Leave the installation of solar panels in Hadano City, Kanagawa Prefecture to Kakeru Koumuten Co., Ltd.!
For Solar Panel and Battery Installation in
Hadano City,
trust Kakeru Koumuten!
Kakeru Koumuten is a company specializing in exterior renovations based in Kanagawa Prefecture.
As a company strong in roofing work, we are entrusted withsolar panel installation and battery installation considering roofs and waterproofing!
“How to Choose a Solar Panel Contractor in Hadano City”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Hadano City”
We will also explain the above three points!
Installing solar panels carries risks such as“the occurrence of leaks” and other troubles.
We recommend obtainingthree or so estimates to ensure you do not regret your solar panel installation!
Table of Contents (tap to open/close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Hadano City
- Roof Inspection Before Installing Solar Panels
- Subsidies and Grants That May Be Applicable in Hadano City
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installation Company in Hadano City
- 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 Hadano City
- If You Are Looking for a Solar Panel Installation Company in Hadano City, Contact Kakeru Koumuten
- Characteristics of Hadano City and Points for Solar Installation
- Service Area in Hadano City
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Hadano City
Regarding why our company is entrusted with solar panel installation by customers in Hadano City,
“Our Unique Strengths in Solar Panel Installation That Cannot Be Imitated by Other Companies”
have received high praise from many customers.
Because we are confident, we welcome estimates from as many companies as you like!
1. We Can Also Handle Exterior Renovations Besides Solar Panel Installation!
Problems such as leaks caused by the installation of solar panels may arise from insufficient checks on the roof and waterproofing at the installation site.
Even if one is knowledgeable about solar panels, there may be cases where the roof and waterproofing at the installation site are outside their expertise, so caution is necessary.
It is reassuring to have expertise in roofing to avoid maintenance 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 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 and can assemble scaffolding in-house.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also cut costs for scaffolding work.
We own scaffolding materials for approximately 50 single-family homes!
Even in cases where there are height differences on the site, our in-house scaffolding team will plan the scaffolding according to the local conditions.
Storage of Materials in Our Large Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, enabling us torespond quickly in emergencies!
Sorting and Transporting Waste Materials In-House
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior Renovation Dedicated Showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on roofing materials!
We can also provide simulations of potential earnings and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany renovations, 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 a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof renovations at reduced costs.
Additionally, one representative will handle everything from the estimate to project completion.
Since the same person is responsible throughout, smooth communication is possible.
We can perform consistent in-house construction from temporary scaffolding installation, exterior wall painting, to roof renovations!
4. Various Permits and Skilled Workers
We have obtained permits for the construction industry and for the collection and transportation of industrial waste!
We also have nationally certified sheet metal workers and painting specialists, and we are confident in our construction techniques.
We can also handle large-scale roof projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation, our own construction warranty (leakage warranty) is also included!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, a roof renovation may be required to provide the warranty. The construction warranty is separate from the manufacturer’s product warranty, and the coverage and conditions vary based on the warranty details.)
Aftercare is available every year, and we send out annual notification DM.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
If you cannot access the roof at high altitudes, we can utilize a drone to assist!
During leak investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of your solar panels decreases due to dirt or other factors, we can provide cleaning services using specialized brushes.
We will respond according to your preferences.
7. Human Resource Development
To enhance 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 all staff can handle various scenarios.
8. Creation of Easy-to-Understand Materials and Simulations
Kakeru Koumuten provides not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar construction guidebook” and a “profit and loss simulation” that takes into account loan interest rates and electricity costs.
The profit and loss simulation can be created for projected cumulative profits and losses over 20 to 30 years.
Even customers who are not familiar with solar construction will receive materials that clearly summarize important points and disadvantages!
We encourage you to obtain comparative estimates and review plans from other companies!
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, specializing in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing 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 fastening strength and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, Slope, and Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, can affect power generation. We will create a layout diagram from the drawings and the site, and you can check it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels that can be installed (installation capacity) is determined by the shape and size of the roof. The number of panels that can be installed varies depending on the size of the panels, so we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will confirm whether the method involves drilling holes in the roofing material for fixing or using brackets to secure the roofing material. The fixing method varies by technique, so please check the waterproofing treatment method for the fixing parts during the estimate. |
| 6. Weight of the Roof | With the addition of panels, the roof will become heavier. After investigating the existing roof, substrate, and load-bearing capacity, switching to lighter roofing materials may also be an option if necessary. |
| 7. Installation Location of Equipment and Wiring | We will check the installation location for the power conditioner and storage batteries, as well as the wiring route to the distribution board. The length of the wiring will also affect costs. |
| 8. Ease of Scaffolding Setup and Delivery Routes | If there are elevation differences on the site, careful planning for scaffolding and delivery routes for equipment and materials may be necessary. We will also check the width of the front road and any steps on the site during the on-site survey. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproof treatment of fixing parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suitable for the type of tile (even if the method does not drill holes in the tiles, fixing to the substrate is performed) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be a method to replace with lightweight roofing material before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, a method that does not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you carry out roof renovations 10 to 20 years after installation, additional costs for removing and reinstalling solar panels will apply. If the roof is deteriorating, renovating to a highly durable roofing material before installation may help reduce costs in the long run.
Kakeru Koumuten Co., Ltd. specializes in roofing work and can also handle the removal and reinstallation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Hadano City
PossibleSubsidies and Grants in Hadano City, Kanagawa Prefecture
If you introduce solar panels or storage batteries in Hadano City, there is a possibility that “national,” “Kanagawa Prefecture,” and “Hadano City” systems may apply.
The following information is based on the official pages of each system as of October 6, 2026. The acceptance status may change depending on the budget, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Period for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Hadano City “Zero Carbon Living Creation Subsidy” (Solar Power System & Storage Battery System) | Individuals who have an address in Hadano City at the time of application (or those who plan to have an address in Hadano City after the new construction or purchase of a residence) and have paid city taxes. Must not have received the same subsidy in the past. Solar power must be self-owned, PPA, or leased. Storage batteries must be those that store electricity generated by solar power equipment, and those used only as emergency backup power are not eligible. | Solar Power: 15,000 JPY per kW (maximum 75,000 JPY) Storage Battery: 10,000 JPY per kWh (maximum 50,000 JPY) |
According to the official city page (updated May 1, 2026), applications for the fiscal year 2026 have ended due to reaching the budget limit (solar power applications ended on June 15, and storage battery applications ended on June 12). Applications are currently not accepted. |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Residential Solar Power and Storage Battery Installation Subsidy” | Installation of both solar power and storage systems in residential buildings (with earthquake resistance). Applications must be made by the individual, and construction can begin 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: Starts September 7, 2026 (first-come, first-served) Applications reached the budget limit on September 7, 2026, and are now closed. Please check the prefecture’s official page for future announcements. |
| National “DR Home Storage Battery Project” (Fiscal Year 2025 Supplement) | New installation of home storage systems that can be used for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 34,500 JPY per kWh (subsidy rate within 30% & maximum 600,000 JPY per application). | As of May 29, 2026, the budget has been reached, and the public recruitment has ended (the official site states there are no plans to reopen applications, and they are currently not accepted). |
| 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 structures; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 JPY/unit | Ends as soon as the budget limit is reached. As of October 5, 2026, the application amount for renovations is displayed as 8% of the budget on the official site. Please check the official site for the status of applications. |
| 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 power must have a generation output of 10 kW or more, for business facilities, and equipment not certified under FIT/FIP, etc. | Solar Power: 80,000 JPY/kW, etc. Storage System: 50,000 JPY/kWh (maximum 5,000,000 JPY) |
Recruitment ended on September 3, 2026 (application amounts reached the budget limit). |
The subsidy for creating a zero-carbon lifestyle in Hadano City has ended for the fiscal year Reiwa 8. The subsidy for housing in Kanagawa Prefecture also requires that construction begins after receiving the “grant decision”; starting work beforehand will make you ineligible. Each program has different eligibility conditions, application procedures, and whether they can be combined, and applying does not guarantee that you will receive the grant, so please check before signing a contract or starting work.
At Kakeru Koumuten Co., Ltd., we will guide you on the eligibility conditions and application periods for each program after confirming them.
National Subsidy “DR Home Storage Battery Project (Support Project for Introducing Home Storage Systems for DR Resource Implementation)”
The government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those who are introducing new storage systems that can be used for demand response (DR) with registered products. In the fiscal year 2027 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 being ineligible if contracted or ordered before the grant decision.
However, the fiscal year 2027 supplementary budget reached its application amount on May 29, 2026, and the public offering has ended. The official website also states that there are no plans to reopen the public offering, and applications cannot be made at this time. Please check the official website for future public offerings.
Additionally, there are currently no subsidies available from the government specifically for the installation of solar panels on existing homes.
👉 Click here for the official DR Home Storage Battery Project website
Kanagawa Prefecture “Fiscal Year 8 Kanagawa Prefecture Housing Solar Power Generation and Storage Battery Installation Subsidy”
Kanagawa Prefecture provides subsidies for those who install both “solar panels” and “storage batteries” in their homes.
The subsidy details are 70,000 yen per kW of solar power generation output and 150,000 yen per storage system.
For example, if you install a 4 kW solar panel and one storage battery, the subsidy amount would be calculated as 4 kW × 70,000 yen + 150,000 yen = 430,000 yen.
The eligibility is for houses that ensure seismic performance, the storage system must be a registered product, if construction begins before the grant decision, it will be ineligible, and the application must be made by the individual (applications by the construction contractor on behalf of the individual are not allowed), among other conditions. The possibility of combining this with the Hadano City subsidy varies by program, so please check the official pages of each program before signing a contract.
In fiscal year 8, the first phase (May 11 to June 30) and the second phase (starting September 7, first-come-first-served) were conducted, and the second phase has closed as the application amount reached the budget amount on September 7, 2026. For future recruitment, please check the official Kanagawa Prefecture page.
👉 Click here for the official Kanagawa Prefecture page
Kanagawa Prefecture “Fiscal Year 8 Kanagawa Prefecture Subsidy for Introducing Self-Consumption Type Renewable Energy” (for businesses)
In Kanagawa Prefecture, subsidies are being implemented for businesses that introduce “self-consumption type” systems that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and installations for individual residences are not eligible.
Solar power generation must have an output of 10kW 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 kW for solar power generation and 50,000 yen per kWh for the accompanying storage system (with a maximum of 5 million yen).
Applications for the 2026 fiscal year have closed as the application amount reached the budget limit on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Hadano City should check the official Kanagawa Prefecture page for the next application period.
👉 Click here for details
Hadano City “Zero Carbon Living Creation Subsidy”
Hadano City is implementing the “Zero Carbon Living Creation Subsidy,” which partially subsidizes the installation costs of residential solar power generation systems and storage battery systems (together as ZEH).
● Solar power generation system: 15,000 yen per kW (maximum 75,000 yen)
● Storage battery system: 10,000 yen per kWh (maximum 50,000 yen)
Eligible applicants are those who have an address in Hadano City at the time of application (or those who plan to have an address in Hadano City after the new construction or purchase of a residence), have paid city taxes, and are individuals who have not received this subsidy in the past. Solar power generation systems must be self-owned, PPA, or leased, and storage battery systems must store electricity generated by solar power equipment, designed for regular charging and discharging (not for emergency backup power). Solar power and storage batteries can be used together.
Applications for the 2026 fiscal year have ended as the budget limit has been reached (solar power generation applications closed on June 15, storage battery system applications closed on June 12, and ZEH applications closed on May 15). The information published on the city’s official page (updated May 1, 2026) indicates that applications are currently not being accepted. The grant guidelines will be enforced from May 1, 2026, until March 31, 2031. Please check the city’s official page for future application periods.
👉 Click here for Hadano City’s official page
Solar Panel Installation & Storage Battery Installation Price List
⇧Service Menu | For Costs Related to Solar Panel and Battery Installation, Click Here
⇧Service Menu | For Costs Related to Solar Panel Removal and Water Heater Dismantling, 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 the installation capacity, equipment grade, and roof condition.
Understanding 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 priced at 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 factors such as wiring length, scaffolding area, existing roofing materials, and panel layout.)
▶ Installation Menu | Costs for Solar Panel Installation and Battery Installation
Items to Check in the Estimate (Cost Confirmation)
When comparing estimates, it is common to compare different capacities and equipment. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, and 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 battery as well. |
| 3. 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 fixing points, and whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | How much support is included for applications to the power company, certification for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If it coincides with roofing work or exterior painting, check that the same scope and quantity are not double-counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters or old panels, and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether the price includes tax or not, conditions under which additional costs may arise, and the 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 Simulation for Solar Power Generation
With the simulator above,
you can obtain an estimated quote and a financial simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can get an estimated quote and financial simulation!
*The simulation results are estimates. Actual financial results may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection and replacement.
Customer Voices
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Examples of Solar Panel Installations
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh |
| Base Mounting Hardware Used |
| Niigata Manufacturing/Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed using catch type hardware gripping the horizontal metal roof (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| About 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the introduction of solar panels and storage batteries. I heard that grants are available, and I would like to know how much will be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of grants, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Hadano City
There are many solar panel installation contractors available in Hadano City, and you may be unsure which contractor to choose.
For this reason,when requesting the installation of solar panels or storage batteries, let’s confirm the following 4 points.
● Not only knowledge of solar power but also extensive knowledge of roofs
● Confirm the presence of warranties and aftercare services
● Obtain estimates from multiple contractors (3 companies as a guideline)
● Check if they provide support for subsidy applications
By confirming the above 4 points, you will be able to choose a reliable contractor.
Knowledge of roofs as well as solar panels
Defective installation of solar panels can be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge of 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
・Installing solar panels on a severely deteriorated roof, leading to leaks
・Installing solar panels on a roof with a short lifespan, necessitating renovations to detach and reattach the solar panels within a few years
・Misjudging the type of waterproofing and applying incorrect treatment, resulting in leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unforeseen troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the presence of warranties and aftercare services
When choosing a solar installation contractor, let’s confirm the presence of warranties. It is important to check not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While solar panels and storage batteries come with manufacturer warranties, also check for the presence of a workmanship warranty in case leaks occur after installation!
If the contractor offers a workmanship warranty, they may cover any leaks that occur after installation within the warranty period and conditions.
Additionally, some contractors provide aftercare services separate from warranties, so be sure to check if the contractor you are considering has aftercare services.
Since abnormalities or damage on the roof may not be visible, you might not notice them yourself.
By conducting inspections during aftercare, you can detect abnormalities early and prevent major repairs or failures!
At Kakeru Koumuten Co., Ltd., the installation of solar panels comes with a leak warranty as part of the workmanship warranty. (The warranty for solar panel installation is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovations are performed.)
We also conduct aftercare maintenance and send out annual DM!
After checking the DM, if you wish, we will visit for aftercare maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, let’s obtain estimates from multiple contractors.
Even for the same manufacturer and the same construction content, costs may vary, and warranties and after-sales services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request your preferred contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates,
“Check the estimate items”
“Type of solar panels”
“Warranties and after-sales services”
let’s compare them in detail and make a judgment! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid judging solely based on price!
▶ Go to “Breakdown of Installation Capacity, Equipment, and Construction Costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for solar panel installation and battery installation, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
For systems like Kanagawa Prefecture’s housing subsidies, where proxy applications by contractors are not allowed, it is reassuring to have a contractor that can support the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining a grant decision) before proceeding with the construction!
In the case of the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the flow will be to grant after review! (The flow of procedures varies by system)
▶ Go to “Subsidies and Grants that May Apply in Hadano City” in this article
Benefits of Introducing Solar Equipment
The benefits of introducing solar panels are as follows!
Benefit 1: Economic Benefits
The biggest advantage of introducing solar panels is the economic benefit!
The selling price of electricity has decreased compared to ten years ago, but by consuming the electricity generated, you can reduce the amount of electricity purchased from the utility company and gain benefits!
As electricity prices rise, the ability to cover your power consumption with solar power becomes attractive!
If you want to use the generated electricity at night, installing a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) will be set as “24 JPY/kWh for the first four years, and 8.3 JPY/kWh from the fifth to the tenth year” for certifications after October 2025, and the same price will apply for the 2026 fiscal year. After the fifth year, it is generally more advantageous to use it at home (self-consume) rather than sell it, making the combination with a storage battery a viable option.
👉 Ministry of Economy, Trade and Industry | For purchase prices and periods, click here
Advantage 2 You can utilize subsidies!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
The reduction of the actual burden due to subsidies is a significant advantage!
In Hadano City, you may be eligible for programs from the national government, Kanagawa Prefecture, and Hadano City (please check the application status for each program).
Advantage 3 Environmentally friendly!
Solar power generation has low carbon dioxide emissions and can reduce dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices like power conditioners do have operational noise.)
Advantage 4 Heat insulation effects can be expected!!
By installing them on the roof or rooftop, the panels block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the rise in roof temperature, providing expected heat insulation effects!
（This does not improve the building’s insulation performance itself）
Benefit 5 Electricity can be used even during power outages!!
If a storage battery is installed, it is possible to use electricity even during emergencies such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capabilities, 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 roof renovations 10 to 20 years later, there will be costs for removing and reinstalling the solar panels.
If the existing roof is deteriorated, 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 simulations before introducing solar panels!
Point 2 The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix hardware with screws to the roofing material or substrate, waterproofing of the fixed parts is crucial.
In methods that create holes in the roof, the risk of leaks inevitably arises.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and fixing the solar panels using the catch method is also an option. (The catch method has compatibility conditions between the roofing material and hardware, and cannot be used with all metal roofs)
Catch-type base hardware 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 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 Output of the Roof
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and generating more power is always better!
Solar panels vary in size and output depending on the manufacturer.
A panel with an output of 350W and a panel with an output of 400W may seem 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 the number of panels that can be installed on the same roof may differ 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 a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is the calculation of total output (kW). The actual power generation (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 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 the warranty and does not indicate the actual degradation rate or power generation amount.
Choosing solar panels without considering only the initial output but also the degradation rate will lead to a regret-free decision!
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!
It’s always better to have a longer warranty, so let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Battery Installation in Hadano City
We have compiled frequently asked questions from customers considering the installation of solar panels and batteries in Hadano City. (Tap to open the answers)
How much does it cost to install solar panels and batteries in Hadano City?
The cost varies depending on the installation capacity, equipment, and roof condition. In the above case study (solar panel 4.3kW + battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines for costs by capacity are published on the solar panel installation and 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 battery installation in Hadano City?
As of October 6, 2026, the Hadano City Zero Carbon Living Creation Subsidy (1.5 million yen per kW for solar power, with a maximum of 750,000 yen; 10,000 yen per kWh for batteries, with a maximum of 50,000 yen) has reached the budget limit for the fiscal year 2026 and is no longer accepting applications. The Kanagawa Prefecture subsidy (70,000 yen per kW for solar power, 150,000 yen per unit for batteries) reached its budget limit on September 7 for the second phase of fiscal year 2026, and the national DR household battery program has ended its public recruitment.
The application status may change, so please check the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies even after the construction is completed?
For Kanagawa Prefecture subsidies, procedures must be completed before construction, and “construction must begin after the grant decision” is a condition; if you start construction beforehand, you will be ineligible. The application timing and procedures for Hadano City subsidies are also specified in the guidelines, so please check the official page before signing a contract or starting construction.
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 beforehand. The fixing method varies by construction method, and if the method involves fixing brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is essential.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation, and if deterioration is advanced, we can also propose methods such as roof overlay (cover method) or re-roofing before installation.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed after 10 to 20 years of installation, the cost for removing and reattaching 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 about the installation process after confirming the condition of the roof through an on-site inspection!
Is it better to install a storage battery together with solar panels?
For those who want to use generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it in your home rather than selling it.
Additionally, Kanagawa Prefecture’s subsidies require the simultaneous installation of solar panels and storage batteries, and the subsidy for creating a zero-carbon lifestyle in Hadano City also targets storage batteries that store electricity generated by solar power systems. You can compare “solar only” and “solar + 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 inspection, and provide you with the installation capacity and power generation simulation.
Hadano City has locations near the Tanzawa mountain range, flat areas in basins, and places close to rivers, so the shading from surrounding buildings and trees and the installable capacity will differ for each house. 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 if roof work is done simultaneously or depending on the shape of the roof 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 (under 10 kW), from the certification after October 2025, the first 4 years will be 24 yen/kWh, and from the 5th to the 10th year, it will be 8.3 yen/kWh, and the same price will apply for the 2026 fiscal year.
The idea is to recover initial costs more quickly in the first 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-maintenance notices via DM and visits customers who wish to have inspections. We can also clean solar panels with a special brush if the power generation is reduced due to dirt.
Since it is difficult to check areas on the roof by yourself, please feel free to consult us if you have any concerns.
Can you also renovate roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten can remove and reattach solar panels in-house, allowing us to remove the panels, perform roof overlay (cover method) or re-roofing, and then reinstall them in a consistent manner. The removed panels can be stored in our own warehouse.
For costs, please refer to the solar panel removal and water heater removal pricing page.
If you are looking for a solar panel installation company in Hadano City, please consult Kakeru Koumuten
Our company handles a wide range of exterior renovations in Hadano City, including solar panel installations, roofing work, and exterior wall work.
We have received requests from many customers, including renovation companies and real estate agencies!
Kakeru Koumuten promises “high-quality renovations at low cost”, and we have received great feedback from numerous customers.
We continue to update our construction performance records every 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 installations for exterior walls.
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 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 focused on profit!
We always stand in our customers’ shoes and will propose the best construction plans!
We are confident that we will not lose in terms of cost, quality, and organization compared to other companies in exterior work!
We are confident, so we welcome competitive quotes!
Estimates are completely free, and if our company is inferior to others, you are free to decline!
Characteristics of Hadano City and Points for Solar Work
Hadano City is a city that spreads across the Hadano Basin, surrounded by the Tanzawa mountain range on the east, north, and west, including Mount Oyama, Mount Minotō, Mount Tōno, and Nabewari Mountain, and blocked by the Shibusawa Hills to the south. Within the city, there are areas near the mountains, flatlands in the basin, and places close to rivers. We have summarized the characteristics of Hadano City’s terrain and climate, as well as points to consider when installing solar panels and storage batteries below. (Tap to open)
View Characteristics of Hadano City and Points for Solar Work
■ Areas near the mountains: Be cautious of tree shadows, fallen leaves, and access routes for scaffolding and delivery
Hadano City features a maximum elevation of 1,490.9 meters at Mount Tōno and a minimum elevation of 16.2 meters in the Tsurumaki area, indicating a significant elevation difference within the city. In areas close to mountains and trees, it is important to pay attention to the way shadows fall and the decrease in power generation due to fallen leaves and dirt. Additionally, in sloped areas or those with elevation differences, careful planning may be required for scaffolding and the transportation routes for equipment and materials. Kakeru Koumuten Co., Ltd. responds on-site with its own scaffolding team and owned scaffolding materials, and can also handle solar panel cleaning with specialized brushes and rain gutter cleaning.
■ Even in a climate with little snowfall, check roof conditions before installation
According to the city’s official page, Hadano City belongs to a Pacific coastal climate and experiences little frost and snowfall due to the influence of marine weather. Seasonal winds predominantly blow from the northwest in winter and from the south in summer, with generally weak wind speeds. However, conditions can vary based on the shape of the roof, the age of the building, and the surrounding buildings and trees, so it is essential to check the panel fixation methods and roof conditions on-site for each individual case before installation.
■ For sites near rivers, also check the placement of batteries and equipment
The rivers in the city mainly flow out from the Tanzawa mountain range, with the Mizunogawa in the central basin, and the Katsuragawa and Kanamegawa to the east, and the Shijuhasegawa to the west. For sites close to rivers, it is important to plan by checking the surrounding environment of the installation locations for batteries, distribution boards, power conditioners, etc. (such as whether water tends to accumulate). Please consult with us regarding the installation site after checking the information about your area on hazard maps.
■ Because conditions differ between mountainous areas and flatlands, check roofs and sites individually through on-site surveys
In Hadano City, where conditions vary between mountainous sites, flatlands in basins, and areas near rivers, the types of roofs, their ages, and sunlight exposure differ from house to house. Kakeru Koumuten Co., Ltd. will confirm the type and condition of the roof and the situation of the site before installation, and propose fixation methods, waterproofing details, and scaffolding plans.
■ Kanagawa Prefecture’s annual sunshine hours are approximately 2,018 hours (observational data from Yokohama)
According to the Japan Meteorological Agency’s average values (1991–2020), the annual sunshine hours at Yokohama, a representative observation point in Kanagawa Prefecture, are approximately 2,018 hours. Monthly, August (approximately 206 hours) has the most, while June during the rainy season (approximately 136 hours) has the least.
Power generation varies by season and location, so conducting annual power generation simulations and selecting battery capacities that match peak electricity usage times are key points.
Our company is based in Kanagawa Prefecture and handles many exterior construction and solar projects in Hadano City.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us about any sudden troubles!
Service Area in Hadano City
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and Tokyo Metropolis.
List of Areas in Hadano City
Hadano City Imaizumi / Hadano City Imaizumidai / Hadano City Imagawa-cho / Hadano City Irifune-cho / Hadano City Ojiri / Hadano City Ochiai / Hadano City Kasuga-cho / Hadano City Kamimigawacho / Hadano City Kamiootsuki / Hadano City Kawaharacho / Hadano City Kitayanama / Hadano City Kotobuki-cho / Hadano City Komino / Hadano City Saiwai-cho / Hadano City Sakae-cho / Hadano City Sakuracho / Hadano City Miya / Hadano City Shibusawa / Hadano City Shibusawa Kami / Hadano City Shimizu-cho / Hadano City Shimoootsuki / Hadano City Shimoochiai / Hadano City Ayame / Hadano City Shinmachi / Hadano City Suijin-cho / Hadano City Suehiro-cho / Hadano City Suzubari-cho / Hadano City Soya / Hadano City Oohata-cho / Hadano City Ritenodai / Hadano City Chikura / Hadano City Tsurumaki / Hadano City Tsurumaki Minami / Hadano City Tsurumaki Kita / Hadano City Terayama / Hadano City Togawa / Hadano City Tochikubo / Hadano City Nagaki / Hadano City Namikicho / Hadano City Nishi Otake / Hadano City Nishi Tahara / Hadano City Numashiro Shinmachi / Hadano City Hagioka / Hadano City Hazawa / Hadano City Hane / Hadano City Higashitahara / Hadano City Hibari Gaoka / Hadano City Hirasawa / Hadano City Fujimimachi / Hadano City Bunkyo-cho / Hadano City Bodai / Hadano City Horikawa / Hadano City Horiyamashita / Hadano City Horinishi / Hadano City Honmachi / Hadano City Magarimatsu / Hadano City Matsubara-cho / Hadano City Mikkaibu / Hadano City Midori-cho / Hadano City Minami Gaoka / Hadano City Minami Yanama / Hadano City Minoge / Hadano City Murocho / Hadano City Motomachi / Hadano City Yanagawa / Hadano City Yanagicho / Hadano City Yayoi-cho / Hadano City Yokono / Hadano City Wakamatsu-cho
・Please leave the exterior wall painting in Hadano City to Kakeru Koumuten Co., Ltd.!
・Please leave the roof renovation in Hadano City to Kakeru Koumuten Co., Ltd.!
・Please leave the exterior renovation in Hadano City to Kakeru Koumuten Co., Ltd.!
・Kakeru Koumuten Co., Ltd. construction achievements
・Kakeru Koumuten Co., Ltd. after maintenance
・Kakeru Koumuten Co., Ltd. construction menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of comparison estimates and points to consider!
・12 major manufacturers of solar power generation! Features and selection points are also introduced!
・What are the installation costs for solar power generation? Tips for reducing costs are thoroughly explained!
・What are the suitable locations for installing solar power generation? Points for selecting installation locations are also introduced!
・Here is the introduction 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!
