovations at reduced costs.
Additionally, one representative will handle everything from the estimate to the completion of the work.
Since the same person will be in charge, whether it’s sales or construction management, smooth communication is possible.
We can perform consistent in-house construction from temporary scaffolding installation, exterior wall painting, to roof renovations!
4. Various Permits and Skilled Workers
We have obtained permits for the construction industry and for the collection and transportation of industrial waste!
We also have nationally certified sheet metal workers and painting specialists on staff, and we are confident in our construction techniques.
We can also handle large-scale roof projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation work, our own construction warranty (leak warranty) is also included!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, a roof renovation may be required to provide the warranty. 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.
If you cannot access the roof at high altitudes, we can utilize a drone for inspections!
During leak 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 provide cleaning services using specialized brushes.
We will respond according to the customer’s wishes.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training so that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
Kakeru Koumuten provides not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar installation guidebook” and “profit and loss simulations” that take into account loan interest rates and electricity costs.
Profit and loss simulations can be created for projected cumulative profits and losses over 20 to 30 years.
We compile easy-to-understand materials for customers who may not be familiar with solar installations, including points to consider 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.
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, specializing 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 material, such as slate, tiles, metal roofs, and flat roofs (rooftop waterproofing). If the remaining lifespan of the roofing material is short, we may suggest roof renovation first. |
| 2. Condition of the Substrate and Waterproof Sheet | If the sheathing or roofing (waterproof sheet) under the roofing material is damaged, it will affect the fastening strength and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, Slope, and Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, 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. The number of panels that can be installed varies depending on the size of the panels, so we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will check whether the method involves drilling holes in the roofing material for fixing or using brackets to secure the roofing material. The fixing method varies by construction method, so please confirm the waterproof treatment method for the fixing parts during the estimate. |
| 6. Weight of the Roof | The roof will become heavier due to the panels. After investigating the existing roof, substrate, and load-bearing capacity, switching to lighter roofing materials may be an option if necessary. |
| 7. Installation Location of Equipment and Wiring | We will confirm the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect the cost. |
| 8. Ease of Scaffolding Setup and Delivery Routes | If there is a height difference on the site, planning for scaffolding and the delivery route for equipment and materials may require some ingenuity. The width of the front road and any steps on the site will also be checked during the site survey. |
Fixing Methods and 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) | Waterproof treatment of fixing 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 a method to replace with lightweight roofing material 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, a method that does not drill holes may be selectable. |
| 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 renovation 10 to 20 years after installation, there will be additional costs for removing and re-installing 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 is strong in roofing work and can also handle the removal and re-installation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovation in Komae City, Tokyo
Potential Subsidies and Grants
If you are introducing solar panels or storage batteries in Komae City, Tokyo, there is a possibility that the systems from the “National Government,” “Tokyo,” and your local “Komae City” may apply.
The following information is based on the official pages of each system as of October 7, 2026. The acceptance status may change depending on the budget, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Tokyo “Home Solar Power Generation Promotion Project” | Individuals, corporations, or management associations installing unused solar power systems (under 50kW output, JET certification, etc.) in residential properties within Tokyo. The generated power must be used in the residential area. Pre-application is required | Existing homes: 15,000 JPY per kW for up to 3.75kW (maximum 450,000 JPY), 12,000 JPY/kW for over 3.75kW to under 50kW New homes: 12,000 JPY/kW for up to 3.6kW (maximum 360,000 JPY), 10,000 JPY/kW for over 3.6kW |
For the fiscal year Reiwa 8, pre-applications are being accepted from May 29 (ends when the budget is reached). From the pre-application for Reiwa 8, submission of certificates issued by financial institutions will be mandatory at the time of performance reporting. |
| Tokyo “Home Storage Battery Promotion Project” | Owners of eligible devices (storage batteries registered with SII) excluding national and local governments. Must be installed between April 1, Reiwa 8 and March 30, Reiwa 11. If applying after October 1, Reiwa 8, only products registered with the national SII for Reiwa 8 are eligible | Storage battery package: 100,000 JPY per kWh (maximum 1,200,000 JPY per household) Additional for DR demonstration participation (100,000 JPY per unit; 150,000 JPY per unit if energy management devices are installed) Expansion of storage battery units: 60,000 JPY/kWh (maximum 720,000 JPY per household) |
For the fiscal year Reiwa 8, pre-applications are being accepted from May 29. Grant application and performance reporting will start from June 30. |
| Komae City “Global Warming Countermeasure Equipment Installation Subsidy” (Fiscal Year Reiwa 8) | Individuals (residents), condominiums (owners, management associations), and businesses are eligible, provided there are no tax delinquencies. Application is required before installation, and installations made before grant decision are not eligible. | Solar power generation (purchase): 20,000 JPY per kW (maximum 80,000 JPY) Storage battery (purchase): 50,000 JPY High insulation windows: 50,000 JPY (100,000 JPY if installed with solar power generation) Fuel cells: 50,000 JPY |
Applications started on April 1, Reiwa 8, and closed on September 8, Reiwa 8 as the budget limit was reached, as stated on Komae City’s official page. |
| National “DR Home Storage Battery Project” (Reiwa 7 Fiscal Year Supplement) | Newly introducing home storage systems that can be utilized for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 34,500 JPY per kWh (subsidy rate within 3/10; maximum 600,000 JPY per application). | As of May 29, 2026, the budget has been reached, and the public recruitment has ended (there are no plans to reopen public recruitment, and applications are currently not accepted). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but must be combined with essential works such as insulation renovations of windows (openings) and structures; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities | Storage battery: 96,000 JPY per household | As soon as the budget limit is reached, it will end. As of October 5, 2026, the application amount for renovations is displayed as 8% of the budget on the official website. Please check the reception status on the official site. |
The Tokyo solar power and storage battery subsidies require prior application. For storage batteries applied for after October 1, 2026, only products registered with the national SII will be eligible, and the equipment requirements will change. The subsidy in Komae City requires an application before the installation of the equipment, and the budget limit for the fiscal year 2026 has been reached, and applications are now closed. Each program has different eligibility conditions, application procedures, and whether they can be combined, and applying does not guarantee that subsidies will be granted, so please confirm before contracting or starting work.
Kakeru Koumuten Co., Ltd. will provide guidance on eligibility conditions and application periods for each program after confirming them.
National Subsidy “DR Home Storage Battery Project (Support Project for Introducing Home Storage Systems for DR Resource Implementation)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those who are newly introducing registered storage systems that can be used for demand response (DR), and in the fiscal year 2025 supplementary budget, the subsidy amount was determined based on a standard amount of 34,500 JPY per 1 kWh of initial effective capacity, with a subsidy rate of up to 30% and a maximum of 600,000 JPY per application. There are also conditions such as that contracts or orders made before the grant decision are not eligible.
However, the fiscal year 2025 supplementary budget reached its application amount on May 29, 2026, and the public recruitment has ended. The official site also states that there are no plans to resume public recruitment, and applications are currently not possible. Please check the official site for future public recruitment.
Furthermore, there are currently no subsidies confirmed for the installation of solar panels for existing homes.
👉 Click here for the official site of the DR Home Storage Battery Project
Tokyo “Promotion Project for Introducing Solar Power Generation in Homes”
This subsidy is for those who are newly installing unused solar power generation systems in residential homes in Tokyo. The simultaneous installation of storage batteries is not a condition.
● Existing homes: 150,000 JPY per kW for 3.75 kW or less (maximum 450,000 JPY), 120,000 JPY per kW for over 3.75 kW and less than 50 kW
● New homes: 120,000 JPY per kW for 3.6 kW or less (maximum 360,000 JPY), 100,000 JPY per kW for over 3.6 kW and less than 50 kW
● Additional amounts are available for the installation of rooftop frames and waterproofing work.
The target is to install unused panels with an output of less than 50 kW that have obtained JET certification, for use in residential areas. The process involves making a prior application and then applying for the grant after installation. Starting from the prior application for the fiscal year 2026, submission of a certificate issued by a financial institution at the time of performance reporting has become mandatory.
According to the official page of Tokyo, prior applications have been accepted since May 29, 2026. It will end as soon as the budget is reached, so please check the official page for the reception status.
👉 Click here for the official page of Tokyo (Cool Net Tokyo)
Tokyo “Home Battery Installation Promotion Project”
This is a subsidy for the installation costs of battery systems aimed at increasing self-consumption of electricity from solar power and improving energy independence during emergencies.
●Battery package: 100,000 JPY per kWh (up to 1,200,000 JPY per household)
●Additional for participating in DR demonstration: 100,000 JPY per unit (150,000 JPY per unit if energy management equipment is installed)
●Battery unit expansion: 60,000 JPY per kWh (up to 720,000 JPY per household)
Eligible applicants are owners of the subsidized equipment (excluding national and local governments), and installation must be completed between April 1, 2026, and March 30, 2027. If applying in advance after October 1, 2026, only products registered in the national SII for the fiscal year 2026 will be eligible.
The official Tokyo page states that advance applications have been accepted since May 29, 2026. For detailed information, including conditions for combining with solar power generation, please check the official page.
👉 Click here for the official Tokyo (Cool Net Tokyo) page
Komae City “Subsidy for Equipment Installation for Global Warming Countermeasures” (Fiscal Year 2026)
Komae City’s “Subsidy for Equipment Installation for Global Warming Countermeasures” provides subsidies for individuals (residents), condominiums (owners and management associations), and businesses in the city when installing equipment such as solar power generation and batteries. Conditions include no delinquency in city taxes, and applications must be submitted before the installation of the equipment. If installed before the grant decision, it will not be eligible, as stated on the city’s official page.
●Solar power generation (purchase): 20,000 JPY per kW (maximum 80,000 JPY)
●Battery (purchase): 50,000 JPY
●High-insulation windows: 50,000 JPY (100,000 JPY if installed together with solar power generation)
●Fuel cells: 50,000 JPY
For fiscal year 2026, applications started on April 1, 2026, and were closed after reaching the budget limit at 5 PM on September 8, 2026, as stated on Komae City’s official page (confirmed as of October 7, 2026). The implementation details for the next fiscal year are not posted on the official page, so those considering applying should check the latest information on the city’s official page.
Conditions for eligible equipment and application methods may change.
👉 Click here for the official Komae City page
Solar Panel Installation & Battery Installation Price List
⇧Service Menu | For Costs Related to Solar Panel Installation and Battery Installation, Click Here
⇧Service Menu | For Costs Related to Solar Panel Removal and Water Heater Removal, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and batteries should be checked 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.
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 (kilowatts). Battery capacity is compared in kWh (kilowatt-hours), which represents the amount of electricity that can be stored.
The amount of kW that can be placed on the 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 as approximately 800,000 JPY to 1,200,000 JPY for 3-5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6-10 kW. (These are just estimated amounts 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 Check in the Estimate (Cost Confirmation)
When comparing estimates, it is common to compare different capacities and equipment. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) are specified. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls the battery as a unit. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range usable during a power outage (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Fittings | Name of fittings suitable for roofing materials and method of securing (whether it involves drilling holes or clamping). |
| 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 fixing points, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | Extent of support for applications to the power company, certification application for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If it is simultaneous with roof work or exterior painting, check that the same scope and quantity are not double-counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters or old panels and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether 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 capacities differ, both the amounts and power generation will change. Kakeru Koumuten Co., Ltd. welcome comparisons, so if you bring estimates from other companies, we will explain the differences item by item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can get an estimated quote and income 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 income simulation!
*The simulation results are estimates. Actual income 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)!
Examples of Solar Panel Installation
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh |
| Base Mounting Hardware Used |
| Niigata Manufacturing/Aluminum Catch-Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed using catch-type hardware gripping the horizontal metal roof (Catch Method) |
| Price Range |
| 2,200,000 JPY – 2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8-9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction and may differ under the current system. |
| Construction Period |
| About 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that grants are available, and I would like to know how much will be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of the grant, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Komae City, Tokyo
There are many solar panel installation contractors available in Komae City, Tokyo, and you may be unsure which contractor to choose.
For this reason,when requesting solar panel installation or battery storage installation work, let’s check the following four 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 (three companies is a guideline)
● Check if they provide support for subsidy applications
By confirming the above four points, you will be able to choose a reliable contractor.
Knowledge about roofs as well as solar panels
Improper installation of solar panels can 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, leading to leaks
・Solar panels were installed on a roof with a short lifespan, requiring a renovation to detach and reattach the solar panels within a few years
・Incorrect processing due to misjudgment of the type of waterproofing, resulting in leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the presence of warranties and 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, disclaimers, and cost conditions.
While the solar panels and battery storage come with manufacturer warranties, also check for the presence of a workmanship warranty in case leaks occur after installation!
If the contractor has a workmanship warranty, they may cover any leaks that occur after installation within the warranty period and conditions.
Additionally, some contractors offer after-sales services separate from warranties, so make sure to check if the contractor you are considering has after-sales service.
Since abnormalities or damages on the roof may not be visible, you might not notice them yourself.
By conducting inspections of invisible areas during after-sales maintenance, you can more easily detect abnormalities early and prevent major repairs or failures!
Kakeru Koumuten Co., Ltd. offers 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 provide aftercare maintenance and send out annual DM!
If you check the DM and wish to proceed, we will visit for aftercare maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, let’s obtain estimates from multiple contractors.
Even for the same manufacturer and the same construction details, costs may vary, as well as warranties and after-sales services.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check:
“Verification of estimate items”
“Types of solar panels”
“Warranties and after-sales services”
and make detailed comparisons for your judgment! Avoid judging solely based on costs, as using lower-grade materials or skipping processes can reduce costs!
▶ Go to “Breakdown of installation capacity, equipment, and construction costs” in this article
Confirm if they provide support for subsidy applications
There may be subsidies available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
Since there are systems like the Tokyo subsidy that require prior application, it is reassuring to work with contractors who support the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for Tokyo subsidies, prior application) before proceeding with the construction!
For Tokyo subsidies, after installation, you will need to submit a grant application and performance report, and it will go through a review process before the grant is provided! (The flow of procedures varies by system)
▶ Go to “Subsidies and grants that may be applicable in Komae City, Tokyo” in this article
Benefits of Introducing Solar Equipment
The benefits of introducing solar panels are as follows!
Benefit 1 Economic Benefits
The biggest advantage of introducing solar panels is the economic benefit!
The selling price of electricity has decreased compared to 10 years ago, but by consuming the electricity generated, you can reduce the amount of electricity purchased from the utility company and gain benefits!
As electricity costs 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 as “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 is likely to be more advantageous to use it at home (self-consume) rather than sell it, making the combination with a storage battery a viable option.
👉 Ministry of Economy, Trade and Industry | For purchase prices, periods, etc., click here
Advantage 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 through subsidies is a significant advantage!
In the case of Komae City, you may be eligible for programs from the national government, Tokyo Metropolitan Government, and Komae City. Komae City’s grant requires an application before installation, but it has been reported that the budget limit was reached in the fiscal year 2026, and applications have ended (please check the application status for each program).
Advantage 3 Environmentally friendly!
Solar power generation has low carbon dioxide emissions and can reduce dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices such as power conditioners may have operational noise.)
Advantage 4 Heat insulation effects are expected!!
By installing on the roof or rooftop, the panels block direct sunlight to the roof.
Especially in summer, it can help reduce the temperature of the roof, providing expected heat insulation effects!
（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 is possible to use electricity even during emergencies such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capability, you may be able to use electricity from a dedicated outlet during daytime generation.
（The devices, output, and duration that can be used during a power outage vary depending on the model and wiring method）
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1 Maintenance costs can be incurred
A particularly overlooked maintenance cost is for the roof where solar panels are installed.
If you perform roof remodeling 10 to 20 years later, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorated, it is reassuring to remodel it with durable roofing materials before installing solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It would be reassuring to consider maintenance costs in the simulation before introducing solar panels!
Point 2 The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix brackets to the roofing material or substrate with screws, waterproofing of the fixed parts is crucial.
In methods that create 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 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 brackets, and 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, replacing it with 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!
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 come in various sizes and outputs depending on the manufacturer.
A panel with an output of 350W and a panel with an output of 400W may seem at first glance that the higher output panel is better.
However, if the size of the panel does not fit well with the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” 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.
How to Choose 2: Compare by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases over 10 or 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or power generation itself.
Choosing solar panels by considering the degradation rate, rather than just the initial output, will help you avoid regrets!
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.
For output warranties, 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 Komae City, Tokyo
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Komae City, Tokyo. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Komae 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.
For cost estimates by capacity, please refer to 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 Komae City, Tokyo?
As of October 7, 2026, Tokyo’s “Promotion Project for Solar Power Generation in Households” (for existing homes, 15,000 yen per kW for systems under 3.75kW, with a maximum of 450,000 yen) and “Promotion Project for Storage Battery Installation in Households” (100,000 yen per kWh, with a maximum of 1.2 million yen per household) are accepting pre-applications starting May 29, 2026, as stated on the official Tokyo (Cool Net Tokyo) page. Komae City offers subsidies for equipment installation to combat global warming (20,000 yen per kW for solar power with a limit of 80,000 yen, and 50,000 yen for storage batteries), but the budget limit was reached on September 8, 2026, and applications have closed, as noted on Komae City’s official page. The national DR household storage battery project has ended 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?
This varies by program. Tokyo’s subsidies require pre-application, and Komae City’s grants also require application before equipment installation. Conditions regarding whether you can sign a contract or start construction before applying may differ by program, so please confirm before signing a contract.
The order of procedures varies by program, so please check before signing a contract or starting construction.
Can solar panels be installed on slate roofs? I’m worried about leaks.
Installation is possible on slate roofs, but it is necessary to check the condition of the roofing material and substrate. The fixing method varies by construction method, and when fixing 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 and suggest methods such as roof overlay (cover method) or re-roofing if deterioration is progressing.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed after 10 to 20 years post-installation, there will be additional costs for removing and reinstalling solar panels. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with durable roofing materials before installation.
Please consult us on how to proceed with the installation after checking the condition of the roof through a site survey!
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 (100,000 yen per kWh for Reiwa 8, with a maximum of 1.2 million yen per household) aims to increase self-consumption of electricity generated by solar power. The subsidy program in Komae City also includes storage batteries (50,000 yen for purchase) (applications for Reiwa 8 have ended). You can compare “solar only” and “solar + storage battery” through a financial simulation.
How many kW can I install 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 provide you with the installation capacity and power generation simulation.
Komae City is located in an area where the Tama River flows to the south of the city, and the shape and orientation of the roof, as well as the shading from surrounding buildings, will differ for each house. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
For the above construction example (solar panel 4.3 kW + storage battery), it took about 3 days. The duration may vary if roofing work is done simultaneously or depending on the shape of the roof and installation capacity.
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), the selling price will be 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 2026 fiscal year.
The idea is to recover initial costs more quickly in the first four 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 notices via DM and visits customers who wish to have inspections. We can also clean solar panels with a special brush if the power generation decreases due to dirt.
It is difficult to check areas on the roof by yourself, so please feel free to consult us if you have any concerns.
Can you also renovate roofs that already have solar panels installed?
It is possible. Kakeru Koumuten Co., Ltd. can detach and reattach solar panels in-house, allowing us to perform roof overlay (cover method) or re-roofing after removing the panels, and we will handle everything consistently until reinstallation. The removed panels can be stored in our own warehouse.
For costs, please refer to the solar panel detachment and hot water heater removal pricing page.
If you are looking for a solar panel installation company in Komae City, Tokyo, please consult Kakeru Koumuten.
Our company handles a wide range of exterior renovations, including solar panels, roof work, and exterior wall work in Komae City, Tokyo.
We receive requests from many customers, including renovation companies and real estate agencies!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received positive feedback from many customers.
We continue to update our annual construction performance and strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay (cover method) and re-roofing but also partial roof repairs, exterior painting, and exterior wall cover methods.
We are also happy to handle small jobs like partial repairs and rain gutter cleaning!
In urgent cases like leak repairs, we may be able to provide emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult us!
“I want to know recommended solar panels”, “I want to keep costs down as much as possible”, “I just want an estimate for now”, we will provide optimal solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in the customer’s position and propose the best construction plans!
We are confident that we will not be outdone in terms of cost, quality, and organization compared to other companies in exterior construction!
We welcome competitive quotes with confidence!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Features of Komae City, Tokyo, and Points for Solar Construction
Komae City is bordered by Setagaya Ward to the east, Chofu City to the west and north, and Kawasaki City in Kanagawa Prefecture to the south across the Tamagawa River, with an area of 6.39 square kilometers (2,940 meters east-west and 3,660 meters north-south), as stated on the city’s official page. Below are summarized the characteristics of the terrain in Komae City, Tokyo, and points to consider when installing solar panels and storage batteries. (Tap to open)
View the features of Komae City, Tokyo, and points for solar construction
■ The city area is approximately 2.9 kilometers east to west and 3.7 kilometers north to south. Confirm the delivery route for each site
The city area is not large, and the width of the front road, the distance between neighboring houses, and the elevation differences of the site vary from house to house. The method of scaffolding and the delivery routes for panels and storage batteries will be confirmed on-site. At Kakeru Koumuten, our own scaffolding team plans the scaffolding according to the site, creates layout diagrams from the drawings and site surveys, and you can confirm them through power generation simulations.
■ Check the flood and internal water hazard maps for the Tamagawa, Nogawa, and Iruma rivers. Pay attention to the installation locations of equipment
The disaster prevention map and hazard map of Komae City include floods (the Tamagawa flood version assumes a total rainfall of 588 millimeters over 48 hours, and the Nogawa and Iruma flood versions assume a maximum rainfall of 153 millimeters in one hour and a total rainfall of 690 millimeters over 24 hours, representing the maximum possible rainfall), internal water, and landslide warning areas (updated April 16, 2026). Depending on where the power conditioner and storage battery are installed, separate from the panels on the roof, the impact during water damage may vary. Please check the assumptions for your residence on the city map and consult with us regarding the installation location and height, in accordance with the installation conditions of the manufacturer you are using.
■ The types of roofs and their ages vary from house to house. Check the roof and waterproofing before installation
Even within the same city, the types of roofs, their ages, and the shapes of the sites vary from house to house. The capacity that can be installed and the fixing methods also change depending on the shape and orientation of the roof and the roofing materials used. At Kakeru Koumuten, we will check the type and condition of the roof and the site situation before installation and propose fixing methods, waterproofing details, and scaffolding plans.
■ The annual sunshine hours at the Tokyo Observatory are approximately 1,927 hours
According to the Japan Meteorological Agency’s average values (1991-2020), the annual sunshine hours at the Tokyo Observatory are approximately 1,927 hours, with January (about 193 hours) having the most and June during the rainy season (about 124 hours) having the least. (This is a reference value, not based on measurements within Komae City)
The power generation in Komae City can also be affected by shadows from surrounding buildings and trees, so conducting annual power generation simulations and selecting the capacity of the storage battery according to the times of high electricity usage are key points.
Our company handles many exterior construction and solar power projects in Komae 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 for any sudden troubles!
Service Area in Komae City, Tokyo
Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Komae City, Tokyo
Izumi Honcho, Komae City / Inokata, Komae City / Iwato Minami, Komae City / Iwato Kita, Komae City / Komai Cho, Komae City / Naka Izumi, Komae City / Nishi Izumi, Komae City / Nishi Nogawa, Komae City / Higashi Izumi, Komae City / Higashi Nogawa, Komae City / Moto Izumi, Komae City
・For exterior wall painting in Komae City, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・For roof renovations in Komae City, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・For exterior renovations in Komae City, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・Kakeru Koumuten Co., Ltd. project achievements
・Kakeru Koumuten Co., Ltd. aftercare services
・Kakeru Koumuten Co., Ltd. service menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of getting multiple estimates and points to compare!
・12 major manufacturers of solar power generation! Features and selection tips included!
・What are the installation costs for solar power generation? Thorough explanation of tips to reduce costs!
・What are the best locations for installing solar power generation? Points for selecting installation sites included!
・Here for solar power generation 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!
