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,
trust Kakeru Koumuten!
Kakeru Koumuten is a company specializing in exterior renovations based in Kanagawa Prefecture.
As a company strong in roofing work, we are entrusted withsolar panel installations and battery work 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 obtainingthree or so estimates!
Table of Contents (Tap to Open/Close)
- Reasons Why 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 Installation Contractor 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 Installation Contractor in Ayase City, Contact Kakeru Koumuten
- Characteristics of Ayase City and Key Points for Solar Installation
- Service Area in Ayase City
Reasons Why Kakeru Koumuten Is Chosen for Solar Panel Installation in Ayase City
Regarding why we are entrusted with solar panel installation by customers in Ayase City,
“Our Unique Strengths in Solar Panel Installation That Others Cannot Imitate”
have received high praise from many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We Also Handle Exterior Renovations Beyond Solar Panel Installation!
Issues such as leaks that occur with solar panel installations may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if one is knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside their expertise, so caution is necessary.
It is reassuring to have expertise in roofing to avoid maintenance and issues 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 prepared 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 scaffolding materials necessary for temporary scaffolding based on construction conditions and can assemble scaffolding in-house.
By not outsourcing scaffolding work and conducting it with our own scaffolding team, we can also cut costs associated with scaffolding construction.
We own scaffolding materials for approximately 50 single-family homes!
Even in cases where there are height differences on the property, our in-house scaffolding team will plan the scaffolding according to the site conditions.
Storage of Materials in Our Large Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, enabling us torespond 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 installed on roofing materials!
We can also provide simulations for potential earnings and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also have samples of roofing materials and models that explain the structure, allowing for detailed explanations!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is its complete in-house construction.
By 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 everything, including 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 permits for the construction industry and for the collection and transportation of industrial waste!
We also have nationally certified sheet metal workers and painting specialists on staff, and we are confident in our construction techniques.
We can also handle large-scale roof projects for factories and other facilities!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation work, we also provide our own construction warranty (leakage warranty)!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless a roof renovation is performed. The construction warranty is separate from the manufacturer’s product warranty, and the coverage and conditions vary based on the warranty details.)
Aftercare is available every year, and we send out a notification DM each year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
If you cannot access the roof due to height, we can utilize a drone for inspections!
During leak 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 provide cleaning with a specialized brush.
We will respond according to our customers’ wishes.
7. Human Resource Development
We create various roof models for skill enhancement and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training so that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
Kakeru Koumuten provides not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar installation guidebook” and “profit and loss simulations” that take into account loan interest rates and electricity costs.
Profit and loss simulations can be created for projected cumulative profits and losses over 20 to 30 years.
We compile easy-to-understand materials that include points to consider and disadvantages for customers who may not be familiar with solar installations!
We encourage you to obtain comparative estimates and review plans from other companies!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 to 30 years.
Confirming “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, specializing in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing material, such as slate, tiles, metal roofs, and flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of the Substrate and Waterproof Sheet | If the sheathing or roofing (waterproof sheet) under the roofing material is damaged, it will affect the fastening strength and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, Slope, and Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, will affect the power generation. 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 that can be installed (installation capacity) is determined by the shape and size of the roof. The number of panels that can be installed varies depending on the panel size, so 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 fastening or using brackets 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. After investigating the existing roof, substrate, and load-bearing capacity, switching to lighter roofing materials may also be an option if necessary. |
| 7. Installation Location of Equipment and Wiring | We will 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 is a height difference on the site, planning for scaffolding and the delivery route 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 the roof material and substrate with screws) | Waterproof treatment of fixing parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suited to 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 a method to replace with lightweight roofing material 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, a method that does not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you renovate the roof 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the roof is deteriorating, 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 Ayase City
PossibleSubsidies and Grants in Ayase City, Kanagawa Prefecture
If you introduce 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 Period for Subsidy Programs
| Program | 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. Applications are to be made after the completion of installation work, delivery of equipment, and payment, referred to as “post-application.” It is possible to combine with subsidies from the national or prefectural government, but there may be restrictions on combination from the national or prefectural programs. | Solar power generation equipment: 10,000 yen per kW (up to 30,000 yen) Stationary lithium-ion storage system: Fixed amount of 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 city’s official 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” | Installation of both solar power generation and storage systems in residential buildings (with earthquake resistance). 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 limit, and applications are closed. Please check the prefectural official page for future recruitment. |
| National “DR Home Storage Battery Project” (Reiwa Year 7 Supplement) | New installation of registered home storage systems that can be utilized for DR (demand response). | Calculated based on an initial effective capacity of 34,500 yen per kWh (subsidy rate within 3/10, maximum of 600,000 yen per application). | As of May 29, 2026, the budget has been reached, and public recruitment has ended (the official site states there are no plans to reopen public recruitment, and applications cannot be made at this time). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but they must be combined with essential works such as insulation renovations of windows (openings) and the structure; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities. | Storage battery: 96,000 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 application status. |
| Kanagawa Prefecture “Subsidy for Introduction of Self-Consumption Renewable Energy in Reiwa Year 8” | Corporations and individuals conducting blue return declarations (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) |
Application closed on September 3, 2026 (Application amount reached the budget amount) |
In Ayase City, the subsidy is applied for after the completion of installation work, once the equipment has been handed over and payment has been made, which is a “post-application” process, and it will end on a first-come, first-served basis as soon as the budget is reached. On the other hand, the Kanagawa Prefecture housing subsidy requires that construction begins only after receiving the “grant decision,” and starting work beforehand will disqualify the application. The eligibility conditions, application procedures, and the possibility of combining different systems vary by program, and applying does not guarantee that a grant will be awarded, so please confirm before contracting or starting work.
Kakeru Koumuten Co., Ltd. will provide guidance on the eligibility conditions and application periods for each program after confirming them.
National Subsidy “DR Home Battery Project (Support for the Introduction of Home Battery Systems for DR Resource Implementation)”
The national government has been implementing the “DR Home Battery Project” to support the installation of home batteries.
This program targets those who are introducing new registered battery systems that can be used for demand response (DR), and in the fiscal year 2025 supplementary budget, the subsidy amount was determined based on a standard amount of 34,500 JPY per 1 kWh of initial effective capacity, with a subsidy rate of up to 30% and a maximum of 600,000 JPY per application. There are conditions such as being ineligible for items contracted or ordered before the grant decision.
However, the fiscal year 2025 supplementary budget application amount reached the budget on May 29, 2026, and the public recruitment has ended. The official site also states that there are no plans to reopen the public recruitment, and applications cannot be made at this time. Please check the official site for future public recruitment.
Additionally, there are currently no subsidies specifically for the installation of solar panels on existing homes confirmed by the national government.
👉 Click here for the official site of the DR Home Battery Project
Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Housing Solar Power Generation and Battery Installation Subsidy”
Kanagawa Prefecture provides subsidies for those who install both “solar panels” and “batteries” in their homes.
The subsidy details are 70,000 JPY per 1 kW of solar power generation output and 150,000 JPY per battery system.
For example, if you install a 4 kW solar panel and one battery, the subsidy amount would be calculated as 4 kW × 70,000 JPY + 150,000 JPY = 430,000 JPY.
The eligibility includes homes that ensure seismic performance, the battery system must be a registered product, starting construction before the grant decision will disqualify the application, and the application must be made by the individual (applications by the construction contractor on behalf of the individual are not allowed). It is stated on the official city page that it is possible to combine this with the Ayase City subsidy, but there are also conditions from the prefectural program, so please check the official pages of each program before contracting.
For the fiscal year Reiwa 8, applications for the first phase (May 11 to June 30) and the second phase (starting September 7, first-come-first-served) were accepted. The second phase has been closed as of September 7, 2026, when the application amount reached the budget amount. Please check the official Kanagawa Prefecture page for future recruitment.
👉 Here is the official page of Kanagawa Prefecture
Kanagawa Prefecture “Reiwa 8 Fiscal Year Kanagawa Prefecture Subsidy for Introducing Self-Consumption Type Renewable Energy” (for businesses)
Kanagawa Prefecture is also implementing subsidies for businesses introducing “self-consumption type” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and individual residential installations are not eligible.
Conditions include that the solar power generation must have an output of 10 kW or more and supply power to business facilities within the prefecture, and that it must not be a facility certified under FIT or FIP.
The subsidy amount is 80,000 yen per kW for solar power generation and 50,000 yen per kWh for the accompanying storage system (with a maximum of 5 million yen).
As the application amount reached the budget amount for the fiscal year Reiwa 8, 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.
👉 For more details, click here
Ayase City “Subsidy for Introducing Renewable Energy and Energy-Saving Equipment for Individual Residences (Reiwa 8 Fiscal Year)”
Ayase City is implementing the “Subsidy for Introducing Renewable Energy and Energy-Saving Equipment for Individual Residences” for individuals installing renewable energy and energy-saving equipment in residences within the city.
● Solar power generation equipment: 10,000 yen per kW (maximum 30,000 yen)
● Stationary lithium-ion storage system: fixed 50,000 yen
● HEMS (Home Energy Management System): fixed 10,000 yen
● Home fuel cell system (Enefarm): fixed 50,000 yen
● Electric vehicle charging station (V2H): fixed 50,000 yen
● ZEH addition: fixed 100,000 yen
Eligible applicants are individuals who have resident registration at the location of the equipment installation, have no outstanding municipal taxes, use the equipment for home purposes, and do not fall under the Ayase City Organized Crime Exclusion Ordinance.
This subsidy is post-application, and applications are made after the installation work is completed, and the equipment has been delivered and payment has been made. The application period is from April 1, 2026, to March 15, 2027, and it will end as soon as the budget is reached on a first-come-first-served basis. The city’s official page (updated April 1, 2026) states that applications are currently being accepted, but 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 governments, so please check the conditions of each system.
👉 Click here for Ayase City official page
Solar Panel Installation & Battery Storage Fee Schedule
⇧Service Menu | For costs related to solar panel installation & battery storage, click here
⇧Service Menu | For costs related to solar panel removal & hot water heater removal, click here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and battery storage should be checked separately for “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, equipment grade, and roof condition.
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, represented 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, 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 as approximately 800,000 JPY to 1,200,000 JPY for 3 to 5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6 to 10 kW. (These are just rough estimates and may vary based on wiring length, scaffolding range, existing roofing materials, panel layout, etc.)
▶ Installation Menu | Costs for Solar Panel Installation and Battery Installation
Items to Confirm in the Estimate (Cost Confirmation)
When comparing estimates, it is common to compare different capacities and equipment by just looking at the amounts. 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 if it is a type that controls the battery together. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range usable during a power outage (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of hardware 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 for fixed parts, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | Extent of support 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 counted twice. |
| 9. Removal and Disposal | Whether the removal of existing solar 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, details and duration of manufacturer warranty and workmanship warranty. |
If the capacities differ, the amounts and power generation will also change. Kakeru Koumuten welcome price comparisons, so if you bring estimates from other companies, we will explain the differences item by item!
Self-Estimate and Profit and Loss Simulator for Solar Power Generation
With the simulator above,
you can obtain an estimated quote and income simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can get an estimated quote and income simulation!
*The simulation results are estimates. Actual income may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspections or replacements.
Customer Feedback
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installations
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh |
| Base Mounting Hardware Used |
| Niigata Manufacturing/Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| 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 subsidy being granted, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The subsidy 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 subsidies are available, and I would like to know how much will be granted. |
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 subsidies that will be granted, and we explained this 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.
For this reason,when requesting the installation of solar panels and storage batteries, let’s check the following four points.
● Not only knowledge of solar power but also extensive knowledge of roofing
● Confirm the presence or absence of warranties and aftercare
● Obtain estimates from multiple contractors (three companies as a guideline)
● Check if they provide support for subsidy applications
By confirming the above four points, you will be able to choose a reliable contractor.
Knowledge of roofing as well as solar panels
Improper installation of solar panels can be caused by a lack of knowledge and verification regarding roofing and waterproofing.
While knowledge of solar panels is certainly important, understanding the roofing and waterproofing of the installation area is also crucial.
⚠︎Examples of troubles caused by insufficient verification of roofing and waterproofing
・Solar panels installed on a deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring renovations to detach and reattach the panels within a few years
・Incorrect processing due to misjudgment of the type of waterproofing, leading to leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the presence or absence of warranties and aftercare
When choosing a solar installation contractor, make sure to check for warranties. It is important to verify not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While the solar panels and storage batteries come with a manufacturer’s warranty, also check for the presence of a workmanship warranty in case leaks occur after installation!
If the contractor offers a workmanship warranty, they may cover any leaks that occur after installation within the warranty period and conditions.
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 hidden areas, you may not notice them yourself.
By conducting inspections during aftercare, you can easily detect abnormalities early and prevent major repairs or failures!
At Kakeru Koumuten Co., Ltd., the installation of solar panels comes with a leak warranty as part of our workmanship warranty. (The warranty for solar panel installation is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovation is performed.)
We also conduct aftercare maintenance and send out annual DM!
Please check the DM, and if you wish, we will visit 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-sales 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,
“Check the items in the estimate”
“Type of solar panels”
“Warranties and after-sales services”
let’s carefully compare and make a judgment! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid judging solely based on price!
▶ Go to “Breakdown of installation capacity, equipment, and construction costs” in this article
Check if they provide support for subsidy applications
Subsidies may be available for solar panel installation and battery installation, but if the order of procedures is incorrect or if there are deficiencies in the documents, the grant may not be awarded.
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 grant approval) before proceeding with the construction!
For the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the grant will be awarded after a review! (The flow of procedures varies by system)
▶ Go 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!
The selling price for electricity has decreased compared to ten years ago, but by consuming the electricity generated, you can reduce the amount of electricity purchased from the utility company and gain benefits!
As electricity costs rise, the ability to cover 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 follows for certifications after October 2025: “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year.” The same price will apply for the fiscal year 2026. After the fifth year, it is generally more advantageous to use it at home (self-consume) rather than sell it, so combining it with a storage battery becomes an option.
👉 For purchase prices and periods, visit the Agency for Natural Resources and Energy
Advantage 2 Subsidies can be utilized!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
Reducing the actual burden through subsidies is a significant advantage!
In Ayase City, there is a possibility of being eligible for programs from the national government, Kanagawa Prefecture, and Ayase City (please check the application status for each program).
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 expected heat insulation effects!
（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 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 capability, 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 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 hardware with screws to the roofing material or substrate, 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 perform thorough waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and fixing the solar panels using the catch method is also an option. (The catch method has compatibility conditions between the roofing material and hardware, and it cannot be used with all metal roofs)
Catch-type base metal fittings for horizontal metal roofs
Note 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load capacity, replacing it with a lighter roof may be one 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 by Total Output of the Roof
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 vary in size and output depending on the manufacturer.
A panel with an output of 350W and a panel with an output of 400W may seem at first glance that the higher output panel is better.
However, if the size of the panel does not fit well with the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different installable quantities on the same roof due to the size difference.
400W × 15 panels = 6kW (total output of the roof)
350W × 20 panels = 7kW (total output of the roof)
As shown above, even if the output of a single panel is low, 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 (kWh) will vary depending on conditions such as the roof’s orientation, slope, and shading.
How to Choose 2: Compare by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases over 10 years and 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or electricity generation itself.
Choosing solar panels while considering the degradation rate will help avoid regrets!
How to Choose 3: Compare by 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!
It’s always better to have a longer warranty, so 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 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 roof condition. 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.
For cost estimates by capacity, please refer to our solar panel installation and storage battery installation pricing page. We will create a layout diagram from the drawings and site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Ayase City?
As of October 6, 2026, the Ayase City subsidy for renewable energy and energy-saving equipment for individual residences includes 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 official city page (updated April 1, 2026) states that applications are being accepted, but it will end as soon as 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 the 2026 fiscal year and has closed, while the national DR household storage battery project has ended its public recruitment.
Since the application status may change, please check 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 is a “post-application” that can be applied for after the installation work is completed and the equipment has been handed over and payment has been made. On the other hand, the Kanagawa Prefecture housing subsidy requires “commencement of work after grant decision,” and starting work beforehand will make it ineligible.
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 when fixing brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is essential.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation and, if deterioration is advanced, we can propose methods such as roof overlay (cover method) or replacement before installation.
The roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed after 10 to 20 years post-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 confirming the condition of the roof during the on-site survey!
Is it better to install a storage battery together with solar panels?
For those who want to use generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it in your home rather than selling it.
Additionally, Kanagawa Prefecture’s subsidy requires the simultaneous introduction of solar panels and storage batteries. In Ayase City, the subsidy specifies a fixed amount of 50,000 yen for stationary lithium-ion storage systems as eligible equipment. You can compare “solar panels only” and “solar panels + storage batteries” through a financial simulation.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram based on the drawings and on-site survey, and we will provide you with the installation capacity and generation simulation.
Ayase City has a terrain consisting of river terraces and flat land, and since the conditions of each site and surrounding area differ, the shadows cast by nearby buildings and trees and the installable capacity will also vary from house to house. You can check the expected generation amount through the generation simulation.
How long will the construction period be?
In the above construction example (solar panels 4.3 kW + storage battery), it took about 3 days. The duration may vary if roof work is done simultaneously or depending on the shape of the roof and installation capacity.
Please note that there will be additional time required for applications for subsidies and power companies, so please consult us as soon as possible.
What is the current selling price (FIT) for electricity?
For residential use (under 10 kW), from the certification after October 2025, the first four years will be 24 yen/kWh, and from the fifth to the tenth year, it will be 8.3 yen/kWh, and the same price will apply for the 2026 fiscal year.
The idea is to recover initial costs more 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 notices via DM and visits customers who wish to have inspections. We can also clean solar panels with a special brush if their generation capacity 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 renovate roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten can remove and reinstall solar panels in-house, allowing us to remove the panels, perform roof overlay (cover method) or re-roofing, and then reinstall them in a consistent manner. The removed panels can be stored in our own warehouse.
For costs, please refer to the solar panel removal and water heater removal pricing page.
If you are looking for a solar panel installation contractor in Ayase City, please consult Kakeru Koumuten
Our company handles a wide range of exterior renovations, including solar panels, roofing work, and exterior wall work in Ayase City.
We have received many requests from customers, including renovation companies and real estate agencies!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received positive feedback from many customers.
We continue to update our annual construction achievements and strive to improve quality to satisfy even more customers in the future.
Our company is capable of performing all exterior renovations, including roof overlay work and re-roofing, as well as partial roof repairs, exterior painting, and exterior cover methods.
We are also happy to assist with small jobs like partial repairs and rain gutter cleaning!
In urgent cases like water leak repairs, we may be able to provide temporary fixes without setting up scaffolding, as long as safety can be ensured, so please consult with 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 propose the best construction plans!
We are confident that we will not be outdone by other companies in terms of cost, quality, and organization for exterior work!
We are confident, so we welcome competitive estimates!
Estimates are completely free, and if our company is found 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.We have summarized the characteristics of Ayase City’s terrain and climate, as well as points to consider when installing solar panels and storage batteries below. (Tap to open)
View the features of Ayase City and points for solar work
■ The city formed by river terraces and flat land requires on-site confirmation of elevation differences and delivery routes
Ayase City is said to be formed by river terraces and flat land created by three rivers. In cases where there are elevation differences on the site, such as near the steps of the terrace, it may be necessary to devise plans for scaffolding and the delivery routes for equipment and materials like panels and storage batteries. Kakeru Koumuten Co., Ltd. plans scaffolding to match the site even when there are elevation differences, using its own scaffolding team and materials.
■ The city with three rivers checks equipment placement using hazard maps
Within Ayase City, the three rivers, Tade River, Hirukawa River, and Mekujiri River flow. The placement of 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 using hazard maps and consult us about the installation location.
■ The climate is relatively mild. The decrease in power generation due to shade and dirt is checked for each house
The climate of Ayase City is considered relatively mild. Power generation is affected not only by temperature but also by the amount of shade from surrounding buildings and trees, as well as the accumulation of fallen leaves and dirt. Before installation, we check the orientation and slope of the roof and the surrounding conditions on-site. If power generation decreases after installation, we can also respond with solar panel cleaning using a dedicated brush and rain gutter cleaning.
■ The types and ages of roofs 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. Kakeru Koumuten Co., Ltd. will propose methods for securing and waterproofing, as well as scaffolding plans, after confirming the type and condition of the roof and the site situation before installation.
■ The annual sunshine hours of the AMeDAS in the adjacent city of Ebina 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 an annual power generation simulation and selecting the capacity of storage batteries 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 sudden troubles!
Service Area in Ayase City
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and Tokyo.
List of Areas in Ayase City
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 Kamida / 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 Hon Tade River / Ayase City Yoshioka / Ayase City Yoshioka Higashi / Ayase City Ayase Nishi
・Leave your exterior wall painting in Ayase City to Kakeru Koumuten Co., Ltd.!
・Leave your roof renovation in Ayase City to Kakeru Koumuten Co., Ltd.!
・Leave your exterior renovation in Ayase City to Kakeru Koumuten Co., Ltd.!
・Kakeru Koumuten Co., Ltd.施工実績
・Kakeru Koumuten Co., Ltd. After Maintenance
・Kakeru Koumuten Co., Ltd.施工メニュー・料金表
・Kakeru Koumuten Co., Ltd. Staff Blog & 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!
・What are the best locations for installing solar power generation? Points to consider when selecting installation locations!
・Check out our solar power generation estimates here!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!
