Leave Your Solar Panel Installation Work in Yamato City, Kanagawa Prefecture to Kakeru Koumuten Co., Ltd.!
For
Solar Panel and Storage Battery Installation in Yamatocity 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 with solar panel installation and storage battery work considering roofs and waterproofing!
“How to Choose a Solar Panel Contractor in Yamatocity”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Yamatocity”
We will also explain the above three points!
Installing solar panels carries risks such as “the occurrence of leaks” and other troubles.
To ensure you have no regrets about your solar panel installation, we recommend obtaining estimates from about three companies!
Table of Contents (Tap to Open/Close)
- Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Yamato City
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Yamato City
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installer in Yamato City
- 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 Yamato City
- If You Are Looking for a Solar Panel Installer in Yamato City, Contact Kakeru Koumuten
- Characteristics of Yamato City and Points for Solar Construction
- Service Area in Yamato City
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Yamato City
Regarding why our company is entrusted with solar panel installation by customers in Yamato City,
“Our Unique Strengths in Solar Panel Installation That Cannot Be Imitated by Other Companies”
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 Also Handle Exterior Renovations Aside from Solar Panel Installation!
Issues 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 are cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have someone knowledgeable about roofs to avoid maintenance and trouble 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 issues 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 Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding based on construction conditions and can assemble scaffolding in-house.
By not outsourcing scaffolding work and using our own scaffolding team, we can also cut costs on scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
Even if there are height differences on the site, our in-house scaffolding team will plan the scaffolding according to the local conditions.
Storage of Materials in Our Large In-house 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, so we canrespond quickly in emergencies!
In-house sorting and transportation of waste materials
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!
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 explain the structure, allowing for detailed explanations!
3.All work performed by our own team
One of Kakeru Koumuten’s major strengths is its complete in-house construction.
By having Kakeru Koumuten handle everything from inquiries to project completion in a consistent manner, we can keep costs down and provide high-quality roof renovations.
Additionally, one representative will assist you from the estimate to the completion of the work.
Since the same person will handle sales and construction management, smooth communication is possible.
We can provide consistent in-house construction from temporary scaffolding installation to exterior wall painting and 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 workers and painting technicians, and we are confident in our construction techniques.
We can also handle large-scale roof work for factories and other buildings!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation work, we also provide our own construction warranty (leakage warranty)!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovations are performed. The construction warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary by warranty content.)
Aftercare is available every year, and we send out notification DM each year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
Even if you cannot access the roof at high altitudes, we can utilize drones to assist!
During leak investigations, we can also conduct surveys using a thermal imaging camera.
If the power generation of solar panels decreases due to dirt, we can provide cleaning using a specialized brush.
We will respond according to your wishes.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods change 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 panel installation guidebook” and “profit and loss simulations” that take into account loan interest rates and electricity costs.
Profit and loss simulations can be created for projected cumulative profits and losses over 20 to 30 years.
For customers who are not familiar with solar panel installations, we compile easy-to-understand materials that include points to note and potential drawbacks!
We encourage you to obtain comparative estimates and compare them with other companies’ plans!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 or 30 years.
Confirming “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, specializing in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing materials such as slate, tiles, metal roofs, and flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of the Substrate and Waterproof Sheet | If the sheathing or roofing (waterproof sheet) under the roofing material is damaged, it can affect the fastening strength and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, Slope, and Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, can affect the power generation. We will create a layout diagram from the drawings and the site, and you can check it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels (installation capacity) that can be placed depends on the shape and size of the roof. Since the number of panels that can be installed varies depending on the panel size, we will compare based on the overall output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will confirm whether the method involves drilling holes in the roofing material for fastening or using brackets to secure the roofing material. The fixing method varies by technique, so please check 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 added. After investigating the existing roof, substrate, and load-bearing capacity, switching to lighter roofing materials may also be an option if necessary. |
| 7. Location of Equipment Installation and Wiring | We will check the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect the cost. |
| 8. Ease of Scaffolding Setup and Delivery Routes | If there is a height difference on the site, planning for scaffolding and the delivery routes for equipment and materials may require some ingenuity. The width of the front road and any steps on the site will also be confirmed during the site survey. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets 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 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 secure to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lighter roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you carry out roof renovations 10 to 20 years after installation, there will be additional costs for the removal and reinstallation of solar panels. If the roof is deteriorating, 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 reinstallation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Yamato City
PossibleSubsidies and Grants in Yamato City, Kanagawa Prefecture
When introducing solar panels and storage batteries in Yamato City, there is a possibility of being eligible for the programs from “the national government,” “Kanagawa Prefecture,” and “Yamato City.”
The following information is based on the official pages of each program as of October 6, 2026. The acceptance 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 |
|---|---|---|---|
| Yamato City “Regional Decarbonization Transition & Renewable Energy Promotion Key Measures Acceleration Project Subsidy” (for self-consumption type without FIT/FIP certification) | Residents of homes in Yamato City. Must not obtain FIT/FIP certification and self-consume more than 30% of generated electricity. Storage batteries must be installed simultaneously with solar power. Application must be submitted at least two weeks before the scheduled start date, and construction can begin only after the grant decision (construction before grant decision is not eligible). Cannot be combined with other national subsidies, but can be combined with Kanagawa Prefecture subsidies. | Solar: 70,000 JPY per kW (or the lesser of installation costs) Storage battery (5-20 kWh): “1/3 of capacity kWh × 155,000 JPY” or 1/3 of installation costs, whichever is less. |
April 10, 2026 – January 29, 2027 (first-come, first-served) According to the city’s official page (updated August 19, 2026), the program may end during the period if the budget is reached, and they do not respond to inquiries about the number of applications submitted. |
| Yamato City “Subsidy for Installation Costs of Residential Solar Power Generation Systems” (when selling electricity with FIT certification) | Solar cell modules with a maximum output or power conditioner rated output of less than 10 kW, and must obtain FIT certification by the performance report. Storage batteries must be installed simultaneously with solar power (ZEH registered products). Pre-application must be submitted at least two weeks before construction, and a performance report must be submitted within 30 days after completion. Can be combined with prefectural and national subsidies. | Solar: 10,000 JPY per kW (up to 40,000 JPY) Storage battery: up to 30,000 JPY. |
April 1, 2026 – February 15, 2027 (first-come, first-served) According to the city’s official page (updated October 2, 2026), the program may end during the application period if the budget is reached, and as of October 1, 36 applications have been submitted. |
| Kanagawa Prefecture “FY 2026 Kanagawa Prefecture Residential Solar Power Generation & Storage Battery Installation Subsidy” | Must install both solar power generation and storage systems in residential homes (homes with seismic performance ensured) within the prefecture. Applications must be made by the individual, and construction can begin after the grant decision. | Solar: 70,000 JPY per kW Storage battery: 150,000 JPY per unit. |
Phase 1: May 11, 2026 – June 30, 2026 Phase 2: Starts September 7, 2026 (first-come, first-served) As of September 7, 2026, the application amount reached the budget limit, and applications are now closed. Please check the prefecture’s official page for future recruitment. |
| National “DR Home Storage Battery Project” (FY 2025 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 34,500 JPY per kWh (subsidy rate within 3/10; maximum 600,000 JPY per application). | As of May 29, 2026, the budget has been reached, and public recruitment has ended (the official site states there are no plans to reopen public recruitment, and applications cannot be submitted at this time). |
| National “Future Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but they must be combined with essential construction work such as insulation renovation of windows (openings) and the structure; applications cannot be made with just the installation of storage batteries. Solar panels are not included as eligible facilities | Storage Battery: 96,000 JPY/unit | Ends as soon as the budget limit is reached. As of October 5, 2026, the official site indicates that the application amount for renovations is 8% of the budget. Please check the official site for the current status. |
| Kanagawa Prefecture “Reiwa 8 Fiscal Year Kanagawa Prefecture Self-Consumption Type Renewable Energy Introduction Subsidy” | Corporations and individual business owners filing blue returns (individual residences are not eligible). Solar power must have a generation capacity of 10 kW or more, for business facilities, and equipment not certified under FIT/FIP. | Solar Power: 80,000 JPY/kW, etc. Storage System: 50,000 JPY/kWh (maximum 5 million JPY) |
Application period ended on September 3, 2026 (application amount reached the budget amount) |
For both subsidy programs in Yamato City, a preliminary application must be submitted at least two weeks before the scheduled start date, and the subsidy for the priority measures acceleration project is not applicable for construction started before the grant decision. The housing subsidies in Kanagawa Prefecture also require construction to begin after receiving the “grant decision”; starting work beforehand will disqualify the application. Additionally, the two city programs are on a first-come, first-served basis, and may end during the period once the budget is reached. Eligibility conditions, application procedures, and the possibility of combining programs vary by system, and applying does not guarantee a grant, so please confirm before contracting or starting work.
Kakeru Koumuten will provide guidance on eligibility conditions and application periods for each program after confirming them.
National Subsidy “DR Home Storage Battery Project (Support Project for Home Storage System Introduction 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 storage systems of registered products that can be utilized for demand response (DR). 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 1 kWh, with a subsidy rate of up to 30% and a maximum of 600,000 JPY per application. There are conditions such as that contracts or orders made before the grant decision are not eligible.
However, the fiscal year 2025 supplementary applications reached the budget on May 29, 2026, and the public offering has ended. The official site also states that there are no plans to reopen the public offering, and applications cannot be made at this time. Please check the official site for future public offerings.
Currently, there are no subsidies confirmed for the installation of solar panels for existing homes.
👉 Click here for the official site of the DR Home Storage Battery Project
Kanagawa Prefecture “Reiwa 8 Fiscal Year Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Introduction Subsidy”
In Kanagawa Prefecture, subsidies are provided for those who introduce both “solar panels” and “storage batteries” together in their homes.
The subsidy details are as follows: 70,000 yen per 1kW of solar power generation output, and 150,000 yen 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 yen + 150,000 yen = 430,000 yen.
The eligible homes must ensure seismic performance, and the storage system must be a registered product. Additionally, if construction begins before the subsidy decision is made, it will not be eligible, and the application must be made by the individual (applications by contractors on behalf of the individual are not allowed). The subsidies in Yamato City can be combined with both Kanagawa Prefecture’s subsidies, as stated on the city’s official page. Please check the official pages of each program before signing a contract.
For the fiscal year 2026, the first application period (May 11 – June 30) and the second application period (starting September 7, first-come-first-served) were held. The second period was 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 “Subsidy for Introducing Self-Consumption Type Renewable Energy for Fiscal Year 2026” (for businesses)
Kanagawa Prefecture also offers subsidies for businesses introducing “self-consumption type” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and the introduction to individual residences is not eligible.
Conditions include that the solar power generation must have an output of 10kW or more, supply electricity to business facilities within the prefecture, and not be a facility certified under FIT or FIP.
The subsidy amount is 80,000 yen per 1kW of solar power generation, and 50,000 yen per 1kWh of the storage system installed together (with a maximum of 5 million yen).
For fiscal year 2026, 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 Yamato City should check the official page of Kanagawa Prefecture for the next recruitment.
👉 Click here for details
Yamato City “Subsidy for Accelerating Regional Decarbonization Transition and Renewable Energy Promotion (Fiscal Year 2026)”
This subsidy is for residential solar power generation systems and storage batteries that do not obtain FIT or FIP certification, aimed at those who use the generated electricity at home (self-consumption).
●Solar Power Generation Equipment: 70,000 yen per kW (or the lesser of this amount and installation costs)
●Storage Battery (5–20 kWh): “Capacity kWh × 155,000 yen divided by 3” or one-third of the installation cost, whichever is less
The target is residents of homes in Yamato City, and the condition is that they must consume more than 30% of the generated power for self-use. Storage batteries are eligible only when installed simultaneously with solar power generation equipment. Applications must be submitted at least two weeks before the scheduled start date, and construction must begin after the grant decision; if construction starts before the grant decision, it will not be eligible for subsidies. The application period is April 10, 2026 – January 29, 2027.
Applications are accepted on a first-come, first-served basis, and may close during the period if the budget is reached. The city’s official page (updated August 19, 2026) states that they do not respond to inquiries about the number of applications submitted. It is noted that this subsidy cannot be combined with other national subsidies, but it can be combined with Kanagawa Prefecture subsidies.
👉 Click here for the official Yamato City page
Yamato City “Subsidy for Installation Costs of Residential Solar Power Generation Systems (Reiwa Year 8)”
This subsidy is for those who sell electricity (feed-in tariff) after receiving FIT certification.
●Solar Power Generation System: 10,000 yen per kW (maximum 40,000 yen)
●Lithium-ion Storage Battery: Maximum 30,000 yen (only for simultaneous applications with solar power)
For solar power, the maximum output of the solar cell module or the rated output of the power conditioner must be less than 10 kW, and FIT certification must be obtained by the time of performance reporting. Storage batteries are eligible only when installed simultaneously with the solar power generation system, and they must be registered ZEH products. Pre-application must be made at least two weeks before construction, and performance reporting must be completed within 30 days after the construction is finished. The application period is April 1, 2026 – February 15, 2027.
Applications are accepted on a first-come, first-served basis, and may close during the application period if the budget is reached. The city’s official page (updated October 2, 2026) states that as of October 1, there have been 36 applications submitted. It is noted that it is possible to combine this subsidy with prefectural and national subsidies.
👉 Click here for the official Yamato City page
Solar Panel Installation & Storage Battery Installation Price List
⇧Service Menu | For Costs of Solar Panel Removal and Hot Water Heater Dismantling, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and storage batteries should be confirmed by separating them into “Equipment Costs (Device Costs)” and “Construction Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.
Understanding Installation Capacity (kW) and Storage Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatt). Storage batteries are compared based on the amount of electricity they can store, measured in kWh (kilowatt-hour).
The amount of kW that can be placed on the roof varies for each house depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panels as approximately 800,000 JPY to 1,200,000 JPY for 3-5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6-10 kW. (These are just approximate amounts and may vary based on wiring length, scaffolding range, existing roofing materials, panel layout, etc.)
▶ Service Menu | For Costs of Solar Panel Installation and Storage Battery Installation, Click Here
Items to Check in the Estimate (Cost Confirmation)
When comparing estimates, it is common to compare different capacities and equipment by looking only at the amounts. Please check if the following items are clearly stated in the estimates from each company!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) are specified. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls in conjunction with a storage battery. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range of use during power outages (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Fittings | Name of fittings suitable for roofing materials and method of securing them (whether it is a method that drills holes or a method that grips and secures). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, presence of a monitor to check power generation. |
| 6. Roof Reinforcement and Waterproofing | Contents of waterproofing treatment for fixed parts, 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 counted twice. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters and old panels, as well as disposal costs for waste materials, are included. |
| 10. Tax Classification and Warranty | Whether it is tax-inclusive or tax-exclusive, conditions under which additional costs may arise, and details and duration of manufacturer warranty and workmanship warranty. |
If the capacity differs, both the price and power generation will change. Kakeru Koumuten Co., Ltd. warmly welcomes comparative 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 a rough estimate and a profit simulation up to 30 years later!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can get a rough estimate and profit simulation!
*The simulation results are approximate. Actual profits may vary based on assumptions such as electricity rates, self-consumption ratio, selling price of electricity, 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 Installation
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh range |
| Base Mounting Hardware Used |
| Niigata Manufactured / Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed using catch type hardware gripping the horizontal metal roof (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| 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 when solar panels are placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of the grant, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Yamato City
There are many solar panel installation contractors available in Yamato City, and you may be unsure which one to choose.
Therefore, when requesting solar panel installation and battery storage installation work, let’s confirm the following 4 points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the presence of warranties and after-sales 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.
Have knowledge not only about solar panels but also about roofs
Defective installation of solar panels can sometimes be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient verification of roofs and waterproofing
・Solar panels installed on a severely deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring renovations for removal and reinstallation within a few years
・Incorrect processing due to misjudgment of the type of waterproofing, 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 after-sales maintenance
When choosing a solar installation contractor, let’s confirm the presence of warranties. It is important to check not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
Solar panels and battery storage units come with manufacturer warranties, but also confirm whether there is a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may cover it under the warranty if it falls within the warranty period and conditions.
Additionally, some contractors provide after-sales services separate from the warranty, so make sure to check if the contractor you are considering has after-sales service.
Since abnormalities or damages on the roof may not be visible, you might not notice them yourself.
By conducting inspections of invisible areas during after-sales maintenance, you can more easily detect abnormalities early and prevent major repairs or failures!
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 lasts for 10 years, and depending on the condition of the roof before installation, we may not be able to provide the warranty without performing roof renovations.)
We also offer aftercare maintenance, and we send out annual DM!
After confirming the DM, we will visit for aftercare maintenance if you wish!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, let’s obtain estimates from multiple contractors.
Even for the same manufacturer and the same work content, costs may differ, and warranties and after-sales services may vary.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check:
“Confirmation of estimate items”
“Types of solar panels”
“Warranties and after-sales services”
and make a detailed comparison! Avoid judging solely based on cost, as using lower-grade materials or skipping processes can reduce costs!
▶ 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 there are deficiencies in the documents, the grant may not be awarded.
For systems like Kanagawa Prefecture’s housing subsidies, where contractors cannot apply on behalf of clients, it is reassuring to have a contractor who can support 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 grant approval) before proceeding with the construction!
For the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the grant will be awarded after review! (The flow of procedures varies by system)
▶ To “Subsidies and grants that may be applicable in Yamato City” 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, you can reduce the amount of electricity purchased from the utility company and gain benefits!
As electricity prices rise, the ability to cover your consumption with solar power becomes attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) will be set as “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year” for certifications after October 2025, and the same price will apply for the 2026 fiscal year. After the fifth year, it is often more advantageous to use it at home (self-consume) rather than sell it, making the combination with a storage battery a viable option.
👉 Ministry of Economy, Trade and Industry | For purchase prices and periods, click here
Advantage 2 Subsidies can be utilized!
Subsidy conditions and amounts vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
Reducing the actual burden through subsidies is a significant advantage!
In the case of Yamato City, there is a possibility of being eligible for programs from the national government, Kanagawa Prefecture, and Yamato City (please check the application status for each program).
Advantage 3 Environmentally friendly!
Solar power generation has low carbon dioxide emissions and can reduce dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices like power conditioners may have operational noise.)
Advantage 4 Heat insulation effects can be expected!!
By installing panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, this can help reduce the temperature of the roof, providing expected heat insulation effects!
(Note that this does not improve the insulation performance of the building itself.)
Benefit 5 Power 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.
(The devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1 Maintenance costs can be incurred
A particularly easy-to-overlook maintenance cost is for the roof where solar panels are installed.
If you perform roof renovations 10 to 20 years later, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorating, it is reassuring to renovate 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 simulations before introducing solar panels!
Point 2 The risk of leaks may increase depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that secure fixtures with screws to the roofing material or substrate, waterproofing of the fixed parts becomes crucial.
In methods that involve making holes in the roof, the risk of leaks inevitably arises.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and securing the solar panels using the catch method is also an option. (The catch method has compatibility conditions between the roofing material and fixtures, and it cannot be used with all metal roofs.)
Catch-type base fixture exclusively for horizontal metal roofs
Point 3 The Roof Becomes Heavier
Installing solar panels will make the roof heavier. After investigating the existing roof, substrate, and load capacity, replacing it with a lighter roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
How to Choose 1: Compare Based on Total Output of the Roof
When installing solar panels on the roof, it is important to consider how much electricity can be generated in a limited area, and the more electricity generated, the better!
Solar panels come in various sizes and outputs depending on the manufacturer.
A 350W output panel and a 400W output panel may seem that the higher output panel is better at first glance.
However, if the size of the panels does not fit well on the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different installation capacities 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 electricity generation (kWh) will vary depending on conditions such as roof orientation, slope, and shading.
How to Choose 2: Compare Based on Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases over 10 years and 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or electricity generation itself.
By not deciding solely based on initial output and considering the degradation rate, you can choose solar panels without regrets!
How to Choose 3: Compare 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 output warranties, some manufacturers offer a 30-year warranty while others offer a 10-year warranty, so it varies!
Longer warranties are better, so be sure to check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Yamato City
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Yamato City. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Yamato City?
The cost varies depending on the installation capacity, equipment, and the condition of the roof. In the above construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Estimates by capacity are published on the solar panel installation and storage battery installation pricing page. We will create a layout diagram from the drawings and site survey and provide a free estimate!
Are there any subsidies available for solar and storage battery installation in Yamato City?
As of October 6, 2026, there are two subsidy programs in Yamato City. The “Regional Decarbonization Transition and Renewable Energy Promotion Priority Measures Acceleration Project Subsidy” for self-consumption types that do not obtain FIT/FIP certification offers 70,000 yen per kW for solar power, while the “Subsidy for Installation Costs of Residential Solar Power Generation Systems” for those receiving FIT certification offers 10,000 yen per kW (up to 40,000 yen). Both are accepted on a first-come, first-served basis on the city’s official page, and may end during the period if the budget is reached. The Kanagawa Prefecture subsidy (70,000 yen/kW for solar power and 150,000 yen/unit for storage batteries) reached its budget on September 7 for the second phase of Reiwa 8 and has closed, while the national DR household storage battery project has ended its public recruitment.
Since the application status may change, please check the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies after the construction is completed?
No, you cannot. Both subsidy programs in Yamato City require prior application at least two weeks before construction starts, and the acceleration project subsidy requires construction to begin after the grant decision. The Kanagawa Prefecture residential subsidy also requires “construction to start after the grant decision,” and starting work 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 beforehand. The fixing method varies by construction method, and when fixing brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is essential.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation, and if deterioration is advanced, we can also suggest methods such as roof overlay (cover method) or replacement before installation.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed within 10 to 20 years after installation, the cost of removing and reinstalling the solar panels will be additional. If the remaining lifespan of the roof is short, renovating with durable roofing materials before installation may help reduce total costs.
Please consult us on how to proceed with the installation after checking the condition of the roof during the site survey!
Is it better to install a storage battery together with solar panels?
If you want to use generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it at home rather than selling it.
Additionally, the subsidy in Kanagawa Prefecture requires the simultaneous introduction of solar power and storage batteries, and the subsidies in Yamato City also apply only when the storage batteries are installed at the same time as the solar power generation system. You can compare “solar only” and “solar + storage battery” in the income and expenditure simulation for your consideration.
How many kW can be installed on our roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and on-site survey, and we will provide you with the installation capacity and power generation simulation.
Yamato City has almost no hilly terrain, but the shading from surrounding buildings and trees, as well as the installable capacity, varies from house to house. You can check the expected power generation through the power generation simulation.
How long is the construction period?
In the above construction example (solar panel 4.3kW + 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.
Please note that there will be a separate period for applying for subsidies and to the power company, so please consult us as soon as possible.
What is the current selling price (FIT)?
For residential use (under 10kW), from the certification after October 2025, the first 4 years will be 24 yen/kWh, and from the 5th to the 10th year it will be 8.3 yen/kWh, and the same price will apply for the 2026 fiscal year.
The idea is to recover initial costs quickly in the first four years and then focus on self-consumption. Kakeru Koumuten provides income and expenditure simulations that take 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 notices and visits customers who wish for inspections. We can also clean solar panels with a special brush if the power generation is reduced due to dirt.
Since the roof is a place that is difficult to check by yourself, please feel free to consult us if you have any concerns.
Can you also handle renovations of roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten can detach and reattach solar panels in-house, so we will consistently handle the process of removing the panels, performing the 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 hot water heater removal pricing page.
If you are looking for a solar panel installation company in Yamato City, please consult Kakeru Koumuten Co., Ltd.
Our company handles a wide range of exterior renovations in Yamato City, including solar panel installations, roof work, and exterior wall work.
We have received requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten Co., Ltd. promises “high-quality renovations at low cost”, and we have received great feedback from numerous customers.
We continue to update our construction performance records every year, and we will strive to improve quality to satisfy even more customers in the future.
Our company is capable of performing all exterior renovations, not only roof overlay work and re-roofing but also partial roof repairs, exterior painting, and exterior wall 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!
Whether you want to know about recommended solar panels, keep costs as low as possible, or just get an estimate, we will provide the best solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in our customers’ shoes and will propose the most suitable construction plans!
We are confident that we will not be outdone by other companies in terms of cost, quality, and organization for exterior work!
We welcome competitive estimates with confidence!
Estimates are completely free, and if you find our company to be inferior to others, you are free to decline!
Characteristics of Yamato City and Points for Solar Work
Yamato City is located almost in the center of Kanagawa Prefecture, within 40 km of the city center, and is a long, narrow city with an area of 27.09 square kilometers. It is situated on a plateau collectively referred to as the Sagamino Plateau, which is characterized by minimal hilly terrain. Below, we have summarized the characteristics of Yamato City’s terrain and points to consider when installing solar panels and storage batteries. (Tap to open)
View the characteristics of Yamato City and points for solar work
■ Even in a city with minimal hilly terrain, confirm the site and delivery route on-site
Yamato City is said to have a long and narrow area from north to south, with almost no hills. The highest elevation in the city is about 91m, and the lowest is about 28m. Even in a city with little elevation change, the planning of scaffolding and the routes for transporting equipment and materials such as panels and storage batteries will vary depending on the height differences of the site and the width of the front road. Kakeru Koumuten Co., Ltd. plans scaffolding to match the site even when there are height differences, using its own scaffolding team and owned scaffolding materials.
■ Check the placement of equipment near rivers flowing through valleys between plateaus using hazard maps
Between the Sagamino Plateau, there are narrow valleys, with the Sakai River flowing on the east side of the city and the Hijirigawa flowing on the west side. The suitable placement of equipment such as storage batteries and power conditioners changes depending on the surrounding environment of the installation site (such as whether it is prone to water accumulation). Please check the information about your area using hazard maps and consult us about the installation location.
■ Shadows and dirt from surrounding buildings and trees should be checked for each house
The amount of power generation can change due to the shadows cast by surrounding buildings and trees, and the accumulation of fallen leaves and dirt. Before installation, we will check the roof orientation, slope, and surrounding conditions on-site, and if the power generation decreases after installation, we can also provide cleaning of the solar panels with a dedicated brush and rain gutter cleaning.
■ The type of roof and age of the building vary for each house. Check the roof and waterproofing before installation
Even in areas with similar terrain, the type of roof, age of the building, and sunlight exposure vary for each house. At Kakeru Koumuten Co., Ltd., we will check the type and condition of the roof and the site conditions before installation, and propose methods for securing the roof, waterproofing details, and scaffolding planning.
■ The annual sunshine hours in the neighboring city of Yokohama is about 2,018 hours
According to the Japan Meteorological Agency’s average values (1991-2020), the annual sunshine hours in Yokohama City, adjacent to Yamato City, is 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 and location, so conducting an annual power generation simulation and selecting the capacity of the storage battery to match the times when electricity is used the most is key.
Our company is based in Kanagawa Prefecture and handles many exterior construction and solar projects in Yamato 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 sudden troubles!
Service Area in Yamato City
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and Tokyo Metropolis.
List of Areas in Yamato City
Yamato City Kamikusayanagi / Yamato City Kamiwada / Yamato City Sakuramori / Yamato City Shibuya / Yamato City Shimokusayanagi / Yamato City Shimotsuruma / Yamato City Shimowada / Yamato City Kusayanagi / Yamato City Daikan / Yamato City Chuo / Yamato City Chuo Rinkan / Yamato City Chuo Rinkan Nishi / Yamato City Tsukiminomori / Yamato City Tsuruma / Yamato City Nishitsuruma / Yamato City Fukami / Yamato City Fukami Dai / Yamato City Fukami Higashi / Yamato City Fukami Nishi / Yamato City Fukuda / Yamato City Minami Rinkan / Yamato City Yanagihashi / Yamato City Yamato Higashi / Yamato City Yamato Minami / Yamato City Rinkan
・Leave your exterior wall painting in Yamato City to Kakeru Koumuten!
・Leave your roof renovation in Yamato City to Kakeru Koumuten!
・Leave your exterior renovation in Yamato City to Kakeru Koumuten!
・Kakeru Koumuten Co., Ltd. Project Achievements
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・Kakeru Koumuten Co., Ltd. Construction Menu and Price List
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・Explaining the Importance of Comparing Estimates!
・Top 12 Solar Power Generation Manufacturers! Features and Selection Tips!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
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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!
