Leave the installation of solar panels in Samukawa Town, Koza District, Kanagawa Prefecture to Kakeru Koumuten Co., Ltd.!
For solar panel and battery installation in
Samukawa Town, Koza District, Kanagawa Prefecture,
Kakeru Koumuten is your trusted choice!
Kakeru Koumuten is a specialized exterior renovation company headquartered in Aoba Ward, Yokohama City.
As a company strong in roofing work, we are entrusted withsolar panel and battery installation considering roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Samukawa Town”
“Costs for Solar Panel and 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 avoid regrets, we recommend obtainingthree 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 our company is 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 unique strengths in solar panel installation that cannot be imitated by other companies, which has 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!
Problems such as leaks that occur during solar panel installation may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if you are knowledgeable about solar panels, there 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 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 organized the following warehouses and material storage areas to provide low-cost, high-quality solar and exterior renovation work.
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 and can assemble the scaffolding ourselves.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also cut costs on scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
In Samukawa Town, where flat residential areas extend from lowlands along the Sagami River to plateaus, our in-house scaffolding team will plan the scaffolding according to the site conditions.
Storage of materials in our large warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, we canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we canrespond quickly in emergencies!
In-house separation 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 separating and recycling waste materials, we can significantly cut waste disposal costs.
Exterior remodeling dedicated showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on the roofing materials!
It is also possible to simulate the revenue and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also provide samples of roofing materials and models that illustrate 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 maintaining a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof renovations at reduced costs.
Additionally, one representative will handle everything from the estimate to project completion.
Since the same person will manage sales and construction, smooth communication is possible.
We can perform consistent in-house work from temporary scaffolding installation to exterior wall painting and roof renovations!
4. Various Permits and Skilled Workers
We have obtained construction industry permits and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal and painting technicians on staff, and we are confident in our construction techniques.
We can also handle large-scale roofing projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty, our solar panel installation work comes with our own workmanship warranty (leakage warranty)!
(The workmanship warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovation is performed. The workmanship warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty details.)
Aftercare maintenance is available every year, and we send out annual notification DM.
If you have any questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roof troubles and situations.
Even if we cannot access the roof at high places, we can respond using a drone!
During leakage investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of the solar panels decreases due to dirt, we can also provide cleaning with a specialized brush.
We will respond according to the customer’s wishes.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly conduct skill enhancement education so that each staff member can handle various cases.
8. Creation of Easy-to-Understand 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.
We compile easy-to-understand materials that include important points and disadvantages for customers who may not be familiar with solar installations!
We encourage you to obtain comparative estimates and review plans from other companies!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 to 30 years.
Confirming “whether it is okay to install them directly on the current roof” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, which specializes in roofing work, has summarized the items to check before installation.
| 1. Type of roofing material and age | The method of securing 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 installed depends on the shape and size of the roof. The number of panels that can be installed varies depending on the size of the panels, so we compare based on the total output of the roof. |
| 5. Fixing method 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 fixing method varies by technique, so please confirm the waterproofing treatment of the fixed parts at the time of estimation. |
| 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 also be an option if necessary. |
| 7. Location of equipment installation and wiring | We check the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring also affects costs. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | 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 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 frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you renovate the roof 10 to 20 years after installation, there will be additional costs for removing and reinstalling 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 Samukawa Town, Koza District, Kanagawa Prefecture
PotentialSubsidies and Grants
If you introduce solar panels or storage batteries in Samukawa Town, there is a possibility of being eligible for the systems from “the national government,” “Kanagawa Prefecture,” and “Samukawa Town.”
The following information is based on the official pages of each system as of October 6, 2026. The application status may change depending on the budget and application period, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Samukawa Town “Zero Carbon Promotion Measures Equipment Subsidy” (Solar Power Systems, Storage Batteries, etc.) | Individuals registered as residents in the town, with no delinquent town taxes, and who have a Samukawa Pay account. Solar power systems must be unused items listed on 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 set (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 recruitment. |
| National “DR Home Storage Battery Project” (Reiwa 7 Year Supplement) | Newly introducing home storage systems that can be utilized for DR (demand response) with registered products. | Calculated based on a standard amount of 34,500 JPY per initial effective capacity of 1 kWh (subsidy rate within 3/10; maximum 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 Renewable Energy Installation Subsidy” | Corporations and individual business owners filing blue returns (individual residences are not eligible). Solar power must have a generation 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 (application amounts reached the budget). |
As of October 6, 2026, the subsidy for Samukawa Town is still in the application period, but it will close once the total number of points is reached. The Kanagawa Prefecture housing subsidies have passed the application deadline for the second period of Reiwa 8, and the national DR household storage battery project has also ended its public recruitment. 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 is different. If the order is incorrect, it may result in ineligibility, and applying does not guarantee that the grant will be awarded, so please confirm before contracting or starting construction.
At Kakeru Koumuten Co., Ltd., we will guide you on eligibility conditions for each system after confirming them.
Samukawa Town “Zero Carbon Promotion Measures Equipment Installation Subsidy” (Solar Power Systems, Storage Batteries, etc.)
Samukawa Town is implementing the “Zero Carbon Promotion Measures Equipment Installation Subsidy” for those who install solar power systems, storage batteries, EneFarm, etc., in residential homes 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 delinquency in 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 storage batteries receive 50,000 points per unit. Solar power systems must be unused products listed on the JPEA registration list with an output of less than 10kW, and storage batteries must be unused products registered with SII’s storage 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. The application will close once the initial 5 million points for Reiwa 8 are reached, 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 Household Storage Battery Project (Support Project for Household Storage System Introduction for DR Resource Introduction)”
The national government has been implementing the “DR Household Storage Battery Project” to support the installation of household storage batteries.
This project targets those who are introducing new registered storage 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 kWh of initial effective capacity, with a subsidy rate of up to 30% and a maximum of 600,000 JPY per application. There are conditions such as that contracts or orders made before grant approval are not eligible.
However, the Reiwa 7 supplementary budget applications reached the budget on May 29, 2026, and public recruitment has ended (the previous year’s Reiwa 6 supplementary budget also ended public recruitment on July 2, 2025). Applications are currently not possible, so please check the official site for future public recruitment.
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 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 not be eligible, and the application must be made by the individual (applications by contractors on behalf are not allowed). The eligible homes must also ensure seismic performance. Please check each subsidy program for compatibility with other subsidy systems, as this may vary.
In Reiwa 8, the first application period (May 11 – June 30) and the second application period (September 7 – September 30, first-come-first-served) were held, and the second period has reached its application deadline. 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 from solar panels.
Eligible applicants are corporations or individual business owners who file 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, supply power to business facilities within the prefecture, and not be a facility 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 storage system installed together (with a maximum of 5 million yen).
In Reiwa 8, applications reached the budget limit, and recruitment was closed on September 3, 2026.
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 Related to Solar Panel and Battery Installation, Click Here
⇧Service Menu | For Costs Related to 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 confirmed by separating them into “Equipment Costs (Device Costs)” and “Construction Costs.”
Even for the same “Complete Solar Panel Installation,” the amount can vary greatly depending on the installation capacity, equipment grade, and roof condition.
Understanding 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 (kilowatt). Batteries are compared in terms of the amount of electricity they can store, measured in kWh (kilowatt-hour).
The amount of kW that can be installed on a roof varies for each house based on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panels priced at 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 may vary based on wiring length, scaffolding area, existing roofing materials, panel layout, etc.)
▶ Installation Menu | Costs for Solar Panel Installation and Battery Installation
Items to Check in the Estimate (Cost Confirmation)
When comparing estimates, it’s common to compare different capacities and equipment. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) should be listed. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls in conjunction with the battery. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range of use 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 involves drilling holes or clamping). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, and whether there is a monitor to check the power generation amount. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at the fixed points, and whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | How much support is included for applications to the power company, feed-in tariff (FIT) certification applications, 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 water heaters and old panels, as well as disposal costs for waste materials, are included. |
| 10. Tax Classification and Warranty | Whether the price is tax-inclusive or tax-exclusive, conditions under which additional costs may arise, and details and duration of manufacturer and workmanship warranties. |
If the capacities differ, both the price and power generation will change. Kakeru Koumuten Co., Ltd. welcome comparisons, so if you bring estimates from other companies, we will explain the differences item by item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can get an estimated quote and income simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can obtain an estimated quote and income simulation!
*The simulation results are estimates. Actual income may vary depending on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection and 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 Installations
| Work Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh range |
| Base Mounting Hardware Used |
| Niigata Manufacturing / Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed by catching 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 Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that grants are available, and I would like to know how much will be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have understood the expected amount of the grant, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Samukawa Town, Koza District, Kanagawa Prefecture
There are many solar panel installation contractors serving Samukawa Town, Koza District, Kanagawa Prefecture, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and storage battery installation work, let’s check the following 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 contractors (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 contractor.
Knowledge about roofs as well as solar panels
Defective installation of solar panels can sometimes be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles due to 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 for removal and reinstallation within a few years
・Misjudging 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 unexpected troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the existence of warranties and after-sales maintenance
When choosing a solar installation contractor, confirm the existence of warranties. It is important to check not only the years of coverage but also the scope of coverage, disclaimers, and cost conditions.
Solar panels and storage batteries come with manufacturer warranties, but 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 the warranty, provided it is within the warranty period and conditions.
Additionally, some contractors offer after-sales service separate from the warranty, so be sure to check if the contractor you are considering has after-sales service.
Changes or damage on the roof may occur in areas that are not visible, so there is a possibility that customers may not notice them.
By conducting inspections of these hidden areas during after-sales maintenance, you can more easily prevent major repairs or failures by discovering issues early!
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, it may not be possible to provide a warranty without performing roof renovations.)
We also conduct after-sales maintenance and send out annual direct mail (DM)!
Please check the DM, and if you wish, we will visit you 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, please check:
“Verification of estimate items”
“Types of solar panels”
“Warranties and after-sales services”
and make a detailed comparison to make your judgment! If the rank of 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 the Kanagawa Prefecture housing subsidy, where the contractor cannot apply on your behalf 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!
In the case of the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the subsidy will be granted after a review! (The flow of procedures varies by system)
▶ To “Subsidies and Grants That May Be Applicable in Samukawa Town” within this Article
Benefits of Introducing Solar Power Systems
The benefits of installing solar panels are summarized in the following 5 points!
Benefit 1: Economic Benefits
The biggest advantage of installing solar panels is the economic benefit!
While the feed-in tariff for selling electricity has decreased compared to 10 years ago, you can gain benefits by reducing the amount of electricity purchased from power companies through self-consumption of generated electricity!
As electricity prices rise, the ability to cover consumption with solar power becomes increasingly attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
For residential use (less than 10kW), the feed-in tariff (FIT) for electricity sold 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 for the 2026 fiscal year. After the 5th year, it is often more advantageous to use the electricity at home (self-consumption), 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: Subsidies Can Be Utilized!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
Reducing the actual burden through subsidies is a significant advantage!
In the case of Samukawa Town, there may be programs available from the national government, Kanagawa Prefecture, and Samukawa Town. The town’s subsidy 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 like power conditioners do have operational noise.)
Benefit 4: Heat Insulation Effects Can Be Expected!!
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 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 that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1: Maintenance costs can be incurred
A particularly easy-to-overlook maintenance cost is for the roof where the solar panels are installed.
If you perform roof remodeling 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 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 ask for a simulation that considers maintenance costs before introducing solar panels!
Point 2: The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix hardware to the roofing material or substrate with screws, waterproofing of the fixed parts is crucial.
In methods that involve making holes in the roof, the risk of leaks inevitably arises.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and fixing the solar panels using the catch method is also an option. (The catch method has compatibility conditions between the roofing material and hardware, 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 capacity, replacing it with a lighter roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
Choosing Method 1: Compare based on total roof output
When installing solar panels on the roof, it is important to consider how much electricity can be generated in the limited area, and generating more electricity is always better!
Solar panels come in various sizes and outputs depending on the manufacturer.
If you compare a 350W output panel with a 400W output panel, at first glance, the panel with the higher output may seem better.
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 numbers of panels that can be installed on the same roof due to size differences.
400W×15 panels = 6kW (total output of the roof)
350W×20 panels = 7kW (total output of the roof)
As shown above, even if the output of one panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above calculations are for total output (kW). The actual electricity generation (kWh) will vary depending on conditions such as 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 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 electricity generation itself.
By considering the degradation rate along with 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 widely!
Since a longer warranty is generally better, let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar 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 the 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 from the drawings and on-site survey and provide a free estimate!
Are there any subsidies available for solar and storage battery installation in Samukawa Town?
As of October 6, 2026, Samukawa Town’s “Zero Carbon Promotion Measures Equipment Subsidy” 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 solar power system, 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 phase of the 2026 fiscal year, and the national DR household storage battery project 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 within the application period), while the Kanagawa Prefecture subsidy requires “construction to start after the grant decision,” which can vary by program. If the order is incorrect, you may be excluded from eligibility.
The order of procedures differs 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 fixing method varies by construction method, and if using a method that fixes brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is crucial.
Kakeru Koumuten Co., Ltd. is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation. If deterioration is progressing, we can also propose methods such as roof overlay (cover method) or complete replacement before installation.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed within 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with durable roofing materials before installation.
Please consult us about the installation process after checking the condition of the roof during the on-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 of 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 assistance applies 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 capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram based on the drawings and on-site survey, and we will provide you with the installation capacity and power generation simulation.
In Samukawa Town, there are many residential areas with flat terrain, but the shading from neighboring houses, trees, and utility poles varies from one house to another. You can check the expected power generation through the power generation simulation.
How long does the construction period take?
For the above construction example (solar panels 4.3 kW + storage battery), it took about 3 days. The duration may vary if roofing work is performed 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 as soon as possible.
What is the current selling price (FIT)?
For residential use (less than 10 kW), the selling price from certifications after October 2025 will be 24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year, and the same price will apply for the 2026 fiscal year.
The idea is to recover initial costs more 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 DM notifications and visits for inspections upon request from customers. We can also clean solar panels with a special brush if the power generation decreases due to dirt.
The roof is a place that is difficult to check by yourself, so if you have any concerns, please feel free to consult us.
Can you also handle renovations for roofs that already have solar panels installed?
Yes, it is possible. Kakeru Koumuten Co., Ltd. can detach and reattach solar panels in-house, allowing us to remove the panels, perform roof overlay (cover method) or re-roofing, and then reinstall them consistently. The removed panels can be stored in our own warehouse.
For costs, please refer to the solar panel detachment and water heater removal pricing page.
If you are looking for a solar panel installation contractor in Samukawa Town, please consult Kakeru Koumuten
Our company handles a wide range of exterior renovations, including roof work and wall work, in Samukawa Town, Koza District, Kanagawa Prefecture, including solar panel installations.
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 many customers.
We continue to update our number of completed projects each 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 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 optimal 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 be outdone in terms of cost, quality, and organization compared to other companies in exterior construction!
We welcome competitive estimates because we are confident!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Characteristics of Samukawa Town, Koza District, Kanagawa Prefecture and Points of Solar Construction
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 nearly flat terrain. The eastern side is part of the southwestern area of the Sagamino Plateau, while other regions are lowlands created by the river, with residential areas and fields on the plateau and rice paddies and residential areas in the lowlands.
We have summarized the characteristics of Samukawa Town and points to consider when installing solar panels and storage batteries below. (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) states that the town features a nearly flat terrain with an elevation of about 5 to 27 meters. While shadows due to elevation differences are less likely, the way shadows appear from neighboring houses, garden trees, utility poles, and roof shapes varies from house to house. At Kakeru Koumuten, we create layout diagrams based on blueprints and the actual site conditions, allowing you to confirm through power generation simulations.
■ In lowlands created by rivers, also check the installation locations of equipment
Except for the eastern side of the town, the area is considered lowlands created by three rivers. When deciding on the installation locations for storage 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, also check the specifications of the equipment
Samukawa Town is located about 6 km upstream on the left bank from the mouth of the Sagami River. If you live in a location near the sea or river, it is reassuring to check the environmental conditions for the installed equipment (such as salt damage areas) 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 reception
Subsidy for introducing zero-carbon promotion measures in Samukawa Town (official) will close reception once the total number of points granted by the town is reached. The order of application differs from the prefectural subsidies (construction must begin 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 homes that have been built for several 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 reattaching 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 power generation. Kakeru Koumuten can also handle cleaning solar panels with specialized brushes and rain gutter cleaning.
Our company is based in Kanagawa Prefecture and has undertaken 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 / Oogawa, Samukawa Town / Okada, Samukawa Town / Kurami, Samukawa Town / Kotani, Samukawa Town / Kodou, Samukawa Town / Tabata, Samukawa Town / Nakase, Samukawa Town / Miyayama, Samukawa Town
・For exterior wall painting in Samukawa Town, Koza District, Kanagawa Prefecture, trust Kakeru Koumuten Co., Ltd.!
・For roof renovations in Samukawa Town, Koza District, Kanagawa Prefecture, trust Kakeru Koumuten Co., Ltd.!
・For exterior renovations in Samukawa Town, Koza District, Kanagawa Prefecture, trust Kakeru Koumuten Co., Ltd.!
・Kakeru Koumuten Co., Ltd. project achievements
・Kakeru Koumuten Co., Ltd. aftercare services
・Kakeru Koumuten Co., Ltd. service menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of comparative estimates and key points!
・12 major manufacturers of solar power generation! Features and selection tips included!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
・What are the best locations for solar power installation? Key points for site selection included!
・Find out more about solar power generation estimates here!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!
