Leave the installation of solar panels in Samukawa Town, Koza District, Kanagawa Prefecture to Kakeru Koumuten Co., Ltd.!
For solar panel and storage battery installation in
Samukawa Town, Koza District, Kanagawa Prefecture,
trust Kakeru Koumuten Co., Ltd.!
Kakeru Koumuten Co., Ltd. is a company specializing in exterior renovations based in Aoba Ward, Yokohama City.
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 Samukawa Town”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Samukawa Town”
We will also explain the above three points!
Installing solar panels carries risks, such as “the occurrence of leaks” and other troubles.
To ensure a satisfactory solar panel installation, we recommend obtaining about three estimates!
Table of Contents (tap to open/close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Samukawa Town, Koza District, Kanagawa Prefecture
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Samukawa Town
- 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 Samukawa Town, Koza District, Kanagawa Prefecture
- 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 Samukawa Town
- If You Are Looking for a Solar Panel Installation Contractor in Samukawa Town, Contact Kakeru Koumuten
- Characteristics of Samukawa Town, Koza District, Kanagawa Prefecture, and Points for Solar Construction
- Service Area in Samukawa Town, Koza District, Kanagawa Prefecture
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Samukawa Town, Koza District, Kanagawa Prefecture
The reasons why we are entrusted with solar panel installation by customers in Samukawa Town, Koza District, Kanagawa Prefecture include
one reason being that Kakeru Koumuten has a base in Kanagawa Prefecture,
and we have strengths in solar panel installation that cannot be imitated by other companies, which have received high praise from many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We Can Also Handle Exterior Renovations Other Than Solar Panel Installation!
Troubles such as leaks caused by solar panel installation may be due to insufficient checks on the roof and waterproofing at the installation site.
Even if you are knowledgeable about solar panels, there 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 expertise in roofing to avoid maintenance issues and troubles after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can perform solar panel removal and installation in-house, allowing for quick responses to maintenance and urgent troubles after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide low-cost, high-quality solar work and exterior renovations.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding depending on the construction conditions and can assemble scaffolding in-house.
By not outsourcing scaffolding work and using our own scaffolding team, we can also reduce the costs of scaffolding work.
We own scaffolding materials for approximately 50 single-family homes!
Even in Samukawa Town, where flat residential areas extend from low-lying areas along the Sagami River to plateaus, our in-house scaffolding team will plan scaffolding according to the local conditions.
Storage of Materials in Our Large In-house Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we canrespond quickly in emergencies!
In-house sorting and transportation of waste materials
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut 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!
We can also provide simulations of potential earnings and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany renovations, we also have samples of roofing materials and models that show the structure, allowing us to provide 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 manage 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 handle everything from the estimate to project completion.
Since the same person will be in charge, whether in sales or construction management, smooth communication is possible.
We can provide consistent in-house construction from temporary scaffolding installation, exterior wall painting, to roof renovations!
4. Various Permits and Skilled Workers
We have obtained construction industry licenses and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal workers and painting specialists, and we are confident in our construction techniques.
We can also handle large-scale roof projects for factories and other facilities!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation, we also provide our own construction warranty (leakage warranty)!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless 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.
If you cannot access the roof due to height, we can utilize drones to assist!
During leak investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of solar panels decreases due to dirt or other factors, we can provide cleaning with a specialized brush.
We will respond according to your wishes.
7. Human Resource Development
To improve skills, we create various roofing models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly conduct technical training so that each staff member can handle various cases.
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 panel 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 panel installations will receive materials that clearly summarize important points and disadvantages!
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 “Is it okay to install them directly on the current roof?” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, which specializes in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing material, such as slate, tiles, metal roofs, and flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest roof renovation first. |
| 2. Condition of Substrate and Waterproof Sheet | If the sheathing boards or roofing (waterproof sheet) under the roofing material are damaged, it will affect the fastening strength and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, Slope, and Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, will affect the amount of power generated. We will create a layout diagram from the drawings and the site, and you can confirm it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels that can be installed (installation capacity) is determined by the shape and size of the roof. Since the number of panels that can be installed varies depending on the panel size, we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will check whether the method involves drilling holes in the roofing material for fixing or using brackets to secure the roofing material. The fixing method varies by technique, so please confirm the waterproofing treatment 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-bearing capacity, switching to lighter roofing materials may also be an option if necessary. |
| 7. Installation Location of Equipment and Wiring | We will confirm the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect costs. |
Fixing Methods and Confirmation Points by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproofing of fixed parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay 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 lighter 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 is strong 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 Samukawa Town, Koza District, Kanagawa Prefecture
Potential Subsidies and Grants in Samukawa Town, Koza District, Kanagawa Prefecture
If you introduce solar panels or storage batteries in Samukawa Town, you may be eligible for programs from the “National Government,” “Kanagawa Prefecture,” and “Samukawa Town”.
The following information is based on the official pages of each program as of October 6, 2026. The application status may change depending on budget and recruitment periods, 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 |
|---|---|---|---|
| Samukawa Town “Zero Carbon Promotion Equipment Installation Subsidy” (Solar Power Systems, Storage Batteries, etc.) | Individuals registered as residents in the town, with no tax arrears, and who have a Samukawa Pay account. Solar power systems must be unused items listed in the JPEA registration list with an output of less than 10kW, and storage batteries must be unused products registered with SII. Applications are to be made after installation. | Solar Power: 50,000 points per system (100,000 points for ZEH certified homes) Storage Battery: 50,000 points per unit (Granted as administrative points through Samukawa Pay) |
Installation/Purchase Period: February 16, 2026 – February 15, 2027 Application Period: April 1, 2026 – March 16, 2027 Applications will close once the total points (initially 5 million points for Reiwa 8) are reached. |
| Kanagawa Prefecture “Reiwa 8 Year Kanagawa Prefecture Residential Solar Power and Storage Battery Installation Subsidy” | For single-family homes or multi-family residences in the prefecture, it is required to install both solar power and storage batteries in homes that ensure seismic performance. Applications must be made by the individual, and construction can begin after the grant decision. | Solar Power: 70,000 JPY/kW Storage Battery: 150,000 JPY/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 applications. |
| National “DR Home Storage Battery Project” (Reiwa 7 Year Supplement) | Newly install home storage systems that can be used for DR (demand response) with registered products. | 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). | Applications have closed as of May 29, 2026, when the budget was reached (currently, applications cannot be made). |
| 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 renovation of windows (openings) and the structure; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 JPY/unit | Applications will close once the budget limit is reached. Please check the official site for application status. |
| Kanagawa Prefecture “Reiwa 8 Year Kanagawa Prefecture Self-Consumption Type Renewable Energy Installation Subsidy” | Corporations and individuals filing blue returns (individual residences are not eligible). Solar power must have an output of 10 kW or more, for business facilities, and equipment not certified under FIT/FIP. | Solar Power: 80,000 JPY/kW, etc. Storage System: 50,000 JPY/kWh (maximum 5 million JPY) |
Applications closed on September 3, 2026 (when the application amount reached the budget). |
As of October 6, 2026, the subsidies in Samukawa Town are still within the application period, but applications will close once the total points are reached. The housing subsidies in Kanagawa Prefecture have passed the application deadline for the second period of Reiwa 8, and the national DR home battery project has also ended its public offering. The town’s subsidy is a system where applications are made after installation, while the prefectural housing subsidy requires construction to start after receiving “grant approval”, which means the order of procedures differs. If the order is incorrect, it may result in ineligibility, and applying does not guarantee approval, so please confirm before contracting and starting construction.
At Kakeru Koumuten Co., Ltd., we will guide you on the eligibility conditions for each system after confirming them.
Samukawa Town “Zero Carbon Promotion Measures Equipment Subsidy” (Solar Power Systems, Batteries, etc.)
In Samukawa Town, the “Zero Carbon Promotion Measures Equipment Subsidy” is implemented for those who install solar power systems, batteries, and Ene-Farm in residential properties within the town. Starting from Reiwa 7, the subsidy is provided not in cash but through administrative points via the Samukawa Pay app, and conditions include being an individual registered as a resident in the town, having no delinquent town taxes, and possessing a Samukawa Pay account.
For the points in Reiwa 8, solar power systems receive 50,000 points per set (100,000 points for ZEH certified homes), and batteries receive 50,000 points per unit. Solar power systems must be unused products listed in the JPEA registration list with an output of less than 10kW, and batteries must be unused products registered in the SII battery system.
The installation and purchase period is from February 16, 2026, to February 15, 2027, and the application period is from April 1, 2026, to March 16, 2027, with applications made after installation. Applications will close once the initial points of 5 million are reached in Reiwa 8, so please check the latest application status on the town’s official page.
👉 Click here for the official page of Samukawa Town
National Subsidy “DR Home Battery Project (Support Project for the Introduction of Home Battery Systems for DR Resource Introduction)”
The national government has been implementing the “DR Home Battery Project” to support the installation of home batteries.
This project targets those who introduce new registered products of battery systems that can be utilized for demand response (DR), and in the Reiwa 7 supplementary budget, the subsidy amount was determined based on a standard amount of 34,500 JPY per initial effective capacity of 1kWh, with a subsidy rate of up to 3/10 and a maximum of 600,000 JPY per application. There are also conditions such as excluding contracts and orders made before grant approval.
However, the Reiwa 7 supplementary budget applications reached the budget on May 29, 2026, and the public offering has ended (the previous year’s Reiwa 6 supplementary budget also ended its public offering on July 2, 2025). Applications are currently not possible, so please check the official site for future public offerings.
Currently, there are no subsidies confirmed by the government specifically for the installation of solar panels on existing homes.
👉 Click here for the official site of the DR Home Battery Project
Kanagawa Prefecture “Reiwa 8 Year Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Installation Subsidy”
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 subsidy amount would be calculated as 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 are not allowed). Additionally, the eligible homes must ensure seismic performance. Please check as the eligibility for combining with other subsidy programs may vary by program.
For Reiwa 8, the first phase (May 11 to June 30) and the second phase (September 7 to September 30, first-come-first-served) have been conducted, and the second phase is now closed. For future recruitment, please check the official page of Kanagawa Prefecture.
👉 Click here for the official page of Kanagawa Prefecture
Kanagawa Prefecture “Reiwa 8 Year Kanagawa Prefecture Self-Consumption Type Renewable Energy Installation Subsidy” (for businesses)
Kanagawa Prefecture also offers subsidies for businesses that install “self-consumption type” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and installations in individual homes are not eligible.
Conditions include that the solar power generation must have an output of 10kW or more and supply electricity to business facilities within the prefecture, and the equipment must not be 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).
For Reiwa 8, applications were closed on September 3, 2026, as the application amount reached the budget amount.
Businesses considering the installation of solar panels on commercial buildings in Samukawa Town should check the official page of Kanagawa Prefecture for the next recruitment.
👉 Click here for details
Solar Panel Installation & Storage Battery Installation Price List
⇧Service Menu | For Costs of Solar Panel Installation and Battery Installation, Click Here
⇧Service Menu | For Costs of Solar Panel Removal and Hot Water Heater Removal, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and batteries should be checked 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, equipment grade, and roof condition.
Considerations for Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatts). The battery is compared in terms of the amount of electricity it can store, represented in kWh (kilowatt-hours).
The amount of kW that can be installed on the roof varies for each house based on the roof’s shape, orientation, and size. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panels as approximately 800,000 JPY to 1,200,000 JPY for 3 to 5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6 to 10 kW. (These are just estimated amounts and can vary based on wiring length, scaffolding range, existing roofing materials, panel layout, etc.)
▶ Service Menu | For Costs of Solar Panel Installation and Battery Installation, Click Here
Items to Confirm in the Estimate (Cost Confirmation)
When comparing prices in multiple estimates, it is common to compare items with different capacities and equipment. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) should be listed. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also confirm whether it is a type that controls the battery together. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range usable during power outages (whole house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of the hardware suitable for the roofing material and the method of securing it (whether it is a method that drills holes or a method that clamps to secure). |
| 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 the fixed points, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | How much support is included for applications to the power company, certification applications for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If roof work and exterior painting are done simultaneously, check that the same scope and quantity are not double counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters and old panels, as well as disposal costs for waste materials, are included. |
| 10. Tax Classification and Warranty | Whether prices are tax-inclusive or tax-exclusive, conditions under which additional costs may arise, and details and duration of manufacturer and workmanship warranties. |
If the capacities are different, both the price and power generation will change. Kakeru Koumuten Co., Ltd. welcome multiple 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 Testimonials
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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 |
| Base Mounting Hardware Used |
| Niigata Manufactured Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed by gripping the horizontal metal roof with catch type hardware (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Expected recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction and may differ under the current system. |
| Construction Period |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that grants are available, and I would like to know how much will be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of the grant, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Samukawa Town, Koza District, Kanagawa Prefecture
There are many solar panel installation contractors available in Samukawa Town, Koza District, Kanagawa Prefecture, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and battery storage installation work, be sure to check the following 4 points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the existence of warranties and aftercare services
● Obtain estimates from multiple 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.
Have knowledge not only about solar panels but also about roofs
Defective installation of solar panels can be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient verification of roofs and waterproofing
・ Solar panels were installed on a severely deteriorated roof, leading to leaks
・ Solar panels were installed on a roof with a short lifespan, requiring renovations to detach and reattach the solar panels within a few years
・ Misjudgment of the type of waterproofing led to incorrect processing and subsequent leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unforeseen troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” within this article
Confirm the existence of warranties and aftercare services
When choosing a solar installation contractor, be sure to check for warranties. It is important to confirm not only the duration of the warranty but also the scope of coverage, disclaimers, and cost conditions.
While the solar panels and battery storage units come with manufacturer warranties, also check for the existence of workmanship warranties in case leaks occur after installation!
For contractors that offer workmanship warranties, if leaks occur after installation, they may be able to respond under warranty, provided it is within the warranty period and conditions.
Additionally, some contractors offer after-sales service separate from warranties, so be sure to check if the contractor you are considering has after-sales service.
Since abnormalities or damage on the roof can occur in areas that are not visible, there is a possibility that customers may not notice them themselves.
By conducting inspections of these hidden areas during after-sales 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-sales maintenance and send out DM every year!
If you check the DM and wish to proceed, we will visit for after-sales maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting the installation of solar panels, 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-sales services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request services from your preferred contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates,
“Check the items in the estimate”
“Type of solar panel”
“Warranties and after-sales services”
and make detailed comparisons for your judgment! If the quality of the auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid judging solely based on price!
▶ Go to “Breakdown of installation capacity, equipment, and construction costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for the installation of solar panels and storage batteries, 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 Kanagawa Prefecture’s housing subsidies, where contractors cannot apply on behalf of the client and personal application is required, 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 prefectural housing subsidy, this means obtaining a grant decision) before proceeding with the construction!
For 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)
▶ To “Subsidies and Grants That May Be Applicable in Samukawa Town” in this Article
Benefits of Introducing Solar Equipment
The benefits of introducing solar panels are summarized in the following 5 points!
Benefit 1: Economic Benefits
The biggest benefit of introducing solar panels is the economic advantage!
Although the selling price of electricity has decreased compared to 10 years ago, you can gain benefits by reducing the electricity you buy from power companies by consuming the electricity you generate!
As electricity prices rise, the ability to cover your consumption with solar power becomes attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
For residential use (under 10kW), the selling price (FIT) will be set at “24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year” for certifications after October 2025, and the same price will apply for the 2026 fiscal year. After the 5th year, it is likely to be more advantageous to use it in your home (self-consumption) rather than selling it, making the combination with a storage battery a viable option.
👉 Ministry of Economy, Trade and Industry | For purchase prices, periods, etc., click here
Benefit 2: You Can Utilize Subsidies!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
Reducing the actual burden amount through subsidies is a significant advantage!
In the case of Samukawa Town, there may be systems available from the national government, Kanagawa Prefecture, and Samukawa Town. The town’s grant system requires an application after installation, and you can check the status of points on the town’s official page.
Benefit 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 such as power conditioners may have operational noise.)
Benefit 4: Heat Insulation Effects Are Expected!!
By installing them on the roof or rooftop, the panels block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the temperature of the roof, providing expected heat insulation effects!
(Note that this does not improve the building’s insulation performance itself.)
Benefit 5 Power usage is possible 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 functionality, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration available 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 remodeling 10 to 20 years later, there will be costs for removing and reinstalling the solar panels.
If the existing roof is deteriorated, it is reassuring to remodel it with durable roofing materials before installing the solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to 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 parts is 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 fasteners, and it cannot be used with all metal roofs.)
Catch-type base hardware for horizontal metal roofs
Point 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load capacity, switching to a lightweight roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “This manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
Choosing Method 1: Compare based on total roof output
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and the more power generated, the better!
Solar panels come in various sizes and outputs depending on the manufacturer.
A panel with 350W output and a panel with 400W output may seem like the higher output panel is better at first glance.
However, if the size of the panel does not fit well on the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different installation capacities on the same roof due to the size difference.
400W × 15 panels = 6kW (total output of the roof)
350W × 20 panels = 7kW (total output of the roof)
As shown above, even if the output of one panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above calculations are for total output (kW). The actual power generation (kWh) will vary depending on conditions such as roof orientation, slope, and shading.
Choosing Method 2: Compare based on degradation rate of solar panels
Solar panels have a degradation rate, and their output gradually decreases over 10 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 itself.
By considering the degradation rate as well as the initial output, you can choose solar panels without regrets!
Choosing Method 3: Compare based on warranty period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
For output warranties, some manufacturers offer a 30-year warranty while others provide 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 Samukawa Town
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Samukawa Town. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Samukawa Town, Kanagawa Prefecture?
The cost varies depending on the installation capacity, equipment, and condition of the roof. In the above case study (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines for different capacities are published on the solar panel installation and storage battery installation pricing page. We will create a layout diagram based on the drawings and on-site survey, and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Samukawa Town?
As of October 6, 2026, the “Zero Carbon Promotion Measures Equipment Installation Subsidy” in Samukawa Town has an application period from April 1, 2026, to March 16, 2027, and will close once the total points are reached (50,000 points for one set of solar power generation, 50,000 points for one storage battery). The Kanagawa Prefecture subsidy (70,000 yen/kW for solar power, 150,000 yen/unit for storage batteries) is approaching the application deadline for the second term of fiscal year 2026, and the national DR household storage battery program has ended its public recruitment. Please check each official page for future applications.
Since the application status may change, please refer to the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies after the construction is completed?
For many programs, procedures are required before construction. The subsidy in Samukawa Town allows for “application after installation” (installation must be completed within the installation period and application must be made within the application period), while the Kanagawa Prefecture subsidy requires “construction to start after the grant decision,” which may differ by program. If the order is incorrect, you may be excluded from eligibility.
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 suggest methods such as roof overlay (cover method) or replacement if deterioration is advanced.
The 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 yen/kWh after the fifth year, making it more advantageous to use it in your home rather than selling it.
Additionally, the subsidy from Kanagawa Prefecture requires the simultaneous introduction of solar panels and storage batteries. The town’s grants apply to both solar panels and storage batteries as eligible equipment. 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 installable capacity 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.
While Samukawa Town has many residential areas with flat terrain, the shading from neighboring houses, trees, and utility poles varies from house to house. You can check the expected power generation through the power generation simulation.
How long will the construction take?
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 done simultaneously or depending on the shape of the roof and installation capacity.
Please note that additional time is required for applications for subsidies and power companies, 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 four years will be 24 yen/kWh, and from the fifth to the tenth year, it will be 8.3 yen/kWh, with the same price applicable for the fiscal year 2026.
The idea is to recover the initial costs quickly in the first four years and focus on self-consumption thereafter. Kakeru Koumuten provides a financial simulation that considers 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 request inspections. We can also clean solar panels using specialized brushes 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 renovate a roof that already has solar panels installed?
Yes, we can. Since Kakeru Koumuten can remove and reinstall solar panels in-house, 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 company in Samukawa Town, please consult Kakeru Koumuten
Our company handles many exterior renovations, including solar panels, roof work, and exterior wall work in Samukawa Town, Koza District, Kanagawa Prefecture.
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 great feedback from numerous customers.
We continue to update our construction performance every year, and we will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, including roof overlay work, roof replacement work, partial roof repairs, exterior painting, and exterior cover methods, all by our own team.
We are also happy to handle small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leak repairs, we may be able to provide emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult us!
“I want to know about recommended solar panels”, “I want to keep costs down as much as possible”, “I just want an estimate for now”, we will provide the best solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in the customer’s position and will propose the best construction plan!
We are confident that we will not lose in terms of cost, quality, and organization compared to other companies in exterior work!
We are confident, so we welcome competitive estimates!
Estimates are completely free, and if our company is inferior to others, you are free to decline!
Characteristics of Samukawa Town, Koza District, Kanagawa Prefecture and Points for Solar Work
Samukawa Town is located on the left bank of the Sagami River, and the official page of the town introduces its area as 13.42 km², with an elevation of about 5 to 27 meters, featuring a mostly flat terrain. The eastern side is the southwestern part of the Sagamino Plateau, while other areas are lowlands created by the river, with residential areas and fields on the plateau and rice fields and residential areas in the lowlands.
Below are the characteristics of Samukawa Town and points to consider when installing solar panels and storage batteries. (Tap to open)
View the characteristics of Samukawa Town and points for solar work
■ Flat residential area. Shadows are mainly caused by buildings, trees, and utility poles
Overview of Samukawa Town (Official Town Site) describes the town as having a nearly flat terrain with an elevation of about 5 to 27 meters. While shadows from elevation differences are less likely to occur, the way shadows are cast by neighboring houses, garden trees, utility poles, and roof shapes varies from house to house. At Kakeru Koumuten, we create layout diagrams based on the blueprints and the actual site conditions, allowing you to check with a power generation simulation.
■ In lowlands created by rivers, confirm the installation location of equipment
Except for the eastern side of the town, it is considered to be lowlands created by three rivers. When deciding on the installation location for batteries and power conditioners, it is reassuring to check the flood risk for your residence on a hazard map. We will propose installation locations considering wiring routes and ease of inspection.
■ In locations close to the Sagami River, confirm the specifications of the equipment
Samukawa Town is located on the left bank about 6 km upstream from the mouth of the Sagami River. If you live in a location close to the sea or a river, it is reassuring to check the environmental conditions for the installed equipment (such as measures against salt damage) according to the manufacturer’s specifications. Please consult us regarding waterproofing treatments for fixed parts and roofing work.
■ Town subsidies are applied for after installation. Check the status of point acceptance
Subsidy for Zero Carbon Promotion Equipment Installation in Samukawa Town (Official Town Site) will close acceptance once the total number of points granted by the town is reached. The order of application differs from the prefectural subsidies (construction must start after the grant decision), so it is important to check in advance in conjunction with the timing of the construction.
■ Check the roof condition according to the age of the building
For houses that have been built for many years, it is important to check for damage to roofing materials and substrates before installing solar panels. Depending on the condition of the roof, installing them simultaneously with roof renovations can reduce future costs for removing and reinstalling solar panels.
■ Be mindful of roof dirt such as fallen leaves and dust
If dirt such as fallen leaves and dust accumulates on the roof, it may affect the power generation capacity. Kakeru Koumuten can also handle cleaning solar panels with specialized brushes and rain gutter cleaning.
Our company is based in Kanagawa Prefecture and has handled many exterior construction and solar projects in Samukawa Town.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us for any sudden troubles!
Service Area in Samukawa Town, Koza District, Kanagawa Prefecture
Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and Tokyo.
List of Areas in Samukawa Town, Koza District, Kanagawa Prefecture
Ichinomiya, Samukawa Town / Okura, Samukawa Town / Oomagari, Samukawa Town / Okada, Samukawa Town / Kurami, Samukawa Town / Kotani, Samukawa Town / Kodou, Samukawa Town / Tabata, Samukawa Town / Nakase, Samukawa Town / Miyayama, Samukawa Town
・Exterior wall painting in Samukawa Town, Koza District, Kanagawa Prefecture is entrusted to Kakeru Koumuten Co., Ltd.!
・Roof renovation in Samukawa Town, Koza District, Kanagawa Prefecture is entrusted to Kakeru Koumuten Co., Ltd.!
・Exterior renovation in Samukawa Town, Koza District, Kanagawa Prefecture is entrusted to Kakeru Koumuten Co., Ltd.!
・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 points are also introduced!
・What are the installation costs for solar power generation? Thorough explanation of tips to reduce costs!
・What are the suitable locations for installing solar power generation? Key points for selecting installation locations are also introduced!
・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!
