Leave Your Solar Panel Installation Work in Saiwai, Kawasaki City to Kakeru Koumuten Co., Ltd.!
For Solar Panel and Battery Installation in
Kawasaki City, Saiwai Ward,
trust Kakeru Koumuten!
Kakeru Koumuten is a company specializing in exterior renovations based in Kanagawa Prefecture.
As a company strong in roofing work, we are entrusted withsolar panel installation and battery installation considering roofs and waterproofing!
“How to Choose a Solar Panel Contractor in Saiwai Ward”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Saiwai 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 obtainingquotes from about three companies!
Table of Contents (Tap to Open/Close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Kawasaki City, Saiwai Ward
- Roof Inspection Before Installing Solar Panels
- Subsidies and Grants That May Be Applicable in Saiwai 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 Kawasaki City, Saiwai Ward
- 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 Saiwai Ward
- If You Are Looking for a Solar Panel Installation Company in Saiwai Ward, Contact Kakeru Koumuten
- Characteristics of Kawasaki City, Saiwai Ward and Points for Solar Construction
- Service Area in Kawasaki City, Saiwai Ward
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Kawasaki City, Saiwai Ward
Here are the reasons why our company is entrusted with solar panel installation by customers in Kawasaki City, Saiwai Ward.
“Our Unique Strengths in Solar Panel Installation That Cannot Be Imitated by Other Companies”
have received high praise from many customers.
Because we are confident, we welcome estimates from any number of companies!
1. We Also Handle Exterior Renovations Beyond Solar Panel Installation!
Problems such as leaks that occur during solar panel installation may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if 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 problems 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 problems after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has prepared the following warehouses and material storage areas to provide low-cost, high-quality solar work and exterior renovations.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding according to construction conditions and can assemble scaffolding in-house.
By not outsourcing scaffolding work and conducting it with our own scaffolding team, we can also cut costs for scaffolding work.
We own scaffolding materials for approximately 50 detached houses!
Even if there are height differences on the site, our in-house scaffolding team will plan the scaffolding according to the site conditions.
Storage of Materials in Our Large Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, allowing us torespond quickly in emergencies!
Sorting and 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 roofing materials!
We can also provide simulations of potential earnings 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 us to provide detailed explanations!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is its complete in-house construction.
By having a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof renovations at reduced costs.
Additionally, one representative will handle everything from the estimate to the completion of the work.
Since the same person will manage sales and construction oversight, smooth communication is possible.
We can provide consistent in-house construction from temporary scaffolding installation, exterior wall painting, to roof renovations!
4. Various Permits and Skilled Workers
We have obtained construction industry permits as well as permits for industrial waste collection and transportation!
We also have nationally certified sheet metal and painting technicians on staff, giving us confidence in our construction techniques.
We are capable of handling large-scale roof projects such as those for factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation work, our own construction warranty (leakage warranty) is also included!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, a roof renovation may be required to provide the warranty. The construction warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty details.)
Aftercare is available annually, and we send out a notification DM each year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
If you cannot access the roof at high altitudes, we can utilize drones to assist!
During leak investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of solar panels decreases due to dirt, we can provide cleaning services with specialized brushes.
We will respond according to the customer’s wishes.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training so that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
Kakeru Koumuten provides not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar construction guidebook” and a “profit and loss simulation” that takes into account loan interest rates and electricity costs.
The profit and loss simulation can be created for projected cumulative profits and losses over 20 to 30 years.
Even customers who are not familiar with solar construction will receive materials that clearly outline 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 to 30 years.
Confirming “Is it okay to install them directly on the current roof?” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, which specializes in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Year of Construction | The fixing method varies depending on the roofing materials such as slate, tiles, metal roofs, and flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest roof renovation first. |
| 2. Condition of Substrate and Waterproof Sheet | If the sheathing boards or roofing (waterproof sheet) under the roofing material are damaged, it will affect the fixing strength of the fittings and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, Slope, and Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, will affect the power generation. We will create a layout diagram from the drawings and the site, and you can confirm it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels that can be installed (installation capacity) is determined by the shape and size of the roof. The number of panels that can be installed varies depending on the size of the panels, so we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will check whether the method involves drilling holes in the roofing material for fixing or using fittings to secure the roofing material. The fixing method varies by technique, so please confirm the waterproofing treatment method for the fixing parts during the estimate. |
| 6. Weight of the Roof | The roof will become heavier due to the panels being installed. After investigating the existing roof, substrate, and load-bearing capacity, switching to lighter roofing materials may also be an option if necessary. |
| 7. Installation Location of Equipment and Wiring | We will confirm the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect the cost. |
| 8. Ease of Scaffolding Setup and Delivery Route | If there is a height difference on the site, planning for scaffolding and the delivery route for equipment and materials may require some ingenuity. The width of the front road and the elevation differences on the site will also be checked during the on-site investigation. |
Fixing Methods and Confirmation Points by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets with screws to the roofing material and substrate) | Waterproof treatment of fixed 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 a method 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, a method that does not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you plan to renovate the roof 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the roof is deteriorating, it may be more cost-effective in the long run to renovate to high-durability roofing materials before installation.
Kakeru Koumuten Co., Ltd. specializes in roofing work and can also handle the removal and reinstallation of solar panels, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Saiwai Ward, Kawasaki City
PossibleSubsidies and Grants
If you are introducing solar panels or storage batteries in Saiwai 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
| Program | 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 a house in Kawasaki City. Solar power systems must be 2kW or more, and the installation must be performed by a registered contractor under Kawasaki City’s “Solar Power Generation Equipment Promotion Business Registration System.” Storage batteries must be eligible products and connected to solar power generation systems (2kW or more). Only purchased equipment is eligible; PPA and leasing are not eligible. | 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 (for new solar power connected to non-FIT: maximum 700,000 JPY per case, FIT applicable or connected to existing equipment: maximum 300,000 JPY per case) |
April 24, 2026 – December 28, 2026 (online application, work started before grant decision is not eligible) Installation completion: by January 31, 2027 Ends once the budget limit is reached. As of September 30, 2026, the official page shows that 49% of the total budget has been applied for. |
| Kanagawa Prefecture “Reiwa 8 Fiscal Year Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Installation Subsidy” | Must introduce both solar power generation and storage systems in a residential building (with seismic performance ensured) 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: Starts September 7, 2026 (first-come, first-served) As of September 7, 2026, the application amount has reached the budget amount, and applications are now closed. Please check the prefecture’s official page for future recruitment. |
| National “DR Home Storage Battery Project” (Reiwa 7 Fiscal Year Supplement) | Newly introduce home storage systems that can be utilized for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 1kWh at 34,500 JPY (subsidy rate within 3/10; maximum 600,000 JPY per application). | As of May 29, 2026, the budget has been reached, and the public recruitment has ended (the official site states there are no plans to reopen applications, and currently, applications cannot be made). |
| 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 renovation of windows (openings) and the structure; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 JPY per unit | Ends once the budget limit is reached. The official site shows that as of October 5, 2026, the application amount for renovations is 8% of the budget. Please check the official site for application status. |
| Kawasaki City “Eco Support Subsidy for Local Businesses” | Applicable when small and medium-sized enterprises in Kawasaki City introduce systems for business facilities (joint housing is not eligible). There are conditions for eligible persons and equipment. | 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) is added. |
2026 April 1 – 2027 January 12 (first-come, first-served, up to budget limit). The budget execution rate is approximately 70% as of September 29. |
| Kanagawa Prefecture “Reiwa 8 Year Kanagawa Prefecture Self-Consumption Type Renewable Energy Introduction Subsidy” | Corporations and individual business owners filing blue returns (individual residences are not eligible). For solar power, 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 (maximum 5,000,000 JPY) |
Application period ended on September 3, 2026 (when the application amount reached the budget amount) |
Subsidies for housing in Kawasaki City and Kanagawa Prefecture require not only application acceptance but also construction to begin after receiving “grant approval”. If construction starts beforehand, it will be ineligible. The prefectural housing subsidy is granted after a performance report and review following the completion of construction. The order of procedures varies by system, and applying does not guarantee a grant, so please confirm before contracting and starting work.
Kakeru Koumuten will guide you on eligibility conditions and business requirements for each system after confirming them.
National Subsidy “DR Home Storage Battery Project (Support for the Introduction of Home Storage Systems for DR Resources)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those introducing new registered products of storage systems that can be utilized for demand response (DR). In the fiscal year 2025 supplementary budget, the subsidy amount was determined based on a standard amount of 34,500 JPY per initial effective capacity of 1kWh, with a subsidy rate of up to 30% and a maximum of 600,000 JPY per application. There are also conditions such as being ineligible for items contracted or ordered before grant approval.
However, the fiscal year 2025 supplementary budget reached its application amount on May 29, 2026, and the public offering has ended. The official website also states that there are no plans to reopen the public offering, and applications are currently not possible. Please check the official website for future public offerings.
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 Home Storage Battery Project
Kanagawa Prefecture “Reiwa 8 Year Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Introduction Subsidy”
Kanagawa Prefecture provides subsidies for those who introduce both “solar panels” and “storage batteries” for residential use.
The subsidy details are 70,000 JPY per kW of solar power generation and 150,000 JPY per storage system.
For example, if you introduce a 4kW solar panel and one storage battery, the subsidy amount would be calculated as 4kW × 70,000 JPY + 150,000 JPY = 430,000 JPY.
The target is residential buildings that ensure seismic performance, and the energy 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 stated on the official page of Kawasaki City that this can be combined with Kawasaki City’s subsidies.
For the fiscal year Reiwa 8, the first phase (May 11 – June 30) and the second phase (starting September 7, first-come-first-served) were accepted. The second phase has closed on September 7, 2026, as the application amount reached the budget amount. For future recruitment, please check the official page of Kanagawa Prefecture.
👉 Click here for the official page of Kanagawa Prefecture
Kanagawa Prefecture “Reiwa 8 Fiscal Year Kanagawa Prefecture Subsidy for Introduction of Self-Consumption Type Renewable Energy” (for businesses)
Kanagawa Prefecture is also implementing subsidies for businesses that introduce “self-consumption type” facilities that use electricity generated by solar panels.
The target is corporations or individual business owners filing blue returns, and the introduction to individual residences is not eligible.
Solar power generation must have a generation output of 10 kW or more and supply electricity to business facilities within the prefecture, and it must be equipment that does not receive FIT/FIP certification.
The subsidy amount is 80,000 yen per kW for solar power generation, and 50,000 yen per kWh (up to 5 million yen) for the energy storage system installed together.
For the fiscal year Reiwa 8, the application amount reached the budget amount, and recruitment was closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Saiwai Ward should check the official page of Kanagawa Prefecture for the next recruitment.
👉 Click here for details
Kawasaki City “Eco Support Subsidy for Local Businesses” (for businesses)
Kawasaki City is implementing a system to subsidize part of the introduction costs of renewable energy facilities, etc. for small and medium-sized enterprises in the city.
The target is business facilities, and collective housing is not eligible. For households, the “Subsidy for Installation Costs of Solar Power Generation Equipment, etc.” below will be the point of contact. Businesses that install solar panels on stores, offices, factories, etc. in Saiwai Ward may have the opportunity to utilize this, but it is necessary to confirm the eligibility conditions for the recipients and equipment.
The subsidy amount is one-third of the eligible expenses (up to 2 million yen), and if solar power generation is included, an additional 10,000 yen per kW (up to 200,000 yen) will be added.
The recruitment period for the fiscal year Reiwa 8 is from April 1, 2026, to January 12, 2027, and if the budget limit is reached, recruitment will end in order of application. As of September 29, the budget execution rate is approximately 70%, so early confirmation is recommended.
For detailed conditions and application methods, please check the official page of Kawasaki City.
👉 Click here for the official page of Kawasaki City
Kawasaki City “Reiwa 8 Fiscal Year Solar Power Generation Equipment Installation Subsidy” (for individual residences)
In Kawasaki City, a “Solar Power Generation Equipment Installation Subsidy” is being implemented for individuals who install solar power generation equipment or storage batteries in residential properties within the city. Residents of Saiwai Ward are also eligible.
◎Subsidy Amount◎
●Solar Power Generation (non-FIT applicable): 70,000 JPY/kW (maximum 280,000 JPY per case)
●Solar Power Generation (FIT applicable): 40,000 JPY per case
●Storage Battery: 100,000 JPY/kWh (maximum 700,000 JPY per case when connecting to new solar power that is non-FIT applicable, maximum 300,000 JPY per case when connecting to FIT applicable or existing equipment)
●ZEH/ZEH Oriented: 250,000 JPY per unit, ZEH+: 400,000 JPY per unit
The main conditions are that the solar power must be 2kW or more and installed by a registered contractor under Kawasaki City’s “Solar Power Generation Equipment Promotion Business Registration System,” the storage battery must be a qualifying product that connects to the solar power generation equipment (2kW or more), and it must be purchased equipment (PPA and leasing are not eligible). Applications are accepted online only, and starting work before receiving the grant decision notification will make the subsidy ineligible.
The application period for the Reiwa 8 fiscal year is from April 24, 2026, to December 28, 2026, with installation completion required by January 31, 2027. The program will end once the budget limit is reached, and as of September 30, 2026, it is reported that 49% of the total has been applied for on the official page. It is noted that this can be combined with other subsidies from the national government and Kanagawa Prefecture.
For detailed conditions and application methods, please check the official page of Kawasaki City.
👉 Click here for Kawasaki City’s official page
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 “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 Storage Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatts). Storage batteries are compared based on the amount of electricity they can store, represented in kWh (kilowatt-hours).
The amount of kW that can be placed on the roof varies for each house based on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panel costs as approximately 800,000 JPY to 1,200,000 JPY for 3-5 kW and 1,200,000 JPY to 1,900,000 JPY for 6-10 kW. (These are just rough estimates and can 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 Confirm in the Estimate (Cost Verification)
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) should be specified. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls the battery together. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range usable during a power outage (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of the hardware suitable for the roofing material and the method of securing it (whether it involves drilling holes or clamping for fixation). |
| 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. Applications | 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 roof work and exterior painting are done simultaneously, check that the same scope and quantity are not counted twice. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters or old panels and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether prices are tax-inclusive or tax-exclusive, conditions under which additional costs may arise, details and duration of manufacturer and workmanship warranties. |
If the capacity differs, both the price and power generation will change. Kakeru Koumuten Co., Ltd. welcome 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 battery, you can get an approximate estimate and profit simulation!
*The simulation results are approximate. Actual profits may vary based on assumptions 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)!
Case Studies of Solar Panel Installations
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh |
| Base Mounting Hardware Used |
| Niigata Manufacturing/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 |
| About 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the introduction of solar panels and storage batteries. I heard that grants are available, and I would like to know how much will be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We 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, Saiwai Ward
There are many solar panel installation contractors available in Kawasaki City, Saiwai Ward, and it can be confusing to choose the right one.
Therefore, when requesting solar panel installation and battery storage installation work, let’s check the following four points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the presence of warranties and aftercare services
● Obtain estimates from multiple contractors (three companies as a guideline)
● Check if they provide support for subsidy applications
By confirming the above four points, you will be able to choose a reliable contractor.
Have knowledge not only about solar panels but also about roofs
Improper installation of solar panels can be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient verification of roofs and waterproofing
・Solar panels installed on a severely deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring a renovation to detach and reattach the solar panels within a few years
・Misjudging the type of waterproofing and performing incorrect treatment, leading to leaks
and more.
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the presence of warranties and aftercare services
When choosing a solar installation contractor, make sure to check for warranties. It is important to 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 within the warranty period and conditions, they may cover the repairs under the warranty.
Additionally, some contractors provide aftercare services separate from warranties, so be sure to check if the contractor you are considering has aftercare services.
Since abnormalities or damages on the roof may not be visible, you might not notice them yourself.
By conducting inspections of invisible areas during aftercare maintenance, you can more easily detect abnormalities early and prevent major repairs or failures!
At Kakeru Koumuten Co., Ltd., the installation of solar panels comes with a leak warranty as part of our workmanship warranty. (The warranty for solar panel installation is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovation is performed.)
We also conduct aftercare maintenance and send out annual direct mail!
After reviewing the DM, if you wish, we will visit for aftercare maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting the installation of solar panels, let’s obtain estimates from multiple contractors.
Even for the same manufacturer and the same work content, costs may vary, and warranties and after-sales services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request your preferred contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check:
“Verification of estimate items”
“Types of solar panels”
“Warranties and after-sales services”
and make detailed comparisons for your judgment! Avoid judging solely based on cost, as using lower-grade materials or skipping processes can reduce costs!
▶ Go to “Breakdown of installation capacity, equipment, and construction costs” in this article
Check if they provide support for subsidy applications
Subsidies may be available for the installation of solar panels and storage batteries, 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 applications cannot be submitted by the contractor and must be done by the individual, it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining a grant decision) before proceeding with the construction!
For the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the grant will be provided after review! (The flow of procedures varies by system)
▶ Go to “Subsidies and grants that may be applicable in Saiwai Ward” in this article
Benefits of Introducing Solar Equipment
The benefits of introducing solar panels are as follows!
Benefit 1: Economic Benefits
The biggest advantage of introducing solar panels is the economic benefit!
The selling price of electricity has decreased compared to ten years ago, but by consuming the electricity generated for your own use, you can reduce the amount of electricity purchased from the utility company and gain benefits!
As electricity prices rise, the ability to cover your consumption with solar power becomes attractive!
If you plan to use the generated electricity at night, the installation of a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) will be set at “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year” for certifications after October 2025, and the same price will apply for the fiscal year 2026. After the fifth year, it is likely to be more advantageous to use it in your home (self-consumption) rather than selling it, so combining it with a storage battery is also an option.
👉 Ministry of the Environment｜For purchase prices and periods, click here
Advantage 2 Subsidies can be utilized!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
Reducing the actual burden amount through subsidies is a significant advantage!
In the case of Saiwai Ward, there may be subsidies available from Kawasaki City and Kanagawa Prefecture.
Advantage 3 Environmentally friendly!
Solar power generation has low carbon dioxide emissions and can reduce dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices such as power conditioners may have operational noise.)
Advantage 4 Heat insulation effects can be expected!!
By installing it on the roof or rooftop, the panels block direct sunlight to the roof.
Especially in summer, it can help reduce the temperature rise of the roof, providing expected heat insulation effects!
（This does not improve the insulation performance of the building itself）
Benefit 5 Electricity can be used even during power outages!!
If a storage battery is installed, it is possible to use electricity even during emergencies such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capability, you may be able to use electricity from a dedicated outlet during daytime generation.
（The devices, output, and time 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 overlooked maintenance cost is for the roof where solar panels are installed.
If you perform roof remodeling after 10 to 20 years, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorated, it is reassuring to remodel it with durable roofing materials before installing solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It would be reassuring to consider maintenance costs in the simulation before introducing solar panels!
Point 2 The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix brackets to the roofing material or substrate with screws, waterproofing of the fixed parts is crucial.
In methods that create 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 brackets, and cannot be used with all metal roofs)
Catch-type base metal fittings for horizontal metal roofs
Note 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load capacity, replacing it with a lightweight roof may be one option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
Choosing Method 1: Compare by Total Output of the Roof
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and the more power generated, the better!
Solar panels vary in size and output depending on the manufacturer.
A panel with an output of 350W and a panel with an output of 400W may seem that the higher output panel is better at first glance.
However, if the size of the panels does not fit well on the roof, “20 panels of 350W can be installed, while only 15 panels of 400W can be installed,” meaning the number of panels that can be installed may differ even on the same roof due to the size difference.
400W × 15 panels = 6kW (total output of the roof)
350W × 20 panels = 7kW (total output of the roof)
As shown above, even if the output of a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual power generation (kWh) will vary depending on conditions such as roof orientation, slope, and shading.
Choosing Method 2: Compare by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases 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 power generation amount.
Choosing solar panels without considering the degradation rate, in addition to the initial output, will lead to a regret-free selection!
Choosing Method 3: Compare by Warranty Period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
Regarding the output warranty, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies!
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 Saiwai Ward
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Saiwai Ward. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Kawasaki City, Saiwai 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 for different capacities are published on our solar panel installation and storage battery installation pricing page. We will create a layout diagram from the drawings and on-site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Saiwai Ward?
As of October 6, 2026, Kawasaki City’s subsidies (solar power: 70,000 yen/kW for non-FIT applications, maximum 280,000 yen; 40,000 yen per case for FIT applications; storage battery: 100,000 yen/kWh) are currently available for application (ending as soon as the budget limit is reached). Kanagawa Prefecture’s subsidies (70,000 yen/kW for solar power; 150,000 yen per unit for storage batteries) reached the budget amount for the second phase of Reiwa 8 on September 7 and have been closed, 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 even after the construction is completed?
For many programs, procedures are required before construction. Kawasaki City and Kanagawa Prefecture’s subsidies require “commencement of construction after grant decision,” and starting construction beforehand will make you ineligible.
The order of procedures varies by program, so please confirm before signing a contract or starting construction.
Can solar panels be installed on a slate roof? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate. The fixing method varies by construction method, and for methods that fix hardware to the roofing material or substrate, waterproofing treatment of the fixed parts is essential.
Kakeru Koumuten is a specialist in exterior renovations strong in roofing work, so we will check the condition of the roof before installation, and if deterioration is advanced, we can also suggest methods such as roof overlay (cover method) or re-roofing 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 of installation, the cost for removing and reinstalling solar panels will be incurred separately. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with highly durable roofing materials before installation.
Please consult us about the installation process after confirming the condition of the roof through a site survey!
Is it better to install a storage battery together with solar panels?
For those who want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. Since the selling price of electricity will be 8.3 yen/kWh after the fifth year, it tends to be more advantageous to use it in your home rather than selling it.
Additionally, Kanagawa Prefecture’s subsidy requires the simultaneous introduction of solar panels and storage batteries, and the subsidy in Kawasaki City also requires that the storage battery be connected to solar power generation equipment (2kW or more). You can compare “solar only” and “solar + storage battery” through a financial simulation.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and site survey, and provide you with the installation capacity and power generation simulation.
In Saiwai Ward, there are places where houses are close together, and areas like around Kaseyama that are near slopes and trees, so the shading from surrounding buildings and trees and the installable capacity will differ for each house. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
For the above construction example (solar panels 4.3kW + storage battery), it took about 3 days. This may vary depending on whether roof work is done simultaneously and the shape and installation capacity of the roof.
Please note that there will be an additional 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 10kW), from the certification after October 2025, the first four years will be 24 yen/kWh, and from the fifth to the tenth year will be 8.3 yen/kWh, and the same price will apply for the 2026 fiscal year.
The idea is to recover the initial costs quickly in the first four years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that takes into account loan interest rates and electricity prices.
Can you handle maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-maintenance DM notifications and visits for inspections upon request from customers. We can also clean solar panels with a specialized brush if the power generation drops due to dirt.
Since it is difficult to check areas on the roof by yourself, please feel free to consult us if you have any concerns.
Can you also handle renovations for roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten can remove and reinstall solar panels in-house, so we can consistently handle the process of removing the panels, performing roof overlay (cover method) or re-roofing, and reinstalling them. The removed panels can be stored in our own warehouse.
For costs, please refer to the solar panel removal and water heater removal pricing page.
If you are looking for a solar panel installation company in Saiwai Ward, please consult Kakeru Koumuten
Our company handles many exterior renovations, including solar panels, roofing work, and exterior wall work in Saiwai Ward, Kawasaki City.
We have received requests from many customers, including renovation companies and real estate agencies!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received great feedback from numerous customers.
We continue to update our construction achievements every year and 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 roof replacement but also partial roof repairs, exterior painting, and exterior cover installations.
We are also happy to handle small jobs like 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 optimal solutions for your specific requests.
We will never propose unnecessary work focused on profit!
We always stand in our customers’ shoes and will propose the best construction plan!
We are confident that we will not lose in terms of cost, quality, and planning compared to other companies in exterior construction!
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 Saiwai Ward, Kawasaki City and Points for Solar Construction
Saiwai Ward is located between Kawasaki Ward and Nakahara Ward, bordered by the Tama River to the east and the Tsurumi River to the west, adjacent to Tokyo and Yokohama. It is known as the smallest ward in terms of area among the seven wards in the city. Below are summarized the terrain and housing conditions of Saiwai Ward, along with points to consider when installing solar panels and storage batteries. (Tap to open)
View characteristics of Saiwai Ward and points for solar construction
■ The smallest ward in the city requires careful consideration of shadows from surrounding buildings and installation capacity
Saiwai Ward has an area of 10.09 km2 and is the smallest ward in Kawasaki City, with a population of 176,225 as of April 1, 2026, the least among the seven wards in the city.
In areas where houses are close together, the shadows from neighboring houses and the number of panels (installation capacity) that can be placed on the roof vary from house to house. At Kakeru Koumuten, we create layout diagrams based on blueprints and the actual site conditions, and you can check them with a power generation simulation.
■ The flat terrain surrounded by the Tama River, Tsurumi River, and Yagami River also requires checking the placement of storage batteries
The terrain of Saiwai Ward is relatively flat, surrounded by the Tamagawa, Tsurumi, and Yagami rivers. It is important to plan the installation of equipment such as storage batteries, distribution boards, and power conditioners by checking the surrounding environment of the installation site (whether it is prone to water accumulation, etc.). Please check the information about your area using hazard maps and consult with us regarding the installation location. If you want to use electricity during a power outage, please consider installing a storage battery.
■ Be cautious of slopes, tree shadows, scaffolding, and delivery routes around Kaseyama
In the southwestern part of the ward, Kaseyama, located at the southern end of the Tama Hills, offers a lush green landscape. In areas close to slopes and trees, such as around Kaseyama, it is necessary to be aware of the effects of shadows and the decrease in power generation due to fallen leaves and dirt. Additionally, if there is a height difference on the site, it may be necessary to devise plans for scaffolding and the delivery routes for equipment and materials. Kakeru Koumuten Co., Ltd. responds on-site with its own scaffolding team and scaffolding materials, and can also handle solar panel cleaning with specialized brushes and rain gutter cleaning.
■ Areas where houses are built on former factory sites. Check the type of roof for each house
In Saiwai Ward, it is reported that factory relocations are progressing, and large-scale housing developments are being constructed on the former sites. The type of roof and the age of the buildings vary depending on the period when the residential area was developed. Kakeru Koumuten Co., Ltd. will check the type and condition of the roof before installation and propose methods for securing and waterproofing.
■ Yokohama’s annual sunshine hours are about 2,018 hours
According to the Japan Meteorological Agency’s average values (1991-2020), Yokohama’s annual sunshine hours are about 2,018 hours. Monthly, August (about 206 hours) has the most, while June during the rainy season (about 136 hours) has the least.
Power generation varies by season, so conducting an annual power generation simulation and selecting the capacity of the storage battery to match the times of high electricity usage is key.
Our company is based in Kanagawa Prefecture and handles many exterior construction and solar projects in Saiwai Ward, Kawasaki City.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us for any urgent issues!
Service Area in Saiwai Ward, Kawasaki City
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and Tokyo.
List of Areas in Saiwai Ward, Kawasaki City
Endo-cho, Saiwai Ward / Omiya-cho, Saiwai Ward / Ogura, Saiwai Ward / Kashimada, Saiwai Ward / Kawahara-cho, Saiwai Ward / Kitakase, Saiwai Ward / Komukai, Saiwai Ward / Konyamachi, Saiwai Ward / Saiwai-cho, Saiwai Ward / Shimohirama, Saiwai Ward / Shinkogura, Saiwai Ward / Shinkawasaki, Saiwai Ward / Shinzukagoshi, Saiwai Ward / Shinmei-cho, Saiwai Ward / Tsukagoshi, Saiwai Ward / Todetohonmachi, Saiwai Ward / Tode, Saiwai Ward / Nakakawai-cho, Saiwai Ward / Higashikogura, Saiwai Ward / Higashokushichiba, Saiwai Ward / Furumachi, Saiwai Ward / Furukawacho, Saiwai Ward / Horikawacho, Saiwai Ward / Minamikase, Saiwai Ward / Minamisaiwai-cho, Saiwai Ward / Miyako-cho, Saiwai Ward / Yagami, Saiwai Ward / Yanagicho, Saiwai Ward
・Exterior wall painting in Saiwai Ward, Kawasaki City, is entrusted to Kakeru Koumuten Co., Ltd.!
・Roof renovation in Saiwai Ward, Kawasaki City, is entrusted to Kakeru Koumuten Co., Ltd.!
・Exterior renovation in Saiwai Ward, Kawasaki City, is entrusted to Kakeru Koumuten Co., Ltd.!
・Kakeru Koumuten Co., Ltd. construction achievements
・Kakeru Koumuten Co., Ltd. after maintenance
・Kakeru Koumuten Co., Ltd. construction menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of comparative estimates and key points!
・12 major manufacturers of solar power generation! Introducing features and selection points!
・What are the installation costs for solar power generation? Thorough explanation of tips to reduce costs!
・What are the suitable locations for installing solar power generation? Introducing key points for site selection!
・Here is the introduction to solar power generation estimates!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!
