Leave Your Solar Panel Installation Work 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!
Kakeru Koumuten is a specialized exterior renovation company headquartered in Aoba Ward, Yokohama City.
As a company strong in roofing work, we are entrusted with solar panel and storage battery installations considering roofing 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 a satisfactory solar panel installation, we recommend obtaining estimates from about three companies!
Table of Contents (Tap to Open/Close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in 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 Consider 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 Installation
- Service Area in Minamiashigara City, Kanagawa Prefecture
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Minamiashigara City, Kanagawa Prefecture
The reasons why we are 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.
Because we are confident, we welcome estimates from any number of companies!
1. We Can Also Handle Exterior Renovations Other Than Solar Panel Installation!
Troubles such as leaks caused by the installation of solar panels may arise from insufficient checks on the roof and waterproofing at the installation site.
Even if you are knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have knowledge about the roof to avoid maintenance 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 organized the following warehouses and material storage areas to provide low-cost, high-quality solar work and exterior renovations.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the necessary scaffolding materials for temporary scaffolding based on construction conditions, allowing us to set up scaffolding ourselves.
By conducting scaffolding work with our own scaffolding team instead of outsourcing, we can also reduce the cost of scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
Even in Minamiashigara City, which has a wide range of locations from sloped areas in the mountains to flat residential areas, our own 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, we canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we canrespond quickly in emergencies!
Sorting and transporting waste materials in-house
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior 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 show the structure, allowing for detailed explanations!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is all work performed by our own team.
By having a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof remodeling at reduced costs.
Additionally, one representative will handle everything from the estimate to project completion.
Since the same person will be in charge, whether it’s sales or construction management, smooth communication is possible.
We can perform consistent in-house work from temporary scaffolding installation to exterior wall painting and roof remodeling!
4. Various Permits and Skilled Workers
We have obtained construction industry permits and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal workers and painting technicians, and we are confident in our construction skills.
We can also handle large-scale roofing work for factories and other facilities!
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 without performing roof renovations. 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 annually, 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 roof troubles and situations.
If we cannot access the roof due to height, we can utilize a drone for inspections!
During leakage investigations, we can also conduct surveys 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 Clear Materials and Simulations
At Kakeru Koumuten Co., Ltd., in addition to “estimates”, “layout diagrams”, and “power generation simulations”, we also provide a “solar installation guidebook” and a “profit and loss simulation” that takes into account loan interest rates and electricity costs.
The profit and loss simulation can be created for projected cumulative profits and losses over 20 to 30 years.
Even customers who are not familiar with solar installations will find our materials easy to understand, including important points and disadvantages!
We encourage you to obtain comparative estimates and review plans from other companies!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 to 30 years.
“Is it okay to install them directly on the current roof?” Checking this before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten Co., Ltd., which specializes in roofing work, has summarized the items to check before installation.
| 1. Type of roofing material and age | The method of securing the panels varies depending on the roofing material, such as slate, tiles, metal roofs, or flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of the substrate and waterproof sheet | If the sheathing or roofing (waterproof sheet) beneath the roofing material is damaged, it will affect the fastening strength and waterproofing. We will also check for 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 power generation. We will create a layout diagram from the drawings and the site, and you can confirm it with the power generation simulation. |
| 4. Shape of the roof and installable area | The number of panels (installation capacity) that can be placed depends on the shape and size of the roof. The number of panels that can be installed varies by panel size, so we 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 of the fixed parts during the estimate. |
| 6. Weight of the roof | The roof will become heavier due to the panels. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may also be an option if necessary. |
| 7. Location of equipment installation and wiring | We will confirm the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect costs. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproofing treatment of fixed parts, cracks and 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 the 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 roofing material (depends on the combination of roofing material and brackets) | Whether the roofing material and brackets are compatible, installation conditions from the roofing material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you perform roof renovations 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the roof is deteriorating, it may be more cost-effective in the long run to renovate to a highly durable roofing material before installation.
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
PossibleSubsidies 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 due to budget and recruitment periods, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Minami Ashigara 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 (until 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 or multi-family homes in the prefecture, must install both solar power generation and storage batteries in earthquake-resistant homes. 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) | New installation of 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%, maximum 600,000 yen per application). | As of May 29, 2026, the budget has been reached, and applications are no longer being accepted. |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but must be combined with essential works such as insulation renovation of windows (openings) and the building structure; 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 cap is reached. Please check the official site for application status. |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Self-Consumption Type 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 amount reached the budget amount). |
In Minamiashigara City, you cannot start construction before applying for the subsidy, and it is a condition that you have already 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, you must start construction after receiving the “grant decision”, and starting construction beforehand may disqualify you. As of October 6, 2026, the application deadline for the second phase of the 2026 fiscal year from the prefecture has passed, and the public recruitment 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 solar power generation and storage systems for residential use is available to individuals residing in the city, with the condition that there are no tax delinquencies.
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 will be accepted from June 1, 2026, to February 26, 2027 (Friday) at 4:00 PM, and will be 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 by the deadline and receive a grant decision for) a subsidy project implemented by the national government or Kanagawa Prefecture. 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 products’ storage systems that can be utilized for demand response (DR), and in the supplementary budget for the 2025 fiscal year, the subsidy amount was determined based on a standard amount of 34,500 yen per 1 kWh of initial effective capacity, with a subsidy rate of up to 30% and a maximum of 600,000 yen per application. There are also conditions such as that contracts or orders made before the grant decision are not eligible.
However, the supplementary budget for the 2025 fiscal year reached its application amount on May 29, 2026, and the public recruitment has ended (the previous fiscal year’s 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 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 Subsidy for Residential Solar Power Generation and Storage Battery Installation Costs”
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 subsidy decision is made, it will be ineligible, and the application must be made by the individual (applications by contractors on behalf of the individual are not allowed). Additionally, the eligible homes must ensure seismic performance. Please confirm the compatibility with other subsidy programs, as it may vary by program.
For the Reiwa 8 year, the first application period (May 11 – June 30) and the second application period (September 7 – September 30, first-come-first-served) were conducted, and the second period has now closed. For future recruitment, please check the official page of Kanagawa Prefecture.
👉 Click here for the official Kanagawa Prefecture page
Kanagawa Prefecture “Reiwa 8 Year Subsidy for Self-Consumption Type Renewable Energy Installation Costs” (for businesses)
Kanagawa Prefecture also offers subsidies for businesses that install “self-consumption type” systems that use electricity generated by 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 certified under FIT or FIP.
The subsidy amount is 80,000 yen per kW for solar power generation and 50,000 yen per kWh for the accompanying storage system (with a maximum of 5 million yen).
As the application amount reached the budget limit for the Reiwa 8 year, the recruitment was 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 and 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 confirmed 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 (kilowatt). Batteries are compared based on the amount of electricity they can store, measured in kWh (kilowatt-hour).
The amount of kW that can be installed on the roof varies for each house based on the roof’s shape, orientation, and size. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panel installation costs as approximately 800,000 JPY to 1,200,000 JPY for 3-5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6-10 kW. (These are just approximate amounts and may vary based on wiring length, scaffold range, existing roofing materials, panel layout, etc.)
▶ Installation Menu | Costs for Solar Panel and Storage Battery Installation
Items to Check in the Estimate (Cost Confirmation)
When comparing estimates from different companies, 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) 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 storage battery. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range usable during power outages (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of the hardware suitable for the roofing material and the fixing method (whether it involves drilling holes or clamping for fixation). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, and whether there is a monitor to check power generation. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at fixing points, 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 it is simultaneous with roof work or exterior painting, check that the same scope and quantity are not double-counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters or old panels and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether 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 of estimates, 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 a financial 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 financial simulation!
*The simulation results are estimates. Actual financial results may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection and 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
| 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 Manufactured / Aluminum Catch Type Hardware |
| Fixing Method and Waterproofing Details |
| Fixed using catch type hardware gripping the horizontal metal roof (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Expected recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that grants are available, and I would like to know how much 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 amount of the grant, 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.
For this reason, when requesting solar panel installation and battery storage installation work, let’s check the following four points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the presence of warranties and aftercare 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.
Have knowledge not only about solar panels but also about roofs
Defective installation of solar panels can sometimes be caused by a lack of knowledge and confirmation regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing where the solar panels will be installed is also crucial.
⚠︎Examples of troubles caused by insufficient checks on roofs and waterproofing
・Solar panels were installed on a severely deteriorated roof, resulting in leaks
・Solar panels were installed on a roof with a short lifespan, necessitating a renovation 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 Check Before Installing Solar Panels” in this article
Confirm the presence of warranties and aftercare maintenance
When choosing a solar installation contractor, let’s confirm the presence of warranties. It is important to check not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
Solar panels and battery storage units come with manufacturer warranties, but also check for the presence of installation warranties in case leaks occur after installation!
For contractors that offer installation warranties, if leaks occur after installation, they may be able to respond under the warranty, provided it falls within the warranty period and conditions.
Additionally, some contractors offer after-sales service separate from warranties, so be sure to check if the contractor you are considering has after-sales service.
Since abnormalities or damage on the roof can occur in areas that are not visible, there is a possibility that customers may not notice them.
By conducting inspections of these hidden areas during after-sales maintenance, it becomes easier to detect abnormalities early, preventing major repairs or breakdowns!
Kakeru Koumuten Co., Ltd. provides a leak warranty as part of the workmanship warranty for solar panel installations. (The warranty for solar panel installations is 10 years, and depending on the condition of the roof before installation, a roof renovation may be required to provide the warranty.)
We also conduct after-sales maintenance and send out DM every year!
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 work content, costs may vary, and warranties and after-sales services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request the 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-sales services”
and make a careful comparison to make your decision! 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, equipment, and 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 that supports the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining a grant decision) before proceeding with the construction!
For the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and it will go through a review process 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 Benefits
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 benefit by reducing the amount of electricity you buy from the power company by consuming the electricity you generate!
As electricity prices rise, the ability to cover your 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 (under 10kW) selling prices (FIT), the price setting 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.” 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.
👉 For purchase prices and periods, visit the Agency for Natural Resources and Energy
Benefit 2: You Can Utilize Subsidies!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the criteria, 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 such as power conditioners do have operational noise.)
Benefit 4: Heat Insulation Effects Are 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 capability, 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 renovations 10 to 20 years later, there will be costs for removing and reinstalling the solar panels.
If the existing roof is deteriorated, it is reassuring to renovate it with durable roofing materials before installing the solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It would be reassuring to consider maintenance costs in simulations before introducing solar panels!
Point 2: The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix the materials and substrate with screws or similar, 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 the fittings, and it cannot be used with all metal roofs.)
Catch-type base metal fittings for horizontal metal roofs
Note 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load-bearing capacity, replacing it with a lighter roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
Choosing Method 1: Compare based on total output of the roof
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and it is 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 that the one with higher output is better at first glance.
However, if the size of the panels 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 installable panels on the same roof due to size differences.
400W×15 panels = 6kW (total output of the roof)
350W×20 panels = 7kW (total output of the roof)
As shown above, even if the output of a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than 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 or 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or power generation amount.
Choosing solar panels considering the degradation rate, rather than just the initial output, will help avoid 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 longer warranties are generally better, let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in 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 condition of the roof. In the above construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines for different capacities are published on the solar panel and storage battery installation pricing page. We will create a layout diagram from the drawings and on-site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Minamiashigara City?
As of October 6, 2026, the “Global Warming Countermeasure Promotion Project Subsidy” in Minamiashigara City (20,000 yen/kW for solar power, maximum 100,000 yen; 20,000 yen/kW for storage systems, maximum 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 term of fiscal year 2026, and the national DR household storage battery project has ended its public recruitment.
Since the application status may change, please refer to the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies 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 begin after grant approval,” meaning that if you start installation beforehand, 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 slate roofs? I’m worried about leaks.
It is possible to install on slate roofs, but it is necessary to check the condition of the roofing material and substrate. The fixing method varies depending on the construction method, and when fixing 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 and suggest methods such as roof overlay (cover method) or re-roofing if deterioration is progressing.
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 on how to proceed with the installation after checking the condition of the roof through a site survey!
Should I install a storage battery together with the solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price of electricity will be 8.3 JPY/kWh after the fifth year, making it more advantageous to use it at home rather than selling it.
Additionally, Kanagawa Prefecture’s subsidy requires the simultaneous introduction of solar panels and storage batteries, and the subsidy from Minamiashigara City is contingent upon applying for national or Kanagawa Prefecture subsidy programs. You can compare “solar panels only” and “solar panels + storage battery” through a financial simulation.
How many kW can I install 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 Co., Ltd., we create a layout diagram from the drawings and site survey, and provide you with the installation capacity and power generation simulation.
In Minamiashigara City, about 70% of the area is forested, and the way shadows are cast by mountains, trees, neighboring houses, and elevation differences varies from house to house. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
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 done simultaneously or depending on the shape of the roof and installation capacity.
Additionally, please note that there will be a separate period for applying for subsidies and to the power company, so please consult us early.
What is the current selling price (FIT)?
For residential use (less than 10 kW), from the certification after October 2025, the first 4 years will be 24 JPY/kWh, and from the 5th to the 10th year it will be 8.3 JPY/kWh, and the same 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 Co., Ltd. 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 Co., Ltd. sends out annual after-service maintenance notices via DM and visits customers who wish for inspections. We can also handle cleaning 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 please feel free to consult us if you have any concerns.
Can you also handle renovations for roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten Co., Ltd. can detach and reattach solar panels ourselves, 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 see the solar panel detachment 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 panels, roof work, and exterior wall work in Minamiashigara City, Kanagawa Prefecture.
We have received requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten Co., Ltd. promises “high-quality renovations at low costs”, and we have received positive feedback from many customers.
We continue to update our construction performance every year and will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay (cover method) and re-roofing but also partial roof repairs, exterior painting, and exterior wall 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 the best solutions for your specific requests.
We will never propose unnecessary work focused on profit!
We always stand in the customer’s position and will propose the best construction plan!
We are confident that we will not be outdone by other companies in terms of cost, quality, and planning for exterior work!
We are confident, so we welcome competitive estimates!
Estimates are completely free, and if we are found to be inferior to other companies, you are free to decline!
Characteristics of Minamiashigara City, Kanagawa Prefecture and Points of Solar Work
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
■ Western high and eastern low terrain. Check sunlight exposure based on housing location
Profile of Minamiashigara City (official) states that the city consists of hilly areas, plateaus, the river valleys of the Karikawa and Uchikawa, and the alluvial plains of the Sakawa River, forming a western high and eastern low terrain. The shadow cast by surrounding terrain and buildings differs between houses near the mountains and those in the plains. In locations close to the mountains, the direction may affect morning and evening sunlight due to the mountains and trees, so it is important to check the roof orientation and surrounding environment on-site before considering the panel layout.
■ About 70% of the city is forested. Consider the shadows of trees and dirt from fallen leaves and branches
The official page of the city (This is Minamiashigara) mentions that about 70% of the city is forested, with designated conservation forests primarily consisting of water source forests. In homes close to greenery, the shadows of garden trees and adjacent trees can affect power generation, and roofs may accumulate fallen leaves and branches. Kakeru Koumuten Co., Ltd. creates layout diagrams based on blueprints and on-site conditions, allowing you to confirm through power generation simulations.
■ 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 year-round. Additionally, there are over 30 sources of spring water, indicating a rich water resource area. When installing panels on the roof, it is crucial to ensure that waterproofing at the fixing 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) 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 approval by the deadline) for subsidy projects conducted by the national government or Kanagawa Prefecture. It is important to confirm the timing of the construction and the order of applications before signing a contract.
■ 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 the condition of the roofing materials and substrate before installing solar panels. Depending on the roof’s condition, 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 can affect power generation. Kakeru Koumuten Co., Ltd. offers specialized cleaning of solar panels with dedicated brushes, as well as rain gutter cleaning.
Our company is based in Kanagawa Prefecture and has handled 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 for work 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, Taiyūmachi / Minamiashigara City, Takematsu / Minamiashigara City, Tsukahara / Minamiashigara City, Nakanuma / Minamiashigara City, Nodata / Minamiashigara City, Numata / Minamiashigara City, Hirochō / Minamiashigara City, Fukuzumi / Minamiashigara City, Banme / Minamiashigara City, Yamashita / Minamiashigara City, Mitate / Minamiashigara City, Mukōda / Minamiashigara City, Yagurazawa / Minamiashigara City, Wada-kawara
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・Trust Kakeru Koumuten for exterior renovations in Minamiashigara City, Kanagawa!
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・Kakeru Koumuten Co., Ltd. Service Menu and Price List
・Kakeru Koumuten Co., Ltd. Staff Blog and Announcements
・Explaining the Importance of Comparing Estimates!
・Top 12 Solar Power Generation Manufacturers! Features and Selection Tips!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
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・Check out our solar power generation estimates here!
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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!
