Leave Your Solar Panel Installation Work in Minami, Yokohama City to Kakeru Koumuten Co., Ltd.!
For solar panel and storage battery installation in
Minami Ward, Yokohama,
Kakeru Koumuten is your trusted partner!
Kakeru Koumuten is a company specializing in exterior renovations, headquartered in Aoba Ward, Yokohama.
As a company strong in roofing work, we are entrusted withsolar panel and storage battery installations considering roofing and waterproofing!
“How to choose a solar panel contractor in Minami Ward”
“Costs for solar panel and storage battery installation”
“Subsidies available for solar system installation in Minami Ward”
We will also explain the above three points!
Installing solar panels carries risks, such as“the occurrence of leaks” and other troubles.
To ensure you have no regrets about your solar panel installation, we recommend obtainingestimates from about three companies!
Table of Contents (tap to open/close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Minami Ward, Yokohama
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Minami Ward
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installation Contractor in Minami Ward, Yokohama
- 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 Minami Ward
- If You Are Looking for a Solar Panel Installation Contractor in Minami Ward, Contact Kakeru Koumuten
- Characteristics of Minami Ward, Yokohama and Key Points for Solar Construction
- Service Area in Minami Ward, Yokohama
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Minami Ward, Yokohama
The reasons why our company is entrusted with solar panel installation by customers in Minami Ward, Yokohama include
the fact that Kakeru Koumuten has a base in the same city of Yokohama,
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 multiple estimates!
1. We Also Handle Exterior Renovations Besides Solar Panel Installation!
Issues 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 someone knowledgeable about the roof to avoid maintenance and trouble after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent issues after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide low-cost, high-quality solar work and exterior renovations.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding depending on the construction conditions, and we can assemble the 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 the residential area of Minami Ward, where lowlands along the Ooka River adjoin hilly and plateau areas, 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 can purchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, 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 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 attached to the roofing materials!
We can also provide simulations for the 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 same person will handle sales and construction management, smooth communication is possible.
We can perform consistent in-house construction from temporary scaffolding installation to exterior wall painting and roof renovations!
4. Various Permits and Skilled Workers
We have obtained construction industry permits as well as permits for industrial waste collection and transportation!
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 work, 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, it may not be possible to provide a warranty unless roof renovations are performed. The construction warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty details.)
Aftercare is available every year, and we send out notification DM each year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
If you cannot access the roof due to height, we can utilize drones to assist!
During leak investigations, we can also conduct surveys using a thermal imaging camera.
If the power generation of solar panels decreases due to dirt, we can provide cleaning with a specialized brush.
We will respond according to your wishes.
7. Human Resource Development
To improve skills, we create various roofing models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training so that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
Kakeru Koumuten provides not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar construction guidebook” and “profit and loss simulations” that take 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 points to consider and potential drawbacks!
We encourage you to obtain comparative estimates and compare them with other companies’ plans!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 to 30 years.
Confirming whether it is safe to install them directly on the current roof is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, which specializes in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing material, such as slate, tiles, metal roofs, and flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest roof renovation first. |
| 2. Condition of Substrate and Waterproof Sheet | If the sheathing boards or roofing (waterproof sheet) beneath the roofing material are damaged, it will affect the fastening strength and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, Slope, and Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, 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. 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 confirm whether the method involves drilling holes in the roofing material for fastening or using brackets to secure the roofing material. The fixing method varies by technique, so please check the waterproofing treatment method for the fixing parts during the estimate. |
| 6. Weight of the Roof | The roof will become heavier due to the panels being installed. After investigating the existing roof, substrate, and load capacity, switching to lighter roofing materials may also be an option if necessary. |
| 7. Location of Equipment Installation and Wiring | We will check the installation locations for the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect costs. |
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 (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suited to the type of tile (even methods that do not drill holes in the tiles will fix to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lighter roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you renovate the roof 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the roof is deteriorating, renovating to a highly durable roofing material before installation may help reduce costs in the long run.
Kakeru Koumuten Co., Ltd. specializes in roofing work and can also handle the removal and reinstallation of solar panels, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Minami Ward, Yokohama City
PossibleSubsidies and Grants
If you are introducing solar panels or storage batteries in Minami Ward, you may be eligible for programs from the “National Government,” “Kanagawa Prefecture,” and “Yokohama City”.
The following information is based on the official pages of each program as of October 6, 2026. The application status may change depending on the budget, 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 |
|---|---|---|---|
| Yokohama City “Yokohama Green Energy Partnership Project (YGrEP)” Fiscal Year 2026 | Yokohama residents installing eligible equipment at their homes. Solar power must be newly installed, and either a storage battery, eco-cute, or electric vehicle must be installed simultaneously or already in place. | Solar Power: 15,000 JPY/kW (up to 4 kW) Storage Battery: 120,000 JPY per case (Refund via cashless points, etc.) |
Participation & Installation Support Application: June 15, 2026 – December 25, 2026 (Application must be made before installation) Installation Completion Application: By January 22, 2027 Ends when budget limit is reached |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Subsidy for Residential Solar Power Generation and Storage Battery Installation Costs” | Must install both solar power generation and storage battery at a residence within the prefecture. The application 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: September 7, 2026 – September 30, 2026 (first-come, first-served) Phase 2 application deadline has been reached. Please check the prefecture’s official page for future applications. |
| National “DR Home Storage Battery Project” (Fiscal Year 2025 Supplement) | Newly install a home storage system that can be utilized for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 1 kWh at 34,500 JPY (subsidy rate within 3/10; maximum 600,000 JPY per application) | As of May 29, 2026, the budget has been reached, and the public offering has ended (applications 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 renovation of windows (openings) and the structure; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 JPY/unit | Ends when the budget limit is reached. Please check the official site for application status. |
| Yokohama City “Solar Power Generation Installation Support Subsidy” | Small and medium-sized enterprises and sole proprietors within Yokohama City (residential use is not eligible). There are conditions regarding the type of equipment and eligibility. | Solar Power + Storage System: 100,000 JPY/kW (up to 5,000,000 JPY) Solar Power Only: 80,000 JPY/kW (up to 4,000,000 JPY) |
May 1, 2026 – October 30, 2026, 5 PM (first-come, first-served until budget limit is reached) |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Subsidy for Self-Consumption Type Renewable Energy Installation Costs” | Corporations and individuals filing blue returns（Personal residences are excluded）。Solar power must have a generation output of 10kW or more, facilities for business use, and equipment not certified under FIT or FIP, etc. | Solar power: 80,000 yen/kW, etc. Storage system: 50,000 yen/kWh (maximum 5,000,000 yen) |
Application period ended on September 3, 2026 (when the application amount reached the budget amount) |
YGrEP requires “participation and installation support application” before installation, and the Kanagawa Prefecture housing subsidy requires not only the acceptance of applications but also that construction begins after receiving the “grant decision”. If you start installation or construction beforehand, you will be excluded from eligibility. The prefectural housing subsidy is granted after completion of work and submission of performance reports and reviews. The order of procedures varies by system, and applying does not guarantee a grant, so please confirm before contracting or starting construction.
Kakeru Koumuten Co., Ltd. will provide guidance on eligibility conditions and business requirements for each system after confirming them.
National Subsidy “DR Home Storage Battery Project (Support Project for Home Storage System Installation for DR Resource Introduction)”
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 newly introducing registered storage systems 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 being excluded if contracted or ordered before the grant decision.
However, the fiscal year 2025 supplementary budget reached the budget amount for grant applications on May 29, 2026, and the public recruitment has ended (the previous fiscal year 2024 supplementary budget also ended on July 2, 2025). Applications are currently not possible, so please check the official website for future public recruitment.
Additionally, there are currently no subsidies confirmed for the installation of solar panels on existing homes.
👉 Click here for the official website of the DR Home Storage Battery Project
Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Housing Solar Power Generation and Storage Battery Installation Subsidy”
Kanagawa Prefecture provides subsidies for those who install both “solar panels” and “storage batteries” in their homes.
The 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 4kW solar panel and one storage battery, the subsidy amount calculation would be 4kW × 70,000 yen + 150,000 yen = 430,000 yen.
Conditions include that the storage system must be a registered product, if construction begins before the grant decision, it will be excluded, and the application must be made by the individual (proxy applications by contractors are not allowed). It is also possible to combine with YGrEP in Yokohama City.
In the fiscal year 2026, the first application period (May 11 – June 30) and the second application period (September 7 – September 30, first-come-first-served) have been conducted, and the second period has reached its application deadline. For future recruitment, please check the official Kanagawa Prefecture page.
👉 Click here for the official Kanagawa Prefecture page
Kanagawa Prefecture “Subsidy for Introduction of Self-Consumption Type Renewable Energy in Fiscal Year 2026” (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 who file blue returns, and the introduction to individual residences is not eligible.
Conditions include solar power generation with an output of 10kW or more, supplying electricity to business facilities within the prefecture, and being a facility that does not receive FIT or FIP certification.
The subsidy amount is 80,000 yen per kW for solar power generation and 50,000 yen per kWh for the accompanying storage system (with a maximum of 5 million yen).
As the application amount reached the budget amount for fiscal year 2026, applications were closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in the Minami Ward should check the official Kanagawa Prefecture page for the next recruitment.
👉 Click here for details
Yokohama City “Subsidy for Introduction of Solar Power Generation” (for businesses)
Yokohama City is implementing a system that subsidizes part of the introduction costs for small and medium-sized enterprises and individual business owners within the city for solar power generation facilities and other installations.
Residential solar power generation is not eligible, and for households, the YGrEP below will be the contact point. Businesses that install solar panels on stores, offices, factories, etc., in the Minami Ward may have the possibility to utilize this, but simply running a business from home does not guarantee eligibility. It is necessary to confirm the requirements for small and medium-sized enterprises and individual business owners, as well as the condition of being a self-consumption type facility (facilities aimed at selling electricity are not eligible).
The subsidy amount is 100,000 yen per kW when introducing solar power generation and storage systems simultaneously (maximum of 5 million yen), and 80,000 yen per kW for solar power generation only (maximum of 4 million yen).
The application period for fiscal year 2026 is from May 1, 2026, to October 30, 2026, at 5 PM, on a first-come-first-served basis until the budget limit is reached. Installation of equipment and commencement of construction must be done after the grant decision date.
For detailed conditions and application methods, please check the official website of Yokohama City.
👉 Click here for the official Yokohama City page
Yokohama City “Reiwa 8 Year Yokohama Green Energy Partnership Project (YGrEP)”
Yokohama Green Energy Partnership (YGrEP) is a project aimed at realizing a decarbonized society.
Yokohama City is providing cashless points and other rewards to households in the city that participate in YGrEP and install eligible equipment (refer to the eligible equipment below). Residents of Minami Ward are also eligible.
◎Eligible Equipment and Reward Amounts◎
● Solar Power Generation Equipment (new installation): 15,000 JPY/kW (up to 4kW)
* It is a condition to install or have already installed either a storage battery, eco-cute, or electric vehicle at the same time.
● Storage Battery: 120,000 JPY per unit
● Eco-Cute: 20,000 JPY per unit
● Electric Vehicle/Plug-in Hybrid Vehicle (set with solar power generation equipment): 100,000 JPY per unit
* It is a condition to install or have already installed the solar power generation equipment at the same time as the storage battery, eco-cute, or electric vehicle (set).
● Electric Vehicle alone (without solar power generation equipment): 50,000 JPY per unit
● Fuel Cell (EneFarm): 30,000 JPY per unit
● Solar Heat Utilization System: 50,000 JPY per unit
● V2H Charging and Discharging Equipment: 100,000 JPY per unit
For example, if you install a 4kW solar panel and a storage battery at the same time, the calculation for the reward amount will be 60,000 JPY for solar power + 120,000 JPY for storage battery = total of 180,000 JPY.
The application process is “Participation and Installation Support Application (before installation) → Installation of Equipment → Completion Application”, and equipment installed before the installation support application is not eligible. The participation and installation support application for Reiwa 8 Year will be from June 15, 2026, to December 25, 2026, and the completion application will be until January 22, 2027, and will end once the budget limit is reached.
When selling electricity, only the surplus that cannot be used at home is eligible, and submission of monitoring data such as power generation amounts approximately once a year is also a condition. Additionally, only V2H charging and discharging equipment is eligible for points and other rewards for businesses.
For information on application methods, combining with national and Kanagawa Prefecture subsidy projects, and point rewards, please check the special site here for details and inquiries.
Solar Panel Installation & Battery Installation Price List
⇧Service Menu | For Costs of Solar Panel Installation & Battery Installation, Click Here
⇧Service Menu | For Costs of Solar Panel Removal & 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 (kilowatt). Batteries are compared based on the amount of electricity they can store, expressed in kWh (kilowatt-hour).
The amount of kW that can be installed on a roof varies for each house based on the roof’s shape, orientation, and size. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we have listed the estimated costs for solar panels as follows: 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 estimates 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 Confirm in the Quotation (Cost Verification)
When comparing quotes, it is common to compare different capacities and equipment. Please check if the following items are clearly stated in each company’s quotation!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) 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 together. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range usable during power outages (entire 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 clamping). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, and whether there is a monitor to check power generation. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at the fixed points, and whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | How much support is included for applications to the power company, certification for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If it is simultaneous with roof work or exterior painting, check that the same scope and quantity are not 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 is tax-inclusive or tax-exclusive, conditions under which additional costs may arise, and details and duration of manufacturer and workmanship warranties. |
If the capacities differ, both the price and power generation will change. Kakeru Koumuten Co., Ltd. welcome comparisons, so if you bring quotes from other companies, we can explain the differences item by item!
Self-Quotation and Profit Simulation for Solar Power Generation
With the simulator above,
you can obtain a rough estimate and a financial simulation 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 a rough estimate and financial simulation!
*The simulation results are approximate. 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 Feedback
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installations
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh 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 subsidy being granted, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The subsidy amount and recovery estimate are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that subsidies are available, and I would like to know how much will be granted. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of subsidy to be granted, and we explained this to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Minami Ward, Yokohama
There are many solar panel installation contractors available in Minami Ward, Yokohama, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and storage battery installation work, let’s confirm the following four points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the presence of warranties and aftercare maintenance
● Obtain estimates from multiple contractors (three companies as a guideline)
● Check if they provide support for subsidy applications
By confirming the above four points, you will be able to choose a reliable contractor.
Knowledge about roofs as well as solar panels
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
・Installing solar panels on a severely deteriorated roof, leading to leaks
・Installing solar panels on a roof with a short lifespan, necessitating a remodel 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 maintenance
When choosing a solar installation contractor, 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.
Solar panels and storage batteries come with manufacturer warranties, but also confirm whether there is a workmanship warranty in case leaks occur after installation!
For contractors that offer workmanship warranties, 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-service separate from the warranty, so be sure to check if the contractor you are considering has after-service.
Since abnormalities or damage on the roof can occur in areas that are not visible, there is a possibility that customers may not notice them themselves.
By conducting inspections in after-maintenance, we can easily prevent significant repairs or failures by discovering abnormalities early!
Kakeru Koumuten Co., Ltd. provides a rain 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, a roof renovation may be required to provide the warranty.)
We also conduct after-maintenance and send out DM every year!
Please check the DM, and if you wish, we will visit you for after-maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting the installation of solar panels, be sure to obtain estimates from multiple contractors.
Even for the same manufacturer and the same construction content, costs may vary, and warranties and after-services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request from your preferred contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates,
“Check the items in the estimate”
“Type of solar panel”
“Warranties and after-services”
and make detailed comparisons to make your judgment! If the rank of auxiliary materials is low or processes are skipped, costs can be reduced, so avoid making judgments based solely on price!
▶ Go to “Breakdown of installation capacity, equipment, and construction costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
For systems like the Kanagawa Prefecture housing subsidy, where the contractor cannot apply on your behalf and personal application is required, it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining 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 be to undergo examination before the grant is provided! (The flow of procedures varies by system)
▶ Go to “Subsidies and Grants That May Be Applicable in Minami Ward” within this article
Benefits of Introducing Solar Power Equipment
The benefits of installing solar panels are summarized in the following 5 points!
Benefit 1: Economic Advantage
The biggest advantage of installing solar panels is the economic benefit!
The selling price of electricity has decreased compared to 10 years ago, but by consuming the generated electricity, you can reduce the amount of electricity purchased from the utility company and gain benefits!
As electricity prices rise, the ability to cover your consumption with solar power becomes attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
For residential use (less than 10kW), the selling price (FIT) from certifications after October 2025 is set at “24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year.” The same price will apply in the 2026 fiscal year. After the 5th year, it is likely to be more advantageous to use it in your home (self-consumption) rather than selling it, making the combination with a storage battery a viable option.
👉 Ministry of Economy, Trade and Industry | For purchase prices and periods, click here
Benefit 2: Subsidies Can Be Utilized!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
Reducing the actual burden through subsidies is a significant advantage!
In Minami Ward, you may be eligible for subsidies from Yokohama City’s YGrEP or Kanagawa Prefecture.
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 like power conditioners may have operational noise.)
Benefit 4: Heat Insulation Effect Expected!!
By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the temperature rise of the roof, providing expected heat insulation effects!
(Note that this does not improve the 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 functionality, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1 Maintenance costs are 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 reinstalling 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 is reassuring to be able 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 differ by construction method, but when using screws or other fasteners to secure the roofing material and substrate, waterproofing of the fixed parts becomes crucial.
When using a method that creates 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, one option is to replace the roofing material with a metal roof and secure the solar panels using the catch method. (The catch method has compatibility conditions between the roofing material and the fasteners, and it cannot be used with all metal roofs.)
Catch-type base metal fittings for horizontal metal roofs
Note 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load capacity, switching to a lighter roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
Choosing Point 1: Compare based on total output of the roof
When installing solar panels on the roof, it is important to consider how much power can be generated in a limited area, and generating more power is always better!
The size and output of solar panels vary by 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, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different numbers of panels that can be installed on the same roof due to size differences.
400W × 15 panels = 6kW (total output of the roof)
350W × 20 panels = 7kW (total output of the roof)
As shown above, even if the output of one panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above calculations are for total output (kW). The actual power generation amount (kWh) will vary depending on conditions such as the roof’s orientation, slope, and shading.
Choosing Point 2: Compare based on 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 values are standard figures for warranty purposes and do not indicate the actual degradation rate or power generation amount.
By considering the degradation rate along with the initial output, you can choose solar panels without regrets!
Choosing Point 3: Compare based on warranty period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
For output warranties, some manufacturers offer a 30-year warranty while others offer a 10-year warranty, so it varies!
Longer warranties are always better, so be sure to check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Minami Ward
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Minami Ward. (Tap to reveal answers)
How much does it cost to install solar panels and storage batteries in Yokohama City, Minami Ward?
The cost varies depending on the installation capacity, equipment, and roof condition. In the above case study (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 our solar panel and storage battery installation pricing page. We will create a layout diagram from the drawings and site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Minami Ward?
As of October 6, 2026, the application period for Yokohama City’s YGrEP (15,000 yen per kW for solar power, up to 4 kW; 120,000 yen per case for storage batteries) is ongoing (it will end once the budget limit is reached). The Kanagawa Prefecture subsidy (70,000 yen per kW for solar power; 150,000 yen per unit for storage batteries) is approaching the application deadline for the second phase of fiscal year 2026, and the national DR home storage battery project has ended its public recruitment.
Since the application status may change, please refer to the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies after the construction is completed?
For most programs, procedures must be completed before construction. Yokohama City’s YGrEP requires a “participation and introduction support application” before installation, and Kanagawa Prefecture’s subsidy requires “starting construction after the grant decision,” so if you install first, you will be ineligible.
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 when securing 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 suggest methods such as roof overlay or replacement if deterioration is advanced.
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 within 10 to 20 years after installation, there will be additional costs for removing and reinstalling the solar panels. 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 on how to proceed with the installation!
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 introduction of solar panels and storage batteries, and Yokohama City’s YGrEP also has conditions for combinations with storage batteries. You can compare “solar panels only” and “solar panels + storage batteries” through a financial simulation.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and on-site survey, and we will provide you with the installation capacity and power generation simulation.
Minami Ward has the highest proportion of residential land use in the city, and the way shadows are cast by neighboring houses, buildings, and the elevation differences of hilly areas varies from house to 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 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 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 the initial costs more quickly in the first 4 years and then focus on self-consumption. Kakeru Koumuten provides financial simulations that take into account loan interest rates and electricity prices.
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 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 handle renovations 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 water heater removal pricing page.
If you are looking for a solar panel installation company in Minami Ward, please consult Kakeru Koumuten
Our company handles a wide range of exterior renovations, including solar panels, roof work, and exterior wall work in Yokohama City, Minami Ward.
We receive 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 many customers.
We continue to update our annual construction achievements 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 and replacement work but also partial roof repairs, exterior painting, and exterior cover installations.
We are also happy to handle small jobs like 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 our customers’ shoes 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 welcome competitive quotes because we are confident!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Characteristics of Minami Ward, Yokohama City and Points for Solar Work
Minami Ward, Yokohama City, is located in the central part of Yokohama City and is a ward with an area of 12.63 km2 (the second smallest ward among the 18 wards in the city).
We have summarized the characteristics of Minami Ward’s terrain and housing situation, along with points to consider when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Minami Ward, Yokohama City and points for solar work
■ Lowlands along the Ooka River, surrounded by hilly and plateau areas
South Ward Urban Development Materials introduces that the Ooka River flows through the center of the ward, branching into the Nakamura River and the Horikiri River. Surrounding the rivers are the alluvial lowlands and reclaimed land created by the Ooka River, encircled by hilly areas and plateaus. The highest point is approximately 91m above sea level (Nagata Sanno-dai).
In residential areas of hilly and plateau regions, the orientation of roofs, elevation differences, and the shadows cast by neighboring houses and trees vary from house to house. At Kakeru Koumuten Co., Ltd., we create layout diagrams based on blueprints and the actual site conditions, and we confirm them through power generation simulations. In areas with slopes and elevation differences, our own scaffolding team plans the scaffolding to fit the site.
■ High Proportion of Residential Land Use, About 60% for Multi-Family Housing
The same materials indicate that the proportion of residential land use in South Ward (as of the end of FY 2013) is the highest among the 18 wards in the city. According to the South Ward Statistical Overview (FY 2025), the construction types are 34.9% for single-family homes (37,520 units) and 64.0% for multi-family housing (68,860 units) (as of the survey on October 1, 2023). The green coverage rate is 14.1%, which is lower than the city average of 27.8%.
If you live in a single-family home, it is important to check the condition of the roofing materials and substrate before installing solar panels. Depending on the condition of the roof, installing them simultaneously with roof renovations can reduce future costs for removing and reinstalling solar panels. For installations on rooftops or common areas of multi-family housing such as apartments, different procedures may be required, including agreements from owners or management associations, separate from those for individual residences.
■ Different Subsidy System for Business Buildings such as Stores and Offices
When installing on business buildings such as stores, offices, or warehouses, there is a different subsidy system than for households. The subsidy for small and medium-sized enterprises and sole proprietors in Yokohama City is available until 5:00 PM on October 30, 2026 (first-come, first-served, until budget limits are reached), and there may be cases where certain conditions exclude eligibility.
■ Yokohama’s Annual Sunshine Duration is Approximately 2,018 Hours
According to the Meteorological Agency’s Average Values (1991-2020), Yokohama’s annual sunshine duration is about 2,018 hours. August has the most sunshine, while June during the rainy season has the least.
Power generation varies by season, so conducting annual power generation simulations and selecting battery capacities that match the times of high electricity usage are key points.
■ Consideration for Residential Area Rules
In South Ward, there are building agreements for the Daiya Bessho-dai residential area, Shimizu-ga-oka housing complex, Yokohama Nagata-cho housing subdivision, Koumyouji “Hikarigaoka” area, and Towa Fresh Town Kamiooka (5 cases) listed (not all areas in the ward have the same rules). In areas with agreements regarding installations on roofs, it is necessary to confirm the details in advance.
Our company is based in Yokohama City and handles many exterior construction and solar projects in Minami Ward, Yokohama.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacements, and leak repairs, as well as other repairs! Please feel free to consult us for any sudden troubles!
Service Area in Minami Ward, Yokohama
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and Tokyo.
List of Areas in Minami Ward, Yokohama
Idogaya Kamimachi, Minami Ward / Idogaya Shimomachi, Minami Ward / Idogaya Nakamachi, Minami Ward / Urakubunecho, Minami Ward / Eirakucho, Minami Ward / Enokicho, Minami Ward / Ooka, Minami Ward / Oohashicho, Minami Ward / Koudai, Minami Ward / Karasawa, Minami Ward / Kyoshincho, Minami Ward / Koyama, Minami Ward / Sannoucho, Minami Ward / Santani, Minami Ward / Shimizuoka, Minami Ward / Shukucho, Minami Ward / Shirokanemachi, Minami Ward / Shiramimachi, Minami Ward / Shinkawacho, Minami Ward / Takasagocho, Minami Ward / Takanecho, Minami Ward / Torimachi, Minami Ward / Nakazatocho, Minami Ward / Nakazato, Minami Ward / Nakajimacho, Minami Ward / Nakamuracho, Minami Ward / Nagata Kita, Minami Ward / Nagata Sannoudai, Minami Ward / Nagata Dai, Minami Ward / Nagata Higashi, Minami Ward / Nagata Minamidai, Minami Ward / Nagata Minami, Minami Ward / Nishinakacho, Minami Ward / Hachimancho, Minami Ward / Hanano Kimachi, Minami Ward / Hieicho, Minami Ward / Higashimakida, Minami Ward / Fushimicho, Minami Ward / Futabacho, Minami Ward / Heiraku, Minami Ward / Bessho Nakazato Dai, Minami Ward / Bessho, Minami Ward / Horinouchicho, Minami Ward / Makidacho, Minami Ward / Maesatocho, Minami Ward / Makanecho, Minami Ward / Manseicho, Minami Ward / Minami Oota, Minami Ward / Minami Yoshidacho, Minami Ward / Miharu Dai, Minami Ward / Miyamotocho, Minami Ward / Mutsukawa, Minami Ward / Mutsumicho, Minami Ward / Yoshinocho, Minami Ward / Wakamiyacho, Minami Ward
・Trust Kakeru Koumuten for exterior wall painting in Minami Ward, Yokohama!
・Trust Kakeru Koumuten for roof renovations in Minami Ward, Yokohama!
・Trust Kakeru Koumuten for exterior renovations in Minami Ward, Yokohama!
・Trust Kakeru Koumuten for leak repairs in Minami Ward, Yokohama!
・Trust Kakeru Koumuten for waterproofing work in Minami Ward, Yokohama!
・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 key points!
・Top 12 solar power generation manufacturers! Features and selection tips included!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
・What are the best locations for solar power generation installation? Key points for site selection included!
・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!
