Leave the installation of solar panels in Hayama Town, Miura District, Kanagawa Prefecture to Kakeru Koumuten Co., Ltd.!
For
Solar Panel and Battery Installation in Hayama Town, Miura
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 withsolar panel and battery installation considering roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Hayama Town, Miura”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Hayama Town, Miura”
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 obtainingestimates from about three companies!
Table of Contents (Tap to Open/Close)
- Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Hayama Town, Miura District
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Hayama Town, Miura District
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Labor 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 Hayama Town, Miura District
- 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 Hayama Town, Miura District
- If You’re Looking for a Solar Panel Installation Contractor in Hayama Town, Miura District, Contact Kakeru Koumuten
- Characteristics of Hayama Town, Miura District and Key Points for Solar Installation
- Service Area in Hayama Town, Miura District
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Hayama Town, Miura District
The reasons why we are entrusted with solar panel installation by customers in Hayama Town, Miura District
“Our Unique Strengths in Solar Panel Installation That Cannot Be Imitated 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 estimates from any number of companies!
1. We Also Handle Exterior Renovations Beyond Solar Panel Installation!
Problems such as leaks that occur during solar panel installation may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if you are knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have expertise in roofing to avoid maintenance issues and troubles after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent troubles after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide low-cost, high-quality solar work and exterior renovations.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house 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 performing it with our own scaffolding team, we can also cut costs for scaffolding work.
We have approximately enough scaffolding materials for 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 price!
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 installed on roofing materials!
We can also provide simulations of potential earnings and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany projects, we also have samples of roofing materials and models that show the structure, allowing us to provide detailed explanations!
3.Complete in-house construction
One of Kakeru Koumuten’s major strengths is complete in-house construction.
By having Kakeru Koumuten handle everything from inquiries to project completion in a consistent system, we can keep costs down and provide high-quality roof renovations.
Additionally, one representative will assist you from the estimate to the completion of the work.
Since the sales and construction management representatives do not change, smooth communication is possible.
We can provide consistent in-house construction from temporary scaffolding installation, exterior wall painting, to roof renovations!
4. Various Permits Obtained & Skilled Workers on Staff
We have obtained construction industry permits as well as permits for industrial waste collection and transportation!
We also have nationally certified sheet metal workers and painting specialists on staff, and we are confident in our construction techniques.
We are capable of handling large-scale roofing projects such as factories!
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 roof renovations are performed. The construction warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary depending on the warranty details.)
Aftercare is available every year, and we send out notification DM each year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
If you cannot access the roof due to height, we can utilize a drone to assist!
During leak investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of solar panels decreases due to dirt, we can provide cleaning with a specialized brush.
We will respond according to your wishes.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly 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.
Even customers who are not familiar with solar construction will receive materials that clearly summarize important points and disadvantages!
We encourage you to obtain comparative estimates and compare them with other companies’ plans!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 to 30 years.
Confirming whether it is safe to install them directly on the current roof 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 method of securing 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 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 can 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, can affect 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 (installation capacity) that can be placed is determined by the shape and size of the roof. Since the number of panels that can be installed varies depending on the size of the panels, we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will 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 being added. 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 locations for the power conditioner and storage batteries, as well as the wiring route to the distribution board. The length of the wiring also affects costs. |
| 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 elevation differences on the site during the on-site survey. |
Fixing Methods and Confirmation Points by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproof treatment of fixing parts, cracks or deterioration of the slate, condition of the substrate. If deterioration is significant, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suitable for the type of tile (even methods that do not drill holes in the tiles will fix to the substrate) | Type and condition of the tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lighter roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you renovate the roof 10 to 20 years after installation, there will be additional costs for removing and re-installing 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 re-installation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Hayama Town, Miura District
PossibleSubsidies and Grants
If you are introducing solar panels or storage batteries in Hayama Town, Miura District, the systems from the “National,” “Kanagawa Prefecture,” and your residence “Hayama Town” may be applicable.
The following information is based on the official pages of each system as of October 6, 2026. The acceptance status may change depending on the budget, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Hayama Town “Renewable Energy System Installation Subsidy” | Must reside in the town and install the eligible system in a residence they occupy, with no outstanding town taxes. Solar power systems under 10kW are eligible. Application required before installation. | Solar power: 15,000 JPY per kW (maximum 50,000 JPY) Stationary lithium-ion batteries: 50,000 JPY Home fuel cells: 50,000 JPY |
According to the town’s official page (confirmed on October 6, 2026), applications are still being accepted. Grants are provided within budget limits, and the application deadline is set for the end of February each fiscal year. |
| Hayama Town “Accelerated Measures Subsidy” | Individuals installing self-consumption solar power generation systems and batteries (owned) in residential properties within the town. For home use, over 30% of the generated power must be self-consumed, and the FIT/FIP system must not be utilized. In principle, work cannot begin before grant approval. | Solar power: 70,000 JPY per kW (for home use) Batteries: Within 1/3 of the price (maximum 141,000 JPY per kWh). Only applicable when installed alongside solar power. |
As of June 19, 2026, applications for the fiscal year 2026 have reached the budget limit, and application acceptance has been suspended. |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Residential Solar Power Generation and Battery Installation Subsidy” | Must install both solar power generation and battery systems in residential properties (with earthquake resistance). Applications must be submitted by the individual, and work can only begin after grant approval. | Solar power: 70,000 JPY per kW Batteries: 150,000 JPY per unit |
Phase 1: May 11, 2026 – June 30, 2026 Phase 2: Starts September 7, 2026 (first-come, first-served) As of September 7, 2026, applications have reached the budget limit, and acceptance has been closed. Please check the prefecture’s official page for future announcements. |
| National “DR Home Battery Project” (Fiscal Year 2025 Supplement) | Newly install registered home battery systems that can be utilized for DR (demand response). | Calculated based on an initial effective capacity of 34,500 JPY per kWh (subsidy rate within 30% and maximum 600,000 JPY 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 applications, and currently, applications cannot be submitted.) |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Batteries are one of the eligible systems, but they must be combined with essential works such as insulation renovations of windows (openings) and structures; applications cannot be made for battery installation alone. Solar panels are not included as eligible systems. | Batteries: 96,000 JPY per unit | Ends as soon as 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 “Reiwa 8 Year Kanagawa Prefecture Self-Consumption Type Renewable Energy Introduction Subsidy” | Corporations and individual business owners filing blue returns (individual residences are not eligible). Solar power must have a generation output of 10kW 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) |
Application closed on September 3, 2026 (when the application amount reached the budget amount) |
Hayama Town’s subsidy requires application before installation work, and the “Priority Measures Acceleration Project Subsidy” also generally prohibits starting the project before the grant decision (applications for Reiwa 8 year have been suspended). For Kanagawa Prefecture’s residential subsidies, construction must start after receiving the “grant decision,” and starting beforehand will make you ineligible. Eligibility conditions, application procedures, and the possibility of combining different systems vary, and applying does not guarantee a grant, so please confirm before contracting or starting work.
At Kakeru Koumuten, we will guide you on the eligibility conditions and application periods for each system after confirming them.
National Subsidy “DR Home Storage Battery Project (Support Project for Home Storage System Introduction for DR Resource Implementation)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
Those introducing new registered products of storage systems that can be utilized for demand response (DR) are eligible, and in the Reiwa 7 fiscal year supplementary project, the subsidy amount was determined based on a standard amount of 34,500 JPY per initial effective capacity of 1kWh, with a subsidy rate of up to 30% and a maximum of 600,000 JPY per application. There are also conditions such as being ineligible for items contracted or ordered before the grant decision.
However, the Reiwa 7 fiscal year supplementary applications 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 are currently not possible. Please check the official site for future public recruitment.
Additionally, there are currently no subsidies confirmed for the installation of solar panels for existing homes.
👉 Click here for the official site of the DR Home Storage Battery Project
Kanagawa Prefecture “Reiwa 8 Year Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Introduction Subsidy”
In Kanagawa Prefecture, subsidies are provided for those who introduce both “solar panels” and “storage batteries” for residential use.
The subsidy details are 70,000 JPY per 1kW of solar power generation, and 150,000 JPY per storage system.
For example, if you introduce a 4kW solar panel and one storage battery, the subsidy amount would be calculated as 4kW × 70,000 JPY + 150,000 JPY = 430,000 JPY.
The target is residential buildings that ensure seismic performance, and the energy storage system must be a registered product. If construction begins before the grant decision, it will be excluded from eligibility. The application must be made by the individual (proxy applications by contractors are not allowed), among other conditions. Whether town and prefectural subsidies can be combined may vary by system, so please confirm with the town office before signing a contract.
For the fiscal year Reiwa 8, the first period (May 11 – June 30) and the second period (starting September 7, first-come-first-served) were accepted, and the second period has closed as of September 7, 2026, when the application amount reached the budget amount. For future recruitment, please check the official page of Kanagawa Prefecture.
👉 Click here for the official page of Kanagawa Prefecture
Kanagawa Prefecture “Reiwa 8 Fiscal Year Kanagawa Prefecture Subsidy for Introducing Self-Consumption Renewable Energy” (for businesses)
Kanagawa Prefecture is also implementing subsidies for businesses that introduce “self-consumption” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and installations in individual residences are not eligible.
Conditions include solar power generation with an output of 10 kW or more, supplying electricity to business facilities within the prefecture, and not being 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 energy storage system installed together (with a maximum of 5 million yen).
For the fiscal year Reiwa 8, applications were closed on September 3, 2026, as the application amount reached the budget amount.
Businesses considering the installation of solar panels on commercial buildings in Hayama Town, Miura District, should check the official page of Kanagawa Prefecture for the next recruitment.
👉 Click here for details
Hayama Town “Subsidy for Installing Renewable Energy Systems”
This subsidy is for residential solar power generation systems and stationary lithium-ion energy storage systems installed in homes within the town. Home fuel cell systems (Enefarm) are also included in the subsidy.
● Residential solar power generation system: 15,000 yen per kW (maximum 50,000 yen)
● Stationary lithium-ion energy storage system: 50,000 yen
● Home fuel cell system: 50,000 yen
Eligible applicants are those who reside in the town and install the eligible systems in their own homes, with the condition of no delinquency in town taxes, etc. Applications must be made before installation work, and after completion, a performance report must be submitted within 30 days of completion or by the end of March of the completion year, whichever comes first.
According to the town’s official page (confirmed on October 6, 2026), this subsidy is still accepting applications. Since the grant will be provided within the budget, please confirm the application status and the possibility of combining it with Kanagawa Prefecture’s subsidies with the town’s Environmental Division before signing a contract.
👉 Click here for Hayama Town’s official page
Hayama Town “Priority Measures Acceleration Project Subsidy” (Applications for Reiwa 8 fiscal year are currently suspended)
This is a subsidy for self-consumption type solar power generation systems and storage batteries (owned by the applicant) installed in residential homes within the town.
● Solar power generation systems (for home use): 70,000 yen per kW
● Storage batteries: Within 1/3 of the price (up to 141,000 yen per kWh). Only when installed alongside solar power.
For home use, it is a condition that more than 30% of the generated electricity is self-consumed and that the FIT/FIP system is not utilized. In principle, work cannot begin before the grant decision is made. The town’s official page states that applications for Reiwa 8 fiscal year reached the budget limit on June 19, thus suspending acceptance. Please check the town’s official page for future resumption or plans for the next fiscal year.
👉 Click here for Hayama Town’s official page
Solar Panel Installation & Storage Battery Installation Price List
⇧Service Menu | Click here for costs related to solar panel removal & water heater removal
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and storage batteries should be confirmed separately as “Equipment Costs (Device Costs)” and “Construction Costs.”
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.
Considerations for Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatts). Storage batteries are compared based on the amount of electricity they can store, represented in kWh (kilowatt-hours).
The amount of kW that can be installed on a roof varies for each house based on the roof’s shape, orientation, and size. At Kakeru Koumuten, we create 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 3-5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6-10 kW. (These are just approximate amounts and can vary based on wiring length, scaffolding range, existing roofing materials, panel layout, etc.)
▶ Construction Menu | Costs for Solar Panel and Storage Battery Installation
Items to Confirm in the Quotation (Cost Confirmation)
When comparing quotes, it is common to compare different capacities and equipment by only looking at the amounts. Please check if the following items are clearly stated in each company’s quotation!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) are specified. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls the battery together. |
| 3. Storage 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 the hardware suitable for the roofing material and the fixing method (whether it is a method that drills holes or a method that clamps and fixes). |
| 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 points, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Application | How much support is included for applications to the power company, certification applications for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If 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 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-excluded, conditions under which additional costs may arise, details and duration of manufacturer warranty and workmanship warranty. |
If the capacity differs, both the amount and power generation will change. Kakeru Koumuten Co., Ltd. warmly welcomes competitive estimates, so if you bring estimates from other companies, we will explain the differences for each item!
Self-Estimate and Profit and Loss Simulator for Solar Power Generation
With the simulator above,
you can obtain an approximate estimate and a profit and loss simulation up to 30 years later!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can obtain an approximate estimate and profit and loss simulation!
*The simulation results are approximate. Actual profit and loss may vary depending on assumptions such as electricity rates, self-consumption ratio, selling price of electricity, and costs for equipment inspection or replacement.
Customer Voices
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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
| Work Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh range |
| Base Mounting Hardware Used |
| Niigata Manufactured / Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed by catching the horizontal metal roof with catch type hardware (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction and may differ under the current system. |
| Construction Period |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that grants are available, and I would like to know how much will be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected grant amount, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Hayama Town, Miura District
There are many solar panel installation contractors serving Hayama Town, Miura District, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and battery installation work, let’s check the following 4 points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the presence of warranties and after-sales maintenance
● Obtain estimates from multiple contractors (3 companies is a guideline)
● Check if they provide support for subsidy applications
By confirming the above 4 points, you will be able to choose a reliable contractor.
Knowledge about roofs as well as solar panels
Defective installation of solar panels can sometimes be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient checks on roofs and waterproofing
・Solar panels installed on a deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring remodeling for removal and reinstallation within a few years
・Misjudging the type of waterproofing and applying incorrect treatment, resulting in leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unforeseen troubles.
▶ Go to “Roof Check Before Installing Solar Panels” in this article
Confirm the presence of warranties and after-sales maintenance
When choosing a solar installation contractor, let’s confirm the presence of warranties. It is important to check not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While solar panels and batteries come with manufacturer warranties, also check for the presence of a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may cover it under the warranty if it falls within the warranty period and conditions.
Additionally, some contractors offer after-sales services separate from warranties, so make sure to check if the contractor you are considering has after-sales service.
Since abnormalities or damages on the roof may not be visible, you might not notice them yourself.
By conducting inspections of hidden areas during after-sales maintenance, you can more easily detect abnormalities early and prevent major repairs or failures!
Kakeru Koumuten Co., Ltd. provides a leak warranty as part of the workmanship warranty for solar panel installations. (The warranty for solar panel installations is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovations are performed.)
We also conduct aftercare maintenance and send out annual DM!
Please check the DM, and 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 construction content, costs may vary, and warranties and after-sales services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check:
“Check the estimate items”
“Type of solar panel”
“Warranties and after-sales services”
and make a detailed comparison! Avoid judging solely based on cost, as using lower-grade materials or skipping processes can reduce costs!
▶ Go to “Breakdown of installation capacity, equipment, and construction costs” in this article
Confirm 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 residential subsidies, where contractors cannot apply on behalf of clients, it is reassuring to have a contractor who can support you in preparing necessary documents and understanding the procedure flow.
Complete the procedures specified for each system (for the prefectural residential subsidy, this means obtaining a grant decision) before proceeding with the construction!
For the prefectural residential subsidy, after the construction is completed, a performance report must be submitted, and the subsidy will be granted after a review! (The procedure flow varies by system)
▶ Go to “Subsidies and grants that may be applicable in Hayama Town, Miura District” 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 of electricity has decreased compared to ten years ago, but by consuming the generated electricity, you can reduce the amount of electricity purchased from the utility company and gain benefits!
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 at “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 generally more advantageous to use it in your home (self-consumption) rather than selling it, so combining it with a storage battery is also an option.
👉 Ministry of the Environment and Energy | For purchase prices, periods, etc., click here
Advantage 2 You can utilize subsidies!
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 Hayama Town, there is a possibility that both national and Kanagawa Prefecture systems, as well as the town’s system, 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 like 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 insulation performance of the building itself.)
Benefit 5 Electricity can be used even during power outages!!
If a storage battery is installed, it becomes possible to use electricity even during emergencies such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation functionality, you may be able to use electricity from a dedicated outlet during daytime generation.
(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 maintenance cost that is often overlooked 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 reinstalling the solar panels.
If the existing roof is deteriorating, 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 ask for a simulation that considers maintenance costs before introducing solar panels!
Point 2 The risk of leaks may increase depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but when fixing hardware to the roofing material or substrate with screws, waterproofing of the fixed parts becomes important.
In methods that involve making holes in the roof, there will inevitably be a risk of leaks.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and fixing the solar panels using a 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 hardware specifically 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 capacity, replacing 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 Output of the Roof
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and generating more power is always better!
Solar panels come in various sizes and outputs depending on the manufacturer.
A 350W output panel and a 400W output panel may seem that the higher output panel is better at first glance.
However, if the size of the panels 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,” leading to different numbers of panels that can be installed on the same roof due to size differences.
400W×15 panels = 6kW (total output of the roof)
350W×20 panels = 7kW (total output of the roof)
As shown above, even if the output of a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual power generation (kWh) will vary depending on conditions such as the roof’s 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 over 10 or 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or power generation itself.
By considering the degradation rate along with the initial output, you can choose solar panels without regrets!
How to Choose 3: Compare Based on Warranty Period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
For output warranties, some manufacturers offer a 30-year warranty while others offer only a 10-year warranty, so they differ!
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 Hayama Town, Miura District
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Hayama Town, Miura District. (Tap to open answers)
How much does it cost to install solar panels and storage batteries in Hayama Town, Miura District?
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.
Estimates by capacity are published on our solar panel installation and storage battery installation pricing page. We will create a layout diagram from the drawings and on-site survey and provide a free estimate!
Are there any subsidies available for solar and storage battery installations in Hayama Town, Miura District?
As of October 6, 2026, Hayama Town’s “Renewable Energy System Installation Subsidy” (1.5 million yen per kW for solar, up to 50,000 yen; 50,000 yen for storage batteries) is still accepting applications as posted on the town’s official page. The town’s “Priority Measures Acceleration Project Subsidy” (70,000 yen per kW for solar) reached its budget on June 19 for the fiscal year 2026, and applications have been suspended. Please check the application status for fiscal year 2026 at the town office. Kanagawa Prefecture’s subsidy (70,000 yen/kW for solar; 150,000 yen per unit for storage batteries) closed on September 7 after reaching its budget 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. Hayama Town’s subsidy requires application before installation, and the Priority Measures Acceleration Project Subsidy also generally prohibits starting the project before the grant decision. Kanagawa Prefecture’s residential subsidy requires “starting construction after grant decision,” and starting beforehand will make you ineligible.
The order of procedures varies by system, so please confirm before signing a contract or starting construction.
Can solar panels be installed on a slate roof? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate. The fixing method varies by construction method, and when fixing brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is essential.
Kakeru Koumuten is a specialist in exterior renovations strong in roofing work, so we will check the roof condition before installation and suggest methods such as roof overlay or replacement if deterioration is advanced.
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 reattaching 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 roof condition through an 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, we recommend simultaneous installation. The selling price will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it in your home rather than selling it.
Additionally, the subsidy in Kanagawa Prefecture requires the simultaneous introduction of solar power and storage batteries. In Hayama Town, the subsidy also specifies that storage batteries are eligible equipment (the fixed lithium-ion storage system is 50,000 yen). You can compare “solar power only” and “solar power + storage battery” through a financial simulation for your consideration.
How many kW can be installed on our 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 provide you with the installation capacity and power generation simulation.
Hayama Town is surrounded by mountains and forests and faces the sea, so the shading from surrounding buildings and trees and the installable capacity differ for each house. You can check the expected power generation through the power generation simulation.
How long does the construction period take?
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 there is a separate period required for applications for subsidies and power companies, so please consult us as soon as possible.
What is the current selling price (FIT)?
For residential use (less than 10 kW), the price from certifications after October 2025 will be 24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year, and the same price will apply for the 2026 fiscal year.
The idea is to recover initial costs quickly in the first four years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that considers loan interest rates and electricity charges.
Can you handle maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-service maintenance notices via DM and visits customers who wish to have inspections. We can also clean solar panels with a special brush if the power generation decreases due to dirt.
It can be difficult to check areas on the roof by yourself, so please feel free to consult us if you have any concerns.
Can you handle renovations on roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten can detach and reattach solar panels in-house, so we will handle the process of removing the panels, performing the roof overlay (cover method) or re-roofing, and then reinstalling them consistently. The removed panels can be stored in our 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 Hayama Town, Miura District, please consult Kakeru Koumuten Co., Ltd.
Our company handles a wide range of exterior renovations, including solar panel installations, roofing work, and exterior wall work in Hayama Town, Miura District.
We have received requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten Co., Ltd. promises “high-quality renovations at low costs”, and we have received great feedback from numerous customers.
We continue to update our number of completed projects each year and will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay work and roof replacement but also partial roof repairs, exterior painting, and cover installations for exterior walls.
We are also 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 emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult with us!
Whether you want to know about recommended solar panels, keep costs as low as possible, or just get an estimate, we will provide the best solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in our customers’ shoes and will propose the optimal construction plan!
We are confident that we will not be outdone by other companies in terms of cost, quality, and organization for exterior work!
We welcome competitive estimates with confidence!
Estimates are completely free, and if you find our company lacking compared to others, feel free to decline!
Characteristics of Hayama Town, Miura District, and Points for Solar Work
Hayama Town is located in the northwestern part of the Miura Peninsula, bordered by Zushi City to the north, Yokosuka City to the east and south, and facing Sagami Bay to the west, with an area of 17.04 square kilometers. The urban area is somewhat elongated east to west and is concentrated in the western half of the town. The town is also characterized by its natural environment, covered with mountain ridges and beautiful forests, due to the Kuroshio current flowing through Sagami Bay and annual precipitation exceeding 1,000 millimeters. Below are the characteristics of the terrain in Hayama Town, Miura District, and points to consider when installing solar panels and storage batteries. (Tap to open)
View the characteristics of Hayama Town, Miura District, and points for solar work
■ A town surrounded by mountain ridges and forests. Check tree shadows and delivery routes on-site.
In the town, the Moritogawa and Shimoyamakawa rivers flow west, surrounded by mountain ridges and beautiful forests. In areas with trees and undulations, the shadows cast on the roof change depending on the time of day and season, so it is important to confirm the arrangement of panels on-site. Additionally, the height differences of each site and the width of the front road will affect the planning of scaffolding and the delivery routes for equipment and materials such as panels and storage batteries. Kakeru Koumuten Co., Ltd. plans scaffolding to suit the site using its own scaffolding team and materials.
■ Annual precipitation exceeds 1,000 millimeters. Plan including roof and waterproofing
In areas with heavy rainfall, the waterproofing of the roof that secures the panels is a crucial point for long-term reliability. As a contractor specializing in roofing and waterproofing, Kakeru Koumuten Co., Ltd. proposes installations after confirming the waterproofing around the panel securing hardware and the condition of the existing roof.
■ A town close to the sea facing Sagami Bay. Confirm installation conditions based on manufacturer standards
In coastal areas, installation conditions for panels, frames, and hardware (handling in salt damage areas) may be specified for each product. The response may vary depending on the distance from the coast, so please check the installation conditions of the manufacturers used when requesting a quote.
■ Roof types and ages vary from house to house. Check roof and waterproofing before installation
Even within the same town, roof types, ages, and sunlight exposure vary from house to house. Kakeru Koumuten Co., Ltd. will propose securing methods, waterproofing arrangements, and scaffolding plans after confirming the type and condition of the roof and the site situation before installation.
■ The annual sunshine hours at the Miura Observatory on the same Miura Peninsula is about 2,147 hours
According to the Japan Meteorological Agency’s average values (1991–2020), the annual sunshine hours at the Miura Observatory on the same Miura Peninsula is about 2,147 hours, with August (approximately 234 hours) being the most and June during the rainy season (approximately 144 hours) being the least. (This is a reference value, not based on measurements in Hayama Town.)
The power generation in Hayama Town is also affected by shadows from surrounding trees and buildings, so conducting an annual power generation simulation and selecting the capacity of storage batteries to match peak electricity usage times is essential.
Our company is based in Kanagawa Prefecture and has handled many exterior construction and solar power projects in Miura District, Hayama Town.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us for any urgent issues!
Service Area in Miura District, Hayama Town
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and Tokyo.
List of Areas in Miura District, Hayama Town
Hayama Town Isshiki / Hayama Town Kamiyamaguchi / Hayama Town Kikoniwa / Hayama Town Shimoyamaguchi / Hayama Town Nagara / Hayama Town Horiuchi
・Trust Kakeru Koumuten for exterior wall painting in Hayama Town, Miura District!
・Trust Kakeru Koumuten for roof renovations in Hayama Town, Miura District!
・Trust Kakeru Koumuten for exterior renovations in Hayama Town, Miura District!
・Kakeru Koumuten Co., Ltd. project achievements
・Kakeru Koumuten Co., Ltd. aftercare services
・Kakeru Koumuten Co., Ltd. service menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of comparative estimates and key points!
・Top 12 solar power generation manufacturers! Features and selection tips included!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
・What are the best locations for solar power installation? Key points for site selection included!
・Find out more about solar power generation estimates here!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!
