Leave Your Solar Panel Installation Work in Isogo, Yokohama City to Kakeru Koumuten Co., Ltd.!
For solar panel and battery installation in
Isogo Ward, Yokohama,
trust Kakeru Koumuten Co., Ltd.!
Kakeru Koumuten Co., Ltd. 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 roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Isogo Ward”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Isogo Ward”
We will also explain the above three points!
Installing solar panels carries risks such as“the occurrence of leaks” and other troubles.
To ensure a satisfactory solar panel installation, we recommend obtainingthree estimates!
Table of Contents (tap to open/close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Isogo Ward, Yokohama
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Isogo 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 Isogo 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 Isogo Ward
- If You Are Looking for a Solar Panel Installer in Isogo Ward, Contact Kakeru Koumuten
- Characteristics of Isogo Ward, Yokohama and Points for Solar Installation
- Service Areas in Isogo Ward, Yokohama
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Isogo Ward, Yokohama
Regarding why our company is entrusted with solar panel installation by customers in Isogo Ward, Yokohama,
“Our Unique Strengths in Solar Panel Installation That Cannot Be Imitated by Other Companies”
have received high praise from many customers.
Because we are confident, we welcome estimates from any number of companies!
1. We Can Also Handle Exterior Renovations Other Than Solar Panel Installation!
Problems 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 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 and troubles after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent troubles after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has prepared the following warehouses and material storage areas to provide low-cost, high-quality solar work and exterior renovations.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding based on construction conditions and can assemble scaffolding in-house.
By not outsourcing scaffolding work and conducting it with our own scaffolding team, we can also cut costs for scaffolding construction.
We own scaffolding materials for approximately 50 detached houses!
Even in residential areas with elevation differences, such as hilly areas, our in-house scaffolding team will plan the scaffolding according to the site conditions.
Storage of Materials in Our Large Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, allowing 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 Renovation Dedicated Showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are attached to the roofing materials!
Simulations for potential earnings and installation costs when introducing solar panels are also available!
Since roofing and exterior wall work often accompany renovations, we also provide samples of roofing materials and models that explain the structure, allowing for detailed explanations!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is its complete in-house construction.
By having a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof renovations at reduced costs.
Additionally, one representative will handle everything from the estimate to project completion.
Since the担当者 does not change, 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 licenses and industrial waste collection and transportation permits!
We also have nationally certified sheet metal workers and painting technicians, and we are confident in our construction techniques.
We can also handle large-scale roof projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation, we also provide our own施工保証 (leak warranty)!
(The施工保証 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 without performing roof renovations. The施工保証 is separate from the manufacturer’s product warranty, and the scope and conditions vary depending on the warranty content.)
Aftercare is available every year, and we send out notification DM each year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
If you cannot access the roof at high places, we can utilize a drone to assist!
During leak investigations, we can also conduct surveys using a thermal imaging camera.
If the power generation of the solar panels decreases due to dirt, we can 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 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 of caution and disadvantages!
We encourage you to obtain comparative estimates and review plans from other companies!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 or 30 years.
Confirming “Is it okay to install them directly on the current roof?” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, 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 (roof 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 sheathing or roofing (waterproof sheet) under the roofing material is damaged, it will affect the fastening strength and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, Slope, and Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, can affect 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 fixing parts during the estimate. |
| 6. Weight of the Roof | The roof will become heavier due to the panels. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may 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. |
| 8. Proximity to the Sea and Preparations for Salt Damage | In locations close to the sea, there may be effects from sea breezes. Please confirm during the estimate whether there are products with salt damage countermeasures for the panels, frames, and brackets, and how the installation conditions and warranty handling differ by manufacturer. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproof treatment of fixing parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suitable for the type of tile (even methods that do not drill holes in the tiles will secure 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 perform roof renovations 10 to 20 years after installation, there will be additional costs for the removal and reinstallation of solar panels. If the roof is deteriorating, it may be more cost-effective in the long run to renovate to a highly durable roofing material before installation.
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 Isogo Ward, Yokohama City
Possible Subsidies and Grants in Isogo Ward, Yokohama City, Kanagawa Prefecture
If you are introducing solar panels or storage batteries in Isogo Ward, there is a possibility that the systems from “the national government,” “Kanagawa Prefecture,” and “Yokohama City” may apply.
The following information is based on the official pages of each system as of October 6, 2026. The acceptance status may change based 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 case (Cashless points, etc. for refunds) |
Participation and installation support applications: June 15, 2026 – December 25, 2026 (Application must be made before installation) Completion application: By January 22, 2027 Ends when 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 in residential buildings (with seismic performance ensured). Applications must be made by the applicant, and construction can begin after grant approval. | 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, applications have reached the budget limit and are now closed. Please check the prefecture’s official page for future applications. |
| 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 public recruitment has ended (the official site states there are no plans to reopen applications, and currently, applications cannot be made). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible installations, but they must be combined with essential renovations such as window (opening) and structural insulation improvements; 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 official site indicates that renovation applications account for 8% of the budget. 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 installations are not eligible). There are conditions regarding the type of equipment and eligibility. | Solar power + storage system: 100,000 JPY/kW (up to 5,000,000 JPY) Solar power only: 80,000 JPY/kW (up to 4,000,000 JPY) |
May 1, 2026 – October 30, 2026, 5 PM (first-come, first-served until budget limit is reached). As of September 7, 2026, it has been announced that applications have reached 70% of the budget. |
| Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Self-Consumption Renewable Energy Installation Subsidy” | Corporations and sole proprietors filing blue returns（Individual residences are not eligible). Solar power must have an output of 10kW or more, for business facilities, and equipment not certified under FIT/FIP, etc. | Solar Power: 80,000 JPY/kW, etc. Storage System: 50,000 JPY/kWh (maximum 5,000,000 JPY) |
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 subsidy requires 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 prefecture’s residential subsidy is granted after a performance report and review following the completion of construction. The order of procedures varies by system, and applying does not guarantee a grant, so please confirm before contracting or starting construction.
At Kakeru Koumuten Co., Ltd., we will inform you of the eligibility conditions and business requirements for each system after confirming them.
National Subsidy “DR Home Storage Battery Project (Support for the Introduction of Home Storage Systems for DR Resources)”
The government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
Those who are introducing new registered storage systems that can be used for demand response (DR) are eligible. In the fiscal year 2027 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 also conditions such as being ineligible for items contracted or ordered before the grant decision.
However, the fiscal year 2027 supplementary budget reached its application amount on May 29, 2026, and the public 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.
Furthermore, there are currently no subsidies confirmed for the installation of solar panels on existing homes.
👉 Click here for the official site of the DR Home Storage 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 is calculated as 4kW × 70,000 JPY + 150,000 JPY = 430,000 JPY.
Eligibility is for homes that ensure seismic performance, the storage system must be a registered product, if construction begins before the grant decision, it will be ineligible, and the application must be made by the individual (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. As of September 7, 2026, the application amount reached the budget amount, and the acceptance has been closed. For future recruitment, please check the official page of Kanagawa Prefecture.
👉 Click here for the official page of Kanagawa Prefecture
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 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 the introduction to individual residences is not eligible.
Conditions include solar power generation with an output of 10 kW or more, supplying electricity to business facilities within the prefecture, and not being a facility 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, the application amount reached the budget amount, and recruitment was closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Isogo Ward should check the official page of Kanagawa Prefecture 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 for small and medium-sized enterprises and individual business owners within the city for solar power generation facilities and more.
Residential solar power generation is not eligible, and for households, the YGrEP below will be the point of contact. Businesses installing solar panels on stores, offices, factories, etc., in Isogo Ward may have the possibility to utilize this, but simply running a business from home does not guarantee eligibility. It is necessary to confirm the requirements for small and medium-sized enterprises and individual business owners, as well as the condition of being a self-consumption type facility (facilities aimed at selling electricity are not eligible).
The subsidy amount is 100,000 yen per kW when introducing solar power generation and storage systems simultaneously (maximum of 5 million yen), and 80,000 yen per kW for solar power generation only (maximum of 4 million yen).
The application period for 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 amount, so early confirmation is recommended. Installation of equipment and commencement of construction must be carried out after the grant decision date.
For detailed conditions and application methods, please check the official website of Yokohama City.
👉 Click here for the official Yokohama City page
Yokohama City “Reiwa 8 Year Yokohama Green Energy Partnership Project (YGrEP)”
Yokohama Green Energy Partnership (YGrEP) is a project aimed at realizing a decarbonized society.
In Yokohama City, households that participate in YGrEP and install eligible equipment (refer to the eligible equipment below) will receive cashless points and other rewards. Residents of Isogo Ward are also eligible.
◎Eligible Equipment and Reward Amounts◎
● Solar power generation equipment (new installation): 15,000 yen/kW (up to 4kW)
* It is a condition to install or have already installed either a storage battery, eco-cute, or electric vehicle simultaneously.
● Storage battery: 120,000 yen per case
● Eco-cute: 20,000 yen per case
● Electric vehicle / plug-in hybrid vehicle (set with solar power generation equipment): 100,000 yen 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 yen per case
● Fuel cell (Ene Farm): 30,000 yen per case
● Solar heat utilization system: 50,000 yen per case
● V2H charging and discharging equipment: 100,000 yen per case
For example, if you install a 4kW solar panel and a storage battery simultaneously, the calculation for the reward amount will be 60,000 yen for solar power + 120,000 yen for storage battery = a total of 180,000 yen.
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 will be from June 15, 2026, to December 25, 2026, and the completion application will be until January 22, 2027, and will end once the budget limit is reached.
If selling electricity, it must only be for 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. Additionally, only V2H charging and discharging equipment will be eligible for rewards for businesses.
For information on application methods, combining with national and Kanagawa Prefecture subsidy projects, point rewards, and more, please check the special site here or contact us.
Solar Panel Installation and Storage Battery Installation Price List
⇧Service Menu | For Costs Related to Solar Panel and Storage 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 storage 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 Storage 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). Storage batteries are compared based on the amount of electricity they can store, expressed 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 the cost of solar panels as approximately 800,000 JPY to 1,200,000 JPY for 3 to 5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6 to 10 kW. (These are just estimated amounts and may vary based on factors such as wiring length, scaffolding area, existing roofing materials, and panel layout.)
▶ Installation Menu | Costs for Solar Panel Installation and Battery Installation
Items to Confirm in the Estimate (Cost Verification)
When comparing estimates from different companies, 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, total installation capacity (kW) should be listed. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also confirm if it is a type that controls the battery together. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range usable during power outages (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of the hardware suitable for the roofing material and the method of securing it (whether it involves drilling holes or clamping). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, presence of a monitor to check power generation. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at the fixed points, 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 counted twice. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters or old panels and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether the price is tax-inclusive or tax-exclusive, conditions under which additional costs may arise, and details and duration of manufacturer and workmanship warranties. |
If the capacities differ, both the price and power generation will change. Kakeru Koumuten Co., Ltd. welcome comparisons, so if you bring estimates from other companies, we will explain the differences item by item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can get an estimated quote and a financial simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can get an estimated quote and financial simulation!
*The simulation results are estimates. Actual financial results may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection and replacement.
Customer 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)!
Examples of Solar Panel Installations
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh |
| Base Mounting Hardware Used |
| Niigata Manufacturing/Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed using catch type hardware gripping the horizontal metal roof (Catch Method) |
| Price Range |
| 2,200,000 JPY – 2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8-9 years (self-consumption) *The grant amount and recovery estimates 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 can be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We 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 Isogo Ward, Yokohama
There are many solar panel installation contractors available in Isogo Ward, Yokohama, and you may be unsure which contractor to choose.
For this reason, when requesting solar panel installation and battery installation work, let’s confirm the following four points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the presence of warranties and aftercare services
● Obtain estimates from multiple contractors (three companies is a guideline)
● Check if they provide support for subsidy applications
By confirming the above four points, you will be able to choose a reliable contractor.
Have knowledge not only about solar panels but also about roofs
Defective installation of solar panels can 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 were installed on a deteriorated roof, leading to leaks
・Solar panels were installed on a roof with a short lifespan, necessitating a costly removal and reinstallation within a few years
・Incorrect treatment due to misjudgment of the type of waterproofing, resulting in leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows for installation that avoids 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, confirm the presence of warranties. It is important to check not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
Solar panels and batteries come with manufacturer warranties, but 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 leaks that occur after installation within the warranty period and conditions.
Additionally, some contractors provide aftercare services separate from warranties, so be sure to check if the contractor you are considering has aftercare services.
Since abnormalities or damages 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 major repairs or failures!
At Kakeru Koumuten Co., Ltd., the installation of solar panels comes with a leak warranty as part of the workmanship warranty. (The warranty for solar panel installation is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovations are performed.)
We also conduct aftercare maintenance and send out annual DM!
After checking the DM, if you wish, we will visit you for aftercare maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, let’s obtain estimates from multiple contractors.
Even for the same manufacturer and the same work content, costs may vary, and warranties and after-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-services”
let’s carefully compare and make a judgment! If the quality of the auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making decisions based solely on price!
▶ Go to “Breakdown of installation capacity, equipment, and construction costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for solar panel installation and battery installation, but if the order of procedures is incorrect or if there are deficiencies in the documents, the grant may not be awarded.
For systems like Kanagawa Prefecture’s housing subsidies, where proxy applications by contractors are not allowed, personal applications are required, so it is reassuring to have a contractor who supports 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 grant approval) before proceeding with the construction!
For the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the flow will be to undergo a review before the grant is awarded! (The flow of procedures varies by system)
▶ Go to “Subsidies and grants that may be applicable in Isogo 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 ten years ago, but by consuming the generated electricity for your own use, you can reduce the amount of electricity purchased from the utility company and gain benefits!
As electricity prices rise, the ability to cover your consumption with solar power becomes attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) will be set as “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year” for certifications after October 2025, and the same price will apply for the 2026 fiscal year. After the fifth year, it is generally more advantageous to use it at home (self-consume) rather than sell it, so combining it with a storage battery is also an 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 Isogo Ward, there is a possibility of being eligible for subsidies from Yokohama City’s YGrEP or Kanagawa Prefecture.
Advantage 3 Environmentally friendly!
Solar power generation has low carbon dioxide emissions and can reduce dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices like power conditioners do have operational noise.)
Advantage 4 Heat insulation effects are expected!!
By installing panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, this can help reduce the temperature 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 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 roof renovations are carried out 10 to 20 years later, there will be costs for removing and reinstalling the solar panels.
If the existing roof is deteriorating, it is reassuring to renovate it with durable roofing materials before installing solar panels!
Additionally, regular inspections of the equipment, repairs or replacements of the power conditioner, and updating costs due to the deterioration of the storage battery will also be incurred.
It would be reassuring to request 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 to the roofing material or substrate with screws, 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-bearing capacity, replacing it with a lighter roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
Choosing Method 1: Compare by Total Output of the Roof
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and generating more power is always better!
Solar panels come in various sizes and outputs depending on the manufacturer.
A panel with an output of 350W and a panel with an output of 400W may seem that the higher output panel is better at first glance.
However, if the size of the panel does not fit well with the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” resulting in different numbers of panels that can be installed on the same roof due to size differences.
400W×15 panels = 6kW (total output of the roof)
350W×20 panels = 7kW (total output of the roof)
As shown above, even if the output of a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual power generation (kWh) will vary depending on conditions such as roof orientation, slope, and shading.
Choosing Method 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 without considering the degradation rate will lead to regrets later!
Choosing Method 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 Isohama Ward
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Isohama Ward. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Yokohama City, Isohama Ward?
The cost varies depending on the installation capacity, equipment, and condition of the roof. In the above construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
For cost estimates by capacity, please refer to the solar panel installation and storage battery installation pricing page. We will create a layout diagram from the drawings and site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Isohama 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 Reiwa 8, and the national DR household storage battery project has ended its public recruitment.
Since the application status may change, please check the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies after the construction is completed?
For many programs, procedures are required before construction. Yokohama City’s YGrEP requires a “participation and introduction support application” before installation, and the Kanagawa Prefecture subsidy requires “commencement of construction after grant decision,” meaning that if you install beforehand, 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 crucial.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation, and if deterioration is advanced, we can also propose methods such as roof overlay (cover method) or re-roofing before installation.
The roof is old. Should I do roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed after 10 to 20 years of installation, the cost for removing and reinstalling solar panels will be incurred separately. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with durable roofing materials before installation.
Please consult us on how to proceed with the installation after confirming the condition of the roof through a site survey!
Is it better to install a storage battery together with solar panels?
For those who 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 at home rather than selling it.
Additionally, the subsidy in Kanagawa Prefecture requires the simultaneous introduction of solar panels and storage batteries, and Yokohama City’s YGrEP also has conditions for combinations with storage batteries. You can compare “solar only” and “solar + storage battery” through a financial simulation.
How many kW can be installed on my roof? Is it okay for roofs near the sea or with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and site survey, and provide you with the installation capacity and power generation simulation.
In Isogo Ward, the terrain changes from flat land facing Negishi Bay to hilly areas, so the shadows cast by surrounding buildings, trees, and elevation differences vary from house to house. Additionally, in locations close to the sea, there may be options for products designed to resist salt damage, and the handling of conditions and warranties varies by manufacturer, so please consult us with your installation location.
How long will the construction period be?
For the above construction example (solar panels 4.3kW + storage battery), it took about 3 days. The duration may vary if roof work is performed simultaneously or depending on the shape and installation capacity of the roof.
Additionally, please note that separate time is required for applications for subsidies and power companies, so consult us as soon as possible.
What is the current selling price (FIT)?
For residential use (under 10kW), 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 applied in the 2026 fiscal year.
The idea is to recover initial costs more quickly in the first 4 years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that considers loan interest rates and electricity costs.
Can you handle maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-maintenance DM notifications and visits for inspections upon request from customers. We can also clean solar panels with a dedicated 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 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 warehouse.
For information on costs, please see the solar panel removal and water heater removal pricing page.
If you are looking for a solar panel installation company in Isogo Ward, consult Kakeru Koumuten
Our company handles a wide range of exterior renovations, including solar panels, roof work, and exterior wall work in Isogo Ward, Yokohama City.
We have received many requests from customers, including renovation companies and real estate agencies!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received positive feedback from many customers.
We continue to update our construction performance numbers 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 complete roof replacement but also partial roof repairs, exterior painting, and exterior cover installations.
We are also happy to assist with small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leak repairs, we may be able to provide temporary measures without setting up scaffolding, as long as safety can be ensured, so please consult with us!
“I want to know about recommended solar panels“, “I want to keep costs down as much as possible“, “I just want an estimate for now“, and other specific requests will be met with optimal solutions.
We will never propose unnecessary work that prioritizes 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 by other companies in terms of cost, quality, and organization for exterior work!
We are confident, so we welcome competitive quotes!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Characteristics of Isogo Ward, Yokohama City, and Points for Solar Work
Isogo Ward, Yokohama City, is located in the southeastern part of the city, consisting of flat land facing Negishi Bay and the hilly areas that surround it!
The roof conditions vary depending on the terrain, from coastal flat land to residential areas in the hills. We have summarized the terrain and location of Isogo Ward and points to consider when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Isogo Ward, Yokohama City, and points for solar work
■ Roof conditions change in flat land facing Negishi Bay and hilly areas
According to materials from Yokohama City, Isogo Ward is described as an area consisting of “flat land facing Negishi Bay, surrounded by hilly areas, and sloped green spaces at the boundary”. The area covers approximately 19 km2.
In residential areas on hilly terrain, the orientation and height of buildings, as well as the shadows cast by neighboring houses, trees, and elevation differences, vary from one house to another. Kakeru Koumuten Co., Ltd. creates layout diagrams based on blueprints and the actual site conditions, and you can confirm this with a power generation simulation.
■ Landfill of Negishi Bay and Housing Development
In Isogo Ward, the landfill of Negishi Bay, which began around Showa 34, led to the creation of a heavy chemical industrial zone that supports the Keihin industrial area, along with large-scale housing developments in Shio-midai and Yoko-dai. For houses that have aged since the development, it is important to check the condition of roofing materials and substrates before installing solar panels. Depending on the condition of the roof, installing them simultaneously with roof renovations can help reduce future costs for removing and reinstalling solar panels.
■ Locations Near the Sea Require Salt Damage Countermeasures and Inspections
In coastal areas facing Negishi Bay, there may be effects from sea breezes. There are products available for panels, frames, and fittings that are designed to counter salt damage, and the conditions for installation and warranty handling vary by manufacturer. We will confirm the manufacturer’s conditions at the time of the estimate, based on the installation location you provide.
After installation, it is important to inspect the condition of the roof and the area around the fittings. Kakeru Koumuten Co., Ltd. provides annual aftercare maintenance notifications and also offers cleaning of solar panels with specialized brushes.
■ Yokohama’s Annual Sunshine Hours are Approximately 2,018 Hours
According to the Japan Meteorological Agency’s average values (1991–2020), Yokohama has approximately 2,018 hours of sunshine annually. 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 a year-round power generation simulation and selecting battery capacity to match peak electricity usage times are key points.
■ Our Own Scaffolding for Sloped and Uneven Sites
In residential areas on hilly terrain, the elevation differences of the front road and the site may require ingenuity in planning scaffolding and transporting equipment. Kakeru Koumuten Co., Ltd. will accommodate the site with our own scaffolding team and our own scaffolding materials.
Our company is based in Yokohama City and handles many exterior construction and solar projects in Isogo 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 about any urgent issues!
Service Area in Isogo Ward, Yokohama City
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Isogo Ward, Yokohama City
Isogodai, Isogo Ward / Isogo, Isogo Ward / Ootori-cho, Isogo Ward / Okamura, Isogo Ward / Kamimachi, Isogo Ward / Kaminakazato-cho, Isogo Ward / Kuriki, Isogo Ward / Sakashita-cho, Isogo Ward / Shio-midai, Isogo Ward / Shimomachi, Isogo Ward / Shin-Isogo-cho, Isogo Ward / Shin-Sugita-cho, Isogo Ward / Shin-Nakahara-cho, Isogo Ward / Shin-Mori-cho, Isogo Ward / Sugita Tsubon, Isogo Ward / Sugita, Isogo Ward / Takiguchi, Isogo Ward / Tanaka, Isogo Ward / Nakahama-cho, Isogo Ward / Nakahara, Isogo Ward / Nishimachi, Isogo Ward / Haramachi, Isogo Ward / Baba-cho, Isogo Ward / Higashimachi, Isogo Ward / Kuki-cho, Isogo Ward / Hitorizawa-cho, Isogo Ward / Hirochi-cho, Isogo Ward / Maruyama, Isogo Ward / Mine-machi, Isogo Ward / Morigaoka, Isogo Ward / Mori, Isogo Ward / Yoko-dai, Isogo Ward
・Leave your exterior wall painting in Isogo Ward, Yokohama to Kakeru Koumuten!
・Leave your roof renovation in Isogo Ward, Yokohama to Kakeru Koumuten!
・Leave your exterior renovation in Isogo Ward, Yokohama to Kakeru Koumuten!
・Kakeru Koumuten Co., Ltd. construction achievements
・Kakeru Koumuten Co., Ltd. after maintenance
・Kakeru Koumuten Co., Ltd. construction menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of comparative estimates and key points!
・12 major manufacturers of solar power generation! Introducing features and selection points!
・What are the installation costs for solar power generation? Thoroughly explaining tips to reduce costs!
・What are the best places for solar power generation installation? Introducing key points for site selection!
・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!
