Leave Your Solar Panel Installation Work in Musashino City, Tokyo to Kakeru Koumuten Co., Ltd.!
For solar panel and battery installation in
Musashino City, Tokyo,
trust Kakeru Koumuten!
Kakeru Koumuten is a specialized exterior renovation company headquartered in Aoba Ward, Yokohama City.
As a company strong in roofing work, we are entrusted withsolar panel installation and battery installation considering roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Musashino City”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Musashino City”
We will also explain the above three points!
Installing solar panels carries risks such as“the occurrence of leaks” and other troubles.
To avoid regrets, we recommend obtainingthree or so estimates!
Table of Contents (Tap to Open/Close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Musashino City, Tokyo
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Musashino City
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installation Company in Musashino 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 Musashino City
- If You Are Looking for a Solar Panel Installation Company in Musashino City, Contact Kakeru Koumuten
- Characteristics of Musashino City, Tokyo and Points for Solar Installation
- Service Area in Musashino City, Tokyo
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Musashino City, Tokyo
The reasons why we are entrusted with solar panel installation by customers in Musashino City, Tokyo include
one reason being that “Kakeru Koumuten serves Kanagawa and Tokyo as its service areas”,
and we have “unique strengths in solar panel installation that cannot be imitated by other companies”, which have received high praise from many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We Also Handle Exterior Renovations Aside from Solar Panel Installation!
Troubles such as leaks that occur during solar panel installation may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if one is knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside their expertise, so caution is necessary.
It is reassuring to have knowledge about the roof to avoid maintenance and troubles after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent troubles after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide solar work and exterior renovations at low cost and high quality.
We have established five bases centered in Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the necessary scaffolding materials for temporary scaffolding based on construction conditions, allowing us to assemble scaffolding ourselves.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also cut costs on scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
In Musashino City, our own scaffolding team will plan the scaffolding according to the site conditions.
Storage of materials in our large warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, we canpurchase materials at a lower cost!
Additionally, we always have stock of roofing materials, enabling 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 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 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 explain 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 renovations 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 sales or construction management, smooth communication is possible.
We can perform consistent in-house work from temporary scaffolding installation to exterior wall painting and roof renovation!
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 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 a 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 every year.
If you have any questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roof troubles and situations.
Even if we cannot access the roof from high places, 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 the customer’s wishes.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training so that each staff member can handle various cases.
8. Creation of Clear Materials and Simulations
At Kakeru Koumuten Co., Ltd., we provide not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar installation guidebook” and a “financial simulation” that takes into account loan interest rates and electricity costs.
The financial simulation can be created for projected cumulative income and expenses over 20 to 30 years.
Even customers who are not familiar with solar installations will find our materials easy to understand, including important points and 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) 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 power generation. A layout diagram will be created based on the drawings and the site, and you can confirm it with the power generation simulation. |
| 4. Shape of the roof and installable area | The shape and size of the roof determine the number of panels (installation capacity) that can be placed. The number of panels that can be installed varies depending on their size, so we will compare based on the total output of the roof. |
| 5. Method of securing and waterproofing details | We will check whether the panels are secured by drilling holes in the roofing material or by using brackets to hold the roofing material. The method of securing 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 panels. After investigating the existing roof, substrate, and load-bearing capacity, switching to lighter roofing materials may be an option if necessary. |
| 7. Location of equipment installation and wiring | We will confirm the installation locations for the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect costs. |
Securing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproof treatment of fixing parts, cracks or deterioration of slate, condition of the substrate. If deterioration is significant, 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 survey results, there may be methods to replace with lightweight roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and condition of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you perform roof renovations 10 to 20 years after installation, there will be additional costs for the removal and reinstallation of solar panels. If the roof is deteriorating, renovating to a highly durable roofing material before installation may help reduce costs in the long run.
Kakeru Koumuten Co., Ltd. specializes in roofing work and can also handle the removal and reinstallation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Musashino City, Tokyo
PossibleSubsidies and Grants
If you are introducing solar panels or storage batteries in Musashino City, Tokyo, there is a possibility that you may be eligible for programs from the “National Government,” “Tokyo Metropolitan Government,” and “Musashino City”.
The following information is based on the official pages of each program as of October 7, 2026. The application status may change depending on the budget and application period, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Period for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Tokyo Metropolitan Government “Reiwa 8 Year Household Solar Power Generation Promotion Project” (Cool Net Tokyo) | A system under 50kW that involves the new installation of certified solar modules on residential properties within the Tokyo area. Pre-application before installation is required. | Existing homes: 150,000 JPY/kW for 3.75kW or less (maximum 450,000 JPY), 120,000 JPY/kW for over 3.75kW New homes: 120,000 JPY/kW for 3.6kW or less (maximum 360,000 JPY), 100,000 JPY/kW for over 3.6kW (Additional costs for mounting, waterproofing, and renovation defect insurance, etc.) |
Pre-application: From May 29, 2026 Grant application and performance report: From June 30, 2026 to March 30, 2029 |
| Tokyo Metropolitan Government “Reiwa 8 Year Household Storage Battery Promotion Project” (Cool Net Tokyo) | New installation of storage batteries in residential properties within Tokyo, which must be SII registered devices. This project is intended for simultaneous installation with solar power, but applications can be made for storage batteries alone. Pre-applications after October 1, 2026 will only be eligible for SII registered products for Reiwa 8. | Storage battery package: 100,000 JPY/kWh (maximum 1,200,000 JPY per household) Expansion of storage battery units: 60,000 JPY/kWh (maximum 720,000 JPY per household) (Additional incentives for participating in DR demonstrations, etc.) |
Pre-application: From May 29, 2026 Grant application and performance report: From June 30, 2026 |
| Musashino City “Efficient Energy Utilization Promotion Subsidy Program” (Reiwa 8 Year) | This program is for residents listed in the Musashino City Basic Resident Register who install unused solar power generation systems for personal use. Applications must be made after installation, within 6 months of completion. Storage batteries are not eligible. | Solar power generation: 150,000 JPY, or 30,000 JPY × maximum output kW (whichever is lower, maximum 5kW) (Additionally, EneFarm 60,000 JPY and high-insulation windows are also eligible) |
Applications are being accepted until February 28, 2027, within the budget limits (the city will notify if the budget is reached on its page). |
| National Government “DR Household Storage Battery Project” (Reiwa 7 Year Supplement) | New installation of household storage systems that can be utilized for DR (demand response) with registered products. | Calculated based on 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 recruitment has ended (applications cannot be made at this time). |
| National Government “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but they must be combined with essential works such as insulation renovations of windows (openings) and structures; applications cannot be made for storage battery installation alone. Solar panels are not included as eligible facilities. | Storage battery: 96,000 JPY per household | As soon as the budget limit is reached, it will end. Please check the reception status on the official website. |
In Tokyo, a pre-application before installation is required for subsidies, and starting construction beforehand may result in ineligibility. It is necessary to meet the requirements for eligible equipment and conditions, and applying does not guarantee approval. The Musashino City subsidy system allows applications after installation (within 6 months of completion), which differs from the order of applications in Tokyo’s system. Since the procedures vary by system, please confirm before contracting and starting construction.
Kakeru Koumuten Co., Ltd. will guide you on the eligibility conditions for each system after confirming them.
Tokyo “Reiwa 8 Year Household Solar Power Generation Promotion Project”
In Tokyo, subsidies are provided for those installing solar power generation systems in residential homes through Cool Net Tokyo. The target is systems using certified solar cell modules installed newly in residential homes or their premises, with a capacity of less than 50kW. A pre-application before installation is required.
For existing homes, the subsidy amount is 150,000 JPY/kW for 3.75kW or less (maximum 450,000 JPY), and 120,000 JPY/kW for over 3.75kW. Additionally, there are supplementary items such as installation of mounting frames, waterproofing work, and renovation defect insurance. The pre-application period is from May 29, 2026, and the application for grants and performance reports is from June 30, 2026, to March 30, 2029. For details on eligible equipment and conditions, as well as the budget status, please check the official page.
👉 Cool Net Tokyo | Official page for solar power generation is here
Tokyo “Reiwa 8 Year Household Storage Battery Promotion Project”
Tokyo is also providing subsidies for newly installed storage batteries in residential homes. The subsidy amount is 100,000 JPY per 1kWh of storage battery package (maximum 1,200,000 JPY per household), and for additional storage battery units, it is 60,000 JPY per 1kWh (maximum 720,000 JPY per household), with additional amounts for participation in DR demonstrations.
The target is equipment registered with SII (Environmental Collaboration Initiative). If applying for pre-application after October 1, 2026, only equipment listed in the Reiwa 8 Year SII registered product list will be eligible. This project is intended for simultaneous installation with solar power, but applications can be made for storage batteries alone. The application for grants and performance reports has been accepted since June 30, 2026.
👉 Cool Net Tokyo | Official page for storage batteries is here
Musashino City “Efficient Energy Utilization Promotion Subsidy System”
Musashino City has implemented the Efficient Energy Utilization Promotion Subsidy System for the introduction of energy-saving and energy-generating equipment. The eligible equipment for Reiwa 8 Year includes solar power generation systems, fuel cell cogeneration systems (Enefarm), and insulation renovations of existing windows, with storage batteries being ineligible. The subsidy amount for solar power generation systems is 150,000 JPY, or 30,000 JPY × maximum output kW (whichever is lower, maximum 5kW).
The target is for individuals listed in the resident basic registry of Musashino City who install equipment for personal use, and in the case of rental housing, the owner’s consent is required. Applications must be made after the installation of the equipment and must be submitted within 6 months of the completion of the work. Applications for the fiscal year 2026 must be submitted by February 28, 2027, and will be accepted within the budget (as of October 7, 2026, there is no indication of acceptance ending on the city’s page). It can be used in conjunction with subsidy programs from the national government and Tokyo Metropolitan Government, but the total amount cannot exceed the eligible expenses for subsidies. If the budget is reached, notifications will be provided on the city’s page, so please check the acceptance status before signing a contract.
👉 Here is the official page of Musashino City (Subsidy Program for Promoting Efficient Energy Use)
Solar Panel Installation & Battery Installation Price List
⇧Service Menu | For costs related to solar panel installation & battery installation, click here
⇧Service Menu | For costs related to solar panel removal & water heater removal, click here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and storage batteries should be confirmed by separating them into “Equipment Costs (Device Costs)” and “Construction Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.
Understanding Installation Capacity (kW) and Storage Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatt). Storage batteries are compared based on the amount of electricity they can store, expressed in kWh (kilowatt-hour).
The amount of kW that can be installed 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 to 5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6 to 10 kW. (These are just rough estimates, and the actual cost may vary based on wiring length, scaffolding range, existing roofing materials, and panel layout.)
▶ Construction Menu | Click here for costs of solar panel installation and storage battery installation
Items to Check in the Quotation (Cost Confirmation)
When comparing prices in competitive quotations, it is common to compare different capacities and equipment. Please check if the following items are clearly stated in each company’s quotation!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) are listed. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls the battery together. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range usable during a power outage (whole house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of hardware suitable for roofing materials and method of securing (whether it is a method that drills holes or a method that grips and secures). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, presence of a monitor to check power generation. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at fixed points, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Application | How much support is included for applications to the power company, certification applications for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If roof work and exterior painting are done simultaneously, confirm that the same scope and quantity are not double counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters and old panels, as well as disposal costs for waste materials, are included. |
| 10. Tax Classification and Warranty | Whether prices are 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 price 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 and Loss Simulator for Solar Power Generation
With the above simulator,
you can obtain an estimated quote and a profit and loss simulation 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 profit and loss simulation!
*The simulation results are estimates. Actual profits and losses 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 Manufactured/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 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 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 Musashino City, Tokyo
There are many solar panel installation contractors available in Musashino City, Tokyo, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and storage battery installation work, let’s check the following 4 points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the presence of warranties and after-sales maintenance
● Obtain estimates from multiple contractors (3 companies as a guideline)
● Check if they provide support for subsidy applications
By confirming the above 4 points, you will be able to choose a reliable contractor.
Knowledge about roofs as well as solar panels
Improper installation of solar panels can sometimes be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient verification of roofs and waterproofing
・Solar panels installed on a severely deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring renovations for removal and reinstallation within a few years
・Misjudging the type of waterproofing and applying incorrect treatment, 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 unforeseen troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the presence of warranties and after-sales maintenance
When choosing a solar installation contractor, let’s confirm the presence of warranties. It is important to check not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While solar panels and storage batteries come with manufacturer warranties, it is also essential to check for the presence of installation warranties in case leaks occur after installation!
For contractors that offer installation warranties, if leaks occur after installation, they may cover the repairs under the warranty, provided it is within the warranty period and conditions.
Additionally, some contractors offer after-sales service separate from warranties, so be sure to check if the contractor you are considering has after-sales service.
Changes or damage on the roof may occur in areas that are not visible, so there is a possibility that customers may not notice them.
By conducting inspections during after-sales maintenance, we can detect abnormalities early, making it easier to prevent major repairs or breakdowns!
Kakeru Koumuten Co., Ltd. provides a leak warranty as part of the workmanship warranty for solar panel installations. (The warranty for solar panel installations is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty without performing roof renovations.)
We also conduct after-sales maintenance and send out annual direct mail!
After checking the direct mail, if you wish, we will visit for after-sales maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, be sure to obtain estimates from multiple contractors.
Even for the same manufacturer and the same work content, costs may vary, as well as warranties and after-sales services.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request from your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates,
“Check the items in the estimate”
“Type of solar panel”
“Warranties and after-sales services”
and make a careful comparison to make your decision! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making decisions based solely on price!
▶ To “Breakdown of installation capacity, equipment, and construction costs” in this article
Check if they provide support for subsidy applications
Subsidies may be available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
There are systems that require personal applications and cannot be handled by the contractor, as well as systems that require pre-application before installation, so it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for Tokyo’s subsidy, a pre-application before installation) before proceeding with the construction!
In the case of subsidies in Tokyo, the process involves submitting a grant application and performance report after the completion of the work, which will be granted after a review! (The procedure varies depending on the system)
▶ Go to “Subsidies and Grants that May Be Available in Musashino City” within this article
Benefits of Introducing Solar Power Equipment
The benefits of introducing solar panels are summarized in the following five points!
Benefit 1: Economic Benefits
The biggest benefit of introducing solar panels is the economic advantage!
Although the selling price of electricity has decreased compared to ten years ago, by consuming the electricity generated, you can reduce the amount of electricity purchased from the utility company and gain benefits!
As electricity prices rise, the ability to cover consumption with solar power becomes increasingly attractive!
If you plan to use the generated electricity at night, the installation of 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 2026 fiscal year. After the fifth year, it is often more advantageous to use it at home (self-consumption), making the combination with storage batteries a viable option.
👉 Ministry of the Environment | For purchase prices, periods, etc., click here
Benefit 2: You Can Utilize Subsidies!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the criteria, you may be able to utilize subsidies!
Reducing the actual burden amount through subsidies is a significant advantage!
In the case of Musashino City, there may be applicable programs from the national government, Tokyo, and Musashino City (the subsidy program in Musashino City applies to solar power generation systems, while storage batteries are not included).
Benefit 3 Environmentally Friendly!
Solar power generation has low carbon dioxide emissions and reduces dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices like power conditioners may have operational noise.)
Benefit 4 Expect Heat Insulation Effects!!
By installing panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the temperature rise of the roof, providing expected heat insulation effects!
(Note that this does not improve the 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 such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capabilities, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1: Maintenance costs can be incurred
One maintenance cost that is often overlooked is the roof where solar panels are installed.
If you perform roof renovations 10 to 20 years later, there will be costs for removing and reinstalling the solar panels.
If the existing roof is deteriorated, 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 ask for a simulation that considers maintenance costs before introducing solar panels!
Point 2: The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but when using screws or other fasteners to secure the roofing material and substrate, waterproofing of the fixed parts is crucial.
If the method involves 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 fasteners, and it cannot be used with all metal roofs.)
Catch-type base metal fittings for horizontal metal roofs
Note 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load-bearing capacity, 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!
Choosing Point 1: Compare based on total output of the roof
When installing solar panels on the roof, it is important to know how much electricity can be generated in a limited area, and the more electricity generated, the better!
Solar panels vary in size and output depending on the manufacturer.
For example, a 350W output panel and a 400W output panel may seem that the one with higher output is better at first glance.
However, if the size of the panels does not fit well on the roof, “20 panels of 350W can be installed, while only 15 panels of 400W can be installed,” which means the number of panels that can be installed may differ even on the same roof due to the size of the panels.
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 calculations are for total output (kW). The actual electricity generation (kWh) will vary depending on conditions such as the orientation, slope, and shading of the roof.
Choosing Point 2: Compare based on 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 decline 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 electricity generation itself.
By not deciding solely based on initial output and considering the degradation rate, you can choose solar panels without regrets!
Choosing Point 3: Compare based on warranty period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
Regarding output warranties, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies widely!
It’s always better to have a longer warranty, so let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Musashino City
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Musashino City. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Musashino 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.
For cost estimates by capacity, please refer to our solar panel installation 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 Musashino City?
As of October 7, 2026, Tokyo’s subsidies for solar power generation and storage batteries (Cool Net Tokyo) are accepting pre-applications. For storage batteries, only SII registered devices (registered products for Reiwa 8) will be eligible from pre-applications made after October 1, 2026. Musashino City’s efficient energy utilization promotion subsidy program targets solar power generation systems (storage batteries are not eligible) and is accepting applications within the budget until February 28, 2027. 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 even after the construction is completed?
For many programs, procedures need to be completed before construction. Tokyo’s subsidies require pre-application before installation, and if you install first, you will be ineligible. On the other hand, Musashino City’s subsidy program allows applications after installation (within 6 months of completion). Procedures vary by program.
Since the order of procedures differs by program, please confirm before signing a contract or starting construction.
Can solar panels be installed on slate roofs? I’m worried about leaks.
It is possible to install 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 in methods that fix brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is crucial.
Kakeru Koumuten Co., Ltd. is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation. If deterioration is progressing, we can also suggest methods such as roof overlay (cover method) or replacement before installation.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed within 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with durable roofing materials before installation.
Please consult us on how to proceed with the installation after checking the condition of the roof through a site survey!
Should I install a storage battery together with the solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it in your home rather than selling it.
Additionally, the Tokyo Metropolitan Government’s subsidy for storage batteries is designed for simultaneous installation with solar panels, but you can also apply for the storage battery alone. You can compare “solar panels only” and “solar panels + storage battery” through a financial simulation.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and site survey, and we will provide you with the installation capacity and power generation simulation.
In Musashino City, the shading caused by surrounding buildings and trees varies from house to house. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
In the above construction example (solar panels 4.3 kW + storage battery), it took about 3 days. The duration may vary if roofing work is done simultaneously or depending on the shape of the roof and installation capacity.
Please note that there will be additional time required for subsidies and applications to the power company, so please consult us early.
What is the current selling price (FIT)?
For residential use (less than 10 kW), from the certification after October 2025, the first 4 years will be 24 yen/kWh, and from the 5th to the 10th year, it will be 8.3 yen/kWh, and the same price will apply in the 2026 fiscal year.
The idea is to recover initial costs quickly in the first 4 years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that considers loan interest rates and electricity costs.
Can you take care of maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-maintenance DM notifications and visits for inspections upon request from customers. We can also clean solar panels with a special brush if the power generation decreases due to dirt.
Since the roof is a place that is difficult to check by yourself, please feel free to consult us if you have any concerns.
Can you also renovate a roof that already has 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 water heater removal pricing page.
If you are looking for a solar panel installation contractor in Musashino City, please consult Kakeru Koumuten
Our company handles many exterior renovations, including solar panels, roof work, and exterior wall work in Musashino City, Tokyo.
We receive requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received great feedback from numerous customers.
We continue to update our construction performance records every year, and we will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay (cover method) and re-roofing but also partial roof repairs, exterior wall 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 with us!
“I want to know recommended solar panels”, “I want to keep costs down as much as possible”, “I just want an estimate for now”, we will provide optimal solutions for specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in the customer’s position and 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 Musashino City, Tokyo and Points for Solar Work
The official page of Musashino City provides disaster prevention information maps and flood hazard maps.
We have summarized the points to be careful about when installing solar panels and storage batteries in the residential environment of Musashino City below. (Tap to open)
View the characteristics of Musashino City, Tokyo and points for solar work
■ Confirm the installation locations of storage batteries and power converters in conjunction with the hazard map assumptions
In Musashino City, the Disaster Prevention Information Map and Flood Hazard Map provides flood prediction area maps for the Kanda River basin, the Shakujii River and Shirako River basins, and the Nogawa, Sengawa, Tanizawa, and Maruko River basins, with a maximum rainfall scenario of 690mm total and 153mm maximum hourly rainfall expected. The expected area for internal water (rainwater discharge) has been announced as the Rainwater Discharge Flood Prediction Area on March 31, 2026. Additionally, the city page states that there are no warning areas for landslides, storm surges, or tsunamis in Musashino City. When deciding on the installation location for storage batteries and power conditioners, it is advisable to check the hazard map for the expected conditions at your residence and consider the height and position of the installation for peace of mind.
■ Tokyo’s annual sunshine hours are approximately 1,927 hours
According to the Meteorological Agency’s average values (1991-2020), Tokyo’s annual sunshine hours are about 1,927 hours.
The power generation varies by season, so it is important to conduct annual power generation simulations and choose the capacity of the storage battery to match the times of high electricity usage.
■ Check for shadows from surrounding buildings and trees
In locations close to buildings or trees, the shadowing will vary for each house depending on the roof’s orientation and height. Since solar panels generate less power when shaded, Kakeru Koumuten creates layout diagrams based on the drawings and the on-site conditions, allowing you to verify through power generation simulations. Additionally, in areas close to trees, branches and fallen leaves may accumulate around the panels and rain gutters, so please consult us about inspections and cleaning after installation.
■ Musashino City’s subsidy requires application after installation, while Tokyo’s subsidy requires prior application
Musashino City’s efficient energy utilization promotion subsidy program targets solar power generation systems, excluding storage batteries. Applications must be made within six months after installation, and they are accepted within the budget until February 28, 2027. On the other hand, Tokyo’s subsidy (Cool Net Tokyo) requires prior application before installation, so it is important to check the order of procedures for each program.
■ In narrow front road areas, plan scaffolding and equipment delivery carefully
In areas with narrow front roads or where surrounding buildings are close, careful planning for scaffolding and equipment delivery may be necessary. Kakeru Koumuten will respond on-site with our own scaffolding team and scaffolding materials.
■ Check the roof condition according to the age of the building
For buildings that have been around for many years, it is important to check the condition of the roofing materials and substrate before installing solar panels. Depending on the condition of the roof, installing them simultaneously with roof renovations can help reduce future costs for removing and re-installing solar panels.
Our company serves Kanagawa Prefecture and Tokyo, and we handle many exterior construction and solar projects in Musashino City, Tokyo.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us about any urgent issues!
Service Area in Musashino City, Tokyo
Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Musashino City, Tokyo
Musashino City, Kichijoji Honcho / Musashino City, Kichijoji Higashimachi / Musashino City, Kichijoji Minamimachi / Musashino City, Kichijoji Kitamachi / Musashino City, Sakaiminami / Musashino City, Goten-yama / Musashino City, Sakae / Musashino City, Sakuradai / Musashino City, Sekimae / Musashino City, Nakacho / Musashino City, Nishikubo / Musashino City, Midorimachi / Musashino City, Hachimancho
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・Kakeru Koumuten Co., Ltd. project achievements
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・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of comparative estimates and key points!
・Top 12 solar power manufacturers! Features and selection tips included!
・What are the installation costs for solar power? Comprehensive tips to reduce costs!
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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!
