Leave Your Solar Panel Installation in Hiratsuka City, Kanagawa Prefecture to Kakeru Koumuten Co., Ltd.!
For solar panel and 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 with solar panel and battery installation considering roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Hiratsuka City”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Hiratsuka City”
We will also explain the above three points!
Installing solar panels carries risks such as “the occurrence of leaks” and other troubles.
To ensure a satisfactory solar panel installation, we recommend obtaining about three estimates!
Table of Contents (tap to open/close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Hiratsuka City, Kanagawa Prefecture
- Roof Inspection Before Installing Solar Panels
- Subsidies and Grants That May Be Applicable 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 Are 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 Why Kakeru Koumuten is Chosen for Solar Panel Installation in Hiratsuka City, Kanagawa Prefecture
The reasons why we are 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 Can 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 you are knowledgeable about solar panels, there may be cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have expertise in roofing to avoid maintenance 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 prepared the following warehouses and material storage areas to provide low-cost, high-quality solar work and exterior renovations.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding according to construction conditions and can assemble scaffolding in-house.
By not outsourcing scaffolding work and using our own scaffolding team, we can also cut costs for scaffolding work.
We own scaffolding materials for approximately 50 single-family homes!
In Hiratsuka City, where residential areas spread from the flatlands opened up in the lower reaches of the Sagami River and Kaname River to plateaus and hilly areas, our in-house scaffolding team will plan scaffolding according to the local conditions.
Storage of Materials in Our Large Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you can purchase materials at a lower cost!
Additionally, we always have roofing materials in stock, so we can respond quickly in emergencies!
In-house sorting and transportation of waste materials
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 reduce waste disposal costs.
Exterior renovation dedicated showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are attached to the roofing materials!
We can also provide simulations of potential earnings and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also have samples of roofing materials and models that explain the structure, allowing for detailed explanations!
3.All work performed by our own team
One of Kakeru Koumuten’s major strengths is its complete in-house construction.
By having Kakeru Koumuten handle everything from inquiries to project completion in a consistent manner, we can keep costs down and provide high-quality roof renovations.
Additionally, one representative will assist you from the estimate to the completion of the work.
Since the担当者 such as sales and construction management 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 and Skilled Workers
We have obtained permits for the construction industry and for the collection and transportation of industrial waste!
We also have nationally certified sheet metal and painting technicians, and we are confident in our construction skills.
We can also handle large-scale roofing projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation, we also provide our own construction warranty (leakage warranty)!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless a roof renovation is performed. The construction warranty is separate from the manufacturer’s product warranty, and the 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.
Even if you cannot access the roof at high places, we can respond using a drone!
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 also provide cleaning services using specialized brushes.
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 technical training to ensure that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
Kakeru Koumuten provides “estimates”, “layout diagrams”, and “power generation simulations”, as well as “solar construction guidebooks” and “profit and loss simulations” that take into account loan interest rates and electricity costs.
Profit and loss simulations can be created for projected cumulative profits and losses over 20 to 30 years.
Even customers who are not familiar with solar construction will receive easy-to-understand materials that include points to consider 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 or 30 years.
Confirming “Is it okay to install them directly on the current roof?” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, which specializes in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing materials, such as slate, tiles, metal roofs, and flat roofs (rooftop waterproofing). If the remaining lifespan of the roofing material is short, we may suggest roof renovation first. |
| 2. Condition of Substrate and Waterproof Sheet | If the sheathing or roofing (waterproof sheet) under the roofing material is damaged, it can affect the fixing strength of the hardware 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 the amount of electricity generated. We will create a layout diagram from the drawings and the site, and you can confirm it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels (installation capacity) that can be placed depends on the shape and size of the roof. Since the number of panels that can be installed varies depending on the panel size, we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will check whether the method involves drilling holes in the roofing material for fixing or using hardware to grip and secure the roofing material. The fixing method varies by technique, so please confirm the waterproofing treatment method for the fixing 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, switching to lighter roofing materials may also be an option if necessary. |
| 7. Installation Location of Equipment and Wiring | We will confirm the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring also affects the cost. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproofing of fixed parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay or replacement first. |
| Tile Roof | Fixed with brackets and methods suited to the type of tile (even methods that do not drill holes in the tiles will secure to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lightweight roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a framework | Type and deterioration status of the waterproof layer, waterproofing around the framework. Consider in conjunction with the timing of waterproofing work. |
If you renovate the roof 10 to 20 years after installation, additional costs for removing and reinstalling solar panels will apply. 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 is strong 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
PossibleSubsidies and Grants in Hiratsuka City, Kanagawa Prefecture
If you introduce solar panels or storage batteries in Hiratsuka City, you may be 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 due to budget and recruitment periods, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| 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). An additional subsidy is available for storage batteries if installed simultaneously with solar power. Application must be made before construction starts. Cannot be combined with the Hiratsuka City Zero Energy House Installation Subsidy. | Solar Power: 50,000 JPY/kW (up to 200,000 JPY, within 1/2 of the installation price excluding tax) Storage Battery: Additional 50,000 JPY |
Applications are being accepted from April 1, 2026 (first-come, first-served. As of September 11, 2026, 69 applications have been received) The deadline for project completion is March 31, 2027. |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Installation Subsidy” | Installation of both solar power generation and storage batteries in earthquake-resistant single-family homes or multi-family residences within the prefecture. Applications must be made by the individual, and construction can start after the grant decision. | Solar Power: 70,000 JPY/kW Storage 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 has reached its application deadline. Please check the prefecture’s official page for future recruitment. |
| National “DR Home Storage Battery Project” (Fiscal Year 2025 Supplement) | New installation of home storage systems using registered products that can be utilized for DR (demand response). | 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 now closed (currently, applications cannot be made). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but they must be combined with essential works such as insulation renovations of windows (openings) and the structure; applications cannot be made for the installation of storage batteries alone. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 JPY/unit | Ends as soon as the budget limit is reached. Please check the official site for application status. |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Self-Consumption Type Renewable Energy Installation Subsidy” | Corporations and individuals filing blue returns (individual residences are not eligible). Solar power must have a generation output of 10 kW or more, for business facilities, and equipment not certified under FIT/FIP. | Solar Power: 80,000 JPY/kW, etc. Storage System: 50,000 JPY/kWh (maximum 5,000,000 JPY) |
Recruitment 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 subsidy will be granted, so please check before signing a contract or starting construction.
At Kakeru Koumuten Co., Ltd., we will guide you on the eligibility conditions and requirements for businesses after confirming them for each system.
Hiratsuka City “Solar Power Generation Equipment Introduction Subsidy”
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 delinquent city taxes.
The subsidy amount is 50,000 yen per 1kW 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 4kW solar panel and a storage battery are installed simultaneously, the subsidy amount’s upper limit would be 4kW × 50,000 yen + 50,000 yen = 250,000 yen.
Applications 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. The project must be completed by March 31, 2027, and applications must be made before starting construction. It 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 Introducing Home Storage Systems for DR Resources)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This project targets those who introduce new storage systems 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 1kWh, with a subsidy rate of up to 30% and a maximum of 600,000 yen per application. There are conditions such as that items contracted or ordered before grant approval are not eligible.
However, the fiscal year 2025 supplementary budget application amount reached the budget on May 29, 2026, and the public recruitment has ended (the previous fiscal year’s supplementary budget also ended public recruitment on July 2, 2025). Currently, applications cannot be made, so 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 DR Home Storage Battery Project site
Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Housing Solar Power Generation and Storage Battery Introduction Cost 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 storage system.
For example, if you introduce a 4 kW solar panel and one storage battery, the calculation for the subsidy amount would be 4 kW × 70,000 yen + 150,000 yen = 430,000 yen.
Conditions include that the storage system must be a registered product, if construction starts before the grant decision, it will be excluded, and the application must be made by the individual (proxy applications by contractors are not allowed). The targeted housing must also ensure seismic performance. Regarding the combination with other subsidy systems, the eligibility may vary by system, so please be sure to check.
In the 2026 fiscal year, the first application period (May 11 – June 30) and the second application period (September 7 – September 30, first-come-first-served) were conducted, and the second period has reached its application deadline. For future recruitment, please check the official page of Kanagawa Prefecture.
👉 Here is the official page of Kanagawa Prefecture
Kanagawa Prefecture “2026 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 by solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and the introduction to individual residences is not eligible.
Conditions include that solar power generation must have an output of 10 kW or more, supply electricity to business facilities within the prefecture, and not be equipment certified under FIT or FIP.
The subsidy amount is 80,000 yen per 1 kW of solar power generation, and 50,000 yen per 1 kWh for the accompanying storage system (with a maximum of 5 million yen).
In the 2026 fiscal year, the application amount reached the budget amount, and applications were 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 & Storage Battery Installation Price List
⇧Service Menu | For Costs of Solar Panel Installation and Battery Installation, Click Here
⇧Service Menu | For Costs of Solar Panel Removal and Water Heater Removal, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and batteries should be confirmed by separating them into “Equipment Costs (Device Costs)” and “Construction Costs.”
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on 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, represented in kWh (kilowatt-hours).
The amount of kW that can be installed on a roof varies for each house depending on the shape, orientation, and size of the roof. 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 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.)
▶ Service Menu | For Costs of Solar Panel Installation and Battery Installation, Click Here
Items to Confirm in the Estimate (Cost Confirmation)
When comparing estimates, 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). |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also confirm whether it is a type that controls the battery together. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range of use during power outages (whole house or specific circuits), installation location. |
| 4. Mounting Frame and Fittings | Name of the fittings suitable for the roofing material and the method of securing them (whether it involves drilling holes or using clamps). |
| 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 the fixed points, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | Extent of support for applications to the power company, certification applications for selling electricity (FIT), 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 and old panels, as well as disposal costs for waste materials, are included. |
| 10. Tax Classification and Warranty | Whether prices are tax-inclusive or tax-exclusive, conditions under which additional costs may arise, 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, so if you bring estimates from other companies, we can explain the differences item by item!
Self-Estimate and Profit and Loss Simulator for Solar Power Generation
With the simulator above,
you can obtain a rough estimate and a profit and loss simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the battery, you can get a rough estimate and profit and loss simulation!
*The simulation results are approximate. Actual profit and loss may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection or replacement.
Customer Testimonials
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel 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 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 will be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of 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 battery storage installation work, let’s confirm the following four points:
● They should have extensive knowledge not only about solar panels but also about roofs
● Confirm whether there is a warranty and aftercare service
● Obtain estimates from multiple contractors (three companies are 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.
They should also have knowledge about roofs, not just 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 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 to remove and reinstall the solar panels within a few years
・Misjudging the type of waterproofing led to incorrect treatment and subsequent leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the presence of warranties and aftercare services
When choosing a solar installation contractor, let’s confirm the presence of a warranty. It is important to check not only the number of years but also the coverage, disclaimers, and cost conditions.
While the solar panels and battery storage units come with a manufacturer’s warranty, it is also important to confirm whether there is a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may be able to respond 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 damage on the roof can 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, we can detect abnormalities early, making it easier to prevent major repairs or breakdowns!
Kakeru Koumuten Co., Ltd. provides a leak warranty as part of the workmanship warranty for solar panel installations. (The warranty for solar panel installations is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty unless a roof renovation is 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, as well as warranties and after-sales services.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request services from your preferred 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 sure to compare these details carefully! If the quality of the auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making judgments based solely on price!
▶ Go to “Breakdown of Installation Capacity and Equipment/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 and the application must be made by the individual, it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Be sure to complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining a grant decision) before proceeding with the construction!
For the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the flow will go through a review before the grant is issued! (The flow of procedures varies by system)
▶ To “Subsidies and Grants That May Apply in Hiratsuka City” within this Article
Benefits of Installing Solar Power Systems
The benefits of installing solar panels are as follows!
Benefit 1: Economic Advantage
The biggest advantage of installing solar panels is the economic benefit!
Although the selling price of electricity has decreased compared to 10 years ago, you can benefit by reducing the electricity you buy from the utility company by consuming the power you generate yourself!
As electricity costs rise, the ability to cover your consumption with solar power becomes more attractive!
If you plan to use the generated power at night, installing a storage battery is essential!
For residential use (under 10kW), the selling price (FIT) for electricity generated from October 2025 onwards 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 it in your home (self-consumption) rather than selling it, so combining it with a storage battery is also an option.
👉 Ministry of Economy, Trade and Industry | For purchase prices and periods, 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 do have operational noise.)
Benefit 4: Expect Heat Insulation Effects!!
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 a heat insulation effect!
(Note that this does not improve the building’s insulation performance itself.)
Benefit 5 Electricity can be used even during power outages!!
If a storage battery is installed, it 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.
(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 the solar panels are installed.
If you perform a roof renovation 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 renovate it with durable roofing materials before installing the solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It would be reassuring to consider maintenance costs in the simulation 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 brackets to the roofing material or substrate with screws, waterproofing of the fixed parts is crucial.
In methods that involve making holes in the roof, there is inevitably a risk of leaks.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, one option is to replace the roofing material with a metal roof and fix the solar panels using the catch method. (The catch method has compatibility conditions between the roofing material and brackets, 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, switching to 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 by Total Roof Output
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and the more power generated, the better!
Solar panels come in various sizes and outputs depending on the manufacturer.
For example, 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 panel does not fit well with the roof, “20 panels of 350W can be installed, while only 15 panels of 400W can be installed,” meaning that the number of panels that can be installed may differ even on the same roof due to the size of the panels.
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 power generation amount (kWh) will vary depending on conditions such as roof orientation, slope, and shading.
How to Choose 2: Compare by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases over 10 years and 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard value for warranty purposes and does not indicate the actual degradation rate or power generation amount.
By not deciding solely based on initial output and considering the degradation rate, you can choose solar panels without regrets!
How to Choose 3: Compare by Warranty Period
Solar panel warranties include various types such as “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
Regarding output warranties, some manufacturers offer a 30-year warranty while others offer a 10-year warranty, so it varies!
Longer warranties are better, so be sure to check the warranty period 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 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.
Guidelines for different capacities are published on the solar panel and storage battery installation pricing page. We will create a layout diagram from the drawings and on-site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in 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 (69 applications received as of September 11, 2026). The Kanagawa Prefecture subsidy (70,000 yen/kW for solar power, 150,000 yen per unit for storage batteries) is nearing the application deadline for the second period 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 subsidies and grants section and consult with us before signing a contract.
Can I apply for subsidies after the construction is completed?
For many programs, procedures are required before construction. The subsidy for Hiratsuka City requires “application before construction starts,” while the Kanagawa Prefecture subsidy requires “start of construction after 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 varies by construction method, and in methods that secure brackets to the roofing material or substrate, waterproofing of the fixed parts is crucial.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation and propose methods such as roof overlay or replacement if deterioration is advanced.
The roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed 10 to 20 years after installation, the cost of removing and reinstalling 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 help reduce total costs.
After confirming the condition of the roof during the on-site survey, please consult us about the installation process!
Is it better to install a storage battery together with 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 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 installation of solar panels and storage batteries, and the subsidy in Hiratsuka City also provides an additional 50,000 yen when the storage battery is installed 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 on-site survey, and provide you with the installation capacity and power generation simulation.
Hiratsuka City has residential areas that spread from plains to plateaus and hilly areas, and the way shadows are cast by neighboring houses, trees, and surrounding buildings varies from house to house. You can check the estimated power generation through the power generation simulation.
How long will the construction period be?
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 performed simultaneously or depending on the roof shape and installation capacity.
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 (less than 10 kW), the selling 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 the initial costs quickly in the first 4 years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that considers loan interest rates and electricity costs.
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 for 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 also handle the renovation of roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten can detach and reattach solar panels in-house, allowing us to remove the panels, perform roof overlay (cover method) or re-roofing, and then reinstall them all in one go. The removed panels can be stored in our own warehouse.
For costs, please refer to the solar panel removal and hot 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 panels, roofing work, and exterior wall work in Hiratsuka City, Kanagawa Prefecture.
We have received requests from many customers, including renovation companies and real estate agencies!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received positive feedback from numerous customers.
We continue to update our construction achievements every year, and we 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 exterior cover methods.
We are also happy to handle small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leak repairs, we may be able to provide temporary measures without setting up scaffolding, as long as safety can be ensured, so please consult with us!
“I want to know about recommended solar panels”, “I want to keep costs down as much as possible”, “I just want an estimate for now”, we will provide optimal solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in the customer’s position and will propose the best construction plan!
We are confident that we will not be outdone in terms of cost, quality, and planning for exterior work compared to other companies!
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!
Characteristics of Hiratsuka City, Kanagawa Prefecture, and Points for Solar Construction
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 spreads 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 mountains in the background.
Below are the characteristics of Hiratsuka City and points to consider when installing solar panels and storage batteries. (Tap to open)
View the characteristics of Hiratsuka City and points for solar construction
■ A city facing Sagami Bay. Check the 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 by model. When providing estimates, 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 structure.
■ From plains to plateaus and hilly areas. Shadow checks for each house
According to the same basic information about the city, it is formed by plains surrounded by plateaus and hills. 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 from blueprints and the actual site conditions, allowing you to confirm through power generation simulations.
■ 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 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 a contract.
■ If exterior wall painting is done simultaneously, check the landscape rules
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 homes that have been built for many years, it is important to check for damage to the roofing materials and substrate before installing solar panels. Depending on the condition of the roof, installing them simultaneously with roof renovations can help 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 undertaken many exterior and solar construction projects 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 Tokyo.
List of Areas in Hiratsuka City, Kanagawa Prefecture
Akashicho, Hiratsuka City / Tenuma, Hiratsuka City / Iijima, Hiratsuka City / Denawa, Hiratsuka City / Irino, Hiratsuka City / Iribe, Hiratsuka City / Enokicho, Hiratsuka City / Oimatsu, 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 / Shirodoko, Hiratsuka City / Kousho, Hiratsuka City / Kyoryotei, Hiratsuka City / Kurobeoka, Hiratsuka City / Kawachi, Hiratsuka City / Goten, Hiratsuka City / Konabesima, 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, Hiratsuka City / Asama, Hiratsuka City / Sengokugawashi, Hiratsuka City / Chisugaya, Hiratsuka City / Sodegahama, Hiratsuka City / Daikancho, Hiratsuka City / Takane, Hiratsuka City / Takahamadai, Hiratsuka City / Takamura, Hiratsuka City / Takaracho, Hiratsuka City / Ritenomachi, Hiratsuka City / Tamura, Hiratsuka City / Tachijougaoka, Hiratsuka City / Tsuchiya, Hiratsuka City / Tsutsumimachi, 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, 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 / Nadeshikohara, Hiratsuka City / Nishimando, Hiratsuka City / Nishiyahata, Hiratsuka City / Nijigahama, Hiratsuka City / Nesakamata, Hiratsuka City / Hanamizudai, Hiratsuka City / Bairin, Hiratsuka City / Bairin Honmachi, Hiratsuka City / Higashimando, Hiratsuka City / Higashitoyoda, Hiratsuka City / Higashinakahara, Hiratsuka City / Higashiyahata, Hiratsuka City / Hinataoka, Hiratsuka City / Hiratsuka, Hiratsuka City / Hirokawa, Hiratsuka City / Fujimimachi, Hiratsuka City / Fujimino, Hiratsuka City / Sabamachi, Hiratsuka City / Beniyamacho, Hiratsuka City / Matsukazecho, Hiratsuka City / Matoi, Hiratsuka City / Mandai, Hiratsuka City / Mitsukecho, Hiratsuka City / Minamikaname, Hiratsuka City / Minamitoyoda, Hiratsuka City / Minamihara, Hiratsuka City / Miya no Mae, Hiratsuka City / Miyamatsucho, Hiratsuka City / Megumigaoka, Hiratsuka City / Momohamacho, Hiratsuka City / Yaezaki, Hiratsuka City / Yachiyocho, Hiratsuka City / Yamashita, Hiratsuka City / Yahata, Hiratsuka City / Yuuhi ga Oka, Hiratsuka City / Yokouchi, Hiratsuka City / Yoshizai, Hiratsuka City / Ryuujo ga Oka
・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.施工実績
・Kakeru Koumuten Co., Ltd. After Maintenance
・Kakeru Koumuten Co., Ltd.施工メニュー・料金表
・Kakeru Koumuten Co., Ltd. Staff Blog & Announcements
・Explaining the Importance of Comparing Estimates!
・Top 12 Solar Power Generation Manufacturers! Features and Selection Tips!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
・What are the best locations for installing solar power generation? Key points for selecting installation sites!
・Here for solar power generation estimates!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!
