Leave Your Solar Panel Installation Work in Kawasaki City, Kawasaki Ward to Kakeru Koumuten Co., Ltd.!
For solar panel and storage battery installation in
Kawasaki City, Kawasaki Ward,
trust Kakeru Koumuten!
Kakeru Koumuten is a specialized exterior renovation company based in Aoba Ward, Yokohama City.
As a company strong in roofing work, we are entrusted withsolar panel installation and storage battery work considering roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Kawasaki Ward”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Kawasaki Ward”
We will also explain the above three points!
Installing solar panels carries risks such as“the occurrence of leaks” and other troubles.
To ensure a satisfactory solar panel installation, we recommend obtainingthree or so estimates!
Table of Contents (Tap to Open/Close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Kawasaki City, Kawasaki Ward
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Kawasaki Ward
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installation Contractor in Kawasaki City, Kawasaki Ward
- Benefits of Introducing Solar Equipment
- Points to Note When Introducing Solar Power Generation
- How to Choose Solar Panels
- Frequently Asked Questions About Solar and Storage Battery Installation in Kawasaki Ward
- If You’re Looking for a Solar Panel Installation Contractor in Kawasaki Ward, Contact Kakeru Koumuten
- Characteristics of Kawasaki City, Kawasaki Ward and Key Points for Solar Installation
- Service Area in Kawasaki City, Kawasaki Ward
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Kawasaki City, Kawasaki Ward
The reasons why our company is entrusted with solar panel installation by customers in Kawasaki City, Kawasaki Ward include
one reason being that Kakeru Koumuten has a base in Kanagawa Prefecture,
and our unique strengths in solar panel installation that cannot be imitated by other companies, which have received high praise from many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We Can Also Handle Exterior Renovations Other Than Solar Panel Installation!
Troubles such as leaks that occur during the installation of solar panels may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if you are knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to be knowledgeable about the roof to avoid maintenance and troubles after construction!
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 in 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 associated with scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
Even in residential areas of Kawasaki Ward, where houses, factories, and commercial facilities are mixed, our own scaffolding team will plan the scaffolding according to the site.
Storage of materials in our large warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, we canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, allowing us torespond quickly in emergencies!
Sorting and transporting waste materials in-house
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior renovation dedicated showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on the roofing materials!
It is also possible to simulate the revenue and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also have samples of roofing materials and models that show the structure, allowing for detailed explanations!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is all work performed by our own team.
By having a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof remodeling at reduced costs.
Additionally, one representative will handle everything from the estimate to project completion.
Since the same person will be in charge, whether it’s sales or construction management, 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 and Skilled Workers
We have obtained construction industry permits and industrial waste collection and transportation permits!
We also have nationally certified sheet metal and painting technicians on staff, and we are confident in our construction techniques.
We are capable of handling large-scale roofing projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty, our solar panel installation work comes with our own workmanship warranty (leakage warranty)!
(The workmanship warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovation is performed. The workmanship warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty details.)
Aftercare maintenance is available annually, and we send out notification DM each year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roof troubles and situations.
Even if we cannot access the roof at high altitudes, we can respond using a drone!
During leakage investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of the solar panels decreases due to dirt, we can also provide cleaning with a specialized brush.
We will respond according to the customer’s wishes.
7. Human Resource Development
We create various roof models for skill enhancement and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly conduct technical training to ensure that each staff member can handle various cases.
8. Creation of 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 “financial simulation” that takes into account loan interest rates and electricity costs.
The financial simulation can project cumulative income and expenses over 20 to 30 years.
We compile easy-to-understand materials that include important points and disadvantages for customers who may not be familiar with solar installations!
We encourage you to obtain comparative estimates and review plans from other companies!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 to 30 years.
Confirming “whether it is okay to install them directly on the current roof” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, specializing in roofing work, has summarized the items to check before installation.
| 1. Type of roofing material and age | The method of securing the panels 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 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 power generation. We create a layout diagram from the drawings and the site, and you can confirm it with the power generation simulation. |
| 4. Shape of the roof and installable area | The number of panels 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 their size, so we compare based on the total output of the roof. |
| 5. Method of securing and waterproofing details | We check whether the panels will be secured by drilling holes in the roofing material or by using brackets to hold the roofing material. The method of securing varies by technique, so please confirm the waterproofing treatment of the fastening parts at the time of the estimate. |
| 6. Weight of the roof | The roof will become heavier due to the panels. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may be an option if necessary. |
| 7. Location of equipment installation and wiring | We confirm the installation locations for the power conditioner and storage batteries, as well as the wiring route to the distribution board. The length of the wiring also affects costs. |
Securing 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 suited to the type of tile (even methods that do not drill holes in the tiles will fix to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with 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 framework | Type and deterioration status of the waterproof layer, waterproofing around the framework. Consider in conjunction with the timing of waterproofing work. |
If you renovate the roof 10 to 20 years after installation, there will be additional costs for removing and re-installing solar panels. If the roof is deteriorating, renovating to a highly durable roofing material before installation may help reduce costs in the long run.
Kakeru Koumuten is strong in roofing work and can also handle the removal and re-installation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Kawasaki City, Kawasaki Ward
PossibleSubsidies and Grants
If you introduce solar panels or storage batteries in Kawasaki Ward, you may be eligible for programs from “the national government,” “Kanagawa Prefecture,” and “Kawasaki City.”
The following information is based on the official pages of each program as of October 6, 2026. The application status may change depending on the budget, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| System | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Kawasaki City “Reiwa 8 Fiscal Year Solar Power Generation Equipment Installation Subsidy” (for individual residences) | Individuals residing (or planning to reside) in homes within the city. Work started before receiving the grant decision notification is not eligible. Can be combined with national and Kanagawa Prefecture subsidies. | Solar Power (non-FIT): 70,000 JPY/kW (maximum 280,000 JPY per case) Solar Power (FIT applicable): 40,000 JPY per case Storage Battery: 100,000 JPY/kWh (non-FIT interconnection maximum 700,000 JPY per case, FIT applicable interconnection maximum 300,000 JPY per case) |
April 24, 2026 – December 28, 2026 Early termination possible depending on budget status (as of September 30, 2026, 49% of the total budget has been executed according to the official page) |
| Kanagawa Prefecture “Reiwa 8 Fiscal Year Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Introduction Subsidy” | Must install both solar power generation and storage batteries in a residence within the prefecture. Applications must be made by the individual, and construction must start after the grant decision. | Solar Power: 70,000 JPY/kW Storage Battery: 150,000 JPY per unit |
Phase 1: May 11, 2026 – June 30, 2026 Phase 2: September 7, 2026 – September 30, 2026 (first-come, first-served) Phase 2 has reached its application deadline. Please check the prefecture’s official page for future recruitment. |
| National “DR Home Storage Battery Project” (Reiwa 7 Fiscal Year Supplement) | Newly introduce a home storage battery system that can be utilized for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 1 kWh at 34,500 JPY (subsidy rate within 30% and maximum 600,000 JPY per application) | As of May 29, 2026, the budget has been reached, and the public recruitment has ended (applications are currently not accepted). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but they must be combined with essential works such as insulation renovations of windows (openings) and structures; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 JPY per unit | Ends as soon as the budget cap is reached. Please check the official site for application status. |
| Kawasaki City “Eco Support Subsidy for Local Businesses” (Reiwa 8 Fiscal Year) | Small and medium-sized businesses with (or newly establishing) a business location within the city (individual residences are not eligible). Solar power generation must be less than 50 kW, and for 10 kW or more, it must be for self-consumption only. | One-third of eligible expenses (maximum 2,000,000 JPY) If solar power generation is included, an additional 10,000 JPY per kW (maximum 200,000 JPY) will be added. |
April 1, 2026 – January 12, 2027 Applications will close once the budget cap is reached (as of September 29, 2026, the budget execution rate is approximately 70% according to the official page). |
| Kanagawa Prefecture “Reiwa 8 Fiscal Year Subsidy for Introduction of Self-Consumption Type Renewable Energy” | Corporations and individual business owners filing blue returns (individual residences are not eligible). Solar power must have a generation output of 10kW or more, facilities for business use, equipment not certified under FIT/FIP, etc. | Solar power: 80,000 JPY/kW, etc. Storage systems: 50,000 JPY/kWh (up to 5,000,000 JPY) |
Application period ended on September 3, 2026 (when the application amount reached the budget amount) |
Kawasaki City’s subsidies do not cover projects that were started before receiving the “Notice of Grant Decision”. Kanagawa Prefecture’s residential subsidies also require construction to begin after receiving the “Grant Decision”, and grants will be provided after a performance report and review following project completion. The order of procedures varies by program, and applying does not guarantee a grant, so please confirm before contracting and starting work.
At Kakeru Koumuten, we will guide you on eligibility conditions and business requirements for each program after confirming them.
Kawasaki City “Reiwa 8 Fiscal Year Solar Power Generation Equipment Installation Subsidy”
Kawasaki City provides subsidies for individuals installing solar power generation equipment and storage batteries in residential properties within the city. Residents of Kawasaki Ward are also eligible.
The subsidy amount for individual residences is 70,000 JPY per kW for solar power generation (not applicable under FIT, with a maximum of 280,000 JPY per case), and 100,000 JPY per kWh for storage batteries. The maximum amount for storage batteries is 700,000 JPY per case when interconnected without FIT, and 300,000 JPY per case when interconnected with FIT, while selling solar power under FIT is treated as 40,000 JPY per case. There are also options for ZEH and ZEH Oriented at 250,000 JPY per unit, and ZEH+ at 400,000 JPY per unit.
For example, if installing a 4kW solar panel without FIT, the subsidy calculation would be 4kW × 70,000 JPY = 280,000 JPY (equal to the maximum amount).
Projects started before receiving the Grant Decision Notice are not eligible. It is also possible to combine this with other subsidies implemented by the national government and Kanagawa Prefecture. There are menus available for management associations and owners of collective housing such as condominiums, but simultaneous application for subsidies for electric vehicle charging facilities is a condition.
The application period for the Reiwa 8 fiscal year is from April 24, 2026, to December 28, 2026, and may end early depending on budget conditions. For detailed eligibility conditions and application methods, please check Kawasaki City’s official page.
👉 Click here for Kawasaki City’s official page
National Subsidy “DR Home Storage Battery Project (Support Project for Introducing Home Storage Systems for DR Resources)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those introducing registered products of storage systems that can be utilized for demand response (DR), and in the fiscal year 2025 supplementary project, the subsidy amount was 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 projects contracted or ordered before the grant decision are not eligible.
However, the supplementary budget for Reiwa 7 reached the application amount on May 29, 2026, and the public recruitment has ended (the previous year’s Reiwa 6 supplementary budget also ended on July 2, 2025). Applications are currently not possible, so please check the official website for future public recruitment.
Additionally, there are currently no subsidies confirmed from the national government specifically for the installation of solar panels on existing homes.
👉 Here is the official site for the DR Home Storage Battery Project
Kanagawa Prefecture “Reiwa 8 Subsidy for Solar Power Generation and Storage Battery Installation for Homes”
In Kanagawa Prefecture, subsidies are provided for those who install both “solar panels” and “storage batteries” in their homes.
The subsidy details are 70,000 yen per kW of solar power generation output and 150,000 yen per storage system.
For example, if you install a 4kW solar panel and one storage battery, the subsidy amount 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 excluded, and the application must be made by the individual (proxy applications by contractors are not allowed). It is also possible to combine this with subsidies from Kawasaki City.
For Reiwa 8, the first application period (May 11 – June 30) and the second application period (September 7 – September 30, first-come-first-served) have been conducted, and the second period has reached its deadline. For future recruitment, please check the official page of Kanagawa Prefecture.
👉 Here is the official page of Kanagawa Prefecture
Kawasaki City “Eco Support Subsidy for Local Businesses” (for businesses)
Kawasaki City is implementing a subsidy for businesses aimed at supporting the introduction of renewable energy such as solar power generation equipment for small and medium-sized businesses that have (or will establish) offices in the city.
Eligible applicants include small and medium-sized enterprises, educational institutions (with fewer than 100 employees), medical corporations (with fewer than 300 employees), and social welfare corporations (with fewer than 100 employees), while individual residential installations are not eligible. Solar power generation must be less than 50kW, and for systems over 10kW, they must be for self-consumption. It is also eligible if combined with the installation of storage batteries or V2H.
The subsidy amount is one-third of the eligible expenses (up to 2,000,000 yen), and if solar power generation is included, an additional 10,000 yen per kW (up to 200,000 yen) is added.
The application period for Reiwa 8 is from April 1, 2026, to January 12, 2027, and applications will close once the budget limit is reached.
Businesses considering the installation of solar panels in stores, offices, or factories within Kawasaki Ward should check the conditions for eligible businesses and equipment on the official page of Kawasaki City.
👉 Here is the official page of Kawasaki City
Kanagawa Prefecture “Reiwa 8 Year Kanagawa Prefecture Self-Consumption Renewable Energy Introduction Subsidy” (For Businesses)
In Kanagawa Prefecture, there are also subsidies for businesses that introduce “self-consumption” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners who file blue returns, and the introduction to individual residences is not eligible.
Conditions include that the solar power generation output is 10 kW or more, supplying electricity to business facilities within the prefecture, and that the equipment is not certified under FIT or FIP.
The subsidy amount is 80,000 yen per kW for solar power generation, and 50,000 yen per kWh for the accompanying storage system (with a maximum of 5 million yen).
As the application amount reached the budget amount for Reiwa 8, the recruitment was closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Kawasaki Ward should check the official page of Kanagawa Prefecture for the next recruitment.
👉 Click here for details
Solar Panel Installation & Storage Battery Installation Price List
⇧Service Menu | Click here for costs related to Solar Panel Removal and Hot Water Heater Dismantling
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 “Solar Panel Installation Set,” the amount can vary greatly depending on the installation capacity, equipment grade, and roof condition.
Understanding Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatts). Storage batteries are compared in terms of the amount of electricity they can store, expressed in kWh (kilowatt-hours).
The amount of kW that can be installed on a roof varies for each house based on the roof’s shape, orientation, and size. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panels at an estimated cost of 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 only estimated amounts and may vary based on wiring length, scaffold range, existing roofing materials, and panel layout.)
▶ Service Menu | Click here for costs related to Solar Panel Installation and Storage Battery Installation
Items to Check in the Estimate (Cost Confirmation)
When comparing estimates, it is common to compare different capacities and equipment by only looking at the amounts. 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) 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 in conjunction with a storage battery. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range usable during a power outage (whole 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 to secure). |
| 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 fixing points, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Application | Extent of support for applications to the power company, certification application for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If roofing work and exterior painting are done simultaneously, 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 prices are tax-inclusive or tax-exclusive, conditions under which additional costs may arise, details and duration of manufacturer warranty and workmanship warranty. |
If the capacities differ, both the price and power generation will change. Kakeru Koumuten Co., Ltd. warmly welcomes competitive estimates, so if you bring estimates from other companies, we will explain the differences for each item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can obtain an approximate estimate and a profit 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 approximate estimate and profit simulation!
*The simulation results are approximate. Actual profits may vary based on conditions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection or replacement.
Customer Voices
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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 Installation
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh class |
| Base Mounting Hardware Used |
| Niigata Manufactured / Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed by catching the horizontal metal roof with catch type hardware (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that grants are available, and I would like to know how much 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 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 grant amount, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Kawasaki City, Kawasaki Ward
There are many solar panel installation contractors available in Kawasaki City, Kawasaki Ward, and it can be confusing to choose the right one.
Therefore, when requesting solar panel installation and battery storage installation work, make sure to check the following 4 points:
● Knowledge of roofs as well as solar panels
● Confirm the presence 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 confirmation regarding roofs and waterproofing.
While knowledge of solar panels is certainly important, understanding the roof and waterproofing at the installation location of the solar panels is also crucial.
⚠︎Examples of troubles due to insufficient checks on roofs and waterproofing
・Solar panels installed on a deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring removal and reinstallation within a few years
・Misjudgment of the type of waterproofing leading to incorrect treatment and resulting in leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Check Before Installing Solar Panels” in this article
Confirm the presence 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.
Solar panels and battery storage units come with manufacturer warranties, but also check for the presence of a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may cover the repairs under the warranty, provided it is within the warranty period and conditions.
Additionally, some contractors offer after-service separate from warranties, so be sure to check if the contractor you are considering has after-service.
Changes or damages 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 in after-maintenance, even in unseen areas, it becomes easier to detect abnormalities early and prevent 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-maintenance and send out DM every year!
After checking the DM, if you wish, we will visit for after-maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, be sure to obtain estimates from multiple contractors.
Even for the same manufacturer and the same construction content, costs may vary, as well as warranties and after-services.
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,
“Check the items in the estimate”
“Type of solar panel”
“Warranties and after-services”
and make detailed comparisons to make your judgment! If the rank of auxiliary materials is low or if processes 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
There may be subsidies 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 grant may not be awarded.
For systems like the Kanagawa Prefecture housing subsidy, where contractors cannot apply on behalf of the client, it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for the prefectural housing subsidy, this means receiving grant approval) before proceeding with the construction!
In the case of the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the grant will be awarded after a review! (The flow of procedures varies by system)
▶ Go to “Subsidies and Grants That May Be Applicable in Kawasaki Ward” within this article
Benefits of Introducing Solar Power Systems
The benefits of introducing solar panels are summarized in the following 5 points!
Benefit 1: Economic Advantage
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 gain benefits by reducing the amount of electricity you buy from the utility company by consuming the electricity you generate!
As electricity costs rise, the ability to cover your consumption with solar power becomes increasingly attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
For residential systems (under 10kW), the selling price (FIT) from certifications after October 2025 is set at “24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year.” The same price will apply in the 2026 fiscal year. After the 5th year, it is often more advantageous to use it at home (self-consumption) rather than selling it, making the combination with a storage battery a viable option.
👉 For details on purchase prices and periods, visit the Agency for Natural Resources and Energy
Benefit 2: Subsidies Can Be Utilized!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the criteria, you may be able to utilize subsidies!
Reducing the actual burden through subsidies is a significant advantage!
In the case of Kawasaki Ward, you may be eligible for the subsidy for solar power system installation costs from Kawasaki City or Kanagawa Prefecture.
Benefit 3: Environmentally Friendly!
Solar power generation has low carbon dioxide emissions and reduces dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices like power conditioners do have operational noise.)
Benefit 4: Heat Insulation Effect Expected!!
By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the temperature rise of the roof, providing expected heat insulation effects!
(Note that this does not improve the 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 such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capability, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1 Maintenance costs are incurred
A particularly easy-to-overlook maintenance cost is for the roof where the 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 deteriorated, it is reassuring to renovate it with durable roofing materials before installing the solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It is reassuring to request a simulation that considers 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 the materials and substrate with screws or other fasteners, waterproofing treatment at the fixed points 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, one option is to replace the roofing material with a metal roof and fix the solar panels using the catch method. (The catch method has compatibility conditions between the roofing material and the fasteners, and cannot be used with all metal roofs.)
Foundation Brackets for Horizontal Metal Roofs
Note 3: The Roof Becomes Heavier
Installing solar panels will make the roof heavier. It is important to investigate the existing roof, substrate, and load-bearing capacity, and if necessary, consider replacing it with a lighter roof.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not accurate to say “This manufacturer has the best solar panels”; instead, it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
Choosing Method 1: Compare Based on Total Roof Output
When installing solar panels on the roof, it is crucial to consider how much electricity can be generated within the limited area, and the more electricity generated, the better!
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 like the higher output panel is better at first glance.
However, if the panel size does not fit well on the roof, you may find that “20 panels of 350W can be installed” while “15 panels of 400W can be installed,” leading to different installation capacities on the same roof due to size differences.
400W × 15 panels = 6kW (Total roof output)
350W × 20 panels = 7kW (Total roof output)
As shown above, even if the output of a single panel is lower, the total output of the roof can be higher!
It is important to consider the total output of the roof rather than just the output of a single panel!
*The above calculations are for total output (kW). Actual electricity generation (kWh) will vary based on conditions such as roof orientation, slope, and shading.
Choosing Method 2: Compare Based on Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases over 10 or 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or electricity generation itself.
By considering the degradation rate along with the initial output, you can choose solar panels without regrets!
Choosing Method 3: Compare Based on Warranty Period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
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 Kawasaki Ward
We have compiled common questions from customers considering the installation of solar panels and storage batteries in Kawasaki Ward. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Kawasaki City, Kawasaki Ward?
The cost varies depending on the installation capacity, equipment, and roof condition. In the above construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines based on capacity are published on the solar panel installation and storage battery installation pricing page. We will create a layout diagram based on the drawings and site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Kawasaki Ward?
As of October 6, 2026, Kawasaki City’s “Reiwa 8 Fiscal Year Solar Power Generation Equipment Installation Subsidy” (for individual residences; solar power is 70,000 yen/kW; maximum 280,000 yen per case, etc.) is accepting applications until December 28, 2026 (there is a possibility of early closure depending on budget conditions). The Kanagawa Prefecture subsidy (70,000 yen/kW for solar power; 150,000 yen per unit for storage batteries) is approaching the application deadline for the second term of Reiwa 8, and the national DR household storage battery project has ended its public recruitment.
The application status may change, so 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. Both Kawasaki City’s and Kanagawa Prefecture’s subsidies require “commencement of construction after the grant decision,” and if you start before receiving the grant decision notification, you will be excluded from eligibility.
The order of procedures varies by program, so please confirm before signing a contract or starting construction.
Can solar panels be installed on a slate roof? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate. The fixing method varies by construction method, and for methods that fix brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is essential.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation, and if deterioration is advanced, we can also propose methods such as roof overlay (cover method) or replacement before installation.
The roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed 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 about the installation process after confirming the condition of the roof through a site survey!
Is it better to install a storage battery together with solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it in your home rather than selling it.
Additionally, the subsidy in Kanagawa Prefecture requires the simultaneous introduction of solar panels and storage batteries, and there are subsidy options for storage batteries in Kawasaki City. 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 based on the drawings and site survey, and provide you with the installation capacity and power generation simulation.
Kawasaki Ward has a mix of residential, industrial, and commercial areas, and the shading from neighboring houses, buildings, and surrounding mid- to high-rise buildings varies from one property to another. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
In the above construction example (solar panels 4.3 kW + storage battery), it took about 3 days. The duration may vary if roof work is done simultaneously or depending on the shape of the roof and installation capacity.
Additionally, there will be a separate period for applying for subsidies and with 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 for the 2026 fiscal year.
The idea is to recover initial costs quickly within 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 provide maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-maintenance notices via direct mail and visits for inspections upon request. We can also clean solar panels with a specialized 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 renovate a roof that already has solar panels installed?
Yes, we can. Kakeru Koumuten can remove and reinstall solar panels ourselves, allowing us to remove the panels, perform roof overlay (cover method) or re-roofing, and then reinstall them, all in one process. 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 company in Kawasaki Ward, please consult Kakeru Koumuten
Our company handles a wide range of exterior renovations, including solar panels, roofing work, and exterior wall work in Kawasaki City, Kawasaki Ward.
We have received many requests from customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten promises “high-quality renovations at low cost”, and we have received positive feedback from many customers.
We continue to update our annual construction achievements and will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay work and re-roofing but also partial roof repairs, exterior painting, and exterior cover methods.
We are also happy to handle small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leak repairs, we may be able to provide temporary measures without setting up scaffolding, as long as safety can be ensured, so please consult us!
“I want to know about recommended solar panels”, “I want to keep costs down as much as possible”, “I just want an estimate for now”, we will provide the best solutions for your specific requests.
We will never propose unnecessary work focused on profit!
We always stand in the customer’s position and will propose the best construction plan!
We are confident that we will not be outdone 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 we are found to be inferior to other companies, you are free to decline!
Characteristics of Kawasaki City, Kawasaki Ward and Points for Solar Work
Kawasaki City, Kawasaki Ward is located on the easternmost side of Kawasaki City. It features a terrain that expands from Kawasaki Station to Tokyo Bay, with commercial areas, residential areas, and industrial areas all gathered in one ward.
Below are the characteristics of Kawasaki Ward and points to consider when installing solar panels and storage batteries (tap to open).
View the characteristics of Kawasaki City, Kawasaki Ward and points for solar work
■ A ward that expands from Kawasaki Station to Tokyo Bay
Overview of Kawasaki Ward (Kawasaki City Official) states that Kawasaki Ward is located on the easternmost side of Kawasaki City, bordered to the north by the Tama River and Ota Ward in Tokyo, and to the south by Tsurumi Ward in Yokohama. It is described as a terrain that expands to the eastern Tokyo Bay from JR Kawasaki Station and Keikyu Kawasaki Station. The area covers 40.25 square kilometers and is divided into three districts: the Central District (commercial area centered around Kawasaki Station), Daishi District, and Tajima District.
The types of housing and building density vary by district. At Kakeru Koumuten, we will check the shape and orientation of the roof and the shadows cast by surrounding buildings on-site, and provide explanations with layout diagrams and power generation simulations.
■ For sites near the coastal area, confirm specifications for salt damage resistance of equipment
Overview and Characteristics of Kawasaki Ward (Kawasaki City Official, October 2008) indicates that the coastal area is composed of reclaimed land, forming a heavy chemical industrial zone concentrated with steel and petroleum complexes. In sites close to the coastline facing Tokyo Bay, there may be effects from salt contained in sea breezes, so it is advisable to confirm whether the panels, mounting structures, and power conditioners are designed to withstand salt damage according to the manufacturer’s specifications. Please consult us for equipment selection based on the conditions of the installation site.
■ In densely populated residential areas, planning for scaffolding and delivery routes is essential
In residential areas where buildings are closely situated, careful planning for scaffolding and delivery routes for equipment may be necessary. Kakeru Koumuten will respond to the on-site conditions with our own scaffolding team and scaffolding materials.
■ Check the roof condition according to the age of the building
For homes that have been built for several years, it is important to check for damage to the roofing materials and substrate before installing solar panels. Depending on the condition of the roof, installing them simultaneously with roof renovations can reduce future costs for removing and reinstalling solar panels. For buildings with flat roofs, it is also necessary to check the waterproofing condition.
■ Different subsidy systems for commercial buildings such as factories and warehouses
The same document states that Kawasaki Ward has been a region where factories have been established since the Meiji period. When installing in commercial buildings such as factories, warehouses, stores, and offices, there is a separate subsidy system from that for households. The Kawasaki City Eco Support Subsidy for local businesses is accepting applications until January 12, 2027, and will end when the budget limit is reached, with conditions for eligible businesses and equipment.
■ Yokohama’s annual sunshine hours are approximately 2,018 hours
Meteorological Agency’s average values (1991–2020) indicate that Yokohama’s annual sunshine hours are approximately 2,018 hours (this is not the value for Kawasaki Ward, but for an observation point in eastern Kanagawa Prefecture). August has the most sunshine, while June during the rainy season has the least.
Power generation varies by season, so conducting an annual power generation simulation and selecting battery capacity to match peak electricity usage times are key points.
Our company is based in Kanagawa Prefecture and has handled many exterior construction and solar projects in Kawasaki City, Kawasaki 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 Kawasaki City, Kawasaki Ward
Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and Tokyo Metropolis.
List of Areas in Kawasaki City, Kawasaki Ward
Kawasaki Ward Asada / Kawasaki Ward Asahimachi / Kawasaki Ward Ikegami Shinmachi / Kawasaki Ward Ikegami Cho / Kawasaki Ward Ikeda / Kawasaki Ward Sunako / Kawasaki Ward Isecho / Kawasaki Ward Egawa / Kawasaki Ward Ekimae Honcho / Kawasaki Ward Enokicho / Kawasaki Ward Oiwakecho / Kawasaki Ward Oshima / Kawasaki Ward Oshima Kamimachi / Kawasaki Ward Ogawacho / Kawasaki Ward Oda / Kawasaki Ward Oda Sakae / Kawasaki Ward Kaizuka / Kawasaki Ward Kawanakajima / Kawasaki Ward Kyomachi / Kawasaki Ward Kokan Dori / Kawasaki Ward Sakaimachi / Kawasaki Ward Sakuramoto / Kawasaki Ward Shimonamiki / Kawasaki Ward Showa / Kawasaki Ward Shinkawa Dori / Kawasaki Ward Daimachi / Kawasaki Ward Tajimacho / Kawasaki Ward Tamachi / Kawasaki Ward Daishi Ekimae / Kawasaki Ward Tsutsumine / Kawasaki Ward Dekino / Kawasaki Ward Tonocho / Kawasaki Ward Nakajima / Kawasaki Ward Nakase / Kawasaki Ward Nisshincho / Kawasaki Ward Hamacho / Kawasaki Ward Higashidacho / Kawasaki Ward Higashimonzen / Kawasaki Ward Hinode / Kawasaki Ward Fujisaki / Kawasaki Ward Horinouchicho / Kawasaki Ward Honcho / Kawasaki Ward Minatomachi / Kawasaki Ward Minamimachi / Kawasaki Ward Miyamaecho / Kawasaki Ward Miyamotocho / Kawasaki Ward Motoki / Kawasaki Ward Yotsuyakami Machi / Kawasaki Ward Watada / Kawasaki Ward Watada Sannocho / Kawasaki Ward Watada Shinmachi / Kawasaki Ward Watada Higashimachi / Kawasaki Ward Watada Mukaimachi
・Trust Kakeru Koumuten for exterior wall painting in Kawasaki City, Kawasaki Ward!
・Trust Kakeru Koumuten for roof renovations in Kawasaki City, Kawasaki Ward!
・Trust Kakeru Koumuten for exterior renovations in Kawasaki City, Kawasaki Ward!
・Trust Kakeru Koumuten for waterproofing work in Kawasaki City, Kawasaki Ward!
・Kakeru Koumuten Co., Ltd.施工実績
・Kakeru Koumuten Co., Ltd. after maintenance
・Kakeru Koumuten Co., Ltd.施工メニュー・料金表
・Kakeru Koumuten Co., Ltd. staff blog 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 solar power generation installation? Key points for site selection included!
・Check here 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!
