Leave Your Solar Panel Installation in Hiratsuka City, Kanagawa Prefecture to Kakeru Koumuten Co., Ltd.!
For solar panel and storage battery installation in
Hiratsuka City, Kanagawa Prefecture,
trust Kakeru Koumuten!
Kakeru Koumuten is a specialized exterior renovation company headquartered in Aoba Ward, Yokohama City.
As a company strong in roofing work, we are entrusted withsolar panel installation and storage battery work that considers roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Hiratsuka City”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Hiratsuka City”
We will also explain the above three points!
Installing solar panels carries the risk of“water leaks” and other troubles.
To avoid regrets, we recommend obtainingthree or so estimates!
Table of Contents (Tap to Open/Close)
- Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Hiratsuka City, Kanagawa Prefecture
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Hiratsuka City
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installer in Hiratsuka City, Kanagawa Prefecture
- Benefits of Introducing Solar Equipment
- Points to Note When Introducing Solar Power Generation
- How to Choose Solar Panels
- Frequently Asked Questions about Solar and Storage Battery Installation in Hiratsuka City
- If You’re Looking for a Solar Panel Installer in Hiratsuka City, Contact Kakeru Koumuten
- Characteristics of Hiratsuka City, Kanagawa Prefecture, and Points for Solar Construction
- Service Area in Hiratsuka City, Kanagawa Prefecture
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Hiratsuka City, Kanagawa Prefecture
The reasons our company is entrusted with solar panel installation by customers in Hiratsuka City, Kanagawa Prefecture include
one reason being that Kakeru Koumuten has a base in Kanagawa Prefecture,
and our unique strengths in solar panel installation that cannot be imitated by other companies, which have received high praise from many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We also handle exterior renovations other than solar panel installation!
Troubles 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 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 knowledge about the roof to avoid maintenance and troubles after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent troubles after solar panel installation!
2.Equipment Specialized for Exterior Renovation
Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide low-cost, high-quality solar work and exterior renovations.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the necessary scaffolding materials for temporary scaffolding based on construction conditions, allowing us to assemble scaffolding ourselves.
By conducting scaffolding work with our own scaffolding team instead of outsourcing, we can also reduce scaffolding construction costs.
We have scaffolding materials for approximately 50 single-family homes!
In Hiratsuka City, where residential areas spread from the flatlands of the Sagami River and Kaname River to plateaus and hilly areas, our own 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, we 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 remodeling dedicated showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on the roofing materials!
It is also possible to simulate the revenue and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also 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 all work performed by our own team.
By having a consistent system from inquiry to completion, Kakeru Koumuten can provide high-quality roof renovations at reduced costs.
Additionally, one representative will handle everything from the estimate to the completion of the work.
Since the person in charge does not change, whether it is the sales representative or the construction management representative, smooth communication is possible.
We can perform consistent in-house work from the installation of temporary scaffolding to exterior wall painting and roof renovation!
4. Obtaining Various Permits and Skilled Workers on Staff
We have obtained construction industry permits and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal workers and painting technicians on staff, and we are confident in our construction techniques.
We can also handle large-scale roofing work for factories and other facilities!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty, our solar panel installation work comes with our own workmanship warranty (leakage warranty)!
(The workmanship warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless a roof renovation is performed. The workmanship warranty is separate from the manufacturer’s product warranty, and the coverage and conditions vary based on the warranty details.)
Aftercare maintenance is available annually, and we send out notification DM every year.
If you have any questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roof troubles and situations.
If you cannot access the roof at high altitudes, we can respond using a drone!
During leakage investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of the solar panels decreases due to dirt, we can also provide cleaning with a specialized brush.
We will respond according to your preferences.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly conduct skill enhancement education so that each staff member can handle various cases.
8. Creation of Clear Materials and Simulations
At Kakeru Koumuten Co., Ltd., we provide not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar installation guidebook” and a “financial simulation” that takes into account loan interest rates and electricity costs.
The financial simulation can project cumulative income and expenses over 20 to 30 years.
We compile easy-to-understand materials that include important points 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.
It is crucial to confirm before installation whether it is safe to place them directly on the current roof, as this is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten Co., Ltd., which specializes in roofing work, has summarized the items to check before installation.
| 1. Type of roofing material and age | The method of securing the panels varies depending on the roofing material, such as slate, tiles, metal roofs, or flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of the substrate and waterproof sheet | If the sheathing or roofing (waterproof sheet) beneath the roofing material is damaged, it can affect the fastening strength and waterproofing. We also check for signs of leaks. |
| 3. Orientation, slope, and shadows of the roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, can affect power generation. We create layout diagrams from blueprints and the site, and you can verify this with power generation simulations. |
| 4. Shape of the roof and installable 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 their size, so we compare based on the total output of the roof. |
| 5. Method of securing and waterproofing details | We check whether the panels will be secured by drilling holes in the roofing material or by using brackets to grip the roofing material. The method of securing varies by technique, so please confirm the waterproofing treatment of the fastening parts during the estimate. |
| 6. Weight of the roof | The roof will become heavier due to the added panels. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may be an option if necessary. |
| 7. Location of equipment installation and wiring | We confirm 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. |
Securing 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 fixed parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods 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 tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lightweight roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Compatibility of roof material and brackets, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you perform roof renovations 10 to 20 years after installation, there will be additional costs for the removal and reinstallation of 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 Hiratsuka City, Kanagawa Prefecture
PotentialSubsidies and Grants
When introducing solar panels or storage batteries in Hiratsuka City, there is a possibility of being eligible for programs from the “National Government,” “Kanagawa Prefecture,” and “Hiratsuka City.”
The following information is based on the official pages of each program as of October 6, 2026. The application status may change depending on the budget and application period, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Hiratsuka City “Solar Power Generation Equipment Installation Subsidy” | Individuals installing new solar power generation equipment in their own residence (or planned residence) within the city (must not have any tax arrears). Battery storage is an additional subsidy when installed simultaneously with solar power. Application must be submitted before construction begins. Cannot be combined with the Hiratsuka City Zero Energy House Subsidy. | Solar: 50,000 JPY/kW (up to 200,000 JPY, within 1/2 of the installation cost excluding tax) Battery: Additional 50,000 JPY |
Applications accepted from April 1, 2026 (first-come, first-served. As of September 11, 2026, 69 applications have been accepted) Project completion deadline is March 31, 2027 |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Residential Solar Power Generation and Battery Installation Subsidy” | Installation of both solar power generation and battery storage in earthquake-resistant single-family or multi-family homes within the prefecture. Applications must be submitted by the individual, and construction can begin after the grant decision. | Solar: 70,000 JPY/kW Battery: 150,000 JPY/unit |
Phase 1: May 11, 2026 – June 30, 2026 Phase 2: September 7, 2026 – September 30, 2026 (first-come, first-served) Phase 2 application period has ended. Please check the prefecture’s official page for future applications. |
| National “DR Home Battery Project” (Fiscal Year 2025 Supplement) | New installation of home battery systems that can be utilized for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 1 kWh at 34,500 JPY (subsidy rate within 3/10, maximum 600,000 JPY per application) | As of May 29, 2026, the budget has been reached, and applications are closed (currently not accepting applications) |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Battery storage is one of the eligible facilities, but it must be combined with essential renovations such as window (opening) and structural insulation improvements; applications cannot be made for battery installation alone. Solar panels are not included as eligible facilities. | Battery: 96,000 JPY/unit | Ends as soon as the budget cap is reached. Please check the official site for application status. |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Self-Consumption Renewable Energy Installation Subsidy” | Corporations and individuals filing blue returns (individual residences are not eligible). Solar must have a generation capacity of 10 kW or more, for business facilities, and equipment not certified under FIT/FIP. | Solar: 80,000 JPY/kW, etc. Battery system: 50,000 JPY/kWh (up to 5,000,000 JPY) |
Application period ended on September 3, 2026 (application amount reached the budget amount) |
In Hiratsuka City, it is necessary to apply for subsidies before starting construction, and for Kanagawa Prefecture’s housing subsidies, the condition is to start construction after receiving “grant approval”. If construction begins beforehand, it may be excluded from eligibility. Additionally, Hiratsuka City’s subsidies cannot be combined with the Hiratsuka City Zero Energy House Introduction Subsidy. The eligibility for combining city and prefectural subsidies must be confirmed for each system. Please note that applying does not guarantee that the grant will be awarded, so please check before signing a contract or starting construction.
At Kakeru Koumuten, we will provide guidance on the eligibility conditions and business requirements for each system after confirming them.
Hiratsuka City “Subsidy for Solar Power Generation Equipment Installation”
In Hiratsuka City, subsidies are provided for those who install solar power generation equipment in their own residence (or planned residence) within the city. Only new equipment is eligible; used items and leases are not eligible. It is also a condition that there are no outstanding municipal taxes.
The subsidy amount is 50,000 yen per 1 kW of solar power (up to 200,000 yen), and it must be within half of the installation price (excluding tax). If a stationary storage system is installed simultaneously, an additional 50,000 yen will be added. For example, if a 4 kW solar panel and a storage battery are installed at the same time, the maximum subsidy amount would be 4 kW × 50,000 yen + 50,000 yen = 250,000 yen.
Applications will be accepted on a first-come, first-served basis starting April 1, 2026, and as of September 11, 2026, 69 applications have been received. The project must be completed by March 31, 2027, and applications must be made before starting construction. This subsidy cannot be combined with the Hiratsuka City Zero Energy House Introduction Subsidy.
👉 Click here for the official Hiratsuka City page
National Subsidy “DR Home Storage Battery Project (Support Project for Home Storage System Installation for DR Resource Introduction)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those who are installing a new storage system of registered products that can be utilized for demand response (DR), and in the fiscal year 2025 supplementary budget, the subsidy amount was determined based on a standard amount of 34,500 yen per initial effective capacity of 1 kWh, with a subsidy rate of up to 30% and a maximum of 600,000 yen per application. There are also conditions such as that contracts or orders made before grant approval are not eligible.
However, the fiscal year 2025 supplementary budget reached its application limit on May 29, 2026, and the public offering has ended (the previous fiscal year 2024 supplementary budget also ended its public offering on July 2, 2025). Applications are currently not possible, so please check the official site for future public offerings.
Currently, there are no subsidies confirmed for the installation of solar panels for existing homes.
👉 Click here for the official DR Home Storage Battery Project site
Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Housing Solar Power Generation and Storage Battery Installation Subsidy”
Kanagawa Prefecture provides subsidies for those who install both “solar panels” and “storage batteries” in their homes.
The details of the subsidy are as follows: 70,000 yen per 1 kW of solar power generation output, and 150,000 yen per battery system.
For example, if you introduce a 4 kW solar panel and one battery, the calculation for the subsidy amount would be 4 kW × 70,000 yen + 150,000 yen = 430,000 yen.
The battery system must be a registered product, and if construction begins before the grant decision, it will be excluded. The application must be made by the individual (applications by the construction contractor are not allowed), and the eligible housing must ensure seismic performance. Regarding the combination with other subsidy systems, the eligibility may differ by system, so please be sure to check.
For the fiscal year Reiwa 8, the first application period is from May 11 to June 30, and the second period is from September 7 to September 30 (first-come, first-served). The second period is approaching its application deadline. For future recruitment, please check the official page of Kanagawa Prefecture.
👉 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 that introduce “self-consumption type” facilities that use electricity generated from solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and the introduction to individual residences is not eligible.
The solar power generation must have an output of 10 kW or more and supply electricity to business facilities within the prefecture, and 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 battery system (with a maximum of 5 million yen).
As the application amount reached the budget amount for the fiscal year Reiwa 8, the recruitment was closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Hiratsuka City should check the official page of Kanagawa Prefecture for the next recruitment.
👉 For more details, click here
Solar Panel Installation & Battery Installation Price List
⇧Service Menu | For Costs Related to Solar Panel Installation and Battery Installation, Click Here
⇧Service Menu | For Costs Related to Solar Panel Removal and Water Heater Removal, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and batteries should be confirmed by separating them into “Equipment Costs (Device Costs)” and “Construction Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary greatly depending on the installation capacity, equipment grade, and roof condition.
Considerations for Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatts). Batteries are compared based on the amount of electricity they can store, measured in kWh (kilowatt-hours).
The amount of kW that can be installed on a roof varies for each house based on the roof’s shape, orientation, and size. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panel installation costs 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 estimated amounts and may vary based on wiring length, scaffolding area, existing roofing materials, panel layout, etc.)
▶ Installation Menu | Costs for Solar Panel and Storage Battery Installation
Items to Confirm in the Estimate (Cost Verification)
When comparing estimates from different companies, it’s common to compare different capacities and equipment. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) should be listed. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also confirm if it is a type that controls the storage battery together. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range of use during power outages (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of the hardware suitable for the roofing material and the method of securing it (whether it involves drilling holes or clamping). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, and whether there is a monitor to check the power generation amount. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at the fixed points, and whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | How much support is included for applications to the power company, feed-in tariff (FIT) certification, and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If roof work and exterior painting are done simultaneously, check that the same scope and quantity are not double-counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters or old panels, and the disposal costs of waste materials are included. |
| 10. Tax Classification and Warranty | Whether the price is tax-inclusive or tax-exclusive, conditions under which additional costs may arise, and details and duration of manufacturer and workmanship warranties. |
If the capacities differ, both the price and power generation will change. Kakeru Koumuten Co., Ltd. welcome comparisons of estimates, so if you bring estimates from other companies, we can explain the differences item by item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can get an estimated quote and 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 obtain 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 inspection and replacement.
Customer Feedback
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Examples of Solar Panel Installation
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panels: 4.3kW Battery: 5kWh |
| Base Mounting Hardware Used |
| Niigata Manufactured / Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Details |
| Fixed using catch type hardware gripping the horizontal metal roof (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimates are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that grants are available, and I would like to know how much can be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of the grant, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Hiratsuka City, Kanagawa Prefecture
There are many solar panel installation contractors available in Hiratsuka City, Kanagawa Prefecture, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and storage battery installation work, let’s check the following four points.
● Have extensive knowledge not only about solar power but also about roofs
● Confirm the presence of warranties and after-sales maintenance
● Obtain estimates from multiple contractors (three companies as a guideline)
● Check if they provide support for subsidy applications
By confirming the above four points, you will be able to choose a reliable contractor.
Knowledge about roofs as well as solar panels
Improper installation of solar panels can be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient verification of roofs and waterproofing
・Solar panels were installed on a severely deteriorated roof, resulting in leaks
・Solar panels were installed on a roof with a short lifespan, necessitating a renovation for removal and reinstallation within a few years
・Misjudging the type of waterproofing led to incorrect treatment and subsequent leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the presence of warranties and after-sales maintenance
When choosing a solar installation contractor, 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 the solar panels and storage batteries come with a manufacturer’s warranty, also verify whether there is a workmanship warranty in case of leaks occurring after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may be able to address the issue under the warranty, provided it is within the warranty period and conditions.
Additionally, some contractors offer after-sales service separate from warranties, so be sure to check if the contractor you are considering has after-sales service.
Changes or damages on the roof may occur in areas that are not visible, so there is a possibility that customers may not notice them.
By conducting inspections during after-sales maintenance, you can easily detect abnormalities early, which helps prevent significant 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 after-sales maintenance and send out annual DM!
Please check the DM, and if you wish, we will visit for after-sales maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting the installation of solar panels, be sure to obtain estimates from multiple contractors.
Even for the same manufacturer and the same 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 the desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check the following:
“Check the items in the estimate”
“Type of solar panels”
“Warranties and after-sales services”
Make detailed comparisons to make your decision! If the quality of the auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making decisions based solely on price!
▶ Go to “Breakdown of Installation Capacity, Equipment, and Construction Costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
For systems like the Kanagawa Prefecture housing subsidy, where contractors cannot apply on behalf of the client, it is reassuring to have a contractor who can support the preparation of necessary documents and the flow of procedures.
Make sure to complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining the grant decision) before proceeding with the construction!
In the case of the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the grant will be provided after a review! (The flow of procedures varies by system)
▶ To “Subsidies and Grants That May Be Applicable in Hiratsuka City” within this Article
Benefits of Introducing Solar Power Systems
The benefits of introducing solar panels are summarized in the following 5 points!
Benefit 1: Economic Benefits
The biggest benefit of introducing solar panels is the economic advantage!
While the selling price of electricity has decreased compared to 10 years ago, you can benefit by reducing the amount of electricity you buy from the utility by consuming the electricity you generate!
As electricity prices rise, the ability to cover your consumption with solar power becomes increasingly attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
For residential use (under 10kW), the selling price (FIT) from certifications after October 2025 is set at “24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year.” The same price will apply for the 2026 fiscal year. After the 5th year, it is generally more advantageous to use the electricity at home (self-consumption), making the combination with a storage battery a viable option.
👉 Ministry of Economy, Trade and Industry | For purchase prices, periods, etc., click here
Benefit 2: You Can Utilize Subsidies!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the requirements, you may be able to utilize subsidies!
Reducing the actual burden through subsidies is a significant advantage!
In the case of Hiratsuka City, there may be subsidies available from the city and Kanagawa Prefecture, so please check the latest application status.
Benefit 3: Environmentally Friendly!
Solar power generation has low carbon dioxide emissions and reduces 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 produce operational noise.)
Benefit 4: Heat Insulation Effects Can Be Expected!!
By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the temperature rise of the roof, providing expected heat insulation effects!
(Note that this does not improve the insulation performance of the building itself.)
Benefit 5: Electricity can be used even during power outages!!
If a storage battery is installed, it becomes possible to use electricity even during emergencies such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capability, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1: Maintenance costs can be incurred
A particularly overlooked maintenance cost is for the roof where solar panels are installed.
If you perform roof remodeling 10 to 20 years later, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorating, it is reassuring to remodel it with durable roofing materials before installing the solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It is reassuring to ask for a simulation that considers maintenance costs before introducing solar panels!
Point 2: The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix hardware to the roofing material or substrate with screws, waterproofing treatment at the fixed points is crucial.
In methods that create holes in the roof, the risk of leaks inevitably arises.
Of course, we will ensure proper waterproofing treatment, 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-bearing capacity, replacing it with a lighter roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
How to Choose 1: Compare by Total Output of the Roof
When installing solar panels on the roof, it is important to consider how much electricity can be generated in a limited area, and generating more electricity is always better!
Solar panels come in various sizes and outputs depending on the manufacturer.
A panel with 350W output and a panel with 400W output may seem that the one with higher output is better at first glance.
However, if the size of the 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 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 one panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual electricity generation (kWh) will vary depending on conditions such as the orientation, slope, and shading of the roof.
How to Choose 2: Compare by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases after 10 years and 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not represent the actual degradation rate or electricity generation itself.
Choosing solar panels while considering the degradation rate, rather than just the initial output, will help you 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.
Regarding the output warranty, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies widely!
Since a longer warranty is always better, let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Hiratsuka City
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Hiratsuka City. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Hiratsuka City, Kanagawa Prefecture?
The cost varies depending on the installation capacity, equipment, and condition of the roof. In the above construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines for different capacities are published on the solar panel and storage battery installation pricing page. We will create a layout diagram from the drawings and site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Hiratsuka City?
As of October 6, 2026, Hiratsuka City’s “Subsidy for Solar Power Generation Equipment Installation” (50,000 yen per 1kW of solar power, with a maximum of 200,000 yen, plus an additional 50,000 yen for simultaneous installation of storage batteries) is currently accepting applications on a first-come, first-served basis (as of September 11, 2026, 69 applications have been accepted). The Kanagawa Prefecture subsidy (70,000 yen/kW for solar power and 150,000 yen per unit for storage batteries) is nearing the application deadline for the second term of fiscal year 2026, and the national DR home storage battery program 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?
In many programs, procedures must be completed before construction. The subsidy for Hiratsuka City requires “application before construction starts,” while the Kanagawa Prefecture subsidy requires “construction to start after the grant decision,” and if you install it beforehand, you may be excluded from eligibility.
The order of procedures varies by program, so please confirm before signing a contract or starting construction.
Can solar panels be installed on a slate roof? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate. The method of securing the panels varies by construction method, and if the method involves securing brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is crucial.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation, and if deterioration is progressing, we can also propose methods such as roof overlay (cover method) or replacement before installation.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed after 10 to 20 years, the cost for removing and reinstalling solar panels will be incurred separately. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with durable roofing materials before installation.
Please consult us on how to proceed with the installation after confirming the condition of the roof through a site survey!
Should I install a storage battery together with the solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 JPY/kWh after the fifth year, making it more advantageous to use it at home rather than selling it.
Additionally, the subsidy in Kanagawa Prefecture requires the simultaneous introduction of solar panels and storage batteries, and the subsidy in Hiratsuka City also provides an additional 50,000 JPY for installing the storage battery at the same time as the solar panels. You can compare “solar panels only” and “solar panels + storage battery” through a financial simulation.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and site survey, and provide you with the installation capacity and power generation simulation.
In Hiratsuka City, residential areas spread from plains to plateaus and hilly areas, and the shading caused by neighboring houses, trees, and surrounding buildings varies from one house to another. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
In the above construction example (solar panels 4.3 kW + storage battery), it took about 3 days. The duration may vary depending on whether roof work is done simultaneously or the shape and installation capacity of the roof.
Please note that there will be an additional period for applying for subsidies and to the power company, so please consult us as soon as possible.
What is the current selling price (FIT)?
For residential use (under 10 kW), from the certification after October 2025, the first 4 years will be 24 JPY/kWh, and from the 5th to the 10th year it will be 8.3 JPY/kWh, and the same price will apply for the 2026 fiscal year.
The idea is to recover the initial costs more quickly in the first 4 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 request inspections. We can also clean solar panels with a specialized brush if the power generation decreases due to dirt.
It is difficult to check areas on the roof by yourself, so 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 warehouse.
For information on costs, please see the solar panel removal and water heater removal pricing page.
If you are looking for a solar panel installation company in Hiratsuka City, please consult Kakeru Koumuten
Our company handles a wide range of exterior renovations, including solar panel installations, roof work, and exterior wall work in Hiratsuka City, Kanagawa Prefecture.
We have received requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received positive feedback from numerous customers.
We continue to update our construction performance 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 re-roofing but also partial roof repairs, exterior painting, and cover method 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 us!
“I want to know about recommended solar panels”, “I want to keep costs as low 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 that prioritizes profit!
We always stand in the customer’s position and will propose the best construction plan!
We are confident that we will not be outdone by other companies in terms of cost, quality, and organization for exterior work!
We are confident, so we welcome competitive quotes!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Features of Hiratsuka City, Kanagawa Prefecture, and Points for Solar Work
Hiratsuka City is located almost in the center of Kanagawa Prefecture, in the southern part of the Sagami Plain, and is a fan-shaped city that extends northwest from the coastline. According to the city’s official page, it is formed by the plains developed in the lower reaches of the Sagami River and the Kaname River, surrounded by plateaus and hills, with the Tanzawa and Oyama mountain ranges in the background.
Below are the features of Hiratsuka City and points to consider when installing solar panels and storage batteries. (Tap to open)
View features of Hiratsuka City and points for solar work
■ A city facing Sagami Bay. Check installation conditions for homes near the sea
Basic Information about Hiratsuka (Official City Site) states that Hiratsuka City is a fan-shaped city extending northwest from a coastline of approximately 3.8 km. In areas close to the sea, the installation conditions for salt damage areas set by manufacturers vary depending on the model. During the estimate, we will confirm the installation location and model conditions together.
Additionally, in locations susceptible to sea breezes, it is important to also check the panel fixation methods and the specifications of the mounting frames.
■ From plains to plateaus and hilly areas. Shadow checks for each individual house
According to the same basic information about the city, it is formed by plains and the plateaus and hills surrounding it. The way shadows fall on roofs varies from house to house due to surrounding buildings, trees, and elevation differences.
At Kakeru Koumuten, we create layout diagrams based on blueprints and the actual site conditions, allowing you to confirm through a power generation simulation.
■ City subsidies are on a first-come, first-served basis. Applications must be made before construction begins
Hiratsuka City Solar Power Generation Equipment Installation Subsidy (Official City Site) will be accepted on a first-come, first-served basis starting from April 1, 2026, and as of September 11, 2026, 69 applications have been received. Applications must be made before construction begins, and the project must be completed by March 31, 2027. It is important to confirm the timing of construction and the order of applications before signing the contract.
■ If exterior wall painting is done simultaneously, check the landscape rules as well
Notification of the Landscape Act and Hiratsuka City Landscape Ordinance (Official City Site) states that exterior repairs or color changes for buildings over 10 meters in height or with a total floor area of over 500 square meters are subject to notification, and even if repainting in the same color as the existing one, procedures are required. If exterior wall painting is done together with solar panels, it is necessary to check whether procedures are required based on the size of the building according to the city’s guidelines.
■ Check the roof condition according to the age of the building
For houses that have been built for many years, it is important to check the condition of the roofing materials and substrate before installing solar panels. Depending on the roof’s condition, installing them simultaneously with roof renovations can reduce future costs for removing and reinstalling solar panels.
■ Be cautious of fallen leaves, dirt, and sand dust from sea breezes
If dirt such as fallen leaves and sand dust accumulates on the roof, it may affect power generation. Kakeru Koumuten can also handle solar panel cleaning with specialized brushes and rain gutter cleaning.
Our company is based in Kanagawa Prefecture and has extensive experience in exterior construction and solar work in Hiratsuka 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 for any sudden troubles!
Service Area in Hiratsuka City, Kanagawa Prefecture
Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Hiratsuka City, Kanagawa Prefecture
Akashi-cho, Hiratsuka City / Tenuma, Hiratsuka City / Iijima, Hiratsuka City / Denawa, Hiratsuka City / Irino, Hiratsuka City / Iribe, Hiratsuka City / Enoki-cho, Hiratsuka City / Oimatsu-cho, Hiratsuka City / Oiwake, Hiratsuka City / Oogami, Hiratsuka City / Ooshima, Hiratsuka City / Oohara, Hiratsuka City / Okazaki, Hiratsuka City / Kataoka, Hiratsuka City / Kamiyoshizawa, Hiratsuka City / Kamihiratsuka, Hiratsuka City / Kitakaname, Hiratsuka City / Kitatoyoda, Hiratsuka City / Shirotokoro, Hiratsuka City / Kousho, Hiratsuka City / Kyoryotei, Hiratsuka City / Kurobeoka, Hiratsuka City / Kawachi, Hiratsuka City / Goten, Hiratsuka City / Konobeshima, Hiratsuka City / Saiwaicho, Hiratsuka City / Sakuragaoka, Hiratsuka City / Sanada, Hiratsuka City / Shironomiya, Hiratsuka City / Shimoyoshizawa, Hiratsuka City / Shimojima, Hiratsuka City / Shinmachi, Hiratsuka City / Suga, Hiratsuka City / Sumirehira, Hiratsuka City / Suwa-cho, Hiratsuka City / Asama-cho, Hiratsuka City / Sengokugawashi, Hiratsuka City / Chisugaya, Hiratsuka City / Sodegahama, Hiratsuka City / Daikan-cho, Hiratsuka City / Takane, Hiratsuka City / Takahamadai, Hiratsuka City / Takamura, Hiratsuka City / Takaracho, Hiratsuka City / Riteno-cho, Hiratsuka City / Tamura, Hiratsuka City / Tachijougaoka, Hiratsuka City / Tsuchiya, Hiratsuka City / Tsutsumi-cho, Hiratsuka City / Teradanawa, Hiratsuka City / Karagehara, Hiratsuka City / Tokunobu, Hiratsuka City / Toyoda Utagaki, Hiratsuka City / Toyoda Komine, Hiratsuka City / Toyoda Byoudouji, Hiratsuka City / Toyoda Hongou, Hiratsuka City / Toyoda Miyashita, Hiratsuka City / Toyohara-cho, Hiratsuka City / Nakazato, Hiratsuka City / Nakado, Hiratsuka City / Nakahara, Hiratsuka City / Nakahara Kamijuku, Hiratsuka City / Nakahara Shitajuku, Hiratsuka City / Nagatoro, Hiratsuka City / Nagamochi, Hiratsuka City / Nadeko-hara, Hiratsuka City / Nishimando, Hiratsuka City / Nishiyahata, Hiratsuka City / Nijigahama, Hiratsuka City / Nesakamata, Hiratsuka City / Hanamizudai, Hiratsuka City / Bairin, Hiratsuka City / Bairin Honcho, Hiratsuka City / Higashi Mando, Hiratsuka City / Higashi Toyoda, Hiratsuka City / Higashi Nakahara, Hiratsuka City / Higashi Yahata, Hiratsuka City / Hinataoka, Hiratsuka City / Hiratsuka, Hiratsuka City / Hirokawa, Hiratsuka City / Fujimicho, Hiratsuka City / Fujimino, Hiratsuka City / Sabamachi, Hiratsuka City / Beniya-cho, Hiratsuka City / Matsukaze-cho, Hiratsuka City / Matoi, Hiratsuka City / Manda, Hiratsuka City / Mitsuke-cho, Hiratsuka City / Minami Kaname, Hiratsuka City / Minami Toyoda, Hiratsuka City / Minamihara, Hiratsuka City / Miya no Mae, Hiratsuka City / Miyamatsu-cho, Hiratsuka City / Megumigaoka, Hiratsuka City / Momohama-cho, Hiratsuka City / Yaezaki-cho, Hiratsuka City / Yachiyo-cho, Hiratsuka City / Yamashita, Hiratsuka City / Yahata, Hiratsuka City / Yuuhi ga Oka, Hiratsuka City / Yokouchi, Hiratsuka City / Yoshikawa, Hiratsuka City / Ryuujo ga Oka, Hiratsuka City
・For exterior wall painting in Hiratsuka City, Kanagawa Prefecture, trust Kakeru Koumuten Co., Ltd.!
・For roof renovations in Hiratsuka City, Kanagawa Prefecture, trust Kakeru Koumuten Co., Ltd.!
・For exterior renovations in Hiratsuka City, Kanagawa Prefecture, trust Kakeru Koumuten Co., Ltd.!
・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!
・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!
