Leave the installation of solar panels in Ayase City, Kanagawa Prefecture to Kakeru Koumuten Co., Ltd.!
For Solar Panel and Battery Installation in
Ayase City,
Kakeru Koumuten is at your service!
Kakeru Koumuten is a company specializing in exterior renovations based in Kanagawa Prefecture.
As a company strong in roofing work, we are entrusted with solar panel and battery installation considering roofs and waterproofing!
“How to Choose a Solar Panel Contractor in Ayase City”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Ayase 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 three or so estimates!
Table of Contents (Tap to Open/Close)
- Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Ayase City
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Ayase 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 Ayase City
- 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 Ayase City
- If You’re Looking for a Solar Panel Installer in Ayase City, Contact Kakeru Koumuten
- Characteristics of Ayase City and Points for Solar Installation
- Service Area in Ayase City
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Ayase City
Here are the reasons why we are entrusted with solar panel installation by our customers in Ayase City:
“Our Unique Strengths in Solar Panel Installation That Cannot Be Replicated by Other Companies”
have received high praise from many customers.
We would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome multiple estimates!
1. We Can Also Handle Exterior Renovations Beyond Solar Panel Installation!
Issues such as leaks that occur during solar panel installation may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if you are knowledgeable about solar panels, there may be cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have expertise in roofing to avoid maintenance and trouble 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 issues 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 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 own the scaffolding materials necessary 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 own scaffolding materials for approximately 50 detached houses!
Even if there are height differences on the site, our in-house scaffolding team will plan the scaffolding according to the local conditions.
Storage of Materials in Our Large In-house Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we canrespond quickly in emergencies!
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 renovation dedicated showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are attached to the roofing materials!
You can also perform revenue simulations and cost simulations for introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also have 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 its complete in-house construction.
By having Kakeru Koumuten handle everything from inquiries to project completion in a consistent manner, we can keep costs down while providing high-quality roof renovations.
Additionally, one representative will assist you from the estimate to the completion of the work.
Since the same person will handle sales and construction management, smooth communication is possible.
We can provide consistent in-house construction from temporary scaffolding installation, exterior wall painting, to roof renovations!
4. Various Permits and Skilled Workers
We have obtained construction industry licenses and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal workers and painting specialists, and we are confident in our construction techniques.
We are capable of handling large-scale roof projects such as those for factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty, solar panel installation work comes with 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, it may not be possible to provide a warranty without performing a roof renovation. 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 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 roofing troubles and situations.
If you are unable to access the roof due to height, we can utilize a drone to assist!
During leak investigations, we can also conduct surveys using a thermal imaging camera.
If the power generation of your solar panels decreases due to dirt or other factors, we can provide cleaning services using a specialized brush.
We will respond according to your wishes.
7. Human Resource Development
To improve skills, we create various roofing models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly 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 construction 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.
For customers who are not familiar with solar construction, we compile easy-to-understand materials that include points to note and disadvantages!
We encourage you to obtain comparative estimates and compare them with other companies’ plans!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 to 30 years.
Confirming “Is it okay to install them directly on the current roof?” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, which specializes in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing materials such as slate, tiles, metal roofs, and flat roofs (rooftop waterproofing). If the remaining lifespan of the roofing material is short, we may suggest roof renovation first. |
| 2. Condition of the Substrate and Waterproof Sheet | If the sheathing boards or roofing (waterproof sheet) under the roofing material are damaged, it will affect the fixing strength of the fittings 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 electricity generated. We will create a layout diagram from the drawings and the site, and you can check it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels (installation capacity) that can be placed depends on 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 confirm whether the method involves drilling holes in the roofing material for fixing or using fittings to secure the roofing material. The fixing method varies by technique, so please check the waterproofing treatment method for the fixing parts during the estimate. |
| 6. Weight of the Roof | The roof will become heavier due to the panels being placed on it. After investigating the existing roof, substrate, and load-bearing capacity, switching to lighter roofing materials may be an option if necessary. |
| 7. Location of Equipment Installation and Wiring | We will check the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect the cost. |
| 8. Ease of Scaffolding Setup and Delivery Routes | If there are elevation differences on the site, planning for scaffolding and the delivery routes for equipment and materials may require some ingenuity. We will also check the width of the front road and any steps on the site during the on-site survey. |
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 roof material and substrate with screws) | Waterproof treatment of fixing parts, cracks or deterioration of slate, condition of substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suitable for the type of tile (even methods that do not drill holes in the tiles will secure 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 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, 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 Ayase City
PotentialSubsidies and Grants in Ayase City, Kanagawa Prefecture
If you are introducing solar panels or storage batteries in Ayase City, you may be eligible for programs from the “National Government,” “Kanagawa Prefecture,” and “Ayase City.”
The following information is based on the official pages of each program as of October 6, 2026. The application status may change based on the budget, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| System | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Ayase City “Subsidy for Introduction of Renewable Energy and Energy-Saving Equipment for Individual Houses” | Individuals with resident registration at the location of the house where the equipment is installed, with no unpaid city taxes. Must be used for household purposes. Application is “post-application” after the completion of installation work and payment for the equipment. It is possible to combine with subsidies from the national and prefectural governments, but there may be restrictions on combination from the national or prefectural system. | Solar power generation equipment: 10,000 yen per kW (maximum 30,000 yen) Stationary lithium-ion storage system: flat 50,000 yen Additionally, HEMS (10,000 yen), household fuel cells (50,000 yen), V2H (50,000 yen), ZEH addition (100,000 yen) |
April 1, 2026 – March 15, 2027 (first-come, first-served, ends when budget is reached) The official city page (updated April 1, 2026) states that it is currently accepting applications. There is a note that inquiries about the remaining number of applications will not be addressed. |
| Kanagawa Prefecture “Subsidy for Introduction of Solar Power Generation and Storage Batteries for Residential Use in Reiwa Year 8” | Must install both solar power generation and storage systems in a residential building (with ensured seismic performance) within the prefecture. The application must be made by the individual, and construction can begin after the grant decision. | Solar power: 70,000 yen/kW Storage battery: 150,000 yen/unit |
Phase 1: May 11, 2026 – June 30, 2026 Phase 2: Starts September 7, 2026 (first-come, first-served) As of September 7, 2026, the application amount has reached the budget amount, and applications are closed. Please check the prefectural official page for future recruitment. |
| National “DR Household Storage Battery Project” (Reiwa Year 7 Supplement) | Newly introduce a household storage system that can be utilized for DR (demand response) with registered products. | Calculated based on a standard amount of 34,500 yen per initial effective capacity of 1 kWh (subsidy rate within 3/10, maximum 600,000 yen per application). | As of May 29, 2026, the budget has been reached, and public recruitment has ended (the official site states that there are no plans to reopen public recruitment, and applications cannot be made at this time). |
| 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 renovation of windows (openings) and the structure, and 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 when the budget limit is reached. As of October 5, 2026, the application amount for renovations is displayed as 8% of the budget on the official site. Please check the official site for the application status. |
| Kanagawa Prefecture “Subsidy for Introduction of Self-Consumption Renewable Energy in Reiwa Year 8” | Corporations and individual business owners filing blue returns (individual residences are not eligible). Solar power must have a generation output of 10 kW or more, for business facilities, and equipment not certified under FIT/FIP, etc. | Solar Power: 80,000 JPY/kW, etc. Storage System: 50,000 JPY/kWh (maximum 5,000,000 JPY) |
Applications closed on September 3, 2026 (the application amount reached the budget) |
The subsidy for Ayase City is a “post-application” process that must be submitted after the installation work is completed and the equipment is handed over and payment is made, and it will end on a first-come, first-served basis once the budget is reached. On the other hand, the subsidy for housing in Kanagawa Prefecture requires that construction begins only after receiving a “grant decision,” and starting work beforehand will disqualify you. The eligibility conditions, application procedures, and the possibility of combining different systems vary by program, and applying does not guarantee that you will receive the grant, so please confirm before signing a contract or starting construction.
At Kakeru Koumuten, we will guide you on the eligibility conditions and application periods for each program after confirming them.
National Subsidy “DR Home Storage Battery Project (Support Project for Introducing Home Storage Systems for DR Resource Implementation)”
The government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those who are introducing new registered storage systems that can be utilized for demand response (DR), and in the fiscal year 2025 supplementary budget, the subsidy amount is determined based on a standard amount of 34,500 JPY per initial effective capacity of 1 kWh, with a subsidy rate of up to 30% and a maximum of 600,000 JPY per application. There are conditions such as being ineligible for items contracted or ordered before the grant decision.
However, the fiscal year 2025 supplementary budget reached its application amount on May 29, 2026, and the public offering has ended. The official website also states that there are no plans to reopen the public offering, and applications are currently not possible. Please check the official website 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 Storage Battery Project
Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Housing Solar Power Generation and Storage Battery Installation Subsidy”
Kanagawa Prefecture provides subsidies for those who install both “solar panels” and “storage batteries” in their homes.
The subsidy details are 70,000 JPY per kW of solar power generation output and 150,000 JPY per storage system.
For example, if you install a 4 kW solar panel and one storage battery, the subsidy amount calculation would be 4 kW × 70,000 JPY + 150,000 JPY = 430,000 JPY.
The eligibility includes having a house that meets seismic performance standards, the storage system must be a registered product, starting construction before the grant decision will disqualify you, and the application must be made by the individual (applications by contractors are not allowed). It is stated on the city’s official page that this can be combined with Ayase City’s subsidies, but there are also conditions from the prefectural program, so please check the official pages of each program before signing a contract.
For the fiscal year 2026, the first phase (May 11 – June 30) and the second phase (starting September 7, first-come-first-served) were conducted. The second phase has been closed for applications as of September 7, 2026, when the application amount reached the budget amount. Please check the official page of Kanagawa Prefecture for future recruitment.
👉 Click here for the official page of Kanagawa Prefecture
Kanagawa Prefecture “Subsidy for Introduction of Self-Consumption Type Renewable Energy (for Businesses) for Fiscal Year 2026”
Kanagawa Prefecture is also implementing a subsidy for businesses that introduce “self-consumption type” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners who file blue returns, and individual residential installations are not eligible.
Conditions include that the solar power generation must have an output of 10kW or more and supply power to business facilities within the prefecture, and that the equipment must not be certified under FIT or FIP.
The subsidy amount is 80,000 yen per kW for solar power generation and 50,000 yen per kWh for the accompanying storage system (with a maximum of 5 million yen).
As the application amount reached the budget amount for fiscal year 2026, recruitment was closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Ayase City should check the official page of Kanagawa Prefecture for the next recruitment.
👉 Click here for details
Ayase City “Subsidy for Introduction of Renewable Energy and Energy-Saving Equipment for Individual Residences (Fiscal Year 2026)”
Ayase City is implementing the “Subsidy for Introduction of Renewable Energy and Energy-Saving Equipment for Individual Residences” for individuals who install renewable energy and energy-saving equipment in residences within the city.
● Solar power generation equipment: 10,000 yen per kW (maximum 30,000 yen)
● Fixed lithium-ion storage system: Fixed amount of 50,000 yen
● HEMS (Home Energy Management System): Fixed amount of 10,000 yen
● Home fuel cell system (EneFarm): Fixed amount of 50,000 yen
● Electric vehicle charging device (V2H): Fixed amount of 50,000 yen
● ZEH addition: Fixed amount of 100,000 yen
Eligible applicants are individuals who are registered residents at the location of the equipment installation, must have no unpaid city taxes, must use the equipment for home use, and must not fall under the Ayase City Organized Crime Exclusion Ordinance.
This subsidy is post-application, and applications are made after the completion of installation work, delivery of equipment, and payment of fees. The application period is April 1, 2026 – March 15, 2027, and it will end as soon as the budget is reached on a first-come-first-served basis. Although the city’s official page (updated April 1, 2026) states that applications are being accepted, it mentions that inquiries regarding the remaining number of applications will not be addressed, so please check the city’s official page as soon as possible.
It is stated on the city’s official page that it is possible to apply in conjunction with subsidies from the national and prefectural governments. However, there may be restrictions on the combination of subsidies from the national and prefectural levels, so please check the conditions of each program.
👉 Click here for Ayase City official page
Solar Panel Installation & Battery Installation Price List
⇧Service Menu | Click here for costs related to solar panel installation and battery installation
⇧Service Menu | Click here for costs related to solar panel removal and water heater removal
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and batteries should be confirmed by separating them into “Equipment Costs (Equipment Price)” and “Construction Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, grade of equipment, and condition of the roof.
Considerations for Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “the output of one panel (W) × number of panels”, with the unit being kW (kilowatts). The battery is compared in terms of the amount of electricity it can store, expressed in kWh (kilowatt-hours).
The amount of kW that can be placed on the roof varies for each house depending on the shape, orientation, and size of the roof. At Kakeru Koumuten Co., Ltd., we create a layout diagram from the blueprints and on-site survey to present the installation capacity.
On our pricing page, we list solar panels at approximately 800,000 yen to 1,200,000 yen for 3 to 5 kW, and 1,200,000 yen to 1,900,000 yen for 6 to 10 kW. (These are just estimated amounts and may vary based on wiring length, scaffolding range, existing roofing materials, and panel layout.)
▶ Installation Menu | Costs for Solar Panel Installation and Battery Installation
Items to Check 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 of one panel (W), number of panels, total installation capacity (kW) are written. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also confirm whether it is a type that controls the battery together. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range available during power outages (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Fittings | Name of fittings suitable for roofing materials and method of securing (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 fixed parts, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | Extent of support included for applications to the power company, certification application for selling electricity (FIT), 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 it 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, the amounts and power generation will also change. Kakeru Koumuten Co., Ltd. welcome comparisons of estimates, so if you bring estimates from other companies, we can explain the differences item by item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can get a rough estimate and income simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can get a rough estimate and income simulation!
*The simulation results are estimates. Actual income may vary depending on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection and replacement.
Customer Feedback
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installation
| 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 Manufacturing/Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed by catching the horizontal metal roof with catch-type hardware (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY ※Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) ※The grant amount and recovery estimate are based on the system and calculations at the time of construction and may differ under the current system. |
| Construction Period |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the introduction of solar panels and storage batteries. I heard that grants are available, and I would like to know how much will be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of grants, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Ayase City
There are many solar panel installation contractors available in Ayase City, 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 aftercare services
● Obtain estimates from multiple contractors (3 companies is a guideline)
● Check if they provide support for subsidy applications
By confirming the above 4 points, you will be able to choose a reliable contractor.
Have knowledge not only about solar panels but also about roofs
Improper 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, resulting in leaks
・Solar panels were installed on a roof with a short lifespan, necessitating renovations to detach and reattach the solar panels within a few years
・Misjudging the type of waterproofing led to incorrect treatment 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 aftercare services
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 within the warranty period and conditions, they may cover the repairs under the warranty.
Additionally, some contractors provide aftercare services separate from warranties, so make sure to check if the contractor you are considering has aftercare services.
Since abnormalities or damages on the roof can be in areas that are not visible, you may not notice them yourself.
By conducting inspections of hidden areas during aftercare maintenance, you can more easily detect abnormalities early and prevent major repairs or failures!
Kakeru Koumuten Co., Ltd. offers 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, we may not be able to provide a warranty unless roof refurbishment is performed.)
We also provide aftercare maintenance, sending out DM every year!
After checking the DM, if you wish, we will visit you for aftercare maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, let’s obtain estimates from multiple contractors.
Even for the same manufacturer and the same work content, costs may vary, and warranties and after-services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check:
“Confirmation of estimate items”
“Types of solar panels”
“Warranties and after-services”
and make a detailed comparison for your judgment! Avoid judging solely based on cost, as using lower-grade materials or skipping processes can reduce costs!
▶ 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 contractors cannot apply on behalf of the client, and personal application is required, it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining a grant decision) before proceeding with the construction!
For the prefectural housing subsidy, after the construction is completed, a performance report is submitted, and the flow is that it is granted after review! (The flow of procedures varies by system)
▶ To “Subsidies and grants that may be applicable in Ayase City” in this article
Benefits of Introducing Solar Equipment
The benefits of introducing solar panels are as follows!
Benefit 1 Economic Benefits
The biggest advantage of introducing solar panels is the economic benefit!
Although the selling price of electricity has decreased compared to ten years ago, you can gain benefits by reducing the electricity you buy from power companies by consuming the electricity you generate yourself!
As electricity costs rise, the ability to cover your consumption with solar power becomes attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) will be set as “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year” for certifications after October 2025, and the same price will apply for the 2026 fiscal year. After the fifth year, it is likely to be more beneficial to use it at home (self-consume) rather than sell it, making the combination with a storage battery a viable option.
👉 Ministry of Economy, Trade and Industry | For purchase prices and periods, click here
Advantage 2 Subsidies can be utilized!
Subsidy conditions and amounts vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
The reduction of the actual burden amount through subsidies is a significant advantage!
In Ayase City, there is a possibility that the national, Kanagawa Prefecture, and Ayase City systems may apply (please check the application status for each system).
Advantage 3 Environmentally friendly!
Solar power generation has low carbon dioxide emissions and can reduce dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices such as power conditioners may have operational noise.)
Advantage 4 Heat insulation effects can be expected!!
By installing panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, this can help reduce the temperature of the roof, providing a heat insulation effect!
(Note that this does not improve the building’s insulation performance itself.)
Benefit 5 Electricity can be used even during power outages!!
If a storage battery is installed, it is possible to use electricity even during emergencies such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation functionality, you may be able to use electricity from a dedicated outlet during daytime generation.
(The devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1 Maintenance costs can be incurred
A particularly overlooked maintenance cost is for the roof where solar panels are installed.
If you perform roof renovations 10 to 20 years later, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorated, it is reassuring to renovate it with durable roofing materials before installing solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It is reassuring to be able to request a simulation that considers maintenance costs before introducing solar panels!
Point 2 The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but when fixing hardware with screws to the roofing material or substrate, waterproofing of the fixed parts becomes crucial.
In methods that involve making holes in the roof, the risk of leaks inevitably arises.
Of course, we will perform thorough waterproofing, but if you are concerned about making holes, one option is to replace the roofing material with a metal roof and fix the solar panels using the catch method. (The catch method has compatibility conditions between the roofing material and hardware, and it cannot be used with all metal roofs.)
Catch-type base hardware exclusive for horizontal metal roofs
Point 3 The Roof Becomes Heavier
Installing solar panels will make the roof heavier. After investigating the existing roof, substrate, and load-bearing capacity, replacing it with 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!
How to Choose 1: Compare Based on Total Roof Output
When installing solar panels on the roof, it is important to know how much electricity can be generated in a limited area, and the more electricity generated, the better!
Solar panels come in various sizes and outputs depending on the manufacturer.
A 350W output panel and a 400W output panel may seem like the higher output panel is better at first glance.
However, if the size of the panel does not fit well on the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” resulting in a different number of panels that can be installed on the same roof due to the size difference.
400W×15 panels = 6kW (total roof output)
350W×20 panels = 7kW (total roof output)
As shown above, even if the output of a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual electricity generation amount (kWh) varies depending on conditions such as roof orientation, slope, and shading.
How to Choose 2: Compare Based on Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases after 10 years and 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or electricity generation amount.
Choosing solar panels while considering the degradation rate, rather than just the initial output, will help avoid regrets!
How to Choose 3: Compare Based on Warranty Period
Solar panels come with various types of warranties, 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 offer a 10-year warranty, which varies widely!
Longer warranties are better, so be sure to check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Ayase City
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Ayase City. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Ayase City?
The cost varies depending on the installation capacity, equipment, and the 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 our 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 and storage battery installation in Ayase City?
As of October 6, 2026, the Ayase City subsidy for renewable energy and energy-saving equipment for individual residences includes subsidies for solar power generation equipment (10,000 yen per kW, up to 30,000 yen) and stationary lithium-ion storage systems (fixed amount of 50,000 yen). The city’s official page (updated April 1, 2026) states that applications are currently being accepted, but they will end once the budget is reached on a first-come, first-served basis. The Kanagawa Prefecture subsidy (70,000 yen/kW for solar power and 150,000 yen per unit for storage batteries) reached its budget on September 7 for the second phase 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?
This depends on the system. The Ayase City subsidy requires a “post-application” after the completion of the installation work, equipment handover, and payment. On the other hand, the Kanagawa Prefecture housing subsidy requires “commencement of work after the grant decision,” and starting work beforehand will disqualify you.
The order of procedures varies by system, so please confirm before signing a contract or starting work.
Can solar panels be installed on a slate roof? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate. The fixing method varies by construction method, and if the method involves fixing brackets to the roofing material or substrate, waterproofing of the fixed parts 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 if deterioration is advanced, we can also propose methods such as roof overlay (cover method) or re-roofing before installation.
My roof is old. Should I do a roof renovation first?
This depends on the condition of the roof. If a roof renovation is needed 10 to 20 years after installation, the cost of removing and re-installing the solar panels will be incurred separately. If the remaining lifespan of the roof is short, renovating to a highly durable roofing material before installation may reduce total costs.
Please consult us on how to proceed with the installation after checking the condition of the roof during the on-site survey!
Is it better to install a storage battery together with solar panels?
If you want to use the electricity generated at night or prepare for power outages, simultaneous installation is recommended. The selling price will be 8.3 JPY/kWh after the fifth year, making it more advantageous to use the electricity at home rather than selling it.
Additionally, the subsidy in Kanagawa Prefecture requires the combined introduction of solar power and storage batteries. In Ayase City, the subsidy specifies that stationary lithium-ion storage systems are eligible for a fixed subsidy of 50,000 JPY. You can compare “solar power only” and “solar power + storage batteries” through a financial simulation for your consideration.
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 on-site survey, and we will provide you with the installation capacity and power generation simulation.
Ayase City has a terrain consisting of river terraces and flat land, and since the conditions of each site and its surroundings differ, the shading from surrounding buildings and trees, as well as the installable capacity, will vary from house to house. You can check the expected power generation through the power generation simulation.
How long is the construction period?
In the above construction example (solar panel 4.3 kW + storage battery), it took about 3 days. The duration may vary if roof work is done simultaneously or depending on the roof shape and installation capacity.
Please note that additional time is required for applications for subsidies and to the power company, so please consult us as soon as possible.
What is the current selling price (FIT)?
For residential use (less than 10 kW), the selling price will be 24 JPY/kWh for the first 4 years and 8.3 JPY/kWh from the 5th to the 10th year for certifications after October 2025, and the same price will apply for the 2026 fiscal year.
The idea is to recover the initial costs quickly in the first four years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that takes into account loan interest rates and electricity costs.
Can you handle maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-maintenance DM notices and visits for inspections upon request from customers. We can also clean solar panels with a special brush if the power generation decreases due to dirt.
Since it is difficult to check areas on the roof by yourself, please feel free to consult us if you have any concerns.
Can you also handle renovations for roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten can detach and reattach solar panels in-house, allowing us to remove the panels, perform roof overlay (cover method) or re-roofing, and then reinstall them consistently. The removed panels can be stored in our warehouse.
For costs, please refer to the solar panel detachment and water heater removal pricing page.
If you are looking for a solar panel installation contractor in Ayase City, please consult Kakeru Koumuten Co., Ltd.
Our company handles a wide range of exterior renovations in Ayase City, including solar panel installations, roof work, and exterior wall work.
We have received requests from many customers, including renovation companies and real estate agencies!
Kakeru Koumuten promises “high-quality renovations at low cost”, and we have received positive feedback from numerous 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 and re-roofing work but also partial roof repairs, exterior painting, and exterior cover methods.
We are happy to assist with small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leak repairs, we may be able to provide temporary measures without setting up scaffolding, as long as safety can be ensured, so please consult us!
“I want to know about recommended solar panels”, “I want to keep costs down as much as possible”, “I just want a quote for now”, we will provide optimal solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in the customer’s position and will propose the best construction plan!
We are confident that we will not be outdone in terms of cost, quality, and planning compared to other companies in exterior work!
We welcome competitive quotes with confidence!
Our estimates are completely free, and if you find our company to be inferior to others, you are free to decline!
Features of Ayase City and Points for Solar Work
Ayase City is located almost in the center of Kanagawa Prefecture, about 40 km from the city center, with a length of 4.2 km east to west and 7.6 km north to south, covering an area of 22.14 square kilometers. It is described as being formed by the river terraces and flatlands created by the three rivers, Tade River, Hirukawa River, and Mekujiri River, which flow gently from north to south within the city.Below are the characteristics of Ayase City’s terrain and climate, along with points to consider when installing solar panels and storage batteries. (Tap to open)
View the features of Ayase City and points for solar work
■ In a city formed by river terraces and flatlands, check the elevation differences and delivery routes on-site
Ayase City is formed by three rivers creating a river terrace and flat land. When there are height differences on the site, such as near the terrace steps, careful planning for scaffolding and the transportation routes for equipment and materials like panels and storage batteries may be necessary. Kakeru Koumuten Co., Ltd. plans scaffolding to match the site even when there are height differences, using its own scaffolding team and materials.
■ In a city with three rivers, check the hazard map for equipment placement
In Ayase City, the three rivers, Tade River, Hiryu River, and Mekujiri River flow. The suitable placement for equipment such as storage batteries and power conditioners varies depending on the surrounding environment of the installation site (whether it is prone to water accumulation, etc.). Please check the information about your area on the hazard map and consult us about the installation location.
■ The climate is relatively mild. Check for shadow and dirt-related decreases in power generation for each house
The climate of Ayase City is considered relatively mild. Power generation is affected not only by temperature but also by the shadows cast by surrounding buildings and trees, and the accumulation of fallen leaves and dirt. Before installation, we will check the roof’s orientation, slope, and surrounding conditions on-site, and if power generation decreases after installation, we can also provide cleaning of solar panels with a dedicated brush and rain gutter cleaning.
■ Roof types and ages vary from house to house. Check the roof and waterproofing before installation
Even in Ayase City, which spreads over river terraces and flat land, the types of roofs, their ages, and sunlight exposure vary from house to house. At Kakeru Koumuten Co., Ltd., we will check the type and condition of the roof and the site conditions before installation and propose methods for securing the roof, waterproofing details, and scaffolding plans.
■ The annual sunshine hours at the AMeDAS station in neighboring Ebina City is about 1,947 hours
According to the Japan Meteorological Agency’s average values (1991-2020), the annual sunshine hours at the observation point in Ebina City, adjacent to Ayase City, is about 1,947 hours. Monthly, August (about 190 hours) has the most, while June during the rainy season (about 123 hours) has the least.
Power generation varies by season and location, so conducting a year-round power generation simulation and selecting the capacity of the storage battery to match the times of high electricity usage is key.
Our company is based in Kanagawa Prefecture and handles many exterior construction and solar projects in Ayase City.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us about any sudden troubles!
Service Area in Ayase City
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and all of Tokyo.
Ayase City Region List
Ayase City Atsugi Air Base / Ayase City Oogami / Ayase City Ochiai Minami / Ayase City Ochiai Kita / Ayase City Kamitodana / Ayase City Kamitodana Naka / Ayase City Kamitodana Minami / Ayase City Kamitodana Kita / Ayase City Kozono / Ayase City Kozono Minami / Ayase City Tade River / Ayase City Terao Kamita / Ayase City Terao Naka / Ayase City Terao Nishi / Ayase City Terao Minami / Ayase City Terao Kita / Ayase City Terao Dai / Ayase City Terao Honcho / Ayase City Hayakawa / Ayase City Hayakawa Shiroyama / Ayase City Fukaya / Ayase City Fukaya Kami / Ayase City Fukaya Naka / Ayase City Fukaya Minami / Ayase City Mototade River / Ayase City Yoshioka / Ayase City Yoshioka Higashi / Ayase City Ayase Nishi
・Please leave the exterior wall painting in Ayase City to Kakeru Koumuten!
・Please leave the roof renovation in Ayase City to Kakeru Koumuten!
・Please leave the exterior renovation in Ayase City to Kakeru Koumuten!
・Kakeru Koumuten Co., Ltd. construction achievements
・Kakeru Koumuten Co., Ltd. after maintenance
・Kakeru Koumuten Co., Ltd. construction menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of comparison estimates and points to consider!
・Top 12 solar power generation manufacturers! Features and selection points are also introduced!
・What are the installation costs for solar power generation? Tips for reducing costs are thoroughly explained!
・What are the best locations for installing solar power generation? Points for selecting installation locations are also introduced!
・Here is the introduction to solar power generation estimates!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!
