Leave the installation of solar panels in Kodaira City, Tokyo to Kakeru Koumuten Co., Ltd.!
For solar panel and storage battery installation in
Kodaira City, Tokyo,
trust Kakeru Koumuten!
Kakeru Koumuten specializes in exterior renovations.
As a company strong in roofing work, we are entrusted withsolar panel installation and storage battery installation considering roofs and waterproofing!
“How to Choose a Solar Panel Contractor in Kodaira City, Tokyo”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Kodaira 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 obtainingthree or so comparative estimates!
Table of Contents (tap to open/close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Kodaira City, Tokyo
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Kodaira 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 Company in Kodaira 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 Kodaira City, Tokyo
- If You Are Looking for a Solar Panel Installation Company in Kodaira City, Tokyo, Contact Kakeru Koumuten
- Characteristics of Kodaira City, Tokyo and Key Points for Solar Installation
- Service Area in Kodaira City, Tokyo
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Kodaira City, Tokyo
Regarding why our company is entrusted with solar panel installation by customers in Kodaira 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 Can Also Handle Exterior Renovations Besides Solar Panel Installation!
Troubles such as leaks caused by solar panel installation may be due to insufficient checks on the roof and waterproofing at the installation site.
Even if you are knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have a good understanding of the roof to avoid maintenance and troubles after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent troubles after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide low-cost, high-quality solar 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 necessary scaffolding materials for temporary scaffolding based on construction conditions, allowing us to set up scaffolding ourselves.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also reduce the cost of scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
Even if there are height differences on the site, our scaffolding team will plan the scaffolding to fit the local conditions.
Storage of materials in our large warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, we canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, allowing us torespond quickly in emergencies!
Sorting and transporting waste materials in-house
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior renovation dedicated showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on the roofing materials!
It is also possible to simulate the revenue and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also have samples of roofing materials and models that show the structure, allowing for detailed explanations!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is all work performed by our own team.
By having a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof remodeling at reduced costs.
Additionally, one representative will handle everything from the estimate to project completion.
Since the person in charge does not change, whether it’s the sales representative or the construction management representative, smooth communication is possible.
We can perform consistent in-house work from temporary scaffolding installation to exterior wall painting and roof remodeling!
4. Various Permits and Skilled Workers
We have obtained construction industry permits and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal workers and painting technicians, and we are confident in our construction skills.
We are capable of handling large-scale roofing work for factories and other facilities!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty, our solar panel installation work comes with our own workmanship warranty (leakage warranty)!
(The workmanship warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovation is performed. The workmanship warranty is separate from the manufacturer’s product warranty, and the coverage and conditions vary based on the warranty details.)
Aftercare maintenance is available annually, 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 roof troubles and situations.
Even if we cannot access the roof at high altitudes, we can respond using a drone!
During leakage investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of the solar panels decreases due to dirt, we can also provide cleaning with a specialized brush.
We will respond according to your preferences.
7. Human Resource Development
We create various roof models for skill enhancement 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
At Kakeru Koumuten Co., Ltd., in addition to the “estimate”, “layout diagram”, and “power generation simulation”, we also provide a “solar installation guidebook” and a “profit and loss simulation” that takes into account loan interest rates and electricity costs.
The profit and loss simulation can be created for projected cumulative profits and losses over 20 to 30 years.
Even customers who are not familiar with solar installations will find the materials easy to understand, including important points and disadvantages!
We encourage you to obtain comparative estimates and review plans from other companies!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 to 30 years.
Confirming “whether it is okay to install them directly on the current roof” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten Co., Ltd., which specializes in roofing work, has summarized the items to check before installation.
| 1. Type of roofing material and age | The method of securing the panels varies depending on the roofing material, such as slate, tiles, metal roofs, or flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of the substrate and waterproof sheet | If the sheathing or roofing (waterproof sheet) beneath the roofing material is damaged, it can affect the fastening strength and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, slope, and shading of the roof | The orientation and slope of the roof surface, as well as shading from neighboring houses, trees, and utility poles, can affect power generation. We will create a layout diagram from the drawings and the site, and you can confirm it with the power generation simulation. |
| 4. Shape of the roof and available installation area | The number of panels (installation capacity) that can be placed depends on 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. Method of securing and waterproofing details | We will check whether the method involves drilling holes in the roofing material for fastening or using brackets to secure the roofing material. The fastening method varies by technique, so please confirm the waterproofing treatment of the fastening parts during the estimate. |
| 6. Weight of the roof | The roof will become heavier due to the added panels. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may be an option if necessary. |
| 7. Location of equipment installation 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 also affects costs. |
| 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 elevation changes on the site will also be checked during the on-site survey. |
Fixing Methods and Confirmation Points by Roofing Material
| Roofing Material | Main Fixing Method | Pre-installation Confirmation Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets with screws to the roofing material and substrate) | Waterproofing of fixed parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suitable for the type of tile (even methods that do not drill holes in the tiles will 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 roofing material (depends on the combination of roofing material and brackets) | Whether the roofing material and brackets are compatible, installation conditions from the roofing 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 plan to renovate the roof 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the roof is deteriorating, 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, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Kodaira City, Tokyo
PotentialSubsidies and Grants in Kodaira City, Tokyo
If you are introducing solar panels or storage batteries in Kodaira City, Tokyo, the systems from the “National Government,” “Tokyo Metropolitan Government,” and your local “Kodaira City” may be applicable.
The following information is based on the official pages of each system as of October 7, 2026. The application 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 “Residential Solar Power Generation Promotion Project” | Individuals, corporations, or management associations installing a new unused solar power system (output less than 50kW, JET certification, etc.) in residential properties within Tokyo. The generated power must be used for residential purposes. Pre-application is required | Existing homes: 150,000 JPY per kW for 3.75kW or less (maximum 450,000 JPY), 120,000 JPY per kW for over 3.75kW and under 50kW New homes: 120,000 JPY per kW for 3.6kW or less (maximum 360,000 JPY), 100,000 JPY per kW for over 3.6kW |
For the 2026 fiscal year, pre-applications are being accepted from May 29 (will end once the budget is reached). From the pre-application for the 2026 fiscal year, submission of a certificate issued by a financial institution will be mandatory at the time of performance report. |
| Tokyo “Residential Storage Battery Promotion Project” | Owners of eligible devices (storage batteries registered with SII, excluding national and local governments). Installation must occur between April 1, 2026, and March 30, 2031. If pre-applying after October 1, 2026, only products registered with the national SII for the 2026 fiscal year are eligible | Storage battery package: 100,000 JPY per kWh (maximum 1,200,000 JPY per household) Additional for DR demonstration participation (100,000 JPY per unit; 150,000 JPY per unit if energy management equipment is installed) Expansion of storage battery units: 60,000 JPY per kWh (maximum 720,000 JPY per household) |
For the 2026 fiscal year, pre-applications are being accepted from May 29. Grant application and performance report will start from June 30. |
| Kodaira City “Energy Conservation, Creation, and Storage Equipment Installation Monitor Subsidy” (2026 fiscal year) | This subsidy program is for those installing eligible devices such as solar power generation and storage batteries in residential properties within the city. Please check the city’s official page for details on eligible persons and devices. | The subsidy amount and maximum for each eligible device can be confirmed on the city’s official page. | For the 2026 fiscal year, applications are closed, as listed on the official page of Kodaira City. |
| National “DR Home Storage Battery Project” (2025 fiscal year supplementary) | New installation of home storage systems that can be utilized for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 34,500 JPY per kWh (subsidy rate within 30% and maximum 600,000 JPY per application). | The budget was reached on May 29, 2026, and the public offering has ended (there are no plans to reopen the public offering as stated on the official site, and applications cannot be made at this time). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but they must be combined with essential works such as insulation 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, the program 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 subsidy program requires prior application. For storage batteries applied for after October 1, 2026, only products registered with the national SII will be eligible, and the equipment requirements will change. The subsidy for Kodaira City has been reported as closed for the fiscal year 2026 on the city’s official page. Eligibility conditions, application procedures, and the possibility of combining different programs vary by system, and applying does not guarantee that subsidies will be granted, so please confirm before contracting and 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 Resources)”
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 utilized for demand response (DR), and in the fiscal year 2025 supplementary project, 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 conditions such as that contracts or orders made before the grant decision are not eligible.
However, the supplementary budget for fiscal year 2025 reached its budget limit on May 29, 2026, and the public offering has ended. The official site also states that there are no plans to reopen the public offering, and applications are currently not possible. Please check the official site for future public offerings.
Furthermore, there are currently no subsidies confirmed for the installation of solar panels on 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: For systems under 3.75 kW, 150,000 JPY per kW (maximum 450,000 JPY); for systems over 3.75 kW and under 50 kW, 120,000 JPY per kW.
● New homes: For systems under 3.6 kW, 120,000 JPY per kW (maximum 360,000 JPY); for systems over 3.6 kW and under 50 kW, 100,000 JPY per kW.
● Additional amounts are available for the installation of rooftop structures and waterproofing work.
The target is for unused panels that have obtained JET certification and are installed in residential homes in Tokyo with an output of less than 50 kW, used in the living area. The process involves making a prior application and then applying for the grant after installation. Starting from the prior application for fiscal year 2026, submission of certificates issued by financial institutions will be mandatory at the time of performance reporting.
On the official page of Tokyo, it is stated that pre-registration is being accepted from May 29, Reiwa 8. It will end once the budget is reached, so please check the official page for the registration status.
👉 Here is the official page of Tokyo (Cool Net Tokyo)
Tokyo’s “Household Battery Installation Promotion Project”
This is a subsidy for the installation costs of battery systems aimed at increasing self-consumption of electricity generated by solar power and improving energy independence during emergencies.
●Battery package: 100,000 JPY per kWh (maximum 1,200,000 JPY per household)
●Additional for participating in DR demonstration: 100,000 JPY per unit (150,000 JPY per unit if energy management equipment is installed)
●Expansion of battery units: 60,000 JPY per kWh (maximum 720,000 JPY per household)
The eligible applicants are owners of the subsidized equipment (excluding national and local governments), and the installation must be completed between April 1, Reiwa 8 and March 30, Reiwa 11. If pre-registration is done after October 1, Reiwa 8, only products registered in the SII for Reiwa 8 will be eligible.
On the official page of Tokyo, it is stated that pre-registration is being accepted from May 29, Reiwa 8. For detailed conditions such as combinations with solar power generation, please check the official page.
👉 Here is the official page of Tokyo (Cool Net Tokyo)
Kodaira City “Energy Conservation, Creation, and Storage Equipment Installation Monitor Subsidy” (Reiwa 8 Fiscal Year)
Kodaira City’s “Energy Conservation, Creation, and Storage Equipment Installation Monitor Subsidy” is a municipal subsidy program for those who install eligible equipment such as solar power generation and batteries in their homes. The eligible applicants, eligible equipment, subsidy amounts, and maximum amounts are determined each fiscal year on the city’s official page.
The application for the Reiwa 8 fiscal year has been closed, as listed on the subsidy list on Kodaira City’s official page (confirmed as of October 7, 2026). We cannot confirm the details for the next fiscal year, so if you are considering applying, please check the latest information on the city’s official page.
The conditions for eligible equipment and the application methods may change.
👉 Here is the official page of Kodaira City (Subsidy List)
Solar Panel Installation and Battery Installation Price List
⇧Service Menu | For Costs Related to Solar Panel and Battery Installation, Click Here
⇧Service Menu | For Costs Related to Solar Panel Removal and Water Heater Removal, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and batteries should be confirmed by separating them into “Equipment Costs (Device Costs)” and “Construction Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary greatly depending on the installation capacity, equipment grade, and roof condition.
Considerations for Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatts). Batteries are compared based on the amount of electricity they can store, represented in kWh (kilowatt-hours).
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 panel installation 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 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) should be listed. |
| 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 together. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range usable during power outages (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of the hardware suitable for the roofing material and the fixing method (whether it is a method that drills holes or a method that clamps and fixes). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, and whether there is a monitor to check the power generation amount. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at the fixing points, and whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | How much support is included for applications to the power company, feed-in tariff (FIT) certification applications, 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 water heaters or old panels and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether the price is tax-inclusive or tax-exclusive, conditions under which additional costs may arise, and details and duration of manufacturer and workmanship warranties. |
If the capacities are different, both the amounts and power generation will vary. Kakeru Koumuten Co., Ltd. welcome comparisons, so if you bring estimates from other companies, we can explain the differences by item!
Self-Estimate and Profit and Loss Simulator 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 Feedback
-
customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
-
customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
-
customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
-
customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
-
customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
-
customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installations
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh |
| Base Mounting Hardware Used |
| Niigata Manufactured / Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed by catching 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 Estimated 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 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 when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of the grant, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Kodaira City, Tokyo
There are many solar panel installation contractors available in Kodaira 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 four points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the existence of warranties and aftercare services
● 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.
Have knowledge not only about solar panels but also about roofs
Defective installation of solar panels can sometimes be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient verification of roofs and waterproofing
・Solar panels were installed on a severely deteriorated roof, 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
・Misjudging the type of waterproofing and incorrect processing led to 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 existence of warranties and aftercare services
When choosing a solar installation contractor, let’s confirm the existence of warranties. It is important to check not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While the solar panels and battery storage units come with manufacturer warranties, also check for the existence of a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may cover the repairs under the warranty, provided it falls within the warranty period and conditions.
Additionally, some contractors offer aftercare services separate from warranties, so make sure to check if the contractor you are considering has aftercare services.
Since abnormalities and damages on the roof may not be visible, you may not notice them yourself.
By conducting inspections of hidden areas through aftercare maintenance, you can more easily detect abnormalities early and prevent major repairs or failures!
Kakeru Koumuten Co., Ltd. offers a rain leak warranty as part of the workmanship warranty for solar panel installations. (The warranty for solar panel installations is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovations are performed.)
We also provide aftercare maintenance, sending out annual DM!
If you check the DM and wish for aftercare maintenance, we will visit you!
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 content, costs may vary, and warranties and after-sales services may differ.
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:
“Confirmation of estimate items”
“Types of solar panels”
“Warranties and after-sales services”
and make a detailed comparison for your judgment! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid judging solely based on price!
▶ Go to “Breakdown of installation capacity, equipment, and construction costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
Since there are systems like the Tokyo subsidy that require prior application, it is reassuring to have a contractor who can support you with the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for the Tokyo subsidy, prior application is required) before proceeding with the construction!
For the Tokyo subsidy, after installation, you will need to submit a grant application and performance report, which will go through a review process before being granted! (The flow of procedures varies by system)
▶ Go to “Subsidies and grants that may be applicable in Kodaira 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 ten years ago, but by consuming the generated electricity, 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 appealing!
If you plan to use the generated electricity at night, installing a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) will be set at “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year” for certifications after October 2025, and the same price will apply for the fiscal year 2026. After the fifth year, it is likely to be more advantageous to use it in your home (self-consumption) rather than selling it, making the combination with a storage battery a viable option.
👉 Ministry of the Environment｜For purchase prices, periods, etc., click here
Advantage 2 Subsidies can be utilized!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
Reducing the actual burden amount through subsidies is a significant advantage!
In the case of Kodaira City, there is a possibility that the programs from the national government, Tokyo Metropolitan Government, and Kodaira City may apply. It is noted that the application for Kodaira City’s subsidy for the fiscal year 2026 has 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 like power conditioners may have operational noise.)
Advantage 4 Heat insulation effects are 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 capability, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1 Maintenance costs can be incurred
A 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 differ depending on the construction method, but in methods where fixtures are secured to the roofing material or substrate with screws, waterproofing of the fixed parts is crucial.
In methods that involve making holes in the roof, the risk of leaks inevitably arises.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material 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 fixtures, 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 capacity, replacing it with a lighter roof may be one 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 the total output of the roof
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and the more power generated, the better!
Solar panels come in various sizes and outputs depending on the manufacturer.
A 350W output panel and a 400W output panel 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 one panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual power generation amount (kWh) will vary depending on conditions such as the roof’s orientation, slope, and shading.
How to Choose 2: Compare the 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 amount.
By not deciding solely based on initial output and considering the degradation rate, you can choose solar panels without regrets!
How to Choose 3: Compare the warranty period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
Regarding the output warranty, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies widely!
Since a longer warranty is generally better, let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar and Storage Battery Installation in Kodaira City, Tokyo
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Kodaira City, Tokyo. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Kodaira City, Tokyo?
The cost varies depending on the installation capacity, equipment, and roof condition. In the above case study (solar panel 4.3kW + 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 and storage battery installation in Kodaira 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 up to 3.75 kW, 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 listed on the official page of Tokyo (Cool Net Tokyo). Kodaira City has a subsidy for energy-saving equipment installation, but it has been reported on the official page of Kodaira City that applications for the 2026 fiscal year have ended. The national DR household storage battery project has also closed its public recruitment.
Since the application status may change, please refer to the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies after the construction is completed?
This depends on the system. Tokyo’s subsidies require pre-application. Including the subsidies from Kodaira City, the timing of the application (before or after installation) and whether you can sign a contract or start construction before applying varies by system, so please confirm before signing a contract.
The order of procedures varies by system, so please check before signing a contract or starting construction.
Can solar panels be installed on a slate roof? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate. The fixing method varies 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. If deterioration is progressing, we can also propose methods such as roof overlay (cover method) or complete replacement before installation.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed within 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with durable roofing materials before installation.
Please consult us about the installation process after checking the condition of the roof during the on-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 (for Reiwa 8, it is 100,000 yen per kWh, with a maximum of 1,200,000 yen per household) aims to increase self-consumption of electricity generated by solar power. The subsidy program in Kodaira City also includes equipment such as storage batteries (applications for Reiwa 8 have ended). You can compare “solar only” and “solar + 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 on-site survey, and we will provide you with the installation capacity and power generation simulation.
Kodaira City is a flat city located entirely on the Musashino Plateau, 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 panels 4.3 kW + storage battery), it took about 3 days. The duration may vary if roofing work is done simultaneously or depending on the shape of the roof and installation capacity.
Please note that there will be an additional period for applying for subsidies and to the power company, so please consult us as soon as possible.
What is the current selling price (FIT) for electricity?
For residential use (less than 10 kW), the selling price from certifications after October 2025 will be 24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year, and the same price will apply for the 2026 fiscal year.
The idea is to recover initial costs 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 DM notices and visits for inspections upon request from customers. We can also clean solar panels with a special brush if power generation decreases due to dirt.
The roof is a place that is difficult to check by yourself, so if you have any concerns, please feel free to consult us.
Can you also handle renovations for roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten Co., Ltd. can detach and reattach solar panels in-house, allowing us to remove the panels, perform roof overlay (cover method) or re-roofing, and then reinstall them consistently. The removed panels can be stored in our own warehouse.
For costs, please refer to the solar panel detachment and water heater removal pricing page.
If you are looking for a solar panel installation company in Kodaira 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 Kodaira City, Tokyo.
We have received requests from many customers, including renovation companies and real estate agencies!
Kakeru Koumuten promises “high-quality renovations at low cost”, and we have received positive feedback from many customers.
We continue to update our construction performance every year, and we will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay work and re-roofing but also partial roof repairs, exterior painting, and exterior wall cover methods.
We are also happy to handle small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as 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 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 best construction plan!
We are confident that we will not be outdone by other companies in terms of cost, quality, and organization for exterior work!
We are confident, so we welcome competitive estimates!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Characteristics of Kodaira City, Tokyo and Points for Solar Work
Kodaira City is located in the northeastern part of the Tama region of Tokyo, 26 kilometers from the city center, with an area of 20.51 square kilometers. The city area is situated on the Musashino Plateau, characterized by a neatly arranged rectangular land division, and was named “Kodaira” due to its flat terrain, as stated in the city’s profile. We have summarized the characteristics of the terrain in Kodaira City, Tokyo, and points to consider when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Kodaira City, Tokyo, and points for solar installation
■ Flat plateau with rectangular plots. Check the delivery route based on the shape of the front road and the plot
The city area spreads over a flat plateau and is characterized by rectangular land divisions. In plots that are narrow in width and deep, the width of the front road and the distance to neighboring houses will affect how scaffolding is set up and the delivery routes for panels and storage batteries. Conditions vary from one property to another even within the same city, so we will confirm 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 check the power generation simulation.
■ Check the flood prediction area map and landslide warning area map. Be cautious about the installation location of equipment
Kodaira City’s hazard map (flood prediction area map and landslide warning area map) is based on Tokyo’s flood prediction area map targeting the Kurome River, Ochiai River, Yanase River, Sorihori River, Narahashi River, Nogawa River, Sengawa River, Iruma River, Tanizawa River, Maruko River, Shakujii River, and Shirako River. The same page states that there is no setting for rainwater discharge (internal water) based on the Flood Control Act (updated July 9, 2026). Depending on where the power conditioner and storage battery are installed, separate from the panels on the roof, the impact during flooding may vary. Please check the assumptions for your location on the city’s map and consult about the installation location and height in conjunction with the installation conditions of the manufacturer you are using.
■ Roof types and ages vary from house to house. Check the roof and waterproofing before installation
Even within the same city, roof types, ages, and plot shapes vary from house to house. The capacity that can be installed and the fixing methods will also change depending on the shape and orientation of the roof and the materials used. At Kakeru Koumuten, we will confirm the type and condition of the roof and the situation of the plot before installation and propose fixing methods, waterproofing details, and scaffolding plans.
■ The annual sunshine hours at the Tokyo observatory are about 1,927 hours
According to the Japan Meteorological Agency’s average values (1991-2020), the annual sunshine hours at the Tokyo observatory are about 1,927 hours, with January (about 193 hours) being the most and June during the rainy season (about 124 hours) being the least. (This is a reference value, not based on measurements within Kodaira City.)
The power generation in Kodaira City can also be affected by shadows from surrounding buildings and trees, so it is important to conduct an annual power generation simulation and choose the capacity of the storage battery according to the times when electricity is used the most.
Our company handles many exterior and solar installation projects in Kodaira City, Tokyo.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us about any sudden troubles!
Service Area in Kodaira City, Tokyo
Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Kodaira City, Tokyo
Onuma-cho, Kodaira City / Ogawa Higashi-cho, Kodaira City / Ogawa Nishi-cho, Kodaira City / Ogawa-cho, Kodaira City / Gakuen Higashi-cho, Kodaira City / Gakuen Nishi-cho, Kodaira City / Kihei-cho, Kodaira City / Sakae-cho, Kodaira City / Kamimizu Shin-cho, Kodaira City / Kamimizu Hon-cho, Kodaira City / Kamimizu Minami-cho, Kodaira City / Suzuki-cho, Kodaira City / Takano-dai, Kodaira City / Tsuda-cho, Kodaira City / Tenjin-cho, Kodaira City / Nakajima-cho, Kodaira City / Nakacho, Kodaira City / Hanakoganei, Kodaira City / Hanakoganei Minami-cho, Kodaira City / Misono-cho, Kodaira City / Miyuki-cho, Kodaira City / Kaida-cho, Kodaira City
・Trust Kakeru Koumuten for exterior wall painting in Kodaira, Tokyo!
・Trust Kakeru Koumuten for roof renovations in Kodaira, Tokyo!
・Trust Kakeru Koumuten for exterior renovations in Kodaira, Tokyo!
・Kakeru Koumuten Co., Ltd. project 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 comparative estimates and key points!
・Top 12 solar power generation manufacturers! Features and selection tips included!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
・What are the best locations for solar power installation? Key points for site selection included!
・Check out our solar power generation estimates here!
We welcome inquiries via LINE as well◎
We are also updating our Instagram regularly◎ Please follow us◎
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!
