Leave Your Solar Panel Installation in Minamiashigara City, Kanagawa Prefecture to Kakeru Koumuten Co., Ltd.!
For solar panel and storage battery installation in
Minamiashigara City, Kanagawa Prefecture,
trust Kakeru Koumuten Co., Ltd.!
Kakeru Koumuten Co., Ltd. is a specialized exterior renovation company based in Aoba Ward, Yokohama City.
As a company strong in roofing work, we are entrusted with solar panel and storage battery installations considering roofs and waterproofing!
“How to Choose a Solar Panel Contractor in Minamiashigara City”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Minamiashigara City”
We will also explain the above three points!
Installing solar panels carries risks such as “the occurrence of leaks” and other troubles.
To ensure you do not regret your solar panel installation, we recommend obtaining estimates from about three companies!
Table of Contents (tap to open/close)
- Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Minamiashigara City, Kanagawa Prefecture
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Minamiashigara City
- 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 Installer in Minamiashigara City, Kanagawa Prefecture
- Benefits of Introducing Solar Equipment
- Points to Note When Introducing Solar Power Generation
- How to Choose Solar Panels
- Frequently Asked Questions About Solar and Storage Battery Installation in Minamiashigara City
- If You Are Looking for a Solar Panel Installer in Minamiashigara City, Contact Kakeru Koumuten
- Characteristics of Minamiashigara City, Kanagawa Prefecture and Points for Solar Construction
- Service Area in Minamiashigara City, Kanagawa Prefecture
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Minamiashigara City, Kanagawa Prefecture
The reasons our company is entrusted with solar panel installation by customers in Minamiashigara City, Kanagawa Prefecture include
one reason being that Kakeru Koumuten has a base in Kanagawa Prefecture,
and our unique strengths in solar panel installation that cannot be imitated by other companies, which have 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 Also Handle Exterior Renovations Besides 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 are cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have expertise in roofing to avoid maintenance issues and troubles after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent troubles after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has prepared the following warehouses and material storage areas to provide low-cost, high-quality solar and exterior renovation work.
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 hold the necessary scaffolding materials for temporary scaffolding according to construction conditions and can assemble scaffolding in-house.
By not outsourcing scaffolding work and using our own scaffolding team, we can also cut costs for scaffolding work.
We have scaffolding materials for approximately 50 houses!
Even in Minamiashigara City, which has a wide range of locations from hilly areas to flat residential areas, our in-house scaffolding team will plan the scaffolding according to the site.
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, you can purchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we can respond quickly in emergencies!
In-house separation and transportation of waste materials
The installation of solar panels often involves roofing work, resulting in various waste materials such as paint, wood, and metal.
By separating 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 installed on roofing materials!
We can also provide simulations for potential earnings and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also have samples of roofing materials and models that explain the structure, allowing for detailed explanations!
3.All work performed by our own team
One of Kakeru Koumuten’s major strengths is its complete in-house construction.
By 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 oversight, smooth communication is ensured.
We can provide consistent in-house construction from temporary scaffolding installation to exterior wall painting and roof renovations!
4. Various Permits and Skilled Workers
We have obtained permits for construction work and industrial waste collection and transportation!
We also have nationally certified sheet metal and painting technicians on staff, giving us confidence in our construction techniques.
We are capable of handling large-scale roof projects such as those for factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation, we also provide our own construction warranty (leakage warranty)!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, a roof renovation may be required to provide the warranty. The construction warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty details.)
Aftercare is available every year, and we send out notification DM each year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
If you 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, we can provide cleaning services using specialized brushes.
We will respond according to the customer’s wishes.
7. Human Resource Development
To enhance skills, we create various roofing models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training so that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
Kakeru Koumuten provides not only “estimates,” “layout diagrams,” and “power generation simulations”, but also a “solar installation guidebook” and a “profit and loss simulation” that takes into account loan interest rates and electricity costs.
The profit and loss simulation can be created for projected cumulative profits and losses over 20 to 30 years.
Even customers who are not familiar with solar installations will 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 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, specializing in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing materials such as slate, tiles, metal roofs, and flat roofs (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 size of the panels, we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will check whether the method involves drilling holes in the roofing material for fastening or using brackets to secure the roofing material. The fixing method varies by technique, so please confirm the waterproofing treatment method for the fixed 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. Location of Equipment Installation and Wiring | We will confirm the installation locations for the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect the cost. |
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) | Waterproof treatment of fixed 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 suited to the type of tile (even methods that do not drill holes in the tiles will fix to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lightweight roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a 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 Minamiashigara City, Kanagawa Prefecture
PotentialSubsidies and Grants
If you are introducing solar panels or storage batteries in Minamiashigara City, you may be eligible for programs from the “National Government,” “Kanagawa Prefecture,” and “Minamiashigara City”.
The following information is based on the official pages of each program as of October 6, 2026. The application status may change depending on the budget and recruitment 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 |
|---|---|---|---|
| Minamiashigara City “Global Warming Countermeasure Promotion Project Subsidy” (Solar Power Generation & Storage System) | Individuals residing in the city with no tax arrears. Must have applied for or received a grant decision for a subsidy project implemented by the national government or Kanagawa Prefecture by February 26, 2027. Work cannot commence before application. | Solar Power: 20,000 yen/kW (up to 100,000 yen) Storage System: 20,000 yen/kW (up to 50,000 yen) |
Applications accepted from June 1, 2026, to February 26, 2027 (by 4 PM) (first-come, first-served) As of September 18, 2026, the city’s official page indicates “Currently accepting applications.” |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Residential Solar Power Generation & Storage Battery Installation Subsidy” | For single-family homes or multi-family residences in the prefecture, must install both solar power generation and storage batteries in a seismically secure home. Applications must be made by the individual, and work can commence only after grant approval. | Solar Power: 70,000 yen/kW Storage Battery: 150,000 yen/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” (Supplementary Budget for Fiscal Year 2025) | Newly install home storage systems that can be utilized for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 1 kWh at 34,500 yen (subsidy rate within 30% and a maximum of 600,000 yen per application). | As of May 29, 2026, the budget has been reached, and public recruitment has ended (applications are currently not accepted). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | While storage batteries are one of the eligible facilities, they must be combined with essential works such as insulation renovations of windows (openings) and structures; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 yen/unit | Ends as soon as the budget limit is reached. Please check the official site for application status. |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Self-Consumption Renewable Energy Installation Subsidy” | Corporations and individuals 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 yen/kW, etc. Storage System: 50,000 yen/kWh (up to 5,000,000 yen) |
Recruitment ended on September 3, 2026 (application amounts reached the budget amount). |
In Minamiashigara City, the subsidy requires that you cannot start construction before applying, and it is a condition that you have applied for (or received a grant decision for) a subsidy project from the national government or Kanagawa Prefecture. For the housing subsidy from Kanagawa Prefecture, it is a condition that construction must start after receiving the “grant decision”, and starting construction beforehand may result in ineligibility. As of October 6, 2026, the application deadline for the second phase of the 2026 fiscal year has passed, and the public offering for the national DR home battery project has also ended, so it is important to check with the city office whether you meet the requirements for the city’s subsidy. It is not guaranteed that you will receive the grant just by applying, so please confirm before signing a contract or starting construction.
At Kakeru Koumuten Co., Ltd., we will guide you on the eligibility conditions for each system after confirming them.
Minamiashigara City “Global Warming Countermeasure Promotion Project Subsidy” (Solar Power Generation and Storage Systems)
Minamiashigara City provides subsidies for the introduction of ZEH, insulation renovations, EVs, solar power generation equipment, and storage systems. The subsidy for residential solar power generation and storage systems is available to individuals residing in the city, with the condition of no outstanding municipal taxes.
The subsidy amount is 20,000 yen per kW for solar power generation (up to 100,000 yen) and 20,000 yen per kW for storage systems (up to 50,000 yen). Applications are accepted from June 1, 2026, to February 26, 2027 (Friday) at 4:00 PM, and are processed on a first-come, first-served basis, either directly or by mail to the Environmental Division of the city hall.
You cannot start construction before applying, and it is also a condition that you have applied for or will apply for a subsidy project implemented by the national government or Kanagawa Prefecture by the deadline and received a grant decision. It is important to confirm the timing of construction and the order of applications before signing a contract.
👉 Click here for the official page of Minamiashigara City
National Subsidy “DR Home Battery Project (Support Project for the Introduction of Home Storage Systems for DR Resource Implementation)”
The national government has been implementing the “DR Home Battery Project” to support the installation of home storage batteries.
This project targets those who are newly introducing registered storage systems that can be utilized for demand response (DR), and in the fiscal year 2025 supplementary budget, the subsidy amount was determined based on a standard amount of 34,500 yen per initial effective capacity of 1 kWh, with a subsidy rate of up to 30% and a maximum of 600,000 yen per application. There are also conditions that exclude items contracted or ordered before the grant decision.
However, the supplementary budget for fiscal year 2025 reached its application amount on May 29, 2026, and the public offering has ended (the public offering for the previous fiscal year 2024 also ended on July 2, 2025). Applications are currently not possible, so please check the official site for future public offerings.
Additionally, there are currently no subsidies confirmed for the installation of solar panels on existing homes.
👉 Click here for the official site of the DR Home Battery Project
Kanagawa Prefecture “Reiwa 8 Fiscal 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” together 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 subsidy decision, it will be excluded, and the application must be made by the individual (applications by contractors on behalf are not allowed). The target homes must also ensure seismic performance. Regarding the combination with other subsidy programs, the eligibility may vary by program, so please be sure to check.
For the Reiwa 8 fiscal year, 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 Fiscal Year Kanagawa Prefecture Self-Consumption Type Renewable Energy Installation Subsidy” (for businesses)
Kanagawa Prefecture also provides subsidies for businesses that install “self-consumption type” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners who file blue returns, and installations in individual residences are not eligible.
Solar power generation must have an output of 10kW or more, supply electricity 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 of solar power generation and 50,000 yen per kWh for the accompanying storage system (with a maximum of 5 million yen).
As the application amount reached the budget amount for the Reiwa 8 fiscal year, applications were closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Minamiashigara City 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 Water Heater Removal, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and batteries should be checked by separating them into “Equipment Costs (Device Costs)” and “Construction Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.
Considerations for Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatts). Batteries are compared in terms of the amount of electricity they can store, expressed in kWh (kilowatt-hours).
The amount of kW that can be installed on a roof varies for each house based on the roof’s shape, orientation, and size. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panels as approximately 800,000 JPY to 1,200,000 JPY for 3-5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6-10 kW. (These are just approximate amounts and can vary based on wiring length, scaffolding range, existing roofing materials, panel layout, etc.)
▶ Service Menu | For Costs of Solar Panel Installation and Battery Installation, Click Here
Items to Confirm in the Estimate (Cost Confirmation)
When comparing estimates, it is common to compare different capacities and equipment. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW). |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also confirm if it is a type that controls in conjunction with a storage battery. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range of use during power outages (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Fittings | Name of the fittings suitable for the roofing material and the method of securing them (whether it is a method that drills holes or a method that clamps and secures). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, presence of a monitor to check power generation. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at the fixing 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 roofing work and exterior painting are done simultaneously, check that the same scope and quantity are not counted twice. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters and old panels, as well as disposal costs for waste materials, are included. |
| 10. Tax Classification and Warranty | Whether prices are tax-inclusive or tax-exclusive, conditions under which additional costs may arise, details and duration of manufacturer warranty and workmanship warranty. |
If the capacities are different, the costs and power generation will also change. Kakeru Koumuten Co., Ltd. welcome comparisons, so if you bring estimates from other companies, we will explain the differences for each item!
Self-Estimate and Profit and Loss Simulator for Solar Power Generation
With the simulator above,
you can obtain a rough estimate and a profit and loss simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can get a rough estimate and profit and loss simulation!
*The simulation results are approximate. Actual profits and losses may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection or replacement.
Customer Testimonials
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installations
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh range |
| Base Mounting Hardware Used |
| Niigata Manufactured / Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing 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 there are grants available, and I would like to know how much can 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 grant amount, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Minamiashigara City, Kanagawa Prefecture
There are many solar panel installation contractors available in Minamiashigara City, Kanagawa Prefecture, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and battery storage installation work, let’s confirm the following 4 points:
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the presence of warranties and after-sales maintenance
● Obtain estimates from multiple contractors (3 companies is a guideline)
● Check if they provide support for subsidy applications
By confirming the above 4 points, you will be able to choose a reliable contractor.
Knowledge of roofs as well as solar panels
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
・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 unforeseen troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the presence of warranties and after-sales maintenance
When choosing a solar installation contractor, confirm the presence of warranties. It is important to check not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While solar panels and battery storage come with manufacturer warranties, also check for the presence of a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may be able to respond under the warranty, provided it is within the warranty period and conditions.
Additionally, some contractors offer after-service separate from warranties, so be sure to check if the contractor you are considering has after-service.
Changes or damages on the roof may occur in areas that are not visible, so there is a possibility that customers may not notice them.
By conducting inspections in after-maintenance, even in areas that are not visible, you can more easily prevent major repairs or failures by discovering abnormalities 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, a roof renovation may be required to provide the warranty.)
We also conduct after-maintenance and send out DM every year!
Please check the DM, and if you wish, we will visit for after-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-services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request from your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates,
“Check the items in the estimate”
“Type of solar panel”
“Warranties and after-services”
and make detailed comparisons to make your judgment! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making decisions based solely on price!
▶ Go to “Breakdown of Installation Capacity and Equipment/Construction Costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
For systems like Kanagawa Prefecture’s housing subsidies, where the contractor cannot apply on your behalf and personal application is required, it is reassuring to have a contractor who can support you in preparing necessary documents and the flow of procedures.
Be sure to complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining the 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 be to undergo review before the grant is provided! (The flow of procedures varies by system)
▶ Go to “Subsidies and Grants That May Be Applicable in Minamiashigara City” within this article
Benefits of Introducing Solar Power Equipment
The benefits of introducing solar panels are summarized in the following 5 points!
Benefit 1: Economic Advantage
The biggest advantage of introducing solar panels is the economic benefit!
While the selling price of electricity has decreased compared to 10 years ago, you can gain benefits by reducing the amount of electricity purchased from the utility company by consuming the generated power yourself!
As electricity prices rise, the ability to cover your consumption with solar power becomes increasingly attractive!
If you plan to use the generated power at night, installing a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) 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 fiscal year 2026. 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 requirements, you may be able to utilize subsidies!
Reducing the actual burden amount through subsidies is a significant advantage!
In the case of Minamiashigara City, there may be subsidies available from the city and Kanagawa Prefecture, so please check the latest application status.
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 may have operational noise.)
Benefit 4: Heat Insulation Effect Expected!!
By installing the panels on the roof or rooftop, they block direct sunlight to the roof.
Especially in summer, it can help reduce the temperature rise of the roof, providing a heat shielding effect!
(Note that this does not improve the insulation performance of the building itself.)
Benefit 5 Electricity can be used even during power outages!!
If a storage battery is installed, it becomes possible to use electricity even during emergencies like power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capability, you may be able to use electricity from a dedicated outlet during daytime generation.
(The devices, output, and time that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1 Maintenance costs can be incurred
A particularly overlooked maintenance cost is for the roof where 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 consider maintenance costs in the simulation 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 becomes crucial.
If the method involves making holes in the roof, there will inevitably be a risk of leaks.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, one option is to replace the roofing material with a metal roof and secure the solar panels using the catch method. (The catch method has compatibility conditions between the roofing material and the fasteners, and it cannot be used with all metal roofs.)
Catch-type base metal fittings for horizontal metal roofs
Note 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load 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 consider how much power can be generated in a limited area, and it is always better to generate more power!
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 with the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different installation capacities on the same roof due to the size difference.
400W × 15 panels = 6kW (total output of the roof)
350W × 20 panels = 7kW (total output of the roof)
As shown above, even if the output of a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual power generation amount (kWh) will vary depending on conditions such as the roof’s 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 decline after long-term use varies by product. The manufacturer’s output warranty values are standard figures for guarantees and do not indicate the actual degradation rate or power generation amount.
By considering the degradation rate along with the initial output, you can choose solar panels without regrets!
Choosing Method 3: Compare based on warranty years
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty years vary by manufacturer.
For output warranties, some manufacturers offer a 30-year warranty while others offer a 10-year warranty, so it varies!
Longer warranties are better, so be sure to check the warranty years and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Minamiashigara City
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Minamiashigara City. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Minamiashigara City, Kanagawa Prefecture?
The cost varies depending on the installation capacity, equipment, and the condition of the roof. In the above case study (4.3kW solar panel + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines for different capacities are published on our solar panel and storage battery installation pricing page. We will create a layout diagram from the drawings and site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Minamiashigara City?
As of October 6, 2026, the “Global Warming Countermeasures Promotion Project Subsidy” in Minamiashigara City (20,000 yen/kW for solar power, up to 100,000 yen; 20,000 yen/kW for storage systems, up to 50,000 yen) is accepting applications on a first-come, first-served basis until February 26, 2027 (there are conditions such as having applied for national or Kanagawa Prefecture subsidy projects). The Kanagawa Prefecture subsidy (70,000 yen/kW for solar power, 150,000 yen per unit for storage batteries) is approaching the application deadline for the second phase of fiscal year 2026, and the national DR home storage battery project has ended its public recruitment.
Since the application status may change, please refer to the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies even after the construction is completed?
For many programs, procedures are required before construction. The subsidy in Minamiashigara City states that “work cannot begin before application,” while the Kanagawa Prefecture subsidy requires “work to commence after the grant decision,” meaning that if you install first, 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 when securing brackets to the roofing material or substrate, waterproofing treatment of the secured areas is crucial.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation and can suggest methods such as roof overlay 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!
Is it better to install a storage battery together with solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it at home rather than selling it.
Additionally, the subsidy in Kanagawa Prefecture requires the simultaneous installation of solar panels and storage batteries, while the subsidy in Minamiashigara City is contingent upon applying for national or Kanagawa Prefecture subsidy programs. You can consider a comparison of “solar only” and “solar + storage battery” through a financial simulation.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and site survey, and we will provide you with the installation capacity and power generation simulation.
In Minamiashigara City, about 70% of the area is forested, and the shadows cast by mountains, trees, neighboring houses, and elevation differences vary from house to house. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
In the above construction example (solar 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 4 years will be 24 yen/kWh, and from the 5th to the 10th year it will be 8.3 yen/kWh, and the same prices 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 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 wish to have inspections. We can also clean solar panels using a special brush if the power generation is reduced 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 contractor in Minamiashigara City, please consult Kakeru Koumuten
Our company handles many exterior renovations, including solar panel installations, roof work, and exterior wall work in Minamiashigara City, Kanagawa Prefecture.
We receive requests from a wide range of customers, including renovation companies and real estate agencies!
Kakeru Koumuten promises “high-quality renovations at low cost”, and we have received positive feedback from many customers.
We continue to update our annual construction achievements and will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay work and re-roofing but also partial roof repairs, exterior painting, and cover method for exterior walls.
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 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 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 are confident, so we welcome competitive quotes!
Estimates are completely free, and if you find our company to be inferior to others, feel free to decline!
Characteristics of Minamiashigara City, Kanagawa Prefecture, and Points for Solar Construction
Minamiashigara City is located at the western edge of Kanagawa Prefecture, surrounded by the Hakone outer mountains and the Ashigara mountain range, forming a fan-shaped terrain. According to the city’s official page, the area is approximately 77 km², with Mount Kintoki (elevation 1,212 m) as the highest peak, and flat land occupies part of the Ashigara Plain.
Below are the characteristics of Minamiashigara City and points to consider when installing solar panels and storage batteries. (Tap to open)
View the characteristics of Minamiashigara City and points for solar construction
■ The terrain is higher in the west and lower in the east. Check sunlight exposure for each residential location
Profile of Minamiashigara City (Official City Site) states that the city consists of a topographically low west and high east area made up of hilly terrain, plateaus, the river valleys of the Karikawa and Uchikawa, and the alluvial plains of the Sakawa River. The shadow cast by the surrounding terrain and buildings differs between homes near the mountains and those in the plains. In locations close to the mountains, the sun exposure in the morning and evening may be affected by the mountains and trees depending on the direction, so we will consider the roof orientation and surrounding environment on-site before deciding on the panel layout.
■ About 70% of the city is forested. Consideration for tree shadows and debris from leaves and branches
The official city page (What Minamiashigara is Like) introduces that about 70% of the city is forested, with designated conservation forests primarily consisting of water source forests. In homes surrounded by greenery, the shadows of garden trees and adjacent trees can affect power generation, and leaves and branches are likely to accumulate on the roof. Kakeru Koumuten Co., Ltd. creates layout diagrams based on the blueprints and on-site conditions, allowing you to check the power generation simulation.
■ Mild climate with an average annual temperature of 15-17 degrees. Check rainwater flow and waterproofing
The same official page states that the average annual temperature in Minamiashigara City is 15-17 degrees, making it a comfortable climate throughout the year. Additionally, the area is rich in water resources, with over 30 springs. When installing panels on the roof, it is important to ensure that waterproofing at the mounting points is properly done to prevent rainwater from entering.
■ City subsidies are on a first-come, first-served basis. Do not start work before applying
Minamiashigara City Global Warming Countermeasure Promotion Project Subsidy (Official City Site) is accepting applications on a first-come, first-served basis from June 1, 2026, to February 26, 2027. Work cannot begin before applying, and it is also a condition that you have applied for (or received a grant decision by the deadline) for subsidy projects implemented by the national government or Kanagawa Prefecture. It is important to confirm the timing of the construction and the order of applications before signing the contract.
■ Check the roof condition according to the age of the building
For homes that have been built for some years, it is important to check the condition of the roofing materials and substrate 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.
■ Pay attention to roof dirt such as leaves and dust
If dirt such as leaves and dust accumulates on the roof, it can affect power generation. Kakeru Koumuten Co., Ltd. can also handle solar panel cleaning with specialized brushes and rain gutter cleaning.
Our company is based in Kanagawa Prefecture and has undertaken many exterior construction and solar projects in Minamiashigara City.
We are happy to assist with partial roof repairs such as roof overlay work and roof replacement, as well as other repairs! Please feel free to consult us for any sudden troubles!
Service Area in Minamiashigara City, Kanagawa Prefecture
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and Tokyo.
List of Areas in Minamiashigara City, Kanagawa Prefecture
Minamiashigara City, Amatsubo / Minamiashigara City, Iizawa / Minamiashigara City, Ikoma / Minamiashigara City, Iwahara / Minamiashigara City, Uchiyama / Minamiashigara City, Kano / Minamiashigara City, Karino / Minamiashigara City, Kitakubo / Minamiashigara City, Koichi / Minamiashigara City, Kōsai-ji / Minamiashigara City, Komagatashinjuku / Minamiashigara City, Sekimoto / Minamiashigara City, Chizushima / Minamiashigara City, Taiyū-chō / Minamiashigara City, Takematsu / Minamiashigara City, Tsukahara / Minamiashigara City, Nakaduma / Minamiashigara City, Nodeta / Minamiashigara City, Numata / Minamiashigara City, Hirochō / Minamiashigara City, Fukuzumi / Minamiashigara City, Banme / Minamiashigara City, Shimo / Minamiashigara City, Mitake / Minamiashigara City, Mukōda / Minamiashigara City, Yagurazawa / Minamiashigara City, Wada-kawahara
・Trust Kakeru Koumuten for exterior wall painting in Minamiashigara City, Kanagawa!
・Trust Kakeru Koumuten for roof renovations in Minamiashigara City, Kanagawa!
・Trust Kakeru Koumuten for exterior renovations in Minamiashigara City, Kanagawa!
・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!
・Top 12 solar power generation manufacturers! Features and selection tips included!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
・What are the best locations for solar power installation? 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!
