Leave the installation of solar panels in Tama City, Tokyo to Kakeru Koumuten Co., Ltd.!
For solar panel and storage battery installation in
Tama City, Tokyo,
Kakeru Koumuten is at your service!
Kakeru Koumuten is a company specializing in exterior renovations.
As a company strong in roofing work, we are entrusted with solar panel and storage battery installations that consider roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Tama City, Tokyo”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Tama 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 do not regret your solar panel installation, we recommend obtaining estimates from about three companies!
Table of Contents (tap to open/close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Tama City, Tokyo
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Tama 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 Tama 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 Tama City, Tokyo
- If You’re Looking for a Solar Panel Installation Company in Tama City, Tokyo, Contact Kakeru Koumuten
- Characteristics of Tama City, Tokyo and Points for Solar Construction
- Service Area in Tama City, Tokyo
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Tama City, Tokyo
Regarding why our company is entrusted with solar panel installation by customers in Tama City, Tokyo,
“Our Unique Strengths in Solar Panel Installation That Cannot Be Imitated by Other Companies”
are highly praised by 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 Besides Solar Panel Installation!
Problems such as leaks that occur with solar panel installations may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if 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 knowledge about the roof to avoid maintenance issues 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 prepared the following warehouses and material storage areas to provide solar panel work and exterior renovations at low cost and high quality.
We have established five bases for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding according to construction conditions and can assemble scaffolding in-house.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also cut costs for scaffolding work.
We own scaffolding materials for approximately 50 single-family homes!
Even if there are height differences on the site, our in-house scaffolding team will plan the scaffolding according to the local conditions.
Storage of Materials in Our Large 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 can purchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we can respond quickly in emergencies!
Sorting and Transporting Waste Materials In-House
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior Renovation Dedicated Showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are attached to the roofing materials!
Simulations for potential earnings and installation costs when introducing solar panels are also available!
Since roofing and exterior wall work often accompany each other, we also provide samples of roofing materials and models that explain the structure, allowing for detailed explanations!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is its complete in-house construction.
By having Kakeru Koumuten handle everything from inquiries to project completion in a consistent manner, we can keep costs down while providing high-quality roof renovations.
Additionally, one representative will assist you from the estimate to the completion of the work.
Since the same person will handle sales and construction management, smooth communication is possible.
We can provide consistent in-house construction from temporary scaffolding installation to exterior wall painting and roof renovations!
4. Various Permits Obtained & Skilled Workers on Staff
We have obtained construction industry licenses as well as permits for industrial waste collection and transportation!
We also have nationally certified sheet metal workers and painting specialists on staff, and we are confident in our construction techniques.
We can also handle large-scale roof projects for factories and other facilities!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation, our own construction warranty (leakage warranty) is also included!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless a roof renovation is performed. The construction warranty is separate from the manufacturer’s product warranty, and the coverage and conditions vary based on the warranty details.)
Aftercare is available every year, and we send out annual notification DM.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
Even if you cannot access the roof at high altitudes, we can utilize drones to assist!
During leak investigations, we can also conduct surveys using a thermal imaging camera.
If the power generation of solar panels decreases due to dirt or other factors, we can also provide cleaning services for solar panels using specialized brushes.
We will respond according to your preferences.
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 conduct technical training to ensure that each staff member can handle various scenarios.
8. Creation of Easy-to-Understand Materials and Simulations
Kakeru Koumuten provides not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar 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 to 30 years.
Confirming whether it is safe to place them directly on the current roof before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, which specializes in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing materials such as slate, tiles, metal roofs, and flat roofs (rooftop 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 boards or roofing (waterproof sheet) beneath the roofing material are 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 power generation. We will create a layout diagram from the drawings and the site, and you can check it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels that can be installed (installation capacity) is determined by the shape and size of the roof. Since the number of panels that can be installed varies depending on the panel size, we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will confirm whether the method involves drilling holes in the roofing material for fastening or using brackets to secure the roofing material. The fixing method varies by technique, so please check the waterproofing treatment method for the fixing parts during the estimate. |
| 6. Weight of the Roof | The roof will become heavier due to the panels being installed. After investigating the existing roof, substrate, and load capacity, switching to lighter roofing materials may be an option if necessary. |
| 7. Installation Location of Equipment and Wiring | We will check the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring also affects the cost. |
| 8. Ease of Scaffolding Setup and Delivery Routes | If there are elevation differences on the site, careful planning for scaffolding and the delivery routes for equipment and materials may be necessary. We will also check the width of the front road and any steps on the site during the on-site investigation. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproofing treatment of the fixing parts, cracks or deterioration of the slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suitable for the type of tile (even methods that do not drill holes in the tiles will fix to the substrate) | Type and condition of the tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lightweight roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you perform roof renovations 10 to 20 years after installation, there will be additional costs for removing and re-installing solar panels. If the roof is deteriorating, renovating to a highly durable roofing material before installation may help reduce costs in the long run.
Kakeru Koumuten Co., Ltd. specializes in roofing work and can also handle the removal and re-installation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Tama City, Tokyo
PossibleSubsidies and Grants in Tama City, Tokyo
When introducing solar panels or storage batteries in Tama City, Tokyo, the systems from the “National Government,” “Tokyo Metropolitan Government,” and your local “Tama City” may be applicable.
The following information is based on the official pages of each system as of October 7, 2026. The application status may change based on the budget, 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 “Home Solar Power Generation Promotion Project” | Individuals, corporations, or management associations installing unused solar power systems (under 50kW output, JET certification, etc.) in residential properties within Tokyo. The generated power must be used in the residential part. Pre-application is required. | Existing homes: 150,000 JPY per kW for up to 3.75kW (maximum 450,000 JPY), 120,000 JPY per kW for over 3.75kW to under 50kW. New homes: 120,000 JPY per kW for up to 3.6kW (maximum 360,000 JPY), 100,000 JPY per kW for over 3.6kW. |
For the 2026 fiscal year, pre-applications are being accepted from May 29 (will end once the budget is reached). From the pre-application for the 2026 fiscal year, submission of a certificate issued by a financial institution during the performance report is mandatory. |
| Tokyo “Home Battery Installation Promotion Project” | Owners of eligible devices (batteries registered with SII, excluding national and local governments). Installation must occur between April 1, 2026, and March 30, 2031. If applying after October 1, 2026, only products registered with the national SII for the 2026 fiscal year are eligible. | Battery package: 100,000 JPY per kWh (maximum 1,200,000 JPY per household). Additional for participating in DR demonstration (100,000 JPY per unit; 150,000 JPY per unit if installing energy management devices). Battery unit expansion: 60,000 JPY per kWh (maximum 720,000 JPY per household). |
For the 2026 fiscal year, pre-applications are being accepted from May 29. Grant applications and performance reports will be accepted from June 30. |
| Tama City “Subsidy for Residential Energy Creation and Energy-Saving Equipment” (2026 fiscal year) | Residents with an address in Tama City who install unused eligible equipment in their own homes, provided there are no outstanding municipal taxes. This is a post-application to be submitted within 6 months from the installation date. | Solar power generation (existing homes): 30,000 JPY per kW for using local businesses (maximum 150,000 JPY), 20,000 JPY per kW for using businesses outside the city (maximum 100,000 JPY). Solar power generation (new homes): 15,000 JPY per kW for using local businesses (maximum 75,000 JPY), 10,000 JPY per kW for using businesses outside the city (maximum 50,000 JPY). Battery systems and insulated windows: 1/4 of the cost (maximum 60,000 JPY for local businesses, maximum 40,000 JPY for outside businesses). |
From April 1, 2026, to March 31, 2027, on a first-come, first-served basis. Applications may close once the budget is reached, even within the application period. |
| Tama City “Residential Priority Measures Acceleration Project Subsidy (for Individuals)” (2026 fiscal year) | Individuals residing in Tama City with no outstanding municipal taxes. Pre-application is required, and construction will occur after grant approval. Solar power generation and battery systems must be purchased and installed using local businesses. | Solar power generation: 30,000 JPY per kW. Battery systems: 3/4 subsidy rate (maximum 200,000 JPY). Solar carports: 1/3 of the cost (maximum 1,000,000 JPY). Insulation renovations: 1/3 of the cost (maximum 1,000,000 JPY for single-family homes). |
From April 27, 2026, to January 29, 2027, on a first-come, first-served basis. Please check the official page for application status. |
| National “DR Home Storage Battery Project” (Reiwa 7 Supplement) | Newly introducing home storage systems that can be utilized for DR (demand response) with registered products | Calculated based on a standard amount of 34,500 yen per initial effective capacity of 1 kWh (subsidy rate within 3/10; maximum of 600,000 yen per application) | As of May 29, 2026, the budget has been reached, and the public offering has ended (the official site states that there are no plans to reopen the public offering, and applications are currently not possible) |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but they must be combined with essential works such as insulation renovations of windows (openings) and the structure; applications cannot be made with just the installation of storage batteries. Solar panels are not included as eligible facilities | Storage battery: 96,000 yen per unit | Ends as soon as the budget limit is reached. As of October 5, 2026, the official site shows that the application amount for renovations is 8% of the budget. Please check the official site for the current status |
The Tokyo solar power and storage battery subsidies require prior application. Storage batteries applied for after October 1, Reiwa 8 will only be eligible if they are registered products with the national SII, and equipment requirements will change. In Tama City, the application timing (before or after installation) varies by program, and it may end as soon as the budget is reached, even within the application period. Eligibility conditions, application procedures, and the possibility of combining programs differ for each system, and applying does not guarantee issuance, 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 Introduction)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This project targets those who are newly introducing storage systems with registered products that can be utilized for demand response (DR). In the Reiwa 7 Supplement project, the subsidy amount was determined based on a standard amount of 34,500 yen per initial effective capacity of 1 kWh, with a subsidy rate within 3/10 and a maximum of 600,000 yen per application. There are conditions such as that contracts or orders made before the grant decision are not eligible.
However, the Reiwa 7 Supplement has ended as of May 29, 2026, when the application amount reached the budget. The official site also states that there are no plans to reopen the public offering, and applications are currently not possible. Please check the official site for future public offerings.
Currently, there are no subsidies confirmed for the installation of solar panels for existing homes.
👉 Click here for the official site of the DR Home Storage Battery Project
Tokyo “Promotion Project for the Introduction of Solar Power Generation in Homes”
This is a subsidy for those who are newly installing unused solar power generation systems in residential homes in Tokyo. The simultaneous installation of storage batteries is not a condition.
●Existing homes: For up to 3.75kW, 150,000 JPY per kW (maximum 450,000 JPY); for over 3.75kW to under 50kW, 120,000 JPY per kW
●New homes: For up to 3.6kW, 120,000 JPY per kW (maximum 360,000 JPY); for over 3.6kW to under 50kW, 100,000 JPY per kW
●There is also an additional amount for the installation of rooftop structures and waterproofing work.
The target is for panels that are unused and certified by JET, installed in residential homes in Tokyo with an output of less than 50kW, used in living areas. The process requires prior application, followed by a grant application after installation. Starting from the prior application for the fiscal year Reiwa 8, submission of a certificate issued by a financial institution during the performance report has become mandatory.
According to the official Tokyo page, prior applications are being accepted from May 29, Reiwa 8. It will end once the budget is reached, so please check the official page for the application status.
👉 Click here for the official Tokyo (Cool Net Tokyo) page
Tokyo’s “Home Battery Introduction Promotion Project”
This is a subsidy for the installation costs of battery systems aimed at increasing self-consumption of electricity from solar power and improving energy independence during emergencies.
●Battery package: 100,000 JPY per kWh (maximum 1,200,000 JPY per household)
●Addition for participating in DR demonstration: 100,000 JPY per unit (150,000 JPY per unit if energy management equipment is installed)
●Expansion of battery units: 60,000 JPY per kWh (maximum 720,000 JPY per household)
The target is owners of eligible equipment (excluding national and local governments), and installation must be completed between April 1, Reiwa 8, and March 30, Reiwa 11. If applying for prior application after October 1, Reiwa 8, only products registered with the national SII for the fiscal year Reiwa 8 are eligible.
According to the official Tokyo page, prior applications are being accepted from May 29, Reiwa 8. For detailed information, including conditions for combination with solar power generation, please check the official page.
👉 Click here for the official Tokyo (Cool Net Tokyo) page
Tama City “Subsidy for Residential Energy Creation and Energy Saving Equipment” (Fiscal Year Reiwa 8)
This subsidy is for residents of Tama City who install unused eligible equipment in their own homes. Conditions include no delinquency on city taxes, and not having received similar subsidies from fiscal year 2 to fiscal year 7 is also a requirement for eligibility. This is a post-application system that must be submitted within six months from the installation date.
●Solar power generation (existing homes): For local businesses, 30,000 JPY per kW (maximum 150,000 JPY); for businesses outside the city, 20,000 JPY per kW (maximum 100,000 JPY)
●Solar power generation (new homes): For local businesses, 15,000 JPY per kW (maximum 75,000 JPY); for businesses outside the city, 10,000 JPY per kW (maximum 50,000 JPY)
●Battery systems and insulated windows: One-fourth of the cost (maximum 60,000 JPY for local businesses, maximum 40,000 JPY for businesses outside the city)
The application period is from April 1, 2026, to March 31, 2027, and is on a first-come, first-served basis. The official page states that applications may be closed even within the application period (updated September 11, 2026).
👉 Click here for the official page of Tama City
Tama City “Residential Priority Measures Acceleration Project Subsidy (for Individuals)” (Fiscal Year 2026)
This subsidy is for individuals residing in Tama City who are introducing self-consumption solar power generation systems, storage systems, solar carports, insulation renovations, etc. Conditions include no delinquency in city taxes, and the process involves applying in advance and carrying out construction after the grant decision. It is stated on the official page that solar power generation and storage systems must be purchased and installed using businesses located within the city (local businesses).
●Solar Power Generation: 30,000 yen per kW
●Storage System: Subsidy rate 3/4 (maximum 200,000 yen)
●Solar Carport: One-third of the cost (maximum 1,000,000 yen)
●Insulation Renovation: One-third of the cost (maximum 1,000,000 yen for detached houses)
The application period is from April 27, 2026, to January 29, 2027, and is on a first-come, first-served basis (updated September 11, 2026). Please check the official page for the eligibility of combining with other subsidy systems and the conditions for eligible businesses.
👉 Click here for the official page of Tama City (for individuals)
Solar Panel Installation & Storage Battery Installation Price List
⇧Service Menu | Click here for costs related to solar panel removal & water heater removal
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and storage batteries should be confirmed separately as “Equipment Costs (Device Costs)” and “Construction Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, the grade of the equipment, and the condition of the roof.
Considerations for Installation Capacity (kW) and Storage Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatts). Storage batteries are compared based on the amount of electricity they can store, measured in kWh (kilowatt-hours).
The amount of kW that can be placed on a roof varies for each house based on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to provide you with 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 rough estimates and can vary based on wiring length, scaffolding range, existing roofing materials, panel layout, etc.)
▶ Construction Menu | Costs for Solar Panel Installation and Storage Battery Installation
Items to Confirm in the Estimate (Cost Verification)
When comparing estimates, it is common to compare different capacities and equipment by looking only at the amounts. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) are listed. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls 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 Fittings | Name of fittings suitable for roofing materials and method of securing them (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 parts, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Application | How much support is included for applications to the power company, certification application for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If roofing 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 or old panels and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether it is tax-inclusive or tax-excluded, conditions under which additional costs may arise, details and duration of manufacturer warranty and workmanship warranty. |
If the capacity differs, both the price and power generation will change. Kakeru Koumuten Co., Ltd. warmly welcomes competitive estimates, so if you bring estimates from other companies, we will explain the differences for each item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can get an estimated quote and a profit simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can get an estimated quote and profit simulation!
*The simulation results are estimates. Actual profits may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection or replacement.
Customer Voices
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installations
| 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 Details |
| 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 |
| About 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the introduction 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 Tama City, Tokyo
There are many solar panel installation contractors available in Tama City, Tokyo, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and battery storage installation work, let’s check the following 4 points.
● Ensure they have extensive knowledge not only about solar panels but also about roofs
● Confirm the presence of warranties and aftercare services
● Obtain estimates from multiple contractors (3 companies is a guideline)
● Check if they provide support for subsidy applications
By confirming the above 4 points, you will be able to choose a reliable contractor.
Knowledge about roofs as well as solar panels
Defective installation of solar panels can 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 checks on roofs and waterproofing
・Solar panels installed on a severely deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring remodeling for removal and reinstallation within a few years
・Misjudging the type of waterproofing and performing incorrect treatment, leading to leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Checks Before Installing Solar Panels” in this article
Confirm the presence of warranties and aftercare services
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 the solar panels and battery storage come with manufacturer warranties, it is also essential to check for the presence of a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may be covered under the warranty as long as it falls within the warranty period and conditions.
Additionally, some contractors provide aftercare services separate from warranties, so be sure to check if the contractor 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 of hidden areas during aftercare maintenance, you can more easily detect abnormalities early, preventing significant repairs or failures!
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, a roof renovation may be required to provide the warranty.)
We also conduct aftercare maintenance and send out annual DM!
If you check the DM and wish to proceed, we will visit for aftercare maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, let’s obtain estimates from multiple contractors.
Even for the same manufacturer and the same work content, costs may vary, and warranties and after-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-services”
and make a detailed comparison! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid judging solely based on price!
▶ To “Breakdown of installation capacity, equipment, and construction costs” in this article
Confirm if they provide support for subsidy applications
There may be subsidies available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the grant may not be awarded.
Since there are systems like the Tokyo subsidy that require prior application, 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 the Tokyo subsidy, prior application is required) before proceeding with the construction!
For the Tokyo subsidy, after installation, you will need to submit a grant application and performance report, and it will be awarded after review! (The flow of procedures varies by system)
▶ To “Subsidies and grants that may apply in Tama 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 for electricity has decreased compared to ten years ago, but by consuming the electricity generated, you can reduce the amount of electricity purchased from the utility company and gain benefits!
As electricity costs rise, the ability to cover your consumption with solar power becomes attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) will be set as “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year” for certifications after October 2025, and the same price will apply for the fiscal year 2026. After the fifth year, it is generally more advantageous to use it at home (self-consume) rather than selling it, making the combination with a storage battery a viable option.
👉 Ministry of the Environment｜For purchase prices and periods, click here
Advantage 2 Subsidies can be utilized!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
The reduction of the actual burden amount through subsidies is a significant advantage!
In the case of Tama City, there is a possibility that the national, Tokyo Metropolitan, and Tama City systems may apply. The Tama City subsidy for fiscal year Reiwa 8 will be on a first-come, first-served basis, and may end once the budget is reached, even within the application period (please check the application status for each system).
Advantage 3 Environmentally friendly!
Solar power generation has low carbon dioxide emissions and can reduce dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices like power conditioners may have operational noise.)
Advantage 4 Heat insulation effects can be 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 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 capability, you may be able to use electricity from a dedicated outlet during daytime generation.
(The devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1: Maintenance costs can be incurred
A particularly overlooked maintenance cost is for the roof where solar panels are installed.
If you perform roof renovations 10 to 20 years later, there will be costs for removing and reinstalling the solar panels.
If the existing roof is deteriorating, it is reassuring to renovate it with durable roofing materials before installing solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It would be reassuring to consider maintenance costs in simulations before introducing solar panels!
Point 2: The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix brackets to the roofing material or substrate with screws, waterproofing of the fixed parts is crucial.
In methods that involve making holes in the roof, the risk of leaks inevitably arises.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and fixing the solar panels using the catch method is also an option. (The catch method has compatibility conditions between the roofing material and brackets, and it cannot be used with all metal roofs.)
Catch-type base brackets specifically 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-bearing capacity, switching to a lightweight roof may be one option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “This manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
How to Choose 1: Compare Based on Total Roof Output
When installing solar panels on the roof, it is important to know how much electricity can be generated in a limited area, and it is always better to generate more!
Solar panels come in various sizes and outputs depending on the manufacturer.
A 350W output panel and a 400W output panel may seem like the higher output panel is better at first glance.
However, if the size of the panels 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,” resulting in 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 just the output of a single panel!
*The above calculations are for total output (kW). The actual electricity generation (kWh) will vary based 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 standard figure for the warranty 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!
How to Choose 3: Compare Based on Warranty Period
Solar panel warranties include various types such as “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
For output warranties, some manufacturers offer a 30-year warranty while others offer a 10-year warranty, so it varies!
Longer warranties are better, so be sure to check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Tama City, Tokyo
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Tama City, Tokyo. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Tama City, Tokyo?
The cost varies depending on the installation capacity, equipment, and condition of the roof. In the above construction example (4.3kW solar panel + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines 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 Tama 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 listed on the official Tokyo (Cool Net Tokyo) page. Tama City offers subsidies for residential renewable energy and energy-saving equipment (for existing homes, 30,000 yen per kW when using local contractors, with a maximum of 150,000 yen) and the Residential Priority Measures Acceleration Project subsidy (30,000 yen per kW for solar power), with applications for the 2026 fiscal year being accepted on a first-come, first-served basis as posted on Tama City’s official page. 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 even after the construction is completed?
It varies by program. Tokyo’s subsidies require pre-application. In Tama City, the subsidy for residential renewable energy and energy-saving equipment allows applications within six months after installation, while the Residential Priority Measures Acceleration Project subsidy requires a pre-application for construction to be conducted after the grant decision. The order of procedures varies by program, so please confirm whether you can contract and start work before applying.
The order of procedures varies by program, so please confirm before contracting and starting work.
Can solar panels be installed on a slate roof? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate. The fixing method varies by construction method, and when fixing brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is essential.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation and can suggest methods such as roof overlay 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, the cost of removing and reinstalling the solar panels will be incurred separately. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with durable roofing materials before installation.
After confirming the condition of the roof during the on-site inspection, please consult with us on how to proceed with the installation!
Is it better to install a storage battery together with solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it in your home rather than selling it.
Additionally, the subsidy for storage batteries in Tokyo (for Reiwa 8, it is 100,000 yen per kWh, with a maximum of 1.2 million yen per household) is a program aimed at increasing self-consumption of electricity generated by solar power. The subsidy system in Tama City also includes storage systems (please check the official page for application status). You can compare “solar only” and “solar + storage battery” through a financial simulation.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and on-site inspection, and we will provide you with the installation capacity and power generation simulation.
Tama City is located at the northern edge of the Tama Hills, an area with hills and lowlands along the Tama River, where the shape and orientation of the roof, as well as the shadows cast by surrounding buildings, differ for each 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 panel 4.3 kW + storage battery), it took about 3 days. This may vary if roof work is done simultaneously or depending on the shape and installation capacity of the roof.
Please note that additional time is required for subsidies and applications to power companies, so please consult with us as soon as possible.
What is the current selling price (FIT)?
For residential use (less than 10 kW), the selling price from certifications after October 2025 will be 24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year, with the same price applicable for the 2026 fiscal year.
The idea is to recover initial costs more quickly in the first 4 years and focus on self-consumption thereafter. Kakeru Koumuten provides a financial simulation that takes into account loan interest rates and electricity costs.
Can you handle maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-service maintenance notices via DM and visits customers who wish to have inspections. We can also clean solar panels using a special brush if the power generation decreases due to dirt.
Since it is difficult to check areas on the roof by yourself, 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 in-house, allowing us to remove the panels, perform roof overlay (cover method) or re-roofing, and then reinstall them all in one go. 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 contractor in Tama City, Tokyo, please consult Kakeru Koumuten.
Our company handles a wide range of exterior renovations, including solar panels, roofing work, and exterior wall work in Tama City, Tokyo.
We have received requests from many customers, including renovation companies and real estate agencies!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received positive feedback from 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 cover methods.
We are happy to assist with small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leaks, 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 about recommended solar panels”, “I want to keep costs as low as possible”, “I just want an estimate for now”, we will provide optimal solutions for your specific requests.
We will never propose unnecessary work focused on 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 construction!
We welcome competitive quotes with confidence!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Characteristics of Tama City, Tokyo, and Points for Solar Construction
Tama City covers an area of 21.01 square kilometers, occupying the northern end of the Tama Hills, with slightly undulating hills divided by the Koda River and the Oguri River, and there are alluvial lowlands created by gravel and mud carried by the Tama River around Seiseki Sakuragaoka Station, as stated on the city’s official page. The elevation is around 160 meters near the highest point at Tenno Mori Park and around 50 meters in the lowlands along the Tama River. We have summarized the characteristics of the terrain in Tama City, Tokyo, and points to consider when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Tama City, Tokyo, and points for solar construction
■ There is an elevation difference of about 110 meters between the hills and lowlands. Check the delivery route for sites with slopes and steps.
The elevation varies significantly between the hills and lowlands within the city. For sites facing slopes or with elevation differences from the road, it may be necessary to devise a plan for scaffolding and the transportation routes for panels and batteries. The width of the front road and the elevation differences of the site vary from house to house, so we will confirm these on-site. At Kakeru Koumuten Co., Ltd., our own scaffolding team plans the scaffolding according to the site conditions, creates layout diagrams from the drawings and on-site surveys, and you can check the power generation simulation.
■ Check the hazard maps for floods and sediment disasters in the Tamagawa and Oguragawa rivers. Pay attention to the installation locations of equipment.
The flood and sediment disaster hazard map of Tama City assumes heavy rainfall of 588 millimeters over two days in the Tamagawa, Asakawa, and Oguragawa rivers (downstream from the confluence), and a maximum of 153 millimeters in one hour and a total of 690 millimeters over 24 hours in the Koida and Oguragawa rivers (upstream from the confluence), and it also shows the areas that may be flooded by water overflowing from rivers or low-lying areas before reaching the rivers (internal water). The same map includes information on sediment disaster warning areas and special warning areas, and it is dated September 2022 (information as of September 30, 2022). Depending on where the power conditioner and battery 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 us about the installation location and height in conjunction with the installation conditions of the manufacturer you are using.
■ The types and ages of roofs 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 Co., Ltd., we will confirm the type and condition of the roof and the situation of the site before installation, and we will propose fixing methods, waterproofing arrangements, and scaffolding plans.
■ The annual sunshine hours at the Tokyo Observatory are approximately 1,927 hours.
According to the Japan Meteorological Agency’s average values (1991-2020), the annual sunshine hours at the Tokyo Observatory are approximately 1,927 hours, with January (about 193 hours) having the most and June during the rainy season (about 124 hours) having the least. (This is a reference value, not the observation value for Tama City.)
The power generation in Tama City can also be affected by the terrain of the hills and the shadows from surrounding buildings and trees, so it is important to conduct an annual power generation simulation and choose the battery capacity according to the times when electricity is used the most.
Our company handles a lot of exterior work and solar power projects in Tama City, Tokyo.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us about any sudden troubles!
Service Area in Tama City, Tokyo
Kakeru Koumuten Co., Ltd. accepts requests for work throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Tama City, Tokyo
Tama City Atago / Tama City Ichinomiya / Tama City Ochiai / Tama City Otsukawa / Tama City Kaito / Tama City Karakida / Tama City Koida / Tama City Sakuragaoka / Tama City Sanno-shita / Tama City Suwa / Tama City Sekido / Tama City Tsurumaki / Tama City Toyogaoka / Tama City Nakazawa / Tama City Nagayama / Tama City Higashiterakata / Tama City Seigaoka / Tama City Babikizawa / Tama City Minamino / Tama City Hyakugusa / Tama City Renkouji / Tama City Wada
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・Trust Kakeru Koumuten for exterior renovations in Tama City, Tokyo!
・Kakeru Koumuten Co., Ltd. project achievements
・Kakeru Koumuten Co., Ltd. aftercare services
・Kakeru Koumuten Co., Ltd. service menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of obtaining multiple estimates and points for comparison!
・Top 12 solar power generation manufacturers! Features and selection tips included!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
・What are the best locations for solar power installation? Points for selecting installation sites included!
・Find out more about 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!
