Leave Your Solar Panel Installation Work in Higashimurayama City, Tokyo to Kakeru Koumuten Co., Ltd.!
For solar panel and storage battery installation in
Higashimurayama City, Tokyo,
Kakeru Koumuten is at your service!
Kakeru Koumuten is a company specializing in exterior renovations.
As a strong company 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 Higashimurayama City, Tokyo”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Higashimurayama 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 you have no regrets about your solar panel installation, we recommend obtainingquotes from about three companies!
Table of Contents (tap to open/close)
- Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Higashimurayama City, Tokyo
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Higashimurayama 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 Higashimurayama 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 Higashimurayama City, Tokyo
- If You Are Looking for a Solar Panel Installation Company in Higashimurayama City, Tokyo, Contact Kakeru Koumuten
- Characteristics of Higashimurayama City, Tokyo and Points for Solar Construction
- Service Area in Higashimurayama City, Tokyo
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Higashimurayama City, Tokyo
Here are the reasons why our company is entrusted with solar panel installation by customers in Higashimurayama City, Tokyo.
“Our Unique Strengths in Solar Panel Installation That Cannot Be Imitated by Other Companies”
have received high praise from many customers.
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 Beyond Solar Panel Installation!


Issues such as leaks that occur during solar panel installation may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if you are knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have expertise in roofing to avoid maintenance and trouble after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent issues after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has 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 Scaffolding Materials


To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding according to the construction conditions, allowing us to assemble scaffolding in-house.
By not outsourcing scaffolding work and using our own scaffolding team, we can also cut costs on scaffolding work.
We own scaffolding materials for approximately 50 single-family homes!
Even if there is a height difference on the site, our in-house scaffolding team will plan the scaffolding according to the local conditions.
Storage of Materials in Our Large In-house Warehouse

We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we canrespond quickly in emergencies!
In-house sorting and transportation of waste materials
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut down on waste disposal costs.
Exterior renovation dedicated showroom


In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are attached to 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 projects, we also provide samples of roofing materials and models that explain the structure, allowing for detailed explanations!
3.Complete in-house construction
One of Kakeru Koumuten’s major strengths is its complete in-house construction.
By having Kakeru Koumuten handle everything from inquiries to project completion in a consistent manner, we can keep costs down while providing high-quality roof renovations.
Additionally, one representative will assist you from the estimate to the completion of the work.
Since the same person will be in charge without changes in sales or construction management, smooth communication is possible.
We can provide consistent in-house construction from temporary scaffolding installation, exterior wall painting, to roof renovations!
4. Various Permits and Skilled Workers


We have obtained permits for the construction industry and for the collection and transportation of industrial waste!
We also have nationally certified sheet metal workers and painting specialists, and we are confident in our construction techniques.
We can also handle large-scale roofing projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation, we also provide our own construction warranty (leakage warranty)!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovations are performed. The construction warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty details.)
Aftercare is available every year, and we send out notification DM each year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
If you are unable to access the roof due to height, we can utilize drones to assist!
During leak investigations, we can also conduct surveys using a thermal imaging camera.
If the power generation of your solar panels decreases due to dirt or other factors, we can provide cleaning services using specialized brushes.
We will respond according to your wishes.
7. Human Resource Development
To improve skills, we create various roofing models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training so that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
At Kakeru Koumuten, we provide not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar construction 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 construction will receive materials that clearly summarize points to consider and potential drawbacks!
We encourage you to obtain comparative estimates and compare them with other companies’ plans!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 or 30 years.
Confirming whether it is safe to install them directly on the current roof before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, which specializes in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing material, such as slate, tiles, metal roofs, and flat roofs (rooftop waterproofing). If the remaining lifespan of the roofing material is short, we may suggest roof renovation first. |
| 2. Condition of Substrate and Waterproof Sheet | If the underlayment 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 Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, can affect the amount of electricity generated. We will create a layout diagram from the drawings and the site, and you can confirm it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels that can be installed (installation capacity) is determined by the shape and size of the roof. Since the number of panels that can be installed varies depending on the panel size, we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will check whether the method involves drilling holes in the roofing material for fastening or using brackets to secure the roofing material. The fixing method varies by technique, so please confirm the waterproofing treatment method for the fixing parts during the estimate. |
| 6. Weight of the Roof | The roof will become heavier due to the panels being added. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may also 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 the cost. |
| 8. Ease of Scaffolding Setup and Delivery Route | If there are height differences on the site, planning for scaffolding and the delivery route for equipment and materials may require some ingenuity. The width of the front road and any steps on the site will also be checked during the site survey. |
Fixing Methods and Confirmation Points by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproofing treatment of fixing parts, cracks and 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 secure to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, it may be possible to replace with lightweight roofing material before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you perform roof renovations 10 to 20 years after installation, additional costs for removing and reinstalling solar panels will apply. 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 Higashimurayama City, Tokyo
Subsidies and Grants That May Be Applicable inHigashimurayama City, Tokyo
If you are introducing solar panels or storage batteries in Higashimurayama City, Tokyo, there is a possibility that the systems from the “National Government,” “Tokyo Metropolitan Government,” and your local “Higashimurayama City” may apply.
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 generation system (output less than 50kW, JET certification, etc.) in residential properties within Tokyo. The generated power must be used in the residential area. Pre-application is required. | Existing homes: 150,000 JPY per kW for 3.75kW or less (maximum 450,000 JPY), 120,000 JPY/kW for over 3.75kW to less than 50kW. New homes: 120,000 JPY/kW for 3.6kW or less (maximum 360,000 JPY), 100,000 JPY/kW for over 3.6kW. |
For the fiscal year 2026, pre-applications are being accepted from May 29 (will end once the budget is reached). From the pre-application for fiscal year 2026, submission of certificates issued by financial institutions will be mandatory at the time of performance reporting. |
| Tokyo “Battery Storage Promotion Project” | Owners of eligible devices (battery storage registered with SII) excluding national and local governments. Installation must occur between April 1, 2026, and March 30, 2027. If applying after October 1, 2026, only products registered with the national SII for fiscal year 2026 are eligible. | Battery storage 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 devices are installed). Expansion of battery storage unit: 60,000 JPY/kWh (maximum 720,000 JPY per household). |
For the fiscal year 2026, pre-applications are being accepted from May 29. Grant applications and performance reports will be accepted starting June 30. |
| Higashimurayama City “Subsidy for Installation of Equipment for Global Warming Countermeasures in Residential Areas” (Fiscal Year 2026) | Residents listed in the basic resident register of Higashimurayama City who install an unused solar power generation system (with a nominal maximum output of 2kW or more) or a stationary battery that works in conjunction with solar power generation in their own residence between January 1, 2026, and December 31, 2026. Conditions include no delinquency in municipal taxes and not having received similar subsidies from the city in the past. This is a post-application method after installation. | Solar power generation system or battery system: maximum 50,000 JPY (fixed amount). *If both are installed, only one application will be accepted. |
From November 2, 2026 (Monday) to January 8, 2027 (Friday) at 5 PM (must arrive by this time). If there are many applications, grants will be decided within the budget (1,150,000 JPY for solar power and batteries) on a pro-rata basis (updated May 28, 2026). |
| National “DR Home Battery Project” (Fiscal Year 2025 Supplement) | New installation of home battery 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 (there are no plans to reopen public recruitment as stated on the official website, and applications are currently not possible). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | The storage battery is one of the eligible facilities, but it must be combined with essential construction work such as insulation renovation of windows (openings) and the building structure; installation of the storage battery alone cannot be applied for. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 JPY/unit | Applications will close once the budget limit is reached. As of October 5, 2026, the official site indicates that the amount applied for renovations is 8% of the budget. Please check the application 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 in Higashimurayama City is a post-application method, starting from November 2, 2026. Each program has different eligibility conditions, application procedures, and whether they can be combined, and applying does not guarantee that a subsidy will be granted, so please confirm before contracting or starting work.
Kakeru Koumuten will provide guidance on the eligibility conditions and application periods for each program after confirming them.
National Subsidy “DR Home Storage Battery Project (Support Project for the Introduction of Home Storage Systems for DR Resource Implementation)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those who are newly introducing registered storage systems that can be 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 contracts or orders made before the grant decision being ineligible.
However, the fiscal year 2025 supplementary application amount reached the budget on May 29, 2026, and the public recruitment has ended. The official site also states that there are no plans to reopen public recruitment, and applications are currently not possible. Please check the official site for future public recruitment.
Furthermore, there are currently no subsidies confirmed for the installation of solar panels on existing homes.
👉 Click here for the official site of the DR Home Storage Battery Project
Tokyo “Promotion Project for the Introduction of Solar Power Generation in Homes”
This subsidy is for those who are newly installing unused solar power generation systems in residential homes in Tokyo. There is no requirement for simultaneous installation of storage batteries.
●Existing Homes: For up to 3.75 kW, 150,000 JPY per kW (maximum 450,000 JPY); for over 3.75 kW to under 50 kW, 120,000 JPY per kW
●New Homes: For up to 3.6 kW, 120,000 JPY per kW (maximum 360,000 JPY); for over 3.6 kW to under 50 kW, 100,000 JPY per kW
●There are also additions for the installation of rooftop frames and waterproofing work.
The target is for unused panels with an output of less than 50 kW that have obtained JET certification, installed in residential homes in Tokyo, and used in the living area. The process involves prior application, followed by a grant application after installation, and from the fiscal year 2026, submission of certificates issued by financial institutions during the performance report has become mandatory.
According to the official page of Tokyo, 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 (up to 1,200,000 JPY per household)
●Additional for participating in DR demonstration: 100,000 JPY per unit (150,000 JPY per unit if energy management equipment is installed)
●Expansion of battery unit: 60,000 JPY per kWh (up to 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 are eligible.
The official page of Tokyo states that pre-registration is being accepted from May 29, Reiwa 8. For detailed information, including conditions for combination with solar power generation, please check the official page.
👉 Here is the official page of Tokyo (Cool Net Tokyo)
Higashimurayama City “Subsidy for Installation Costs of Global Warming Countermeasure Equipment for Residential Use” (Reiwa 8)
This subsidy is for residents listed in the basic resident register of Higashimurayama City who install a new, unused solar power system or battery system in their own residence between January 1, Reiwa 8 and December 31, Reiwa 8. It is specified that the solar power generation must have a nominal maximum output of 2 kW or more, and the battery must be a stationary type that works in conjunction with solar power generation (portable types are excluded). It is also a requirement that there are no delinquent municipal taxes and that the applicant has not received similar subsidies from the city in the past. Both in-city and out-of-city businesses are eligible, as stated in the application guidelines. This is a post-application method, where applications are made after the installation of the equipment.
●Solar power system or battery system: up to 50,000 JPY (budget amount 11,500,000 JPY)
●If both solar power and battery are installed simultaneously, only one application will be accepted
Applications will be accepted from November 2, Reiwa 8 (Monday) to January 8, Reiwa 9 (Friday) by 5 PM (must arrive), and applications can be made via an internet-only application form, by mail, or at the Shuisui-en window. It is not on a first-come, first-served basis; if applications exceed the budget, the distribution will be determined within the budget amount (updated May 28, 2026).
It is stated that it is possible to receive subsidies from the national government and Tokyo simultaneously, but there is a combined limit. For details, please check the official page.
👉 Here is the official page of Higashimurayama City
Solar Panel Installation & Battery Installation Price List

⇧Service Menu | For Costs Related to Solar Panel Installation and Battery Installation, Click Here

⇧Service Menu | For Costs Related to Solar Panel Removal and Water Heater Removal, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and batteries should be 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.
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 installed on a roof varies for each house based on the roof’s shape, orientation, and size. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panels as approximately 800,000 JPY to 1,200,000 JPY for 3-5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6-10 kW. (These are just approximate amounts and can vary based on wiring length, scaffolding range, existing roofing materials, panel layout, etc.)
▶ Service Menu | For Costs Related to Solar Panel Installation and Battery Installation, Click Here
Items to Confirm in the Estimate (Cost Confirmation)
When comparing estimates from different companies, 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 confirm whether it is a type that controls in conjunction with a storage battery. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range of use during power outages (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Fittings | Name of the fittings suitable for the roofing material and the method of securing them (whether it is a method that drills holes or a method that clamps and secures). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, presence of a monitor to check power generation. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment for fixed parts, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | 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, check that the same scope and quantity are not double-counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters and old panels, as well as disposal costs for waste materials, are included. |
| 10. Tax Classification and Warranty | Whether prices are tax-inclusive or tax-exclusive, conditions under which additional costs may arise, and details and duration of manufacturer and workmanship warranties. |
If the capacities are different, both the price and power generation will vary. Kakeru Koumuten Co., Ltd. welcome comparisons, so if you bring estimates from other companies, we will explain the differences for each item!
Self-Estimate and Profit and Loss Simulator for Solar Power Generation
With the simulator above,
you can obtain a rough estimate and a profit and loss 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 a rough estimate and profit and loss simulation!
*The simulation results are approximate. Actual profits and losses may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection or replacement.
Customer Testimonials
Case Studies 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 range |
| 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 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, and we explained this to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Higashimurayama City, Tokyo
There are many solar panel installation companies that serve Higashimurayama City, Tokyo, and you may be wondering which company to choose.
Therefore, when requesting solar panel installation and battery storage installation work, let’s check the following 4 points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the existence of warranties and aftercare services
● Obtain estimates from multiple companies (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 company.
Have knowledge not only about solar panels but also about roofs
Defective installation of solar panels may be caused by a lack of knowledge and confirmation 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 confirmation of roofs and waterproofing
・Solar panels were installed on a severely deteriorated roof, resulting in leaks
・Solar panels were installed on a roof with a short lifespan, necessitating renovations to remove and reinstall the solar panels within a few years
・Misjudging the type of waterproofing led to incorrect treatment and subsequent leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Confirmation Before Installing Solar Panels” in this article
Confirm the existence of warranties and aftercare services
When choosing a solar installation company, 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.
Solar panels and battery storage units come with manufacturer warranties, but also check for the existence of a workmanship warranty in case leaks occur after installation!
For companies that offer a workmanship warranty, if leaks occur after installation, they may cover the repairs under the warranty, provided it is within the warranty period and conditions.
Additionally, some companies offer aftercare services separate from warranties, so make sure to check if the company you are considering has aftercare services.
Since abnormalities or damages on the roof may not be visible, you might not notice them yourself.
By conducting inspections during aftercare, you can easily detect abnormalities early, preventing major repairs or breakdowns!
At Kakeru Koumuten Co., Ltd., the installation of solar panels comes with a leak warranty as part of the workmanship warranty. (The warranty for solar panel installation 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 notifications!
After checking the DM, if you wish, we will visit for aftercare maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, let’s obtain estimates from multiple contractors.
Even for the same manufacturer and the same work content, costs may vary, and warranties and after-sales services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request from your preferred contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check:
“Verification of estimate items”
“Types of solar panels”
“Warranties and after-sales services”
and make a detailed comparison for your judgment! Avoid judging solely based on cost, as using lower-grade materials or skipping processes can reduce costs!
▶ 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 installation and battery installation, but if the order of procedures is incorrect or if there are deficiencies in the documents, the grant may not be awarded.
Since there are systems that require prior application, such as the Tokyo Metropolitan Government’s subsidies, it is reassuring to have a contractor who can support the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for Tokyo’s subsidies, prior application is required) before proceeding with the construction!
For Tokyo’s subsidies, after installation, you will need to submit a grant application and performance report, which will go through a review process before being awarded! (The flow of procedures varies by system)
▶ Go to “Subsidies and grants that may be applicable in Higashimurayama 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 prices rise, the ability to cover your consumption with solar power becomes attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) will be set at “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year” for certifications after October 2025, and the same price will apply for the 2026 fiscal year. After the fifth year, it is likely to be more advantageous to use it in your home (self-consumption) rather than selling it, so combining it with a storage battery is also an option.
👉 Ministry of Economy, Trade and Industry | For purchase prices and periods, click here
Advantage 2 You can utilize subsidies!
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 Higashimurayama City, there is a possibility of being eligible for the programs from the national government, Tokyo, and Higashimurayama City. The subsidy in Higashimurayama City is applied for after installation, and applications will start being accepted from November 2, 2026 (if there are many applications, they will be prorated. Please check the official page for details).
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 do have operational noise.)
Advantage 4 Heat insulation effect is expected!!
By installing panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, this can help reduce the temperature of the roof, providing a heat insulation effect!
(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 is possible to use electricity even during emergencies such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation functionality, you may be able to use electricity from a dedicated outlet during daytime generation.
(The devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1 Maintenance costs can be incurred
A particularly easy-to-overlook maintenance cost is for the roof where the solar panels are installed.
If you perform a roof renovation 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 the solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to deterioration of the storage battery.
It would be reassuring to ask for a simulation that considers maintenance costs before introducing solar panels!
Point 2 The risk of leaks may increase depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix the roofing material and substrate with screws or other fasteners, waterproofing of the fixed parts is crucial.
In methods that create holes in the roof, the risk of leaks inevitably arises.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and fixing the solar panels using the catch method is also an option. (The catch method has compatibility conditions between the roofing material and fasteners, and it cannot be used with all metal roofs.)
Catch-type base fastener for horizontal metal roofs
Point 3 The Roof Becomes Heavier
Installing solar panels will make the roof heavier. After investigating the existing roof, substrate, and load capacity, one option may be to replace it with a lighter roof if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “This manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
How to Choose 1: Compare 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 generating more electricity is always better!
Solar panels come in various sizes and outputs depending on the manufacturer.
A 350W output panel and a 400W output panel may seem that the one with the higher output is better at first glance.
However, if the size of the panel does not fit well on the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different numbers of panels that can be installed on the same roof due to size differences.
400W×15 panels = 6kW (total output of the roof)
350W×20 panels = 7kW (total output of the roof)
As shown above, even if the output of a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual electricity generation (kWh) will vary depending on conditions such as roof orientation, slope, and shading.
How to Choose 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 reduction after long-term use varies by product. The manufacturer’s output guarantee value is a benchmark for warranty purposes and does not indicate the actual degradation rate or electricity generation itself.
By considering the degradation rate as well as the initial output, you can choose solar panels without regrets!
How to Choose 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.
For output warranties, some manufacturers offer a 30-year warranty while others offer only a 10-year warranty, so they differ!
Longer warranties are better, so be sure to check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Installation and Storage Battery Installation in Higashimurayama City, Tokyo
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Higashimurayama City, Tokyo. (Tap to open answers)
How much does it cost to install solar panels and storage batteries in Higashimurayama City, Tokyo?
The cost varies depending on the installation capacity, equipment, and roof condition. In the above construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines for different capacities are published on our 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 Higashimurayama City, Tokyo?
As of October 7, 2026, Tokyo’s “Promotion Project for Solar Power Generation in Households” (for existing homes, 15,000 yen per kW for systems under 3.75kW, with a maximum of 450,000 yen) and “Promotion Project for Storage Battery Installation in Households” (100,000 yen per kWh for storage batteries, with a maximum of 1.2 million yen per household) are accepting pre-applications starting May 29, 2026, as stated on the official page of Tokyo (Cool Net Tokyo). In Higashimurayama City, there is a subsidy for the installation of equipment to combat global warming in residential areas (for the fiscal year 2026, the maximum for solar power generation or storage batteries is 50,000 yen), which will start accepting applications on November 2, 2026, as mentioned on the official page of Higashimurayama City. The national DR household storage battery project has ended 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 varies by program. Tokyo’s subsidies require pre-application, while the grants from Higashimurayama City allow for post-construction applications. Conditions regarding whether you can contract and start construction before applying may differ by program, so please confirm before signing a contract.
The order of procedures varies by program, so please check before signing a contract or starting construction.
Can solar panels be installed on 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 method of securing the panels varies by construction method, and when securing brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is crucial.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation and suggest methods such as roof overlay (cover method) or replacement if deterioration is advanced.
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 dismantling the 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 during the on-site survey!
Is it better to install a storage battery together with solar panels?
If you want to use the electricity generated at night or prepare for power outages, simultaneous installation is recommended. The selling price 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 subsidy for storage batteries in Tokyo (for the Reiwa 8 fiscal year, it is 100,000 yen per kWh, with a maximum of 1,200,000 yen per household) is a program aimed at increasing self-consumption of electricity generated by solar power. In Higashimurayama City’s subsidy system, stationary storage batteries that work in conjunction with solar power generation are also included, but if solar power generation and storage batteries are installed simultaneously, the city’s subsidy will only accept one of the two. You can compare “solar only” and “solar + storage battery” in the income and expenditure simulation for your consideration.
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.
Higashimurayama City is located almost in the center of 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 does the construction period take?
In the above construction example (solar panel 4.3 kW + storage battery), it took about 3 days. The duration may vary if roof work is done simultaneously or depending on the shape and installation capacity of the roof.
Additionally, applications for subsidies and power companies will take additional time, so please consult us as soon as possible.
What is the current selling price (FIT)?
For residential use (under 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 the initial costs quickly in the first four years and then focus on self-consumption. Kakeru Koumuten provides income and expenditure simulations that take into account loan interest rates and electricity prices.
Can you handle maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-maintenance DM notifications and visits for inspections upon request from customers. We can also clean solar panels with a dedicated brush if the power generation is reduced due to dirt.
It is difficult to check areas on the roof by yourself, so please feel free to consult us if you have any concerns.
Can you also handle renovations for roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten can detach and reattach solar panels ourselves, allowing us to remove the panels, perform roof overlay (cover method) or re-roofing, and then reinstall them in a consistent manner. The removed panels can be stored in our own warehouse.
For costs, please refer to the solar panel removal and hot water heater removal pricing page.
If you are looking for a solar panel installation company in Higashimurayama City, Tokyo, please consult Kakeru Koumuten Co., Ltd.
Our company handles a wide range of exterior renovations, including solar panel installations, roof work, and exterior wall work in Higashimurayama City, Tokyo.
We have received requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received positive feedback from numerous customers.
We continue to update our construction performance records every year and will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay 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 temporary measures without setting up scaffolding, as long as safety can be ensured, so please consult with 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 lose in terms of cost, quality, and planning compared to other companies in exterior work!
We are confident, so we welcome competitive quotes!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Characteristics of Higashimurayama City, Tokyo, and Points for Solar Work
Higashimurayama City is located in the northwestern part of Tokyo, situated in the almost central area of the Musashino Plateau, which spreads from the Arakawa River to the Tama River, with a total area of 17.14 square kilometers. The northwestern part includes the Sayama Hills, which float like an island on the Musashino Plateau, gently sloping down toward the Arakawa direction (northeast), as stated on the city’s official page. It is also mentioned that it is located about 30 kilometers from central Tokyo. Below are summarized the characteristics of the terrain in Higashimurayama City, Tokyo, and points to consider when installing solar panels and storage batteries. (Tap to open)
View the characteristics of Higashimurayama City, Tokyo, and points for solar work
■ Urban area of the Musashino Plateau and the Sayama Hills in the northwest. Check the shadows of surrounding trees and buildings on-site
The majority of the city features the gentle terrain of the Musashino Plateau, with the Sayama Hills spreading in the northwest. The city’s official page also introduces the mixed forests and rural landscapes that retain the essence of Musashino. In areas close to the hills and mixed forests, it is reassuring to check the shadows cast by surrounding trees and buildings, and whether fallen leaves tend to accumulate on roofs and panels for each individual house. Depending on the elevation differences of the site and the width of the front road, there may be a need for ingenuity in the way scaffolding is set up and the routes for transporting panels and storage batteries. At Kakeru Koumuten, our own scaffolding team plans the scaffolding according to the site, creates layout diagrams from blueprints and on-site surveys, and you can confirm this through a power generation simulation.
■ Check the flood inundation assumptions for the Yanase River and Sorihori River, and hazard information for landslide warning areas
The flood hazard map of Higashimurayama City, published by Tokyo Metropolis, shows the flood inundation assumption areas and designated rivers such as the Yanase River and Sorihori River, indicating the areas that would be inundated in the event of flooding due to the maximum expected rainfall, and it has been updated in May of Reiwa 2 on the official page. Additionally, the landslide warning areas include a total of 12 locations such as Tamako Town, Suwa Town, Mawata Town, and Akitsu Town (6 of which are special warning areas), as listed on the city’s official page. Depending on where the power conditioner and storage batteries are installed, separate from the panels on the roof, the impact during flooding may vary. Please check the assumptions for your residence on the city’s map and consult about the installation location and height in conjunction with the installation conditions of the manufacturer you will use.
■ The types of roofs and their ages vary from house to house. Check the roof and waterproofing before installation
Even within the same city, the types of roofs, their ages, and the shapes of the sites vary from house to house. The capacity that can be installed and the fixing methods also change depending on the shape and orientation of the roof and the materials used. At Kakeru Koumuten, we will propose the fixing methods, waterproofing arrangements, and scaffolding plans after confirming the type and condition of the roof and the situation of the site before installation.
■ The annual sunshine hours at the Tokyo Observatory are approximately 1,927 hours
According to the Japan Meteorological Agency’s average values (1991-2020), the annual sunshine hours at the Tokyo Observatory are approximately 1,927 hours, with January (approximately 193 hours) being the most and June during the rainy season (approximately 124 hours) being the least. (This is a reference value, not based on measurements within Higashimurayama City.)
The power generation in Higashimurayama City can also be affected by the shadows of surrounding buildings and trees, so it is important to conduct an annual power generation simulation and choose the capacity of the storage batteries to match the times when electricity is used the most.
Our company handles many exterior construction and solar power projects in Higashimurayama City, Tokyo.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us for any sudden troubles!
Service Area in Higashimurayama City, Tokyo
Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Higashimurayama City, Tokyo
Aoba Town, Higashimurayama City / Akitsu Town, Higashimurayama City / Onda Town, Higashimurayama City / Kumezawa Town, Higashimurayama City / Sakae Town, Higashimurayama City / Suwa Town, Higashimurayama City / Tamako Town, Higashimurayama City / Noguchi Town, Higashimurayama City / Hagiiyama Town, Higashimurayama City / Fujimi Town, Higashimurayama City / Honcho, Higashimurayama City / Misumi Town, Higashimurayama City / Mawata Town, Higashimurayama City
・For exterior wall painting in Higashimurayama City, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・For roof renovations in Higashimurayama City, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・For exterior renovations in Higashimurayama City, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・Kakeru Koumuten Co., Ltd.施工実績
・Kakeru Koumuten Co., Ltd. After Maintenance
・Kakeru Koumuten Co., Ltd.施工メニュー・料金表
・Kakeru Koumuten Co., Ltd. Staff Blog & Announcements
・Explaining the Importance of Comparing Estimates!
・Top 12 Solar Power Generation Manufacturers! Features and Selection Tips!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
・What are the best locations for installing solar power generation? Key points for site selection!
・Check out our solar power generation estimates here!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!





