Leave the solar panel installation work in Totsuka, Yokohama City to Kakeru Koumuten Co., Ltd.!
For Solar Panel and Battery Installation in
Totsuka Ward, Yokohama,
trust Kakeru Koumuten!
Kakeru Koumuten is a company specializing in exterior renovations based in Yokohama.
As a company strong in roofing work, we are entrusted withsolar panel and battery installation considering roofs and waterproofing!
“How to Choose a Solar Panel Contractor in Totsuka Ward”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Totsuka 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 Why Kakeru Koumuten is Chosen for Solar Panel Installation in Totsuka Ward, Yokohama
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Totsuka 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 Totsuka Ward, Yokohama
- Benefits of Introducing Solar Equipment
- Points to Note When Introducing Solar Power Generation
- How to Choose Solar Panels
- Frequently Asked Questions About Solar and Storage Battery Installation in Totsuka Ward
- If You Are Looking for a Solar Panel Installer in Totsuka Ward, Contact Kakeru Koumuten
- Characteristics of Totsuka Ward, Yokohama and Key Points for Solar Installation
- Service Area in Totsuka Ward, Yokohama
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Totsuka Ward, Yokohama
Here are the reasons why our company is entrusted with solar panel installation by customers in Totsuka Ward, Yokohama.
“Our Unique Strengths in Solar Panel Installation That Cannot Be Replicated by Other Companies”
have received high praise from many customers.
Because we are confident, we welcome estimates from any number of companies!
1. We Also Handle Exterior Renovations Aside from Solar Panel Installation!
Problems such as leaks that occur with solar panel installations may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if one is knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside their expertise, so caution is necessary.
It is reassuring to have knowledge about the roof 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 Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding according to the construction conditions and can assemble the scaffolding in-house.
By not outsourcing scaffolding work and using our own scaffolding team, we can also cut costs related to scaffolding work.
We own scaffolding materials for approximately 50 detached houses!
Even if there is a height difference on the site, our in-house scaffolding team will plan the scaffolding according to the local conditions.
Storage of Materials in Our Large Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, enabling us torespond quickly in emergencies!
Sorting and Transportation of Waste Materials In-House
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior Remodeling Dedicated Showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are attached to the roofing materials!
We can also provide simulations of the revenue and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also have samples of roofing materials and models that explain the structure, allowing for detailed explanations!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is its complete in-house construction.
By having a consistent system from inquiry to project completion, Kakeru Koumuten can keep costs down while providing high-quality roof renovations.
Additionally, one representative will handle everything from the estimate to project completion.
Since the same person will manage sales and construction, 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 construction industry permits as well as permits for industrial waste collection and transportation!
We also have nationally certified sheet metal and painting technicians on staff, giving us confidence 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, we also provide our own construction warranty (leakage warranty)!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless a roof renovation is performed. The construction warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty details.)
Aftercare is available annually, and we send out notification DM each year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
If you cannot access the roof at high altitudes, we can utilize a drone to assist!
During leak investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of the solar panels decreases due to dirt, we can also provide cleaning with a specialized brush.
We will respond according to the customer’s 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 conduct technical training to ensure that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
Kakeru Koumuten provides “estimates,” “layout diagrams,” and “power generation simulations”, as well as “Solar Installation Guidebooks” and “profit and loss simulations” that take into account loan interest rates and electricity costs.
Profit and loss simulations can be created for projected cumulative profits over 20 to 30 years.
Even customers who are not familiar with solar installations will receive materials that clearly outline 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 or 30 years.
Confirming “whether it is 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 material, such as slate, tiles, metal roofs, and flat roofs (rooftop waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of Substrate and Waterproof Sheet | If the underlayment or roofing (waterproof sheet) beneath the roofing material is damaged, it will affect the fastening strength and waterproofing. We will also check for any signs of water leakage. |
| 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 power generation. We will create a layout diagram from the drawings and the site, and you can check it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels that can be installed (installation capacity) is determined by the shape and size of the roof. The number of panels that can be installed varies depending on the size of the panels, so we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will check whether the method involves drilling holes in the roofing material for fastening or using brackets to secure the roofing material. The fixing method varies by technique, so please confirm the waterproofing treatment method for the fastening 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 confirm the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect the cost. |
| 8. Ease of Scaffolding Setup and Delivery Routes | If there are elevation differences on the site, planning for scaffolding and the delivery routes for equipment and materials may require some ingenuity. The width of the front road and any steps on the site will also be checked during the site survey. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets with screws to roof material and substrate) | Waterproof treatment of fixing parts, cracks or deterioration of slate, condition of 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 material before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, 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 carry out 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 Totsuka Ward, Yokohama City
PotentialSubsidies and Grants in Totsuka Ward, Yokohama City, Kanagawa Prefecture
If you introduce solar panels or storage batteries in Totsuka Ward, you may be eligible for programs from “the national government,” “Kanagawa Prefecture,” and “Yokohama City.”
The following information is based on the official pages of each program as of October 6, 2026. The application status may change depending on the budget, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Yokohama City “Yokohama Green Energy Partnership Project (YGrEP)” Fiscal Year 2026 | Yokohama residents installing eligible equipment at their homes. Solar power must be newly installed, and either a storage battery, eco-cute, or electric vehicle must be installed simultaneously or already in place. | Solar power: 15,000 JPY/kW (up to 4kW) Storage battery: 120,000 JPY per unit (Cashless points, etc. for refunds) |
Participation & Installation Support Application: June 15, 2026 – December 25, 2026 (Application must be made before installation) Installation Completion Application: By January 22, 2027 Ends when the budget limit is reached |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Installation Subsidy” | Installation of solar power generation and storage systems together in residential buildings (with earthquake resistance). Applications must be made by the individual, and construction can begin after the grant decision. | Solar power: 70,000 JPY/kW Storage battery: 150,000 JPY per unit |
Phase 1: May 11, 2026 – June 30, 2026 Phase 2: Starts September 7, 2026 (first-come, first-served) As of September 7, 2026, the application amount reached the budget limit, and applications are now closed. Please check the prefecture’s official page for future recruitment. |
| National “DR Home Storage Battery Project” (Fiscal Year 2025 Supplement) | New installation of registered home storage systems that can be utilized for DR (demand response). | Calculated based on an initial effective capacity of 1kWh 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 recruitment has ended (the official site states there are no plans to reopen applications, and applications cannot be made at this time). |
| 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 equipment. | Storage battery: 96,000 JPY per unit | Ends when the budget limit is reached. As of October 5, 2026, the application amount for renovations is displayed as 8% of the budget on the official site. Please check the official site for application status. |
| Yokohama City “Solar Power Generation Installation Support Subsidy” | Small and medium-sized enterprises and sole proprietors in Yokohama City (residential applications are not eligible). Must be self-consumption type equipment, among other conditions for eligibility. | Solar power + storage system: 100,000 JPY/kW (up to 5,000,000 JPY) Solar power only: 80,000 JPY/kW (up to 4,000,000 JPY) |
May 1, 2026 – October 30, 2026, 5 PM (first-come, first-served until the budget limit is reached). As of September 7, the application amount has reached 70% of the budget amount. |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Self-Consumption Type Renewable Energy Installation Subsidy” | Corporations and sole proprietors filing blue returns（Personal residences are not eligible). Solar power must have an output of 10kW or more, facilities for business use, and equipment that is not certified under FIT or FIP, etc. | Solar Power: 80,000 JPY/kW, etc. Storage System: 50,000 JPY/kWh (up to 5,000,000 JPY) |
Application closed on September 3, 2026 (when the application amount reached the budget) |
YGrEP requires a “Participation and Introduction 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 Decision”. If you start installation or construction beforehand, you will be ineligible. The prefectural residential subsidies are granted after completion of the work and submission of a performance report and review. 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 Battery Project (Support Project for Introducing Home Storage Systems for DR Resources)”
The national government has been implementing the “DR Home Battery Project” to support the installation of home storage batteries.
This program targets those introducing new storage systems of registered products that can be utilized for demand response (DR). In the fiscal year 2025 supplementary budget, the subsidy amount is determined based on a standard amount of 34,500 JPY per initial effective capacity of 1kWh, with a subsidy rate of up to 30% and a maximum of 600,000 JPY per application. There are conditions such as being ineligible for items contracted or ordered before grant approval.
However, the fiscal year 2025 supplementary budget application amount reached the budget on May 29, 2026, and the public recruitment has ended. The official site also states that there are no plans to reopen public recruitment, and applications are currently not possible. Please check the official site for future public recruitment.
Currently, there are no subsidies confirmed for the installation of solar panels for existing homes.
👉 Click here for the official site of the DR Home Battery Project
Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Residential Solar Power 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 JPY per 1kW of solar power generation output, and 150,000 JPY per storage system.
For example, if you install a 4kW solar panel and one storage battery, the subsidy amount would be calculated as 4kW × 70,000 JPY + 150,000 JPY = 430,000 JPY.
Eligible homes must ensure seismic performance, the storage system must be a registered product, if construction begins before the grant decision, it will be ineligible, and the application must be made by the individual (proxy applications by contractors are not allowed). It is also possible to combine this with Yokohama City’s YGrEP.
For the fiscal year Reiwa 8, applications for the first phase (May 11 to June 30) and the second phase (starting September 7, first-come-first-served) were accepted. The second phase has been closed as of September 7, 2026, when the application amount reached the budget limit. Please check the official Kanagawa Prefecture page for future recruitment.
👉 Here is the official Kanagawa Prefecture page
Kanagawa Prefecture “Reiwa 8 Fiscal Year Kanagawa Prefecture Subsidy for Introducing Self-Consumption Renewable Energy” (for businesses)
Kanagawa Prefecture is also implementing subsidies for businesses that introduce “self-consumption type” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and individual residential installations are not eligible.
Conditions include solar power generation with an output of 10 kW or more, supplying electricity to business facilities within the prefecture, and the equipment must not be 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).
For the fiscal year Reiwa 8, applications have closed as the application amount reached the budget limit on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Totsuka Ward should check the official Kanagawa Prefecture page for the next recruitment.
👉 For more details, click here
Yokohama City “Subsidy for Introducing Solar Power Generation” (for businesses)
Yokohama City is implementing a system to subsidize part of the introduction costs for small and medium-sized enterprises and individual business owners within the city for solar power generation equipment and other installations.
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, or factories in Totsuka Ward may have the opportunity to utilize this, but simply operating 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 (equipment for selling electricity is 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 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. As of September 7, it has been announced that the application amount has reached 70% of the budget limit, so early confirmation is recommended. Installation of equipment and commencement of construction must take place 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 Totsuka Ward are also eligible.
◎Eligible Equipment and Reward Amounts◎
● Solar Power Generation Equipment (New Installation): 15,000 JPY/kW (up to 4 kW)
* It is a condition to install or have already 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 already installed 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 Charging and Discharging Equipment: 100,000 JPY per case
For example, if you install a 4 kW 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 will be 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 you sell electricity, it must only be the excess amount that cannot be used at home, and submission of monitoring data such as power generation amounts approximately once a year is also a condition. Note that only V2H charging and discharging equipment is eligible for rewards for businesses.
For information on application methods, combining with national and Kanagawa Prefecture subsidy projects, and point rewards, please check and inquire from this special site.
Solar Panel Installation and Storage Battery Installation Price List
⇧Service Menu | For Costs Related to Solar Panel Installation and Battery Installation, Click Here
⇧Service Menu | For Costs Related to Solar Panel Removal and Water Heater Removal, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and batteries should be confirmed by separating them into “Equipment Costs (Device Costs)” and “Construction Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.
Understanding Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatts). Batteries are compared based on the amount of electricity they can store, represented in kWh (kilowatt-hours).
The amount of kW that can be placed on the roof varies for each house depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panels as approximately 800,000 JPY to 1,200,000 JPY for 3-5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6-10 kW. (These are just 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 Installation and Battery Installation
Items to Confirm in the Estimate (Cost Verification)
When comparing estimates, it is common to compare different capacities and equipment. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, and total installation capacity (kW) are specified. |
| 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 Fittings | Name of fittings suitable for roofing materials and method of securing (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 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 roofing work or exterior painting, check that the same scope and quantity are not double-counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters or old panels, and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether it 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 amount and power generation will change. Kakeru Koumuten Co., Ltd. welcome comparisons, so if you bring estimates from other companies, we will explain the differences item by item!
Self-Estimate 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 based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection and replacement.
Customer Feedback
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installations
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh |
| 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 |
| About 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 grants, so we explained this to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Totsuka Ward, Yokohama
There are many solar panel installation contractors available in Totsuka 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.
● Ensure they have extensive knowledge not only about solar panels but also about 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 about roofs as well as solar panels
Defective installation of solar panels can sometimes be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient verification of roofs and waterproofing
・Solar panels installed on a severely deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring reinstallation within a few years
・Misjudgment of the type of waterproofing leading to incorrect treatment and subsequent leaks
and more.
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the presence of warranties and aftercare services
When choosing a solar installation contractor, make sure to check for warranties. It is important to verify not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While the solar panels and battery storage come with manufacturer warranties, also check for the presence of a workmanship warranty in case leaks occur after installation!
If the contractor offers a workmanship warranty, they may cover any leaks that occur after installation, as long as it falls within the warranty period and conditions.
Additionally, some contractors provide aftercare services separately from warranties, so be sure to check if the contractor you are considering has aftercare services.
Since abnormalities or damage on the roof may not be visible, you might not notice them yourself.
By conducting inspections of hidden areas during aftercare maintenance, you can more easily detect abnormalities early and prevent significant repairs or failures!
At Kakeru Koumuten Co., Ltd., the installation of solar panels comes with a leak warranty as part of the workmanship warranty. (The warranty for solar panel installation is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovations are performed.)
We also conduct aftercare maintenance and send out annual DM!
After checking the DM, if you wish, we will visit for aftercare maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting the installation of solar panels, let’s obtain estimates from multiple contractors.
Even for the same manufacturer and the same work content, costs may vary, and warranties and after-sales services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates,
“Check the estimate items”
“Type of solar panels”
“Warranties and after-sales services”
let’s carefully compare and make a judgment! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid judging solely based on price!
▶ Go to “Breakdown of installation capacity, equipment, and construction costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for the installation of solar panels and storage batteries, but if the order of procedures is incorrect or if there are deficiencies in the documents, there is a possibility that the subsidy will not be granted.
For systems like the Kanagawa Prefecture housing subsidy, where proxy applications by contractors are not allowed, it is reassuring to have a contractor who can support the preparation of necessary documents and the flow of procedures.
Let’s 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 completion of the work, a performance report will be submitted, and the flow will be to grant after review! (The flow of procedures varies by system)
▶ Go to “Subsidies and grants that may be applicable in Totsuka Ward” in this article
Benefits of Introducing Solar Equipment
The benefits of introducing solar panels are as follows!
Benefit 1: Economic Benefits
The biggest advantage of introducing solar panels is the economic benefit!
The selling price of electricity has decreased compared to 10 years ago, but by consuming the generated electricity, you can reduce the amount of electricity purchased from the utility company and gain benefits!
As electricity costs rise, the ability to cover 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) from certifications after October 2025 is set at “24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year.” The same price will apply in the 2026 fiscal year. After the 5th year, it is generally 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 the Environment | For purchase prices and periods, click here
Advantage 2 Subsidies can be utilized!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
Reducing the actual burden through subsidies is a significant advantage!
In the case of Totsuka Ward, there may be eligibility for Yokohama City’s YGrEP and Kanagawa Prefecture’s subsidies.
Advantage 3 Environmentally friendly!
Solar power generation has low carbon dioxide emissions and can reduce dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices such as power conditioners do have operational noise.)
Advantage 4 Heat insulation effects are expected!!
By installing on the roof or rooftop, the panels block direct sunlight to the roof.
Especially in summer, it can help reduce the temperature rise of the roof, providing expected heat insulation effects!
（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.
（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 remodeling 10 to 20 years later, there will be costs for removing and reinstalling the solar panels.
If the existing roof is deteriorated, it is reassuring to remodel 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 ask for a simulation considering maintenance costs before introducing solar panels!
Point 2 The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix hardware with screws to the roofing material or substrate, waterproofing of the fixed parts is crucial.
In methods that involve making holes in the roof, the risk of leaks inevitably arises.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and fixing the solar panels using the catch method is also an option. (The catch method has compatibility conditions between the roofing material and hardware, and it cannot be used with all metal roofs)
Catch-type base metal fittings for horizontal metal roofs
Note 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load capacity, one option may be to replace it with a lighter roof 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.
A panel with an output of 350W and a panel with an output of 400W may seem at first glance that the panel with the higher output is better.
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 installable quantities 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 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 after 10 years and 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or power generation amount.
Choosing solar panels while considering the degradation rate, rather than just the initial output, will lead to a regret-free selection!
How to Choose 3: Compare by Warranty Period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
Regarding the output warranty, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies widely!
It’s always better to have a longer warranty, so let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Totsuka Ward
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Totsuka Ward. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Totsuka Ward, Yokohama City?
The cost varies depending on the installation capacity, equipment, and roof condition. In the above construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines based on capacity are published on the solar panel installation and storage battery installation pricing page. We will create a layout diagram from the drawings and on-site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Totsuka 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 case for storage batteries) 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 unit for storage batteries) reached its budget limit on September 7 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 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,” meaning 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 fixing method varies by construction method, and if the method involves fixing brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is essential.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation, and if deterioration is advanced, we can also propose methods such as roof overlay (cover method) or re-roofing before installation.
The roof is old. Should I do a roof renovation first?
The condition of the roof will determine this. If a roof renovation is needed after 10 to 20 years of installation, there will be an additional cost for removing and reinstalling solar panels. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with durable roofing materials before installation.
Please consult us about the installation process after confirming the condition of the roof through a site survey!
Is it better to install a storage battery together with solar panels?
For those who want to use generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it in your home rather than selling it.
Additionally, Kanagawa Prefecture’s subsidy requires the simultaneous introduction of solar panels and storage batteries, and Yokohama City’s YGrEP also has conditions for combinations with storage batteries. You can compare “solar only” and “solar + storage battery” in a financial simulation for your consideration.
How many kW can be installed on my roof? Is it okay for north-facing roofs or those 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 based on the drawings and site survey, and provide you with the installation capacity and power generation simulation.
In the Totsuka Ward, the lowlands along the Sakai River and Kashio River, as well as the complex hilly terrain with valleys, mean that the shadows cast by surrounding buildings and trees vary from house to house. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
In the above construction example (solar panels 4.3 kW + storage battery), it took about 3 days. The duration may vary if roof work is done simultaneously or depending on the roof shape and installation capacity.
Please note that additional time is required for applications for subsidies and power companies, so please consult us early.
What is the current selling price (FIT) for electricity?
For residential use (under 10 kW), from the certification after October 2025, the first 4 years will be 24 yen/kWh, and from the 5th to the 10th year it will be 8.3 yen/kWh, with the same price applying for the 2026 fiscal year.
The idea is to recover initial costs more quickly in the first 4 years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that 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-maintenance DM notifications and visits for inspections upon request. We can also clean solar panels using a special brush if the power generation decreases due to dirt.
It can be difficult to check areas on the roof yourself, so please feel free to consult us if you have any concerns.
Can you also renovate roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten can remove and 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 costs, please refer to the solar panel removal and water heater removal pricing page.
If you are looking for a solar panel installation contractor in Totsuka Ward, please consult Kakeru Koumuten
Our company handles a wide range of exterior renovations, including solar panels, roof work, and exterior wall work in Totsuka Ward, Yokohama City.
We receive requests from many customers, including renovation companies and real estate agencies, who contact 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 achievements every year, and we will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay work and re-roofing but also partial roof repairs, exterior painting, and cover installation for exterior walls.
We are also happy to handle small jobs like partial repairs and rain gutter cleaning!
In urgent cases such as water leakage work, we may be able to provide emergency 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 that prioritizes profit!
We always stand in the customer’s position and propose the best construction plan!
We are confident that we will not be outdone in terms of cost, quality, and organization compared to other companies in exterior work!
We welcome competitive quotes because we are confident!
Estimates are completely free, and if our company is inferior to others, you are free to decline!
Characteristics of Totsuka Ward, Yokohama City, and Points for Solar Work
Totsuka Ward, Yokohama City, is the largest ward in Yokohama City, with an area of 35.7 km2, and was established in 1939 (Showa 14) when one town and seven villages in Kamakura District were incorporated into Yokohama City. It has a history represented by the old Tokaido and Totsuka-juku, and is blessed with rich nature, including water and greenery! Below are the topography and housing conditions of Totsuka Ward and points to consider when installing solar panels and storage batteries. (Tap to open)
View the characteristics of Totsuka Ward and points for solar work
■ Low-lying areas along rivers and hills with valleys change the way shadows are cast
According to materials from Yokohama City, in Totsuka Ward, the Sakai River and its seven tributaries flow through the area, with expansive lowlands surrounding the Sakai River and Kashio River, while the Hirado Nagatani River, Kawakami River, Nase River, Akugawa River, Maioka River, and Utagawa River carve valleys, and a complex hilly terrain forms in the surrounding areas.
In the lowlands, valleys, and hills, the shadows cast by neighboring houses, retaining walls, and trees, as well as the orientation of roofs, vary from house to house. At Kakeru Koumuten, we create layout diagrams based on blueprints and the actual site conditions, and you can confirm this through our power generation simulations.
■ The largest ward in the city has various roof conditions due to the timing of residential development
It is noted that in Totsuka Ward, since the 30th year of the Showa era, the population has rapidly increased due to the development of road networks, extension of railways, the advancement of factories, and residential development. The timing of residential development and the year houses were built vary by region, leading to differences in the condition of roofing materials and substrates from house to house.
It is important to check the condition of roofing materials and substrates before installing solar panels. Installing them simultaneously with roof renovations can sometimes reduce future costs for removing and reinstalling solar panels.
■ Yokohama’s annual sunshine duration is approximately 2,018 hours
According to the Japan Meteorological Agency’s average values (1991-2020), Yokohama’s annual sunshine duration is about 2,018 hours. Monthly, August (approximately 206 hours) has the most, while June during the rainy season (approximately 136 hours) has the least.
Power generation varies by season, so conducting annual power generation simulations and selecting battery capacity to match peak electricity usage times are key points.
■ Areas with remaining farmland and wooded land require attention to fallen leaves and dirt
In Totsuka Ward, substantial farmland spreads mainly in urbanization control areas, with some designated as agricultural exclusive zones, as noted in Yokohama City materials. On roofs close to farmland, wooded areas, and valley greenery, fallen leaves and dirt can easily accumulate on panels, leading to shading, which may result in decreased power generation. Kakeru Koumuten can also handle solar panel cleaning with specialized brushes and rain gutter cleaning.
■ Addressing height differences in valleys and hills with our own scaffolding
In the terrain of valleys and hills, the height differences of the front road and property may require ingenuity in planning scaffolding and transporting equipment. Kakeru Koumuten will respond to the site conditions with our own scaffolding team and materials.
Our company is based in Yokohama City and has handled many exterior construction and solar projects in Totsuka Ward, Yokohama City.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us for any urgent issues!
Service Area in Totsuka Ward, Yokohama City
Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and Tokyo Metropolis.
List of Areas in Totsuka Ward, Yokohama City
Totsuka Ward, Akihacho / Totsuka Ward, Kagetoricho / Totsuka Ward, Kashiocho / Totsuka Ward, Kamikashiocho / Totsuka Ward, Kamikuratacho / Totsuka Ward, Kamihinon / Totsuka Ward, Kamiyabemachi / Totsuka Ward, Kawakamimachi / Totsuka Ward, Kumiawacho / Totsuka Ward, Kumiawa / Totsuka Ward, Kosuzumecho / Totsuka Ward, Hinonacho / Totsuka Ward, Shimokuratacho / Totsuka Ward, Totsukacho / Totsuka Ward, Torigaoka / Totsuka Ward, Nasesacho / Totsuka Ward, Harajuku / Totsuka Ward, Higashimatanocho / Totsuka Ward, Hiradomachi / Totsuka Ward, Hirado / Totsuka Ward, Fukayacho / Totsuka Ward, Maiokacho / Totsuka Ward, Maedacho / Totsuka Ward, Matanomachi / Totsuka Ward, Minamaioka / Totsuka Ward, Yabemachi / Totsuka Ward, Yoshidacho
・Leave your exterior wall painting in Totsuka Ward, Yokohama to Kakeru Koumuten Co., Ltd.!
・Leave your roof renovation in Totsuka Ward, Yokohama to Kakeru Koumuten Co., Ltd.!
・Leave your exterior renovation in Totsuka Ward, Yokohama to Kakeru Koumuten Co., Ltd.!
・Kakeru Koumuten Co., Ltd.施工実績
・Kakeru Koumuten Co., Ltd. After Maintenance
・Kakeru Koumuten Co., Ltd.施工メニュー・料金表
・Kakeru Koumuten Co., Ltd. Staff Blog & News
・Explaining the Importance of Comparing Estimates!
・Top 12 Solar Power Manufacturers! Features and Selection Tips!
・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!
・Check out our solar power estimate here!
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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!
