Leave Your Solar Panel Installation Work in Aoba, Yokohama City to Kakeru Koumuten Co., Ltd.!
For solar panel and battery installation in
Aoba Ward, Yokohama,
trust Kakeru Koumuten!
Kakeru Koumuten is a company specializing in exterior renovations based in Aoba Ward, Yokohama.
As a company strong in roofing work, we are entrusted with solar panel and battery installation considering roofs and waterproofing!
“How to Choose a Solar Panel Contractor in Aoba Ward”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Aoba 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 obtaining three estimates!
Table of Contents (tap to open/close)
- Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Aoba Ward, Yokohama
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Aoba Ward
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installation Company in Aoba 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 Aoba Ward
- If You Are Looking for a Solar Panel Installation Company in Aoba Ward, Contact Kakeru Koumuten
- Characteristics of Aoba Ward, Yokohama and Points for Solar Construction
- Service Area in Aoba Ward, Yokohama
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Aoba Ward, Yokohama
The reasons why our company is entrusted with solar panel installation by customers in Aoba Ward, Yokohama
One reason is that Kakeru Koumuten’s headquarters is located in Aoba Ward, Yokohama,
and we have unique strengths in solar panel installation that cannot be imitated by other companies, which has received high praise from many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome multiple estimates!
1. We Can Also Handle Exterior Renovations Other Than Solar Panel Installation!
Troubles 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 you are knowledgeable about solar panels, there may be cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have expertise in roofing 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.Equipment Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide low-cost, high-quality solar and exterior renovation work.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the necessary scaffolding materials for temporary scaffolding based on construction conditions, allowing us to assemble scaffolding ourselves.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also cut costs on scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
Even in the residential areas of Aoba Ward, which often have slopes and elevation differences, our 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, we canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, enabling us torespond quickly in emergencies!
Sorting and transporting waste materials in-house
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut 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 installed on the roofing materials!
It is also possible to simulate the revenue and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also provide samples of roofing materials and models that explain the structure in detail!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is all work performed by our own team.
By maintaining a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof remodeling at a lower cost.
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 perform consistent in-house work from temporary scaffolding installation to exterior wall painting and roof remodeling!
4. Various Permits Obtained & Skilled Workers on Staff
We have obtained construction industry permits and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal and painting technicians on staff, and we are confident in our construction skills.
We are capable of handling large-scale roofing projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty, our solar panel installation work comes with our own workmanship warranty (leakage warranty)!
(The workmanship warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovation is performed. The workmanship warranty is separate from the manufacturer’s product warranty, and the coverage and conditions vary based on the warranty details.)
Aftercare maintenance is available every year, and we send out notification DM each year.
If you have any questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roof troubles and situations.
If you cannot access the roof at high altitudes, we can respond using a drone!
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 also perform cleaning with a specialized brush.
We will respond according to your preferences.
7. Human Resource Development
We create various roof models for skill enhancement and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training to ensure that all staff can handle various cases.
8. Easy-to-Understand Materials and Simulations
At Kakeru Koumuten Co., Ltd., in addition to “estimates”, “layout diagrams”, and “power generation simulations”, we also provide a “solar installation guidebook” and a “profit and loss simulation” that takes into account loan interest rates and electricity costs.
The profit and loss simulation can be created for an estimated cumulative balance over 20 to 30 years.
Even customers who are not familiar with solar installations will find our materials easy to understand, including important points and disadvantages!
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.
It is crucial to confirm before installation whether it is safe to place them directly on the current roof, as this 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. Type of roofing material and age | The method of securing varies depending on the roofing material, such as slate, tiles, metal roofs, or flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of the substrate and waterproof sheet | If the sheathing or roofing (waterproof sheet) beneath the roofing material is damaged, it can affect the fastening strength and waterproofing. We will also check for any signs of leaks. |
| 3. Roof orientation, slope, and shadows | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, can affect power generation. We will create a layout diagram from the drawings and the site, and you can confirm it with the power generation simulation. |
| 4. Roof shape and installable area | The number of panels (installation capacity) that can be placed depends on the shape and size of the roof. The number of panels that can be installed varies depending on their size, so we will compare based on the total output of the roof. |
| 5. Fixing method and waterproofing details | We will confirm whether the method involves drilling holes in the roofing material or using brackets to secure it. The fixing method varies by technique, so please check the waterproofing treatment of the fixing parts during the estimate. |
| 6. Weight of the roof | The roof will become heavier due to the panels. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may also be an option if necessary. |
| 7. Location of equipment installation and wiring | We will confirm the installation locations for the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring also affects costs. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (such as fixing brackets with screws to the roofing material and substrate) | 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 fix to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lighter roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roofing material (depends on the combination of roofing material and brackets) | Whether the roofing material and brackets are compatible, installation conditions from the roofing material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a framework | Type and deterioration status of the waterproof layer, waterproofing around the framework. 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, 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 Aoba Ward, Yokohama City
PossibleSubsidies and Grants in Aoba Ward, Yokohama City, Kanagawa Prefecture
If you are introducing solar panels or storage batteries in Aoba 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 4, 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)” Reiwa 8 | Yokohama citizens installing eligible equipment at their homes in Yokohama City. Solar power must be newly installed, and either a storage battery, eco-cute, or electric vehicle must be installed simultaneously or already in place. | Solar Power: 15,000 JPY/kW (up to 4 kW) Storage Battery: 120,000 JPY per case (Refunds via cashless points, etc.) |
Participation & Installation Support Application: June 15, 2026 – December 25, 2026 (Application before installation) Installation Completion Application: By January 22, 2027 Ends once budget limit is reached |
| Kanagawa Prefecture “Reiwa 8 Subsidy for Residential Solar Power Generation and Storage Battery Installation” | Installation of both solar power generation and storage battery in residential properties within the prefecture. Applications must be made by the individual, and construction can begin after 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: September 7, 2026 – September 30, 2026 (first-come, first-served) Phase 2 is nearing its application deadline. Please check the prefecture’s official page for further recruitment. |
| National “DR Home Storage Battery Project” (Reiwa 7 Supplement) | New installation of home storage systems using registered products that can be utilized for DR (demand response). | Calculated based on an initial effective capacity of 1 kWh at 34,500 JPY (subsidy rate within 3/10; maximum 600,000 JPY per application). | As of May 29, 2026, the budget has been reached, and the public offering has ended (applications are currently not accepted). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but they must be combined with essential works such as insulation renovations of windows (openings) and structures; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 JPY per household | Ends once the budget limit is reached. Please check the official site for application status. |
| Yokohama City “Solar Power Generation Installation Support Subsidy” | Small and medium-sized enterprises and sole proprietors in Yokohama City (residential use is not eligible). There are conditions for the target individuals and equipment, such as being self-consumption type equipment. | Solar Power + Storage System: 100,000 JPY/kW (up to 5,000,000 JPY) Solar Power Only: 80,000 JPY/kW (up to 4,000,000 JPY) |
May 1, 2026 – October 30, 2026, 17:00 (first-come, first-served until budget limit is reached) |
| Kanagawa Prefecture “Reiwa 8 Subsidy for Self-Consumption Type Renewable Energy Installation” | Corporations and individuals filing blue returns（Personal residences are not eligible）。Solar power must have a generation capacity of 10kW or more, facilities for business use, equipment not certified under FIT/FIP, etc. | Solar Power: 80,000 yen/kW, etc. Storage System: 50,000 yen/kWh (maximum 5,000,000 yen) |
Application closed on September 3, 2026 (when the application amount reached the budget amount) |
YGrEP requires “participation and installation support application” before installation, and Kanagawa Prefecture’s residential subsidies require not only application acceptance but also “construction to commence after receiving the grant decision”. If you start installation or construction beforehand, you will be ineligible. The prefecture’s residential subsidies are granted after completion of construction and submission of performance reports and reviews. The order of procedures varies by system, and applying does not guarantee a grant, so please confirm before contracting or starting work.
Kakeru Koumuten Co., Ltd. will guide you on eligibility conditions and business requirements for each system.
National Subsidy “DR Household Storage Battery Project (Support Project for Introducing Household Storage Systems for DR Resources)”
The national government has been implementing the “DR Household Storage Battery Project” to support the installation of household storage batteries.
Those who are introducing newly registered storage systems that can be utilized for demand response (DR) are eligible. In the fiscal year 2025 supplementary project, the subsidy amount was determined based on a standard amount of 34,500 yen per initial effective capacity of 1kWh, with a subsidy rate of up to 30% and a maximum of 600,000 yen per application. There are conditions such as being ineligible for items contracted or ordered before the grant decision.
However, the fiscal year 2025 supplementary application amount reached the budget on May 29, 2026, and the public recruitment has ended (the previous fiscal year’s supplementary application also ended on July 2, 2025). Applications are currently not possible, so please check the official website for future public recruitment.
Additionally, there are currently no subsidies specifically for the installation of solar panels on existing homes confirmed by the national government.
👉 Click here for the official site of the DR Household Storage Battery Project
Kanagawa Prefecture “Fiscal Year 2026 Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Installation Subsidy”
Kanagawa Prefecture provides subsidies for those who install both “solar panels” and “storage batteries” in their homes.
The subsidy details are 70,000 yen per 1kW of solar power generation and 150,000 yen per storage system.
For example, if you install a 4kW solar panel and one storage battery, the subsidy amount would be calculated as 4kW × 70,000 yen + 150,000 yen = 430,000 yen.
Conditions include that the storage system must be a registered product, if construction begins before the grant decision, it will be ineligible, and the application must be made by the individual (proxy applications by contractors are not allowed). It is also possible to combine this with YGrEP in Yokohama City.
In the 2026 fiscal year, the first phase (May 11 – June 30) and the second phase (September 7 – September 30, first-come-first-served) are being accepted, and the second phase has reached its application deadline. For future recruitment, please check the official Kanagawa Prefecture page.
👉 Click here for the official Kanagawa Prefecture page
Kanagawa Prefecture “2026 Fiscal Year Kanagawa Prefecture Self-Consumption Type Renewable Energy Introduction Subsidy” (for businesses)
Kanagawa Prefecture is also implementing a subsidy for businesses introducing “self-consumption type” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and the introduction to individual residences is not eligible.
Conditions include that solar power generation must have a capacity of 10kW or more, supply electricity to business facilities within the prefecture, and not be equipment certified under FIT or FIP.
The subsidy amount is 80,000 yen per kW for solar power generation and 50,000 yen per kWh for the accompanying storage system (with a maximum of 5 million yen).
As the application amount reached the budget amount for the 2026 fiscal year, applications were closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Aoba Ward should check the official Kanagawa Prefecture page for the next recruitment.
👉 Click here for details
Yokohama City “Solar Power Generation Introduction Support Subsidy” (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 in the city for solar power generation facilities and other installations.
Residential solar power generation is not eligible, and for households, the YGrEP below will be the point of contact. Businesses installing solar panels on stores, offices, factories, etc., in Aoba 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 that the equipment is of the self-consumption type (equipment intended 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 2026 fiscal year is from May 1, 2026, to October 30, 2026, at 5 PM, on a first-come-first-served basis until the budget limit is reached. Installation of equipment and commencement of construction must be carried out after the grant decision date.
For detailed conditions and application methods, please check the official website of Yokohama City.
👉 Click here for the official Yokohama City page
Yokohama City “Reiwa 8 Year Yokohama Green Energy Partnership Project (YGrEP)”
Yokohama Green Energy Partnership (YGrEP) is a project aimed at realizing a decarbonized society.
In Yokohama City, households that participate in YGrEP and install eligible equipment (refer to the eligible equipment below) will receive cashless points and other rewards. Residents of Aoba Ward are also eligible.
◎ Eligible Equipment and Reward Amounts ◎
● Solar Power Generation Equipment (new installation): 15,000 yen/kW (up to 4 kW)
* It is a condition to install either a storage battery, eco-cute, or electric vehicle simultaneously or have it already installed.
● 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 the storage battery, eco-cute, or electric vehicle (set) simultaneously with the solar power generation equipment or have it already installed.
● Electric Vehicle alone (without solar power generation equipment): 50,000 yen per case
● Fuel Cell (EneFarm): 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 4 kW 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 = total of 180,000 yen.
The application process is “Participation and Installation Support Application (before installation) → Installation of Equipment → Completion Application”, and equipment installed before the installation support application is not eligible. The participation and installation support application for Reiwa 8 Year will be from June 15, 2026, to December 25, 2026, and the completion application must be submitted by January 22, 2027, and will end once the budget limit is reached.
If selling electricity, only the surplus that cannot be used at home is eligible, and submission of monitoring data such as 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 application methods, information on combining with national and Kanagawa Prefecture subsidy projects, and details about point rewards, please check the special site here for more information and inquiries.
Solar Panel Installation & Battery Installation Price List
⇧Service Menu | For Costs Related to Solar Panel Installation & Battery Installation, Click Here
⇧Service Menu | For Costs Related to Solar Panel Removal & Water Heater 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.
Considerations for Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of one panel (W) × Number of panels”, with the unit being kW (kilowatts). The amount of electricity that can be stored in batteries is compared in kWh (kilowatt-hours).
The amount of kW that can be placed on the roof varies for each house depending on the shape, orientation, and size of the roof. At Kakeru Koumuten Co., Ltd., we create a layout diagram based on the blueprints and on-site survey, and we will present the installation capacity.
On our pricing page, we list solar panels as approximately 800,000 JPY to 1,200,000 JPY for 3 to 5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6 to 10 kW. (These are just approximate amounts and may vary depending on the length of wiring, scaffolding area, existing roofing materials, and panel layout.)
▶ Installation Menu | Costs for Solar Panel Installation and Battery Installation
Items to Check in the Quotation (Cost Confirmation)
When comparing prices in multiple quotations, it is common to compare different capacities and equipment. Please check if the following items are clearly stated in each company’s quotation!
| 1. Solar Panels | Manufacturer, model number, output of one panel (W), number of panels, total installation capacity (kW) are listed. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls the battery together. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range usable during 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 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, 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 double-counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters or old panels and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether the price is tax-inclusive or tax-exclusive, conditions under which additional costs may arise, and details and duration of manufacturer and workmanship warranties. |
If the capacities differ, both the price and power generation will change. Kakeru Koumuten Co., Ltd. welcome multiple quotations, so if you bring quotations from other companies, we will explain the differences for each item!
Self-Quotation and Profit and Loss Simulator 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 obtain 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)!
Case Studies of Solar Panel Installations
| Work 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 Details |
| 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 Expected recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction and may differ under the current system. |
| Construction Period |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that grants are available, and I would like to know how much can be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of the grant, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Aoba Ward, Yokohama
There are many solar panel installation contractors available in Aoba Ward, Yokohama, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and battery storage installation work, make sure to check the following 4 points:
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the existence of warranties and aftercare maintenance
● Obtain estimates from multiple contractors (3 companies is a guideline)
● Check if they provide support for subsidy applications
By confirming the above 4 points, you will be able to choose a reliable contractor.
Knowledge of roofs as well as solar panels
Defective installation of solar panels can sometimes be caused by a lack of knowledge and 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 due to insufficient verification of roofs and waterproofing
・Solar panels were installed on a severely deteriorated roof, leading to leaks
・Solar panels were installed on a roof with a short lifespan, necessitating a renovation for removal and reinstallation within a few years
・Misjudgment of the type of waterproofing led to incorrect treatment, resulting in leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the existence of warranties and aftercare maintenance
When choosing a solar installation contractor, make sure to check for warranties. It is important to confirm not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While the solar panels and battery storage units come with a manufacturer’s warranty, also check for the existence of a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may be able to respond under the warranty, provided it is within the warranty period and conditions.
Additionally, some contractors offer after-sales service separate from warranties, so be sure to check if the contractor you are considering has after-sales service.
Changes or damage on the roof may occur in areas that are not visible, so there is a possibility that customers may not notice them.
By conducting inspections of these hidden areas during after-sales maintenance, it becomes easier to detect abnormalities early, preventing major repairs or breakdowns!
Kakeru Koumuten Co., Ltd. provides a rain leak warranty as part of the workmanship warranty for solar panel installations. (The warranty for solar panel installations is 10 years, and depending on the condition of the roof before installation, a roof renovation may be required to provide the warranty.)
We also conduct after-sales maintenance and send out DM every year!
Please check the DM, and if you wish, we will visit you for after-sales maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, be sure to obtain estimates from multiple contractors.
Even for the same manufacturer and the same construction content, costs may vary, and warranties and after-sales services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request from your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check the following:
“Check the items in the estimate”
“Type of solar panel”
“Warranties and after-sales services”
Make sure to compare these details carefully! 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 and Equipment/Construction Costs” in this article
Check if they provide support for subsidy applications
Subsidies may be available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
For systems like Kanagawa Prefecture’s housing subsidies, where the contractor cannot apply on your behalf and personal application is required, it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Be sure to complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining a grant decision) before proceeding with the construction!
In the case of the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the flow will go through a review before the grant is provided! (The flow of procedures varies by system)
▶ Go to “Subsidies and Grants That May Be Applicable in Aoba Ward” within this Article
Benefits of Introducing Solar Power Equipment
The benefits of introducing solar panels are summarized in the following 5 points!
Benefit 1: Economic Benefits
The biggest advantage of introducing solar panels is the economic benefit!
While the selling price of electricity has decreased compared to 10 years ago, you can benefit by reducing the amount of electricity you purchase from the utility company by consuming the electricity you generate!
As electricity costs rise, the ability to cover your consumption with solar power becomes increasingly attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
For residential use (less than 10kW), the selling price (FIT) from certifications after October 2025 will be set at “24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year.” The same price will apply for the fiscal year 2026. After the 5th year, it is often more advantageous to use the electricity at home (self-consumption), making the combination with a storage battery a viable option.
👉 Ministry of Economy, Trade and Industry | For purchase prices, periods, etc., click here
Benefit 2: You Can Utilize Subsidies!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the criteria, you may be able to utilize subsidies!
Reducing the actual burden amount through subsidies is a significant advantage!
In Aoba Ward, you may be eligible for subsidies from Yokohama City’s YGrEP or Kanagawa Prefecture.
Benefit 3: Environmentally Friendly!
Solar power generation has low carbon dioxide emissions and 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.)
Benefit 4: Expect Heat Insulation Effects!!
By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, this can help reduce the temperature rise of the roof, providing expected heat insulation effects!
(Note that this does not improve the building’s insulation performance itself.)
Benefit 5: Electricity can be used even during power outages!!
If a storage battery is installed, it becomes possible to use electricity even during emergencies like power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capability, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1: Maintenance costs can be incurred
A particularly overlooked maintenance cost is related to the roof where solar panels are installed.
If you perform roof renovations 10 to 20 years later, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorating, it is reassuring to renovate to a highly durable roofing material before installing solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It would be reassuring to consider maintenance costs in simulations before introducing solar panels!
Point 2: The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but when fixing hardware to the roofing material or substrate with screws, waterproofing of the fixed parts becomes 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
To install solar panels, the roof will become heavier. After investigating the existing roof, substrate, and load-bearing capacity, replacing it with a lighter roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
How to Choose 1: Compare by Total Output of the Roof
When installing solar panels on the roof, it is important to consider how much electricity can be generated in a limited area, and it is always better to generate more!
Solar panels come in various sizes and outputs depending on the manufacturer.
For example, a 350W output panel and a 400W output panel may seem that the higher output panel is better at first glance.
However, if the size of the panels does not fit well on the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different numbers of panels that can be installed on the same roof due to size differences.
400W × 15 panels = 6kW (total output of the roof)
350W × 20 panels = 7kW (total output of the roof)
As shown above, even if the output of a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above calculations are for total output (kW). The actual power generation amount (kWh) will vary depending on conditions such as the roof’s orientation, slope, and shading.
How to Choose 2: Compare by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases over 10 years and 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee values are standard figures for warranty purposes and do not indicate the actual degradation rate or power generation amount.
By not deciding solely based on initial output and considering the degradation rate, you can choose solar panels without regrets!
How to Choose 3: Compare by Warranty Period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
Regarding the output warranty, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies!
It’s always better to have a longer warranty, so let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Aoba Ward
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Aoba Ward. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Aoba 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 for different capacities are available on the solar panel and storage battery installation pricing page. We will create a layout diagram from the drawings and site survey, and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Aoba Ward?
As of October 4, 2026, the application period for Yokohama City’s YGrEP (15,000 yen/kW for solar power, up to 4kW; 120,000 yen per storage battery) is ongoing (it will end once the budget limit is reached). The Kanagawa Prefecture subsidy (70,000 yen/kW for solar power; 150,000 yen per storage battery) is approaching the application deadline for the second phase of fiscal year 2026, and the national DR home storage battery project has ended its public recruitment.
Since the application status may change, please 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?
In many cases, procedures are required before construction. For Yokohama City’s YGrEP, “participation and introduction support application” is required before installation, and for Kanagawa Prefecture’s subsidy, “commencement of construction after grant decision” is a condition, so if you install it first, you will be excluded from eligibility.
The order of procedures varies by program, so please confirm before signing a contract or starting construction.
Can solar panels be installed on a slate roof? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate beforehand. The fixing method varies by construction method, and in methods that fix 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 replacement before installation.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed after 10 to 20 years, 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 an on-site inspection!
Is it better to install a storage battery together with solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it in your home rather than selling it.
Additionally, Kanagawa Prefecture’s subsidies require the simultaneous introduction of solar panels and storage batteries, and Yokohama City’s YGrEP also has conditions for combinations with storage batteries. You can compare “solar panels only” and “solar panels + storage batteries” through a financial simulation.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and on-site inspection, and provide you with the installation capacity and power generation simulation.
Aoba Ward has many residential areas in hilly terrain, and the shadows cast by neighboring houses, trees, and elevation differences 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 performed simultaneously or depending on the shape of the roof and installation capacity.
Additionally, please note that there will be a separate period for applying for subsidies and to the power company, so please consult us as soon as possible.
What is the current selling price (FIT)?
For residential use (under 10 kW), the selling price from certifications after October 2025 will be 24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year, with the same 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 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 notices via DM and visits customers who wish for inspections. We can also clean solar panels with a special brush if the power generation decreases due to dirt.
Since it is difficult to check areas on the roof by yourself, please feel free to consult us if you have any concerns.
Can you also 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 all in one go. The removed panels can be stored in our own 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 contractor in Aoba Ward, please consult Kakeru Koumuten
Our company handles many exterior renovations, including solar panels, roof work, and wall work in Aoba Ward, Yokohama City.
We have received requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received positive feedback from numerous customers.
We continue to update our annual construction performance, and we will strive to improve quality to satisfy even more customers in the future.
We can perform all exterior renovations, not only roof overlay work and re-roofing but also partial roof repairs, exterior painting, and cover methods for walls, all by our own team.
We are also happy to handle small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leak repairs, we may be able to provide emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult us!
“I want to know 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 will propose the best construction plan!
We are confident that we will not lose to other companies in terms of cost, quality, and organization in exterior work!
We are confident, so we welcome competitive quotes!
Estimates are completely free, and if we are found to be inferior to other companies, feel free to decline!
Characteristics of Aoba Ward, Yokohama City, and Points for Solar Construction
Aoba Ward, Yokohama City, is an area with quiet residential neighborhoods along the Tokyu Den-en-toshi Line, equipped with both nature and convenient urban functions!
Kakeru Koumuten’s headquarters is also located in Aoba Ward, and we handle many exterior and solar construction projects in the area.
We have summarized the residential environment in Aoba Ward and points to consider when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Aoba Ward, Yokohama City, and points for solar construction
■ In hilly residential areas, checking the roof orientation and shadows is important
Aoba Ward is located in the northwest part of Yokohama City, covering an area of approximately 35 km2, making it the second largest ward in Yokohama City after Totsuka Ward. Since residential areas are primarily developed on hilly terrain, there are many slopes, and even within the same block, the orientation and height of roofs, as well as the shadows cast by neighboring houses, retaining walls, and trees, vary from house to house.
Since solar panels generate less electricity when shaded, Kakeru Koumuten Co., Ltd. creates layout diagrams based on blueprints and the actual site conditions, allowing you to confirm through power generation simulations.
■ Yokohama’s annual sunshine hours are approximately 2,018 hours
According to the Japan Meteorological Agency’s average values (1991-2020), Yokohama’s annual sunshine hours are about 2,018 hours. August has the most hours, while June, during the rainy season, has the least.
Power generation varies by season, so conducting annual power generation simulations and selecting battery capacity to match peak electricity usage times are key points.
■ Check the roof condition before installation in residential areas along the Den-en-toshi Line
Aoba Ward can be accessed directly to Shibuya via the Tokyu Den-en-toshi Line (travel time varies depending on the station, train, and time of day), making it a popular area for commuters and students. Since the opening of the Den-en-toshi Line between Mizonokuchi and Nagatsuta in 1966, residential areas have been developed around stations such as Tamaplaza, Azamino, Aobadai, and Ichigao.
For houses that have been built for several years, it is important to check the condition of the roofing materials and substrate before installing solar panels. Depending on the roof’s condition, installing them simultaneously with roof renovations can help reduce future costs for removing and reinstalling solar panels.
■ We can handle sites with slopes and elevation differences with our own scaffolding
For houses on top of retaining walls or with narrow front roads, careful planning for scaffolding and equipment delivery is necessary. Kakeru Koumuten Co., Ltd. will respond to the site conditions with our own scaffolding team and scaffolding materials.
■ Areas with abundant greenery require attention to fallen leaves and dirt
The rural landscape spreads along the Tsurumi River flowing through the central part of the ward, and the lush scenery, such as “Kodomo no Kuni,” is one of Aoba Ward’s attractions. On the other hand, roofs close to trees are prone to accumulating fallen leaves and dirt on the panels, which can lead to a decrease in power generation. Kakeru Koumuten Co., Ltd. can also provide solar panel cleaning with specialized brushes and rain gutter cleaning.
■ Consideration for residential area rules
In some residential areas of Aoba Ward, there may be building agreements and urban development rules established (not all areas in the ward have the same rules). In regions with agreements related to installations on roofs, it is necessary to confirm the details in advance.
Our company is based in Aoba Ward, Yokohama City, and we handle many exterior construction and solar installation projects in Yokohama City Aoba Ward.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us for any urgent issues!
Service Area in Aoba Ward, Yokohama City
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and Tokyo.
List of Areas in Aoba Ward, Yokohama City
Aoba Ward Aobadai / Aoba Ward Akanedai / Aoba Ward Azamino / Aoba Ward Azamino Minami / Aoba Ward Ichigaocho / Aoba Ward Utsukushigaoka / Aoba Ward Utsukushigaoka Nishi / Aoba Ward Umegaoka / Aoba Ward Enkodate / Aoba Ward Edakita / Aoba Ward Edacho / Aoba Ward Edanishi / Aoba Ward Enogao / Aoba Ward Obacho / Aoba Ward Ondacho / Aoba Ward Kakinokidai / Aoba Ward Katsuradai / Aoba Ward Kamitayamotocho / Aoba Ward Kamoshidacho / Aoba Ward Tetsumachi / Aoba Ward Kurosuda / Aoba Ward Sakuradai / Aoba Ward Satsukigaoka / Aoba Ward Jikecho / Aoba Ward Shimotayamotocho / Aoba Ward Shiratoridai / Aoba Ward Shin-Ishikawa / Aoba Ward Susukino / Aoba Ward Sumiyoshidai / Aoba Ward Tachibanadai / Aoba Ward Tanacho / Aoba Ward Chigusaidai / Aoba Ward Tsutsujigaoka / Aoba Ward Naracho / Aoba Ward Nariagicho / Aoba Ward Fujigaoka / Aoba Ward Matsukazeidai / Aoba Ward Mitakedai / Aoba Ward Midoriyama / Aoba Ward Moegino / Aoba Ward Moto-Ishikawacho / Aoba Ward Mominokidai / Aoba Ward Wakakusaidai / Aoba Ward Misuzugaoka / Aoba Ward Nara
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・Trust Kakeru Koumuten for roof renovations in Aoba Ward, Yokohama!
・Trust Kakeru Koumuten for exterior renovations in Aoba Ward, Yokohama!
・Trust Kakeru Koumuten for leak repairs in Aoba Ward, Yokohama!
・Trust Kakeru Koumuten for waterproofing work in Aoba Ward, Yokohama!
・Kakeru Koumuten Co., Ltd. construction achievements
・Kakeru Koumuten Co., Ltd. aftercare services
・Kakeru Koumuten Co., Ltd. construction menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of comparison estimates and key points!
・Top 12 solar power generation manufacturers! Features and selection tips included!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
・What are the best locations for installing solar power generation? Key points for site selection included!
・Here is the introduction for solar power generation estimates!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!
