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,
trust Kakeru Koumuten!
Kakeru Koumuten is a specialized exterior renovation company headquartered in Aoba Ward, Yokohama.
As a company strong in roofing work, we are entrusted withsolar panel and storage battery installations considering roofs 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 a satisfactory solar panel installation, we recommend obtainingthree estimates!
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 Installer in Minami Ward, Yokohama
- Benefits of Introducing Solar Equipment
- Points to Consider When Introducing Solar Power Generation
- How to Choose Solar Panels
- Frequently Asked Questions About Solar and Storage Battery Installation in Minami Ward
- If You’re Looking for a Solar Panel Installer in Minami Ward, Contact Kakeru Koumuten
- Characteristics of Minami Ward, Yokohama and Key Points for Solar Installation
- Service Area in Minami Ward, Yokohama
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Minami Ward, Yokohama
Regarding why we are entrusted with solar panel installation by customers in Minami Ward, Yokohama,
one reason is that Kakeru Koumuten has a base in the same city of Yokohama,
and we have strengths in solar panel installation that cannot be imitated by other companies, which has received high praise from many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We Can Also Handle Exterior Renovations Aside from 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 are cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have knowledge about the roof to avoid maintenance and troubles after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent 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 solar construction and exterior renovations at low cost and high quality.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the necessary scaffolding materials for temporary scaffolding based on construction conditions, allowing us to assemble scaffolding ourselves.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also cut costs for scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
Even in the residential areas of Minami Ward, where lowlands along the Ooka River meet hilly and plateau regions, our own scaffolding team plans the scaffolding according to the site conditions.
Storage of materials in our large warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, we canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, allowing 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 down on 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 the roofing materials!
It is also possible to simulate the revenue and installation costs when introducing solar panels!
Since roof work and exterior wall work are often involved, we also provide samples of roofing materials and models that show the structure, allowing for detailed explanations!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is all work performed by our own team.
By maintaining a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof remodeling at reduced costs.
Additionally, one representative will handle everything from the estimate to project completion.
Since the person in charge does not change, whether it’s sales or construction management, smooth communication is possible.
We can perform everything from temporary scaffolding installation to exterior wall painting and roof remodeling in-house!
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 workers and painting technicians, giving us confidence in our construction techniques.
We are capable of handling large-scale roofing projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty, our solar panel installation work comes with our own workmanship warranty (leakage warranty)!
(The workmanship warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovation is performed. The workmanship warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty details.)
Aftercare maintenance is available annually, and we send out notification DM each year.
If you have any questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roof troubles and situations.
Even if we cannot access the roof at high altitudes, we can respond using a drone!
During leakage investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of the solar panels decreases due to dirt, we can also perform cleaning with a specialized brush.
We will respond according to the customer’s wishes.
7. Human Resource Development
We create various roof models for skill enhancement 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 Clear Materials and Simulations
At Kakeru Koumuten Co., Ltd., in addition to “estimates”, “layout diagrams”, and “power generation simulations”, we also provide a “solar installation guidebook” and a “financial simulation” that considers loan interest rates and electricity costs.
The financial simulation can be created for projected cumulative income and expenses over 20 to 30 years.
Even customers who are not familiar with solar installations will find the materials easy to understand, including key 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 to 30 years.
“Is it okay to install them directly on the current roof?” Checking this before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten Co., Ltd., which specializes in roofing work, has summarized the items to check before installation.
| 1. Type of roofing material and age | The fixing method varies depending on the roofing material, such as slate, tiles, metal roofs, or flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of the substrate and waterproof sheet | If the plywood or roofing (waterproof sheet) under the roofing material is damaged, it will affect the fixing 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, will affect power generation. We will create a layout diagram from the drawings and the site, and you can confirm it with the power generation simulation. |
| 4. Shape of the roof and installable area | The number of panels (installation capacity) that can be placed depends on the shape and size of the roof. The number of panels that can be installed varies based on their size, so we will compare the overall output of the roof. |
| 5. Fixing method and waterproofing details | We will confirm whether the method involves drilling holes in the roofing material or fixing it with brackets. The fixing method varies by technique, so please check the waterproofing treatment of the fixing parts during the estimate. |
| 6. Weight of the roof | The roof will become heavier due to the panels. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may be an option if necessary. |
| 7. Location of equipment installation and wiring | We will check the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring 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 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 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 perform roof renovations 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 in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Minami Ward, Yokohama City
PotentialSubsidies and Grants in Minami Ward, Yokohama City, Kanagawa Prefecture
When introducing solar panels and storage batteries in Minami Ward, there is a possibility of being 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 Period for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Yokohama City “Yokohama Green Energy Partnership Project (YGrEP)” Reiwa 8 | Yokohama citizens installing eligible equipment at their homes in Yokohama City. 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 (Refunds via cashless points, etc.) |
Participation and installation support application: June 15, 2026 – December 25, 2026 (Application before installation) Installation completion application: By January 22, 2027 Ends when the budget limit is reached. |
| Kanagawa Prefecture “Reiwa 8 Subsidy for Residential Solar Power Generation and Storage Battery Installation” | Must install both solar power generation and storage battery in residential properties within the prefecture. 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 per unit |
Phase 1: May 11, 2026 – June 30, 2026 Phase 2: September 7, 2026 – September 30, 2026 (first-come, first-served) Phase 2 is currently closed for applications. Please check the prefecture’s official page for future recruitment. |
| National “DR Home Storage Battery Project” (Reiwa 7 Supplement) | Newly install a home storage system with registered products that can be used for DR (demand response). | Calculated based on an initial effective capacity of 1 kWh at 34,500 JPY (subsidy rate within 3/10, maximum 600,000 JPY per application). | As of May 29, 2026, the budget has been reached, and applications are closed (currently not accepting applications). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but 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 per 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 in Yokohama City (residential use is not eligible). There are conditions for the target person and equipment, such as being a self-consumption type facility. | 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 the budget limit is reached). |
| Kanagawa Prefecture “Reiwa 8 Subsidy for Self-Consumption Type Renewable Energy Installation” | Corporations and individuals filing blue returns（Individual residences are not eligible）。Solar power must have a generation output of 10kW or more, facilities for business use, equipment not certified under FIT/FIP, etc. | Solar Power: 80,000 yen/kW, etc. Storage System: 50,000 yen/kWh (maximum 5,000,000 yen) |
Application period ends on September 3, 2026 (when the application amount reaches the budget amount) |
YGrEP requires a “Participation and Installation Support Application” before installation, and for Kanagawa Prefecture’s residential subsidies, it is not only necessary to accept applications but also to start construction after receiving the “Grant Decision”. If you begin installation or construction beforehand, you will be ineligible. The prefecture’s residential subsidies are granted after a performance report and review following the completion of construction. The order of procedures varies by system, and applying does not guarantee a grant, so please confirm before contracting or starting work.
At Kakeru Koumuten, we will guide you 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 national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets individuals who are introducing registered products of storage systems that can be utilized for demand response (DR). 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 ineligible for items contracted or ordered before the grant decision.
However, the fiscal year 2025 supplementary budget reached its application amount on May 29, 2026, and the public recruitment has ended (the previous fiscal year’s 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 Residential 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 ineligible, and the application must be made by the individual (applications by the construction contractor are not allowed). It is also possible to combine this with YGrEP in Yokohama City.
For the fiscal year Reiwa 8, the first application period (May 11 to June 30) and the second application period (September 7 to 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 “Reiwa 8 Fiscal Year Kanagawa Prefecture Subsidy for Self-Consumption Type Renewable Energy Introduction” (for businesses)
Kanagawa Prefecture is also implementing subsidies for businesses introducing “self-consumption type” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and individual residential installations are not eligible.
Conditions include solar power generation with an output of 10kW or more, supplying electricity to business facilities within the prefecture, and not being 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).
As the application amount reached the budget amount for the fiscal year Reiwa 8, applications were closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings within Minami Ward should check the official Kanagawa Prefecture page for the next recruitment.
👉 Click here for details
Yokohama City “Subsidy for Solar Power Generation Introduction” (for businesses)
Yokohama City is implementing a system to subsidize part of the introduction costs of solar power generation facilities, etc. for small and medium-sized enterprises and individual business owners within the city.
Residential solar power generation is not eligible, and for households, the YGrEP below will be the point of contact. Businesses installing solar panels on stores, offices, factories, etc., within Minami Ward may have the opportunity 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 self-consumption type equipment (equipment aimed at selling electricity is 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 the fiscal year Reiwa 8 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 carried out 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.
In Yokohama City, households that participate in YGrEP and install eligible equipment (refer to the eligible equipment below) will receive cashless points and other rewards. 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 installed either a storage battery, eco-cute, or electric vehicle simultaneously.
● Storage Battery: 120,000 JPY per case
● Eco-Cute: 20,000 JPY per case
● Electric Vehicle / Plug-in Hybrid Vehicle (set with solar power generation equipment): 100,000 JPY per case
* It is a condition to install or have installed the solar power generation equipment simultaneously with the storage battery, eco-cute, or electric vehicle (set).
● Electric Vehicle alone (without solar power generation equipment): 50,000 JPY per case
● Fuel Cell (EneFarm): 30,000 JPY per case
● Solar Heat Utilization System: 50,000 JPY per case
● V2H Charge/Discharge Equipment: 100,000 JPY per case
For example, if you install a 4kW solar panel and a storage battery simultaneously, 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 is from June 15, 2026, to December 25, 2026, and the completion application is 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. Note that only V2H charge/discharge equipment is eligible for rewards for businesses.
For information on application methods, combined use with national and Kanagawa Prefecture subsidy projects, point rewards, and more, please check the special site here or contact us.
Solar Panel Installation & Battery Installation Price List
⇧Service Menu | For Costs Related to Solar Panel Installation & Battery Installation, Click Here
⇧Service Menu | For Costs Related to Solar Panel Removal & Water Heater Removal, Click Here
Breakdown of Installation Capacity and Equipment & Labor Costs
The costs for solar panels and batteries should be confirmed by separating them into “Equipment Costs (Device Costs)” and “Labor Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.
Considerations for Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of one panel (W) × Number of panels”, with the unit being kW (kilowatts). The battery is compared in terms of the amount of electricity it can store, represented in kWh (kilowatt-hours).
The amount of kW that can be placed on the roof varies for each house depending on the shape, orientation, and size of the roof. At Kakeru Koumuten Co., Ltd., we create a layout diagram from the blueprints and on-site survey to present the installation capacity.
On our pricing page, we list solar panels as approximately 800,000 JPY to 1,200,000 JPY for 3 to 5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6 to 10 kW. (These are just approximate amounts and may vary depending on the length of wiring, 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 based solely on price. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output of one panel (W), number of panels, total installation capacity (kW) are listed. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls the battery together. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range usable during a power outage (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of the hardware suitable for the roofing material and the 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 for fixed parts, 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 estimates from other companies, we can explain the differences item by item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can get an estimated quote and income simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can get an estimated quote and income simulation!
*The simulation results are estimates. Actual income may vary depending on assumptions such as electricity rates, self-consumption ratio, selling price, and costs for equipment inspection or 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 class |
| Base Mounting Hardware Used |
| Niigata Manufactured / 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 |
| Approximately 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 can be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have understood the expected amount of the grant, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Minami Ward, Yokohama
There are many solar panel installation contractors that serve Minami Ward, Yokohama City, and you may be unsure which contractor to choose.
Therefore,when requesting solar panel installation or battery storage installation work, make sure to check the following four points.
● Have extensive knowledge not only about solar power but also about roofs
● Confirm the existence of warranties and aftercare services
● Obtain estimates from multiple contractors (three companies is 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 confirmation regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient checks on roofs and waterproofing
・Solar panels were installed on a severely deteriorated roof, resulting in leaks
・Solar panels were installed 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 led to incorrect processing and subsequent leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unforeseen troubles.
▶ Go to “Roof Check Before Installing Solar Panels” in this article
Confirm the existence of warranties and aftercare services
When choosing a solar installation contractor, make sure to check for warranties. It is important to confirm not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
Solar panels and battery storage units come with manufacturer warranties, but also check for the existence of workmanship warranties in case leaks occur after installation!
For contractors that offer workmanship warranties, if leaks occur after installation, they may cover the repairs under the warranty, provided it is within the warranty period and conditions.
Additionally, some contractors offer after-sales service separate from warranties, so be sure to check if the contractor you are considering has after-sales service.
Changes or damage on the roof may occur in areas that are not visible, so there is a possibility that customers may not notice them.
By conducting inspections of these hidden areas during after-sales maintenance, it becomes easier to detect abnormalities early and prevent major repairs or failures!
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-sales maintenance and send out annual DM!
Please check the DM, and if you wish, we will visit you for after-sales maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, be sure to obtain estimates from multiple contractors.
Even with 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 services from your preferred contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check the following:
“Check the estimate items”
“Type of solar panel”
“Warranties and after-sales services”
Compare these details carefully to make a judgment! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making judgments based solely on price!
▶ To “Breakdown of Installation Capacity, Equipment, and Construction Costs” within this article
Check if they provide support for subsidy applications
Subsidies may be available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
For systems like Kanagawa Prefecture’s housing subsidies, where contractors cannot apply on behalf of the client, it is reassuring to have a contractor who can support the preparation of necessary documents and the flow of procedures.
Be sure to complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining a grant decision) before proceeding with the construction!
In the case of the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the grant will be provided after a review! (The flow of procedures varies by system)
▶ To “Subsidies and Grants That May Be Applicable in Minami Ward” in this Article
Benefits of Introducing Solar Power Equipment
The benefits of installing solar panels are summarized in the following 5 points!
Benefit 1: Economic Benefits
The biggest advantage of installing solar panels is the economic benefit!
Although the selling price of electricity has decreased compared to 10 years ago, you can benefit by reducing the electricity you buy from the utility company by consuming the electricity you generate!
As electricity costs rise, the ability to cover your consumption with solar power becomes attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) will be set at “24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year” for certifications after October 2025, and the same price will apply for the 2026 fiscal year. After the 5th year, it is generally more advantageous to use it at home (self-consumption), making the combination with a storage battery a viable option.
👉 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!
The reduction in the actual burden amount due to subsidies is a significant advantage!
In the case of Minami Ward, subsidies from Yokohama City’s YGrEP and Kanagawa Prefecture may be applicable.
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 do have operational noise.)
Benefit 4: Heat Insulation Effects Are Expected!!
By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the temperature rise of the roof, providing expected heat insulation effects!
(Note that this does not improve the insulation performance of the building itself.)
Benefit 5 Electricity can be used even during power outages!!
If a storage battery is installed, it 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 capability, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1 Maintenance costs can be incurred
A particularly overlooked maintenance cost is for the roof where solar panels are installed.
If you perform roof renovations 10 to 20 years later, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorating, it is reassuring to renovate it with durable roofing materials before installing 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 when using screws or other fasteners to secure the roofing material and substrate, waterproofing of the fixed parts becomes crucial.
If the method involves making holes in the roof, there will inevitably be a risk of leaks.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and securing the solar panels using the catch method is also an option. (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 hardware for horizontal metal roofs
Note 3: The roof will become heavier
To install solar panels, the roof will become heavier. After investigating the existing roof, substrate, and load-bearing capacity, replacing it with a lighter roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
How to Choose 1: Compare by Total Output of the Roof
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and the more power generated, the 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 one with higher output is better at first glance.
However, if the size of the panel does not fit well on the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different numbers of panels that can be installed on the same roof due to size differences.
400W×15 panels = 6kW (total output of the roof)
350W×20 panels = 7kW (total output of the roof)
As shown above, even if the output of one panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual power generation amount (kWh) will vary depending on conditions such as roof orientation, slope, and shading.
How to Choose 2: Compare by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases over 10 or 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or power generation amount.
By considering the degradation rate along with the initial output, you can choose solar panels without regrets!
How to Choose 3: Compare by Warranty Period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
Regarding the output warranty, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies!
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 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 open the 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 construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
For cost estimates by capacity, please refer to 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/kW for solar power, up to 4kW; 120,000 yen per storage battery) is ongoing (it will end once the budget limit is reached). The Kanagawa Prefecture subsidy (70,000 yen/kW for solar power; 150,000 yen per storage battery) 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 check the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies after the construction is completed?
For many programs, procedures are required before construction. Yokohama City’s YGrEP requires a “participation and introduction support application” before installation, and Kanagawa Prefecture’s subsidy requires “commencement of construction after grant decision.” If you install first, you will be excluded from eligibility.
The order of procedures varies by program, so please confirm before signing a contract or starting construction.
Can solar panels be installed on a slate roof? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate. The fixing method varies by construction method, and when fixing brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is crucial.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation, and if deterioration is 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 reinstalling solar panels will be incurred separately. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with durable roofing materials before installation.
Please consult us on how to proceed with the installation after confirming the condition of the roof through a site survey!
Should I install a storage battery together with the solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more beneficial to use it in your home rather than selling it.
Additionally, the subsidy from Kanagawa Prefecture requires the simultaneous introduction of solar panels and storage batteries, and Yokohama City’s YGrEP also requires a combination 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 site survey, and 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 one house to another. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
For the above construction example (solar panels 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 additional time is required for applications for subsidies and to the power company, so please consult us as soon as possible.
What is the current selling price (FIT)?
For residential use (less than 10 kW), the selling price from certifications after October 2025 will be 24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year, with the same prices applied in 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-service maintenance notices via DM and visits customers who wish to have inspections. We can also clean solar panels using specialized brushes if the power generation decreases 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 renovate a roof that already has solar panels installed?
Yes, we can. Kakeru Koumuten can remove and reinstall solar panels in-house, allowing us to remove the panels, perform roof overlay (cover method) or re-roofing, and then reinstall them consistently. The removed panels can be stored in our own warehouse.
For information on costs, please see the solar panel removal and hot water heater removal pricing page.
If you are looking for a solar panel installation contractor in Minami Ward, please consult Kakeru Koumuten
Our company handles many exterior renovations, including solar panels, roofing work, and exterior wall work in Yokohama City, Minami Ward.
We have received requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received great feedback from numerous customers.
We continue to update our construction performance records every year, and we will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay work and re-roofing but also partial roof repairs, exterior painting, and exterior cover methods.
We are also happy to handle small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leak repairs, we may be able to provide emergency measures without setting up scaffolding, within a safe range, so please consult us!
“I want to know about recommended solar panels”, “I want to keep costs as low as possible”, “I just want an estimate for now”, we will provide the best solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in the customer’s position and propose the best construction plan!
We are confident that we will not lose in terms of cost, quality, and organization compared to other companies in exterior construction!
We are confident, so we welcome competitive quotes!
Estimates are completely free, and if you find our company lacking compared to others, you are free to decline!
Characteristics of Yokohama City Minami Ward and Points for Solar Construction
Yokohama City Minami Ward is located in the central part of Yokohama City, covering an area of 12.63 km2 (the second smallest ward among the 18 wards in the city).
We have summarized the topography and housing situation of Minami Ward, along with points to consider when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Yokohama City Minami Ward and points for solar construction
■ Lowlands along the Ooka River, surrounded by hilly and plateau areas
Minami Ward Urban Development Materials introduces that the Ooka River flows through the center of the ward, branching off into the Nakamura River and Horikiri River. Surrounding the rivers are the alluvial lowlands and reclaimed land created by the Ooka River, encircled by hilly and plateau areas. The highest point is approximately 91m above sea level (Nagata Sanno-dai).
In residential areas of hilly and plateau regions, the orientation and elevation differences of roofs, as well as the shadows cast by neighboring houses and trees, vary from house to house. Kakeru Koumuten Co., Ltd. creates layout diagrams based on blueprints and the actual site conditions, and we confirm this through power generation simulations. In areas with slopes and elevation differences, our own scaffolding team plans the scaffolding to suit the site.
■ High Proportion of Residential Land Use, Approximately 60% for Multi-Family Housing
The same document states that the proportion of residential land use in Minami Ward (as of the end of fiscal year 2013) is the highest among the 18 wards in the city. According to the Minami Ward Statistical Overview (Fiscal Year 2025), the construction types are 34.9% (37,520 units) for single-family homes and 64.0% (68,860 units) for multi-family housing (survey as of 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, separate procedures may be required, including agreements from owners and management associations, which differ from those for individual residences.
■ Different Subsidy System for Commercial Buildings such as Stores and Offices
When installing on commercial buildings such as stores, offices, or warehouses, a different subsidy system from that for households will be the point of contact. The subsidy for small and medium-sized enterprises and individual business owners in Yokohama City is accepting applications until 5:00 PM on October 30, 2026 (first-come, first-served, until budget limits), and there may be cases where you are ineligible depending on the conditions.
■ 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 approximately 2,018 hours. By month, August has the most hours, 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 peak electricity usage times are key points.
■ Consideration for Residential Area Rules
In Minami Ward, there are building agreements for residential areas such as Daiya Bessho-dai, Shimizu-ga-oka Housing Complex, Yokohama Nagata-cho Housing Development, Koumyouji “Hikarigaoka” Area, and Towa Fresh Town Kamiooka (5 cases) listed (not all areas in the ward have the same rules). In areas with regulations 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.
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 Shitamachi, Minami Ward / Idogaya Nakamachi, Minami Ward / Urakubocho, Minami Ward / Eirakucho, Minami Ward / Enokicho, Minami Ward / Ooka, Minami Ward / Ohashicho, Minami Ward / Koudai, Minami Ward / Karasawa, Minami Ward / Kyoshincho, Minami Ward / Koyama, Minami Ward / Sannoucho, Minami Ward / Santani, Minami Ward / Shimizugaoka, Minami Ward / Shukucho, Minami Ward / Shirokanemachi, Minami Ward / Shiramiyacho, Minami Ward / Shinkawacho, Minami Ward / Takasagocho, Minami Ward / Takanemachi, 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 Ota, 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. aftercare services
・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 installing solar power generation? 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!
