Leave Your Solar Panel Installation Work in Tama, Kawasaki City to Kakeru Koumuten Co., Ltd.!
For solar panel and battery installation in
Tama Ward, Kawasaki City,
trust Kakeru Koumuten!
Kakeru Koumuten is a specialized exterior renovation company based in Aoba Ward, Yokohama City.
As a company strong in roofing work, we are entrusted withsolar panel and battery installation considering roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Tama Ward”
“Cost of Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Tama Ward”
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 Tama Ward, Kawasaki City
- Roof Inspection Before Installing Solar Panels
- Subsidies and Grants That May Be Applicable in Tama Ward
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installation Contractor in Tama Ward, Kawasaki City
- Benefits of Introducing Solar Equipment
- Points to Note When Introducing Solar Power Generation
- How to Choose Solar Panels
- Frequently Asked Questions About Solar and Storage Battery Installation in Tama Ward
- If You Are Looking for a Solar Panel Installation Contractor in Tama Ward, Contact Kakeru Koumuten
- Characteristics of Tama Ward, Kawasaki City and Points for Solar Construction
- Service Area in Tama Ward, Kawasaki City
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Tama Ward, Kawasaki City
The reasons why our company is entrusted with solar panel installation by customers in Tama Ward, Kawasaki City include
one reason being that Kakeru Koumuten has a base in Kanagawa Prefecture,
and our unique strengths in solar panel installation that cannot be imitated by other companies,
which have been well received by many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We Can Also Handle Exterior Renovations Aside from Solar Panel Installation!
Troubles such as leaks that occur with 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 may be 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 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.Equipment Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has prepared the following warehouses and material storage areas to provide solar work and exterior renovations at low cost and high quality.
We have established five bases centered in Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the necessary scaffolding materials for temporary scaffolding based on construction conditions, allowing us to assemble scaffolding ourselves.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also cut costs associated with scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
Even in the residential areas of Tama Ward, where the terrain changes from flat land along the Tamagawa River to the Tama Hills, our own scaffolding team plans the scaffolding according to the local conditions.
Storage of materials in our large warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, we canpurchase materials at a lower cost!
Additionally, since we always have stock of roofing materials, we can provideswift responses in emergencies!
Sorting and transportation of 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 down on waste disposal costs.
Exterior remodeling dedicated showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on the roofing materials!
It is also possible to simulate the revenue and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also 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 all work performed by our own team.
By having a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof remodeling at reduced costs.
Additionally, one representative will handle everything from the estimate to project completion.
Since the person in charge does not change, whether it’s the sales representative or the construction management representative, smooth communication is possible.
We can perform consistent in-house work from temporary scaffolding installation to exterior wall painting and roof remodeling!
4. Various Permits Obtained & Skilled Workers on Staff
We have obtained construction business licenses and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal and painting technicians on staff, and we are confident in our construction techniques.
We are capable of handling large-scale roofing projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty, our solar panel installation work comes with our own workmanship warranty (leakage warranty)!
(The workmanship warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, it may not be possible to provide a warranty without performing roof renovations. The workmanship warranty is separate from the manufacturer’s product warranty, and the coverage and conditions vary based on the warranty details.)
Aftercare maintenance is available annually, and we send out notification DM each year.
If you have any questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roof troubles and situations.
If it is not possible to access the roof at height, we can utilize a drone for inspections!
During leakage investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of the solar panels decreases due to dirt, we can also provide cleaning with a specialized brush.
We will respond according to the customer’s wishes.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training so that each staff member can handle various cases.
8. Creation of Clear Materials and Simulations
At Kakeru Koumuten Co., Ltd., in addition to “estimates”, “layout diagrams”, and “power generation simulations”, we also provide a “solar installation guidebook” and a “profit and loss simulation” that takes into account loan interest rates and electricity costs.
The profit and loss simulation can be created for projected cumulative profits and losses over 20 to 30 years.
Even customers who are not familiar with solar installations will find the materials easy to understand, including important points and disadvantages!
We encourage you to obtain comparative estimates and review plans from other companies!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 or 30 years.
It is crucial to confirm before installation whether it is safe to place them directly on the current roof, as this is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten Co., Ltd., which specializes in roofing work, has summarized the items to check before installation.
| 1. Type of roofing material and age | The method of securing the panels varies depending on the roofing material, such as slate, tiles, metal roofs, or flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of the substrate and waterproof sheet | If the sheathing or roofing (waterproof sheet) beneath the roofing material is damaged, it can affect the fastening strength and waterproofing. We also check for any signs of leaks. |
| 3. Orientation, slope, and shading of the roof | The orientation and slope of the roof surface, as well as shading from neighboring houses, trees, and utility poles, can affect power generation. We create a layout diagram from the drawings and the site, and you can check it with the power generation simulation. |
| 4. Shape of the roof and installable area | The number of panels (installation capacity) that can be placed depends on the shape and size of the roof. The number of panels that can be installed varies by panel size, so we compare based on the total output of the roof. |
| 5. Method of securing and waterproofing details | We check whether the method involves drilling holes in the roofing material for fastening or using brackets to secure the roofing material. The fastening method varies by technique, so please confirm the waterproofing treatment of the fastening parts during the estimate. |
| 6. Weight of the roof | The roof will become heavier due to the panels. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may be an option if necessary. |
| 7. Location of equipment installation and wiring | We confirm the installation locations for the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring also affects costs. |
Securing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproof treatment of fixing parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suitable for the type of tile (even methods that do not drill holes in the tiles will fix to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lightweight roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the 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 framework | Type and deterioration status of the waterproof layer, waterproofing around the framework. Consider in conjunction with the timing of waterproofing work. |
If you perform roof renovations 10 to 20 years after installation, there will be additional costs for the removal and reinstallation of solar panels. If the roof is deteriorating, renovating to a highly durable roofing material before installation may help reduce costs in the long run.
Kakeru Koumuten Co., Ltd. specializes in roofing work and can also handle the removal and reinstallation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Kawasaki City, Tama Ward
PotentialSubsidies and Grants
If you are introducing solar panels or storage batteries in Tama Ward, you may be eligible for programs from the “National Government,” “Kanagawa Prefecture,” and “Kawasaki City.”
The following information is based on the official pages of each program as of October 6, 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 Timing for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Kawasaki City “Reiwa 8 Year Solar Power Generation Equipment Installation Subsidy” (for individual residences) | Individuals residing (or planning to reside) in homes within the city. Projects started before receiving the grant decision notification are not eligible. Can be combined with national and Kanagawa Prefecture subsidies. | Solar Power (non-FIT applicable): 70,000 JPY/kW (maximum 280,000 JPY per case) Solar Power (FIT applicable): 40,000 JPY per case Storage Battery: 100,000 JPY/kWh (non-FIT applicable interconnection maximum 700,000 JPY per case, FIT applicable interconnection maximum 300,000 JPY per case) |
April 24, 2026 – December 28, 2026 Early termination possible depending on budget status (as of September 30, 2026, 49% of the total budget has been executed according to the official page) |
| Kanagawa Prefecture “Reiwa 8 Year Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Installation Subsidy” | Must install both solar power generation and storage batteries in a residence within the prefecture. Applications must be made by the individual, and construction must begin after grant approval. | Solar Power: 70,000 JPY/kW Storage Battery: 150,000 JPY per unit |
Phase 1: May 11, 2026 – June 30, 2026 Phase 2: September 7, 2026 – September 30, 2026 (first-come, first-served) Phase 2 has reached its application deadline. Please check the prefecture’s official page for future recruitment. |
| National “DR Home Storage Battery Project” (Reiwa 7 Year Supplement) | Newly install home storage systems of registered products that can be utilized for DR (demand response). | Calculated based on an initial effective capacity of 1 kWh at 34,500 JPY (subsidy rate within 30% and a maximum of 600,000 JPY per application). | As of May 29, 2026, the budget has been reached, and applications are now closed (currently, applications cannot be made). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but must be combined with essential works such as insulation renovation of windows (openings) and structures; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 JPY per unit | Ends as soon as the budget cap is reached. Please check the official site for application status. |
| Kawasaki City “Eco Support Subsidy for Local Businesses” (Reiwa 8 Year) | Small and medium-sized businesses with (or newly establishing) a business location within the city (individual residences are not eligible). Solar power generation must be under 50 kW, and for those over 10 kW, it must be for self-consumption. | One-third of eligible expenses (maximum 2,000,000 JPY) If solar power generation is included, an additional 10,000 JPY per kW (maximum 200,000 JPY) will be added. |
April 1, 2026 – January 12, 2027 Applications will close once the budget cap is reached (as of September 29, 2026, the budget execution rate is approximately 70% on the official page). |
| Kanagawa Prefecture “Reiwa 8 Year Kanagawa Prefecture Self-Consumption Renewable Energy Installation Subsidy” | Corporations and individual business owners filing blue returns (individual residences are not eligible). Solar power must have a generation capacity of 10kW or more, facilities for business use, equipment not certified under FIT/FIP, etc. | Solar Power: 80,000 JPY/kW, etc. Storage Systems: 50,000 JPY/kWh (maximum 5,000,000 JPY) |
Application period ended on September 3, 2026 (when the application amount reached the budget amount) |
Kawasaki City’s subsidies do not cover projects that started before receiving the “Notice of Grant Decision”. Kanagawa Prefecture’s housing subsidies also require construction to start after receiving the “Grant Decision”, and grants will be provided after a performance report and review following project completion. The order of procedures varies by program, and applying does not guarantee a grant, so please confirm before contracting or starting work.
At Kakeru Koumuten, we will guide you on the eligibility conditions and business requirements for each program after confirming them.
Kawasaki City “Reiwa 8 Fiscal Year Solar Power Generation Equipment Installation Subsidy”
Kawasaki City provides subsidies to individuals installing solar power generation equipment and storage batteries in residential properties within the city. Residents of Tama Ward are also eligible.
The subsidy amount for individual residences is 70,000 JPY per kW for solar power generation (not applicable under FIT, maximum 280,000 JPY per case), and 100,000 JPY per kWh for storage batteries. The maximum amount for storage batteries is 700,000 JPY per case when interconnected without FIT, and 300,000 JPY per case when interconnected with FIT; when selling solar power under FIT, it is treated as 40,000 JPY per case. There are also options for ZEH/ZEH Oriented at 250,000 JPY per unit and ZEH+ at 400,000 JPY per unit.
For example, if installing a 4kW solar panel not applicable under FIT, the calculation for the solar subsidy would be 4kW × 70,000 JPY = 280,000 JPY (the same as the maximum amount).
Projects that started before receiving the “Notice of Grant Decision” are not eligible. It is possible to combine this with other subsidies provided by the national government and Kanagawa Prefecture. There are also options for management associations and owners of condominiums, but simultaneous application for subsidies for electric vehicle charging facilities is a condition.
The application period for the Reiwa 8 fiscal year is from April 24, 2026, to December 28, 2026, and may end early depending on budget conditions. For detailed eligibility conditions and application methods, please check Kawasaki City’s official page.
👉 Click here for Kawasaki City’s official page
National Subsidy “DR Home Storage Battery Project (Support Project for Introducing Home Storage Systems for DR Resources)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those introducing registered storage systems that can be utilized for demand response (DR), with the fiscal year 2025 supplementary project setting a standard amount of 34,500 JPY per initial effective capacity of 1kWh, with a subsidy rate of up to 30% and a maximum of 600,000 JPY per application. There are also conditions such as projects contracted or ordered before the grant decision are not eligible.
However, the supplementary budget for Reiwa 7 reached the application amount on May 29, 2026, and the public recruitment has ended (the previous year’s Reiwa 6 supplementary budget also ended on July 2, 2025). Applications are currently not possible, so please check the official website for future public recruitment.
Additionally, there are currently no subsidies from the national government specifically for the installation of solar panels on existing homes.
👉 Here is the official site for the DR Home Storage Battery Project
Kanagawa Prefecture “Reiwa 8 Subsidy for Solar Power Generation and Storage Battery Installation for Residential Use”
In Kanagawa Prefecture, subsidies are provided for those who install both “solar panels” and “storage batteries” in their homes.
The subsidy amounts are 70,000 yen per kW of solar power generation output and 150,000 yen per storage system.
For example, if you install a 4kW solar panel and one storage battery, the calculation for the subsidy amount would be 4kW × 70,000 yen + 150,000 yen = 430,000 yen.
Conditions include that the storage system must be a registered product, if construction begins before the grant decision, it will be ineligible, and the application must be made by the individual (applications by contractors on behalf of the individual are not allowed). It is also possible to combine this with subsidies from Kawasaki City.
For Reiwa 8, the first period (May 11 to June 30) and the second period (September 7 to September 30, first-come-first-served) have been accepted, and the second period is now closed. Please check the official page of Kanagawa Prefecture for future recruitment.
👉 Here is the official page of Kanagawa Prefecture
Kawasaki City “Eco Support Subsidy for Local Businesses” (for businesses)
Kawasaki City is implementing a subsidy for businesses aimed at supporting the introduction of renewable energy such as solar power generation equipment for small and medium-sized businesses that have (or will establish) a business location in the city.
Eligible applicants include small and medium-sized enterprises, educational institutions (with fewer than 100 employees), medical corporations (with fewer than 300 employees), and social welfare corporations (with fewer than 100 employees), while individual residential installations are not eligible. Solar power generation must be less than 50kW, and for systems over 10kW, they must be for self-consumption. Installing storage batteries or V2H in conjunction is also eligible.
The subsidy amount is one-third of the eligible expenses (up to 2,000,000 yen), and if solar power generation is included, an additional 10,000 yen per kW (up to 200,000 yen) will be added.
The application period for Reiwa 8 is from April 1, 2026, to January 12, 2027, and applications will close once the budget limit is reached.
Businesses considering the installation of solar panels in stores, offices, or factories within Tama Ward should check the conditions for eligible businesses and equipment on the official page of Kawasaki City.
👉 Here is the official page of Kawasaki City
Kanagawa Prefecture “Reiwa 8 Year Kanagawa Prefecture Subsidy for Self-Consumption Type Renewable Energy Introduction” (For Businesses)
In Kanagawa Prefecture, there are also subsidies for businesses introducing “self-consumption type” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and individual residential installations are not eligible.
Conditions include solar power generation with an output of 10 kW or more, supplying electricity to business facilities within the prefecture, and not being equipment certified under FIT or FIP.
The subsidy amount is 80,000 yen per kW for solar power generation and 50,000 yen per kWh for the accompanying storage system (with a maximum of 5 million yen).
As the application amount reached the budget amount for Reiwa 8, the recruitment was closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Tama Ward should check the official Kanagawa Prefecture page for the next recruitment.
👉 Click here for details
Solar Panel Installation & Storage Battery Installation Price List
⇧Service Menu | Click here for costs related to Solar Panel Removal and Hot Water Heater Dismantling
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and storage batteries should be confirmed by separating them into “Equipment Costs (Device Costs)” and “Construction Costs”.
Even for the same “Solar Panel Installation Set,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.
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 (kilowatt). Storage batteries are compared based on the amount of electricity they can store, expressed in kWh (kilowatt-hour).
The amount of kW that can be placed on the roof varies for each house based on the roof shape, orientation, and size. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panel costs 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.)
▶ Service Menu | Click here for costs related to 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 only looking 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 specified. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls in conjunction with a storage battery. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range available during power outages (whole house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of hardware suitable for roofing material and method of securing it (whether it involves drilling holes or using clamps). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, presence of a monitor to check power generation. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at fixed points, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | Extent of support for applications to the power company, certification application for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If roof work and exterior painting are done simultaneously, check that the same scope and quantity are not counted twice. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters and old panels, as well as disposal costs for waste materials, are included. |
| 10. Tax Classification and Warranty | Whether prices are tax-inclusive or tax-exclusive, conditions under which additional costs may arise, details and duration of manufacturer warranty and workmanship warranty. |
If the capacities differ, both the price and power generation will change. Kakeru Koumuten Co., Ltd. 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 obtain a rough estimate 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 a rough estimate and profit simulation!
*The simulation results are approximate. Actual profits may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection or replacement.
Customer Feedback
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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 Installation
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh class |
| 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 subsidy being granted, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The subsidy 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 subsidies are available, and I would like to know how much will be granted. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of subsidies, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Tama Ward, Kawasaki City
There are many solar panel installation companies that serve Kawasaki City, Tama Ward, and you may be unsure which company to choose.
Therefore, when requesting solar panel installation and battery installation work, let’s confirm the following four points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the existence of warranties and after-sales maintenance
● Obtain estimates from multiple companies (three companies as a guideline)
● Check if they provide support for subsidy applications
By confirming the above four points, you will be able to choose a reliable company.
Knowledge about roofs as well as solar panels
Defective installation of solar panels can sometimes 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 renovations for removal and reinstallation within a few years
・Misjudgment of the type of waterproofing leading to incorrect processing and resulting in leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Check Before Installing Solar Panels” in this article
Confirm the existence of warranties and after-sales maintenance
When choosing a solar installation company, confirm the existence of warranties. It is important to check not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While the solar panels and battery units come with manufacturer warranties, also confirm whether there is a workmanship warranty in case of leaks occurring after installation!
For companies that offer workmanship warranties, if leaks occur after installation, they may cover the repairs under the warranty as long as it is within the warranty period and conditions.
Additionally, some contractors offer after-service separate from the warranty, so be sure to check if the contractor you are considering has after-service.
Changes or damages on the roof may occur in areas that are not visible, so there is a possibility that customers may not notice them.
By conducting inspections of these hidden areas during after maintenance, it becomes easier to detect abnormalities early, preventing major repairs or breakdowns!
Kakeru Koumuten Co., Ltd. provides a rain leak warranty as part of the workmanship warranty for solar panel installations. (The warranty for solar panel installations is 10 years, and depending on the condition of the roof before installation, a roof renovation may be required to provide the warranty.)
We also conduct after maintenance and send out DM every year!
Please check the DM, and if you wish, we will come to perform after maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, be sure to obtain estimates from multiple contractors.
Even for the same manufacturer and the same construction 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 desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates,
“Check the items in the estimate”
“Type of solar panel”
“Warranties and after-services”
and make detailed comparisons to make your judgment! If the rank of auxiliary materials is low or if processes are skipped, costs can be reduced, so avoid making decisions based solely on price!
▶ Go to “Breakdown of Installation Capacity, Equipment, and Construction Costs” in this article
Check if they provide support for subsidy applications
Subsidies may be available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
For systems like the Kanagawa Prefecture housing subsidy, where applications cannot be handled by the contractor and must be submitted by the individual, it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Be sure to complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining a grant decision) before proceeding with the construction!
In the case of the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the flow will go through a review before the grant is provided! (The flow of procedures varies by system)
▶ Go to “Possible Subsidies and Grants in Tama Ward” within this article
Benefits of Installing Solar Power Systems
The benefits of installing solar panels are summarized in the following 5 points!
Benefit 1: Economic Advantage
The biggest advantage of installing solar panels is the economic benefit!
Although the selling price of electricity has decreased compared to 10 years ago, you can gain benefits by reducing the electricity you buy from the power company through self-consumption of the generated power!
As electricity prices rise, the ability to cover your consumption with solar power becomes increasingly attractive!
If you plan to use the generated power at night, installing a storage battery is essential!
For residential use (under 10kW), the selling price (FIT) for electricity generated from October 2025 onwards is set at “24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year.” The same price will apply in the 2026 fiscal year. After the 5th year, it is generally more advantageous to use the power at home (self-consumption) rather than selling it, making the combination with a storage battery a viable option.
👉 For details on purchase prices and periods, visit the Agency for Natural Resources and Energy
Benefit 2: You Can Utilize Subsidies!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the requirements, you may be able to take advantage of subsidies!
The reduction of the actual burden amount through subsidies is a significant benefit!
In the case of Tama Ward, there may be subsidies available for solar power installation costs from Kawasaki City and Kanagawa Prefecture.
Benefit 3: Environmentally Friendly!
Solar power generation has low carbon dioxide emissions and reduces dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them a good method of power generation for the environment. (However, devices like power conditioners may have operational noise.)
Benefit 4: Expected Heat Insulation Effect!!
By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the temperature rise of the roof, providing expected heat insulation effects!
(Note that this does not improve the insulation performance of the building itself.)
Benefit 5: Electricity can be used even during power outages!!
If a storage battery is installed, it becomes possible to use electricity even during emergencies like power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation functionality, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1: Maintenance costs can be incurred
A particularly overlooked maintenance cost is for the roof where solar panels are installed.
If you perform roof renovations 10 to 20 years later, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorating, it is reassuring to renovate it with durable roofing materials before installing solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It 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 when using screws or other fasteners to secure the roofing material and substrate, waterproofing of the fixed areas becomes crucial.
If the method involves making holes in the roof, there will inevitably be a risk of leaks.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and securing the solar panels using the catch method is also an option. (The catch method has compatibility conditions between the roofing material and the fasteners, and it cannot be used with all metal roofs.)
Catch-type base metal fittings for horizontal metal roofs
Note 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load-bearing capacity, replacing it with a lighter roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
How to Choose 1: Compare by Total Roof Output
When installing solar panels on the roof, it is important to consider how much power can be generated in a limited area, and generating more power is always better!
Solar panels come in various sizes and outputs depending on the manufacturer.
A 350W output panel and a 400W output panel may seem that the higher output panel is better at first glance.
However, if the size of the panel does not fit well with the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different installation capacities on the same roof due to the size difference.
400W×15 panels = 6kW (total roof output)
350W×20 panels = 7kW (total roof output)
As shown above, even if the output of a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual power generation amount (kWh) will vary depending on conditions such as roof orientation, slope, and shading.
How to Choose 2: Compare by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases over 10 years and 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or power generation amount.
By considering the degradation rate along with the initial output, you can choose solar panels without regrets!
How to Choose 3: Compare by Warranty Period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
Regarding the output warranty, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies!
It’s always better to have a longer warranty, so let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Tama Ward
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Tama Ward. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Kawasaki City, Tama Ward?
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 installation and storage battery installation pricing page. We will create a layout diagram from the drawings and site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Tama Ward?
As of October 6, 2026, Kawasaki City’s “Reiwa 8 Fiscal Year Solar Power Generation Equipment Installation Subsidy” (for individual residences; solar power is 70,000 yen/kW; maximum 280,000 yen per case, etc.) is accepting applications until December 28, 2026 (there is a possibility of early closure depending on budget conditions). The Kanagawa Prefecture subsidy (70,000 yen/kW for solar power; 150,000 yen per unit for storage batteries) is approaching the application deadline for the second phase of Reiwa 8, and 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?
For many programs, procedures are required before construction. Both Kawasaki City’s and Kanagawa Prefecture’s subsidies require “commencement of construction after the grant decision,” and if you start before receiving the grant decision notification, you will be ineligible.
The order of procedures varies by program, so please confirm 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 varies by construction method, and in methods that secure 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 if deterioration is advanced, we can also propose methods such as roof overlay (cover method) or replacement before installation.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed after 10 to 20 years of installation, the cost for removing and reinstalling 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.
Please consult us on how to proceed with the installation after confirming the condition of the roof through a site survey!
Should I install a storage battery together with the solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 JPY/kWh after the fifth year, making it more beneficial to use it in your home rather than selling it.
Additionally, the subsidy in Kanagawa Prefecture requires the simultaneous introduction of solar panels and storage batteries, and there are subsidy options for storage batteries in Kawasaki City. You can compare “solar panels only” and “solar panels + storage batteries” through a financial simulation.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and site survey, and provide you with the installation capacity and power generation simulation.
The Tama Ward is located between the Tama River and the Tama Hills, and the shadows cast by neighboring houses, trees, and elevation differences vary from one house to another. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
In the above construction example (solar panels 4.3 kW + storage battery), it took about 3 days. The duration may vary if roof work is performed simultaneously or depending on the shape of the roof and installation capacity.
Additionally, please note that there will be a separate period for applying for subsidies and with the power company, so please consult us early.
What is the current selling price (FIT)?
For residential use (less than 10 kW), from the certification after October 2025, the first 4 years will be 24 JPY/kWh, and from the 5th to the 10th year it will be 8.3 JPY/kWh, and the same prices will apply for the 2026 fiscal year.
The idea is to recover the initial costs quickly in the first 4 years, and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that takes into account loan interest rates and electricity costs.
Can you handle maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-service maintenance 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 renovate roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten can remove and reinstall solar panels in-house, so we will handle the process of removing the panels, performing the roof overlay (cover method) or re-roofing, and reinstalling them consistently. The removed panels can be stored in our warehouse.
For information on costs, please see the solar panel removal and water heater removal pricing page.
If you are looking for a solar panel installation contractor in Tama Ward, consult Kakeru Koumuten
Our company handles a wide range of exterior renovations, including solar panels, roofing work, and exterior wall work in Kawasaki City, Tama Ward.
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 cost”, and we have received positive feedback from numerous customers.
We continue to update our construction achievements every year, and we will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay work and re-roofing but also partial roof repairs, exterior painting, and exterior cover methods.
We are also happy to assist with 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 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 optimal solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in the customer’s position and propose the best construction plan!
We are confident that we will not be outdone by other companies in terms of cost, quality, and organization for exterior work!
We are confident, so we welcome competitive quotes!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Characteristics of Kawasaki City, Tama Ward and Points for Solar Work
Kawasaki City, Tama Ward, is an area of 20.39 km2, with the Tama River flowing to the north and the Tama Hills extending to the south. There are areas where green spaces and farmland remain, including Ikuta Ryokuchi located in the Tama Hills.
Below are summarized points to consider regarding the terrain and environment of Tama Ward when installing solar panels and storage batteries. (Tap to open)
View the characteristics of Kawasaki City, Tama Ward and points for solar work
■ Check roofs according to the terrain from the Tama River to the Tama Hills
Overview of Tama Ward, Kawasaki City introduces Tama Ward as an area where the Tama River flows to the north and the Tama Hills spread to the south.
In areas where flatlands and hills are adjacent, the direction and height of roofs, as well as the shadows cast by neighboring houses, buildings, trees, and retaining walls, vary from one house to another. Since solar panels generate less electricity when shaded, Kakeru Koumuten Co., Ltd. creates layout diagrams based on blueprints and the actual site conditions, and we confirm this through power generation simulations.
■ Responding to sloped sites and elevation differences with our own scaffolding
For sites along slopes near hills or residential areas with narrow front roads, careful planning for scaffolding and equipment delivery is necessary. Kakeru Koumuten Co., Ltd. will respond according to the site using our own scaffolding team and scaffolding materials.
■ Areas with green spaces and farmland require attention to fallen leaves and dirt
The overview states that there are many green spaces and farmland remaining in Tama Ward. While areas with abundant greenery are attractive, roofs close to trees are prone to accumulating fallen leaves and dirt, which can lead to a decrease in power generation. Kakeru Koumuten Co., Ltd. can also provide cleaning of solar panels with specialized brushes, as well as rain gutter cleaning.
■ For older homes, check the roof condition before installation
For homes that have been built for many years, it is important to check the condition of the roofing materials and substrate before installing solar panels. Depending on the state of the roof, installing them simultaneously with roof renovations can help reduce future costs for removing and reinstalling solar panels.
■ Yokohama’s annual sunshine hours are approximately 2,018 hours
According to the Japan Meteorological Agency’s average values (1991-2020), Yokohama’s annual sunshine hours are approximately 2,018 hours (this is not the value for Tama Ward, but for an observation point in eastern Kanagawa Prefecture). Monthly, August has the most hours, while June during the rainy season has the least.
Power generation varies by season, so conducting annual power generation simulations and selecting battery capacity to match peak electricity usage times are key points.
■ Different subsidy systems for commercial buildings such as stores and offices
When installing solar panels on commercial buildings such as stores, offices, or factories, there are different subsidy systems than those for households. The Kawasaki City Eco Support Subsidy for local businesses is accepting applications until January 12, 2027, and will end once the budget cap is reached, with specific conditions for eligible businesses and equipment.
Our company is based in Kanagawa Prefecture and has undertaken many exterior construction and solar projects in Tama Ward, Kawasaki City.
We are happy to handle 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 Ward, Kawasaki City
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Tama Ward, Kawasaki City
Ikuta, Tama Ward / Kuritani, Tama Ward / Shukugawara, Tama Ward / Suga, Tama Ward / Suga Inadazutsumi, Tama Ward / Suga Kitaura, Tama Ward / Suga Shiroshita, Tama Ward / Suga Sengoku, Tama Ward / Suga Notoro, Tama Ward / Suga Baba, Tama Ward / Seki, Tama Ward / Teraodai, Tama Ward / Nakanojima, Tama Ward / Nagao, Tama Ward / Nagasawa, Tama Ward / Nishi Ikuta, Tama Ward / Noborito, Tama Ward / Noborito Shinmachi, Tama Ward / Higashi Ikuta, Tama Ward / Higashi Mita, Tama Ward / Fuda, Tama Ward / Masugata, Tama Ward / Mita, Tama Ward / Minami Ikuta
・Trust Kakeru Koumuten for exterior wall painting in Kawasaki City, Tama Ward!
・Trust Kakeru Koumuten for roof renovations in Kawasaki City, Tama Ward!
・Trust Kakeru Koumuten for exterior renovations in Kawasaki City, Tama Ward!
・Trust Kakeru Koumuten for leak repairs in Kawasaki City, Tama Ward!
・Trust Kakeru Koumuten for waterproofing work in Kawasaki City, Tama Ward!
・Kakeru Koumuten Co., Ltd. construction achievements
・Kakeru Koumuten Co., Ltd. after maintenance
・Kakeru Koumuten Co., Ltd. construction menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of comparative estimates and key points!
・Top 12 solar power generation manufacturers! Features and selection tips included!
・What are the installation costs for solar power generation? Thorough explanation of tips to reduce costs!
・What are the best locations for installing solar power generation? Key points for site selection included!
・Here is the introduction to solar power generation estimates!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!
