Leave Your Solar Panel Installation Work in Tsurumi, Yokohama City to Kakeru Koumuten Co., Ltd.!
For solar panel and storage battery installation in
Tsurumi 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 roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Tsurumi Ward”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Tsurumi 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 or so estimates!
Table of Contents (tap to open/close)
- Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Tsurumi Ward, Yokohama
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Tsurumi 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 Tsurumi 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 Tsurumi Ward
- If You’re Looking for a Solar Panel Installation Contractor in Tsurumi Ward, Contact Kakeru Koumuten
- Characteristics of Tsurumi Ward, Yokohama and Points for Solar Construction
- Service Area in Tsurumi Ward, Yokohama
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Tsurumi Ward, Yokohama
The reasons why we are entrusted with solar panel installation by customers in Tsurumi Ward, Yokohama include
one reason being that Kakeru Koumuten has a base in the same city of Yokohama,
and we have unique strengths in solar panel installation that cannot be imitated by other companies, which have received high praise from many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We also handle exterior renovations other than solar panel installation!
Troubles such as leaks that occur during solar panel installation may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if 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 expertise in roofing to avoid maintenance issues and troubles after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent troubles after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has 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 have our own scaffolding materials necessary for temporary scaffolding based on construction conditions, allowing us to set up scaffolding ourselves.
By not outsourcing scaffolding work and using our own scaffolding team, we can also cut costs for scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
Even in the residential areas of Tsurumi Ward, which have diverse topography from hilly areas to riverside and coastal areas, our in-house scaffolding team will plan scaffolding according to the local conditions.
Storage of Materials in Our Large Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we canrespond 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 paints, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior renovation dedicated showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on roofing materials!
We can also provide simulations for potential earnings and installation costs if you decide to introduce 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 while providing high-quality roof renovations.
Additionally, one representative will be in charge from the estimate to the completion of the work.
Since the担当者 does not change, such as sales representatives or construction management personnel, smooth communication is possible.
We can provide consistent in-house construction from temporary scaffolding installation, exterior wall painting, to roof renovations!
4. Various Permits and Skilled Workers
We have obtained permits for the construction industry and for the collection and transportation of industrial waste!
We also have nationally certified sheet metal workers and painting specialists on staff, and we are confident in our construction techniques.
We are capable of handling large-scale roof projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation work, we also provide our own construction warranty (leakage warranty)!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless a roof renovation is performed. The construction warranty is separate from the manufacturer’s product warranty, and the coverage and conditions vary depending on the warranty details.)
Aftercare is available every year, and we send out notification DM each year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
Even if you cannot access the roof at high altitudes, we can utilize drones to assist!
During leak investigations, we can also conduct surveys using a thermal imaging camera.
If the power generation of your solar panels decreases due to dirt or other factors, we can also provide cleaning with a specialized brush.
We will respond according to your wishes.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly 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 installation guidebook” and a “profit and loss simulation” that takes into account loan interest rates and electricity costs.
The profit and loss simulation can be created for projected cumulative profits and losses over 20 to 30 years.
Even customers who are not familiar with solar installations 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 “Is it okay to install them directly on the current roof?” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, which specializes in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing materials, such as slate, tiles, metal roofs, and flat roofs (rooftop waterproofing). If the remaining lifespan of the roofing material is short, we may suggest roof renovation first. |
| 2. Condition of Substrate and Waterproof Sheet | If the sheathing boards or roofing (waterproof sheet) under the roofing material are damaged, it will affect the fixing strength of the fittings 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 the amount of power generated. We will create a layout diagram from the drawings and the site, and you can confirm it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels 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 size of the panels, we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will confirm whether the method involves drilling holes in the roofing material for fixing or using fittings 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-bearing capacity, switching to lighter roofing materials may also be an option if necessary. |
| 7. Installation Location of Equipment and Wiring | We will check the installation location 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 the cost. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproofing treatment of fixing parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suitable for the type of tile (even methods that do not drill holes in the tiles will fix to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lightweight roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | 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 in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Tsurumi Ward, Yokohama City
PossibleSubsidies and Grants
If you are introducing solar panels or storage batteries in Tsurumi Ward, there is a possibility that the “National,” “Kanagawa Prefecture,” and “Yokohama City” systems may apply.
The following is based on information confirmed on the official pages of each system as of October 6, 2026. The acceptance status may change depending on the budget, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Yokohama City “Yokohama Green Energy Partnership Project (YGrEP)” Reiwa 8 Fiscal Year | 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 4kW) Storage Battery: 120,000 JPY per case (Refund via cashless points, etc.) |
Participation & Installation Support Application: June 15, 2026 – December 25, 2026 (Application before installation) Installation Completion Application: By January 22, 2027 Ends once the budget limit is reached. |
| Kanagawa Prefecture “Reiwa 8 Fiscal Year Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Installation Subsidy” | Installation of both solar power generation and storage batteries 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/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 at its application deadline. Please check the prefecture’s official page for future recruitment. |
| National “DR Home Storage Battery Project” (Reiwa 7 Fiscal Year Supplement) | New installation of home storage systems that can be utilized for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 1 kWh at 34,500 JPY (subsidy rate within 3/10; maximum 600,000 JPY per application). | As of May 29, 2026, the budget has been reached, and 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 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 once 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 for the target individuals and equipment, such as being self-consumption type equipment. | 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 “Reiwa 8 Fiscal Year Kanagawa Prefecture Self-Consumption Type Renewable Energy Installation Subsidy” | Corporations and sole proprietors filing blue returns（Individual residences are excluded）。Solar power systems must have a generation output of 10kW or more, and facilities for business use, equipment not certified under FIT/FIP, etc. | Solar power: 80,000 yen/kW, etc. Storage systems: 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, while Kanagawa Prefecture’s residential subsidies require not only the acceptance of applications but also construction to begin after receiving “grant approval”. If you start installation or construction beforehand, you will be excluded from eligibility. The prefecture’s residential subsidies are granted after completion of construction 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 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 the Introduction of Home Storage Systems for DR Resources)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those who are newly introducing registered 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 excluded if contracts or orders are made before grant approval.
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.
👉 Here is the official site for 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 residences.
The subsidy details are 70,000 yen per 1kW of solar power generation 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 grant approval, it will be excluded, and the application must be made by the individual (applications by contractors on behalf are not allowed). It is also possible to combine this with YGrEP in Yokohama.
For the fiscal year Reiwa 8, applications for the first phase (May 11 – June 30) and the second phase (September 7 – September 30, first-come-first-served) are being accepted, and the second phase is approaching 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 being a facility not 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 has reached the budget amount for Reiwa 8, applications were closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Tsurumi 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, targeting 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 serves as the contact point. Businesses installing solar panels on stores, offices, factories, etc., in Tsurumi 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 a self-consumption type facility (facilities aimed at selling electricity are not eligible).
The subsidy amount is 100,000 yen per kW when introducing both 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 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 occur 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 offers cashless point rewards to households in the city that participate in YGrEP and install eligible equipment (refer to the eligible equipment below). Residents of Tsurumi Ward are also eligible.
◎Eligible Equipment and Reward Amounts◎
● Solar Power Generation Equipment (new installation): 15,000 JPY/kW (up to 4kW)
*Condition: Must install or already have either a storage battery, eco-cute, or electric vehicle simultaneously.
● 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
*Condition: Must install or already have solar power generation equipment simultaneously.
● Electric Vehicle alone (without solar power generation equipment): 50,000 JPY per unit
● Fuel Cell (EneFarm): 30,000 JPY per unit
● Solar Thermal 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 simultaneously, the calculation for the reward amount would be 60,000 JPY for solar power + 120,000 JPY for storage battery = a total of 180,000 JPY.
The application process is “Participation and Installation Support Application (before installation) → Equipment Installation → 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.
If selling electricity, only the surplus that cannot be used at home is eligible, and submission of monitoring data such as annual power generation is also a condition. Additionally, only V2H charging and discharging equipment is eligible for point rewards for businesses.
For application methods, information on combining with national and Kanagawa Prefecture subsidy projects, point rewards, and more, please check the special site here for details and inquiries.
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 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 (Equipment Price)” 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, represented in kWh (kilowatt-hour).
The amount of kW that can be placed on the roof varies for each house based on the roof’s shape, orientation, and size. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panel installation costs as approximately 800,000 JPY to 1,200,000 JPY for 3-5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6-10 kW. (These are just estimated amounts and may vary depending on factors such as wiring length, scaffolding range, existing roofing materials, and panel layout.)
▶ Installation Menu | Costs for Solar Panel and Storage Battery Installation
Items to Check in the Quotation (Cost Confirmation)
When comparing quotes, 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 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 check if it is a type that controls the storage battery together. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range of use during power outages (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of the hardware suitable for the roofing material and method of securing it (whether it is a method that drills holes or a method that clamps and secures). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, and whether there is a monitor to check the power generation amount. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at the fixing points, and whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | How much support is included for applications to the power company, certification applications 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 will explain the differences item by item!
Self-Quotation and Profit and Loss Simulator for Solar Power Generation
With the simulator above,
you can get an estimated quote and income simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can obtain an estimated quote and income simulation!
*The simulation results are estimates. Actual income may vary depending 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 class |
| Base Mounting Hardware Used |
| Niigata-made aluminum catch-type hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed by catching the horizontal metal roof with catch-type hardware (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery 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 grants are available, and I would like to know how much will be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of the grant, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Tsurumi Ward, Yokohama
There are many solar panel installation contractors available in Tsurumi Ward, Yokohama, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and battery storage installation work, let’s check the following four points.
● Not only knowledge of solar panels but also extensive knowledge of roofs
● Confirm the presence of warranties and aftercare services
● 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 of 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 of solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient checks of roofs and waterproofing
・Solar panels installed on a deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring remodeling for removal and reinstallation within a few years
・Misjudgment of the type of waterproofing leading to incorrect treatment and 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 Check Before Installing Solar Panels” in this article
Confirm the presence of warranties and aftercare services
When choosing a solar installation contractor, let’s confirm the presence of warranties. It is important to check not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While the solar panels and battery storage units come with manufacturer warranties, it is also important to check for the presence of a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may be able to address the issue under the warranty, provided it falls 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.
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 during after-maintenance, we can easily prevent major repairs or breakdowns by discovering abnormalities early!
Kakeru Koumuten Co., Ltd. provides a leak warranty as part of the workmanship warranty for solar panel installations. (The warranty for solar panel installation is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty without performing roof renovations.)
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 solar panel installation, 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, please check
“Confirmation of estimate items”
“Types of solar panels”
“Warranties and after-services”
and make a detailed comparison before making a decision! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid judging solely based on price!
▶ Go to “Breakdown of Installation Capacity, Equipment, and Construction Costs” in this article
Check if they provide support for subsidy applications
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 the Kanagawa Prefecture housing subsidy, where contractors cannot apply on behalf of the client, 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 go through a review before the grant is provided! (The flow of procedures varies by system)
▶ Go to “Subsidies and Grants That May Be Applicable in Tsurumi 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 Advantage
The biggest advantage of installing solar panels is the economic benefit!
While the selling price of electricity has decreased compared to 10 years ago, you can gain benefits by reducing the amount of electricity purchased from the utility company through self-consumption of generated power!
As electricity prices rise, the ability to cover your consumption with solar power becomes attractive!
If you plan to use the generated power at night, installing a storage battery is essential!
For residential use (under 10kW), the selling price (FIT) for electricity generated from October 2025 onwards is set at “24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year.” The same price will apply for the 2026 fiscal year. After the 5th year, it is often more advantageous to use it at 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, periods, etc., click here
Benefit 2: Subsidies Can Be Utilized!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the criteria, you may be able to utilize subsidies!
Reducing the actual burden through subsidies is a significant advantage!
In the case of Tsurumi Ward, there may be eligibility for subsidies from Yokohama City’s YGrEP and 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 produce 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 insulation performance of the building itself.)
Benefit 5: Electricity can be used even during power outages!!
If a storage battery is installed, it becomes possible to use electricity even during emergencies such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capability, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration available 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 maintenance cost that is often overlooked is the roof where the solar panels are installed.
If you perform roof remodeling 10 to 20 years later, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorating, it is reassuring to remodel it with durable roofing materials before installing the solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It would be reassuring to consider maintenance costs in the simulation before introducing solar panels!
Point 2: The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but when using screws or other fasteners to secure the roofing material and substrate, waterproofing of the fixed areas 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, 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.)
Foundation brackets 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, switching to a lightweight roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply the case that “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 Method 1: Compare based on total roof output
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!
Solar panels come in various sizes depending on the manufacturer, and their outputs differ.
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 installation capacities on the same roof due to the size difference.
400W × 15 panels = 6kW (total output of the roof)
350W × 20 panels = 7kW (total output of the roof)
As shown above, even if the output of a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above calculations are for total output (kW). The actual power generation (kWh) will vary depending on conditions such as roof orientation, slope, and shading.
Choosing Method 2: Compare based on 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 values are standard figures for warranty purposes and do not indicate the actual degradation rate or power generation itself.
By considering the degradation rate along with the initial output, you can choose solar panels without regrets!
Choosing Method 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 may only offer a 10-year warranty, so it varies!
The longer the warranty, the 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 Tsurumi Ward
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Tsurumi Ward. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Tsurumi Ward, Yokohama City?
The cost varies depending on the installation capacity, equipment, and condition of the roof. 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 available on our solar panel and storage battery installation pricing page. We will create a layout diagram from the blueprints and on-site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Tsurumi 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 household 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 many programs, procedures must be completed before construction. Yokohama City’s YGrEP requires a “participation and installation support application” before installation, and the Kanagawa Prefecture subsidy requires “commencement of construction after grant approval.” 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 the panels varies by installation method, and when securing brackets to the roofing material or substrate, waterproofing of the secured areas 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 suggest methods such as roof overlay or replacement if deterioration is advanced.
The roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed within 10 to 20 years after installation, the cost of removing and reinstalling the solar panels will be incurred separately. If the remaining lifespan of the roof is short, renovating to a highly durable roofing material before installation may help reduce total costs.
After confirming the condition of the roof during the on-site survey, please consult us 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 requires a combination with storage batteries. You can compare “solar only” and “solar + storage battery” through a financial simulation.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and on-site survey, and provide you with the installation capacity and power generation simulation.
In Tsurumi Ward, there are residential areas in hilly regions and mixed-use areas, and the shading from neighboring houses, buildings, and trees differs from one house to another. You can check the expected power generation through the power generation simulation.
How long is the construction period?
In the above construction example (4.3 kW solar panel + 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 is an additional period required for subsidies and applications 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), 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 in the 2026 fiscal year.
The idea is to recover the initial costs quickly in the first 4 years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that takes into account loan interest rates and electricity costs.
Can you handle maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-service maintenance notices via DM and visits customers who wish to have inspections. We can also clean solar panels with a special brush if the power generation 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 also handle renovations for 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 detachment and water heater removal pricing page.
If you are looking for a solar panel installation company in Tsurumi Ward, please consult Kakeru Koumuten
Our company handles a wide range of exterior renovations, including solar panels, roof work, and exterior wall work in Tsurumi Ward, Yokohama City.
We receive requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received positive feedback from numerous customers.
We continue to update our 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 work and re-roofing but also partial roof repairs, exterior painting, and exterior wall cover methods.
We are also happy to handle small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leak repairs, we may be able to provide temporary measures without setting up scaffolding, as long as safety can be ensured, so please consult 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 the best solutions for your specific requests.
We will never propose unnecessary work focused on profit!
We always stand in the customer’s position and will propose the best construction plan!
We are confident that we will not be outdone in terms of cost, quality, and planning for exterior work compared to other companies!
We are confident, so we welcome competitive quotes!
Estimates are completely free, and if we are found to be inferior to other companies, you are free to decline!
Characteristics of Tsurumi Ward, Yokohama City, and Points for Solar Work
Tsurumi Ward, Yokohama City, is located in the northeastern part of Yokohama City, with an area of 33.22 km2 (as of July 1, Reiwa 5).
Below are the characteristics of Tsurumi Ward and points to consider when installing solar panels and storage batteries (tap to open).
View characteristics of Tsurumi Ward and points for solar work
■ Three areas: hilly land, lowlands along rivers, and coastal areas
Natural Environment and Landscape of Tsurumi introduces that Tsurumi Ward is divided into three areas: the hilly region in the northwest, the lowlands of the Tsurumi River basin, and the reclaimed land in the coastal area. The hilly area consists of plateaus with heights of 40-50m, featuring many small valleys, while the reclaimed land occupies about one-third of the total area of the ward.
In residential areas of the hilly region, the orientation of roofs, elevation differences, and the shadows cast by neighboring houses, retaining walls, 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 sites with elevation differences, our own scaffolding team plans the scaffolding to suit the site.
■ The hilly area with remaining greenery requires attention to fallen leaves and shadows
The same page introduces major green spaces in the hilly area, such as Shishigaya Citizen’s Forest, Kanagawa Prefectural Mitsuike Park, and Higashi-Terio Friendship Forest.
On roofs close to trees, fallen leaves and dirt can easily accumulate on the panels, which may lead to a decrease in power generation. If there are tall trees nearby, attention is also needed for shadows on the panels. Kakeru Koumuten Co., Ltd. can also handle solar panel cleaning with specialized brushes and rain gutter cleaning.
■ The coastal industrial area and mixed residential-industrial districts
Overview of Tsurumi Ward states that the coastal area is an industrial zone, while the central area mainly consists of commercial and residential regions, with mixed residential-industrial districts also present.
When installing on business buildings such as factories, offices, and stores, there are separate subsidy systems from those for households. Grants for small and medium-sized enterprises and sole proprietors in Yokohama City are accepted until 5 PM on October 30, 2026 (first-come, first-served, until budget limits are reached), and there may be cases where certain conditions exclude eligibility. For buildings with large roofs, it is particularly important to check the type of roofing material and its condition.
■ Yokohama’s annual sunshine duration is about 2,018 hours
Meteorological Agency’s average values (1991-2020) indicate that Yokohama’s annual sunshine duration is about 2,018 hours. By month, 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 capacity to match peak electricity usage times are key points.
■ Building agreements in industrial districts
Building agreements in Tsurumi Ward list three areas: Daikoku-cho Industrial Park, Suehiro Factory Park, and Namamugi Factory Park (not all areas in the ward have the same rules). If installing on business buildings in the relevant areas, it is necessary to check the contents of the agreement in advance.
Our company is based in Yokohama City and handles many exterior construction and solar projects in Tsurumi Ward.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us for any sudden troubles!
Service Area in Tsurumi Ward, Yokohama City
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and Tokyo.
List of Areas in Tsurumi Ward, Yokohama City
Tsurumi Ward Asahicho/Tsurumi Ward Anzencho/Tsurumi Ward Ichibanakamachi/Tsurumi Ward Ichibanshimachi/Tsurumi Ward Ichiban Nishinakacho/Tsurumi Ward Ichiban Higashinakacho/Tsurumi Ward Ichiban Fujimicho/Tsurumi Ward Ichiban Yamatocho/Tsurumi Ward Shiodacho/Tsurumi Ward Egazaki-cho/Tsurumi Ward Ougishima/Tsurumi Ward Onomachi/Tsurumi Ward Kajiyama/Tsurumi Ward Kamisueyoshi/Tsurumi Ward Kamino-miya/Tsurumi Ward Kansei-cho/Tsurumi Ward Kishitani/Tsurumi Ward Kitatera-o/Tsurumi Ward Komaoka/Tsurumi Ward Sakaemachi-dori/Tsurumi Ward Shioiri-cho/Tsurumi Ward Shishigaya/Tsurumi Ward Shimono-tani-cho/Tsurumi Ward Shirite/Tsurumi Ward Shimosueyoshi/Tsurumi Ward Suehiro-cho/Tsurumi Ward Sugazawa-cho/Tsurumi Ward Suwasaka/Tsurumi Ward Okurocho/Tsurumi Ward Okuro-futo/Tsurumi Ward Daito-cho/Tsurumi Ward Tsukudano-cho/Tsurumi Ward Tsurumi Chuo/Tsurumi Ward Tsurumi/Tsurumi Ward Teratani/Tsurumi Ward Toyooka-cho/Tsurumi Ward Nakadori/Tsurumi Ward Ikumaki/Tsurumi Ward Hamacho/Tsurumi Ward Baba/Tsurumi Ward Higashiterao Kitadai/Tsurumi Ward Higashiterao Nakadai/Tsurumi Ward Higashiterao Higashidai/Tsurumi Ward Higashiterao/Tsurumi Ward Heian-cho/Tsurumi Ward Benten-cho/Tsurumi Ward Honmachi-dori/Tsurumi Ward Mitsuike Park/Tsurumi Ward Mukai-cho/Tsurumi Ward Motomiya/Tsurumi Ward Yahata
・Trust Kakeru Koumuten for exterior wall painting in Tsurumi Ward, Yokohama!
・Trust Kakeru Koumuten for roof renovations in Tsurumi Ward, Yokohama!
・Trust Kakeru Koumuten for exterior renovations in Tsurumi Ward, Yokohama!
・Trust Kakeru Koumuten for leak repairs in Tsurumi Ward, Yokohama!
・Trust Kakeru Koumuten for waterproofing work in Tsurumi 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 comparative estimates and key points!
・12 major solar power manufacturers! Features and selection tips included!
・What are the installation costs for solar power? Comprehensive tips to reduce costs!
・What are the best locations for solar power installation? Key points for site selection included!
・Here is the introduction to 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!
