Leave the installation of solar panels in Shinagawa, Tokyo to Kakeru Koumuten Co., Ltd.!
For solar panel and battery installation in
Shinagawa, Tokyo,
Kakeru Koumuten is your trusted choice!
Kakeru Koumuten specializes in exterior renovations.
As a company strong in roofing work, we are entrusted withsolar panel and battery installation considering roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Shinagawa, Tokyo”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Shinagawa, Tokyo”
We will also explain the above three points!
Installing solar panels carries risks such as“the occurrence of leaks” and other troubles.
To avoid regrets, we recommend obtainingthree estimates!
Table of Contents (tap to open/close)
- Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Shinagawa, Tokyo
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Shinagawa, Tokyo
- 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 Shinagawa, Tokyo
- 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 Shinagawa, Tokyo
- If You’re Looking for a Solar Panel Installation Company in Shinagawa, Tokyo, Contact Kakeru Koumuten
- Characteristics of Shinagawa, Tokyo and Key Points for Solar Installation
- Service Area in Shinagawa, Tokyo
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Shinagawa, Tokyo
Regarding the reasons our company is entrusted with solar panel installation by customers in Shinagawa, Tokyo,
“Our Unique Strengths in Solar Panel Installation That Cannot Be Replicated by Other Companies”
have received high praise from many customers.
We would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We Can Also Handle Exterior Renovations Other Than Solar Panel Installation!
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 are 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 issues and troubles after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent troubles after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide low-cost, high-quality solar and exterior renovation work.
We have established five bases for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the necessary scaffolding materials for temporary scaffolding based on construction conditions and can assemble scaffolding in-house.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also cut costs for scaffolding work.
We own 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 attached to the roofing materials!
You can also simulate the potential earnings and costs of introducing solar panels!
Since roofing and exterior wall work are often involved, we also provide samples of roofing materials and models that explain the structure, allowing for detailed explanations!
3.All work performed by our own team
One of Kakeru Koumuten’s major strengths is complete in-house construction.
By having Kakeru Koumuten manage everything from inquiries to project completion in a consistent manner, we can keep costs down while providing high-quality roof renovations.
Additionally, one representative will handle everything from the estimate to project completion.
Since the person in charge does not change, whether it’s the sales representative or the construction manager, smooth communication is possible.
We can perform 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 and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal and painting technicians on staff, and we are confident in our construction techniques.
We can also handle large-scale roof projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation 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 renovation is performed. The construction warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary depending on the warranty details.)
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 inspections using a thermal imaging camera.
If the power generation of solar panels decreases due to dirt or other factors, we can provide cleaning services using specialized brushes.
We will respond according to your preferences.
7. Human Resource Development
To improve skills, we create various roofing 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 “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 construction, we compile easy-to-understand materials that include points to consider 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 Age | The fixing method varies depending on the roofing material, 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 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 water leakage. |
| 3. Roof Orientation, Slope, and Shadows | The orientation and slope of the roof, as well as shadows from neighboring houses, trees, and utility poles, can affect power generation. We will create a layout diagram from the drawings and the site, and you can confirm it with a power generation simulation. |
| 4. Roof Shape and Usable Area | The number of panels that can be installed (installation capacity) is determined by 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 installed. 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 also affects the cost. |
| 8. Ease of Scaffolding Setup and Delivery Routes | If there are elevation differences 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 checked during the site survey. |
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 to the roof material and substrate with screws) | Waterproofing treatment of fixing parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suited to the type of tile (even methods that do not drill holes in the tiles will still fix to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lighter roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you perform roof renovations 10 to 20 years after installation, additional costs for removing and reinstalling solar panels will apply. If the roof is deteriorating, it may be more cost-effective in the long run to renovate to a highly durable roofing material before installation.
Kakeru Koumuten Co., Ltd. specializes in roofing work and can also handle the removal and reinstallation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Shinagawa, Tokyo
Potential Subsidies and Grants in Shinagawa, Tokyo
If you are introducing solar panels or storage batteries in Shinagawa, Tokyo, there is a possibility that the systems from the “National Government,” “Tokyo Metropolitan Government,” and your local “Shinagawa Ward” may apply.
The following information is based on the official pages of each system as of October 7, 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 |
|---|---|---|---|
| Tokyo “Home Solar Power Generation Promotion Project” | Individuals, corporations, or management associations who install a new unused solar power system (output under 50kW, JET certification, etc.) in residential properties within Tokyo. The generated power must be used in the residential part. Pre-application is required | Existing homes: 15,000 JPY per kW for 3.75kW or less (maximum 450,000 JPY), 12,000 JPY/kW for over 3.75kW to under 50kW New homes: 12,000 JPY/kW for 3.6kW or less (maximum 360,000 JPY), 10,000 JPY/kW for over 3.6kW |
For the fiscal year 2026, pre-applications are being accepted from May 29 (will end once the budget is reached). From the pre-application for fiscal year 2026, submission of a certificate issued by a financial institution during the performance report is mandatory |
| Tokyo “Home Battery Installation Promotion Project” | Owners of eligible equipment (batteries registered with SII, excluding national and local governments). Installation must be completed between April 1, 2026, and March 30, 2031. If pre-applying after October 1, 2026, only products registered with the national SII for fiscal year 2026 are eligible | Battery package: 100,000 JPY per kWh (maximum 1,200,000 JPY per household) Additional for participating in DR demonstration (100,000 JPY per unit; 150,000 JPY per unit if energy management equipment is installed) Expansion of battery units: 60,000 JPY/kWh (maximum 720,000 JPY per household) |
For the fiscal year 2026, pre-applications are being accepted from May 29. Grant applications and performance reports will be accepted from June 30 |
| Shinagawa Ward “Shinagawa Zero Carbon Action Subsidy (Solar Power Generation System & Battery System)” | Residents, small business owners, etc. (installations at business locations under 150 square meters) are category A, while management associations, etc., and small business owners (installations at business locations over 150 square meters) are category B. Equipment installed between April 1, 2026, and March 15, 2027, is eligible, and applications must be made after installation completion | Solar power generation: 50,000 JPY per kW (maximum for A 200,000 JPY, for B 500,000 JPY) Battery: 30,000 JPY per kWh of storage capacity (maximum for both A and B 300,000 JPY) |
Application period is from May 25, 2026, to March 15, 2027. Applications for residents (A) have exceeded the planned number (100 cases) and are currently suspended (may resume if there are remaining budget funds). Applications for management associations, etc. (B) have a planned number of 10 cases, and the status is listed as “ample” (updated October 2, 2026) |
| National “DR Home Battery Project” (Fiscal Year 2025 Supplement) | Newly introducing home battery 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) | The budget was reached on May 29, 2026, and the public offering has ended (there are no plans to reopen the public offering as stated on the official website, and applications cannot be made at this time) |
| National “Mirai Eco Housing 2026 Project” (Renovation) | The storage battery is one of the eligible facilities, but it must be combined with essential construction work such as insulation renovation of windows (openings) and the structure; simply installing a storage battery is not sufficient for application. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 JPY/unit | Applications will close once 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 of applications. |
The Tokyo solar and storage battery subsidy program requires prior application. For storage batteries applied for after October 1, 2026, only products registered with the national SII will be eligible, and the equipment requirements will change. The subsidy in Shinagawa Ward is a system where applications are made after installation is completed, and the quota for residents in the fiscal year 2026 has exceeded the planned number, and applications are currently suspended. The eligibility conditions, application procedures, and compatibility with other programs vary by system, and applying does not guarantee that a subsidy will be granted, so please confirm before contracting or starting construction.
Kakeru Koumuten Co., Ltd. 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 Systems for DR Resource Introduction)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those who are newly introducing registered storage systems that can be utilized for demand response (DR), and 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 1 kWh, with a subsidy rate of up to 30% and a maximum of 600,000 JPY per application. There are also conditions such as that contracts or orders made before the grant decision are not eligible.
However, the fiscal year 2025 supplementary budget application amount reached the budget on May 29, 2026, and the public recruitment has ended. The official site also states that there are no plans to reopen public recruitment, and applications are currently not possible. Please check the official site for future public recruitment.
Additionally, there are currently no subsidies confirmed for the installation of solar panels on existing homes.
👉 Click here for the official site of the DR Home Storage Battery Project
Tokyo “Promotion Project for the Introduction of Solar Power Generation in Homes”
This subsidy is for those who are newly installing unused solar power generation systems in residential homes in Tokyo. The simultaneous installation of storage batteries is not a condition.
●Existing Homes: For systems below 3.75 kW, 150,000 JPY per kW (maximum 450,000 JPY); for systems over 3.75 kW and below 50 kW, 120,000 JPY per kW.
●New Homes: For systems below 3.6 kW, 120,000 JPY per kW (maximum 360,000 JPY); for systems over 3.6 kW and below 50 kW, 100,000 JPY per kW.
●There are also additions for the installation of rooftop structures and waterproofing work.
The target is for unused panels that have obtained JET certification or equivalent and are installed in residential homes in Tokyo with an output of less than 50 kW, used in the living area. The process involves making a prior application and then applying for the grant after installation; starting from the fiscal year 2026, submission of certificates issued by financial institutions during the performance report has become mandatory.
According to the official page of Tokyo, pre-registration is being accepted from May 29, Reiwa 8. It will end once the budget is reached, so please check the official page for the registration status.
👉 Here is the official page of Tokyo (Cool Net Tokyo)
Tokyo’s “Household Battery Installation Promotion Project”
This is a subsidy for the installation costs of battery systems aimed at increasing self-consumption of electricity generated by solar power and improving energy independence during emergencies.
●Battery package: 100,000 JPY per kWh (up to 1,200,000 JPY per household)
●Additional for participating in DR demonstration: 100,000 JPY per unit (150,000 JPY per unit if energy management equipment is installed)
●Expansion of battery units: 60,000 JPY per kWh (up to 720,000 JPY per household)
Eligible applicants are owners of the subsidized equipment (excluding national and local governments), and installation must be completed between April 1, Reiwa 8 and March 30, Reiwa 11. If pre-registration is done after October 1, Reiwa 8, only products registered in the national SII for Reiwa 8 will be eligible.
The official page of Tokyo states that pre-registration is being accepted from May 29, Reiwa 8. For detailed information, including conditions for combination with solar power generation, please check the official page.
👉 Here is the official page of Tokyo (Cool Net Tokyo)
Shinagawa Ward “Shinagawa Zero Carbon Action Subsidy (Solar Power Generation System and Battery System)”
This is a subsidy for those who have installed solar power generation systems or battery systems within the ward. Applications are to be made after the installation of the equipment is completed, not before the construction. The eligible applicants are divided into “A” for residents and small business owners (installations in business premises under 150 square meters) and “B” for management associations and small business owners (installations in business premises over 150 square meters).
●Solar power generation: 50,000 JPY per kW output (maximum A 200,000 JPY, B 500,000 JPY)
●Battery: 30,000 JPY per kWh of storage capacity (maximum 300,000 JPY for both A and B)
Eligible equipment must be installed between April 1, Reiwa 8 and March 15, Reiwa 9, and the eligible expenses for the subsidy are defined as “costs for the equipment itself, accessories, and installation.” The application period is from May 25, Reiwa 8 to March 15, Reiwa 9.
However, according to the official page of Shinagawa Ward (updated on October 2, Reiwa 8), the solar power generation and storage battery for residents (A) has reached the status of “exceeding planned number” (planned number 100 cases), and currently, applications are suspended. Applications received by 5:15 PM on the day the planned number is reached will be considered as arriving at the same time and will be subject to a lottery, and if there is a remaining budget, applications may be reopened (notification will be made in the ward newsletter and on the website when reopened). For management associations, etc. (B), the planned number is 10 cases and is listed as “ample availability.” Please check the official page for the latest application status.
👉 Click here for the official Shinagawa Ward page
Solar Panel Installation & Storage Battery Installation Price List
⇧Service Menu | Click here for costs related to solar panel removal & water heater removal
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and storage batteries should be confirmed by separating “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 “the output of one panel (W) × number of panels”, with the unit being kW (kilowatts). The battery is compared in terms of the amount of electricity it can store, expressed in kWh (kilowatt-hours).
The amount of kW that can be placed on the roof varies for each house depending on the shape, orientation, and size of the roof. At Kakeru Koumuten Co., Ltd., we create 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 area, existing roofing materials, panel layout, etc.)
▶ Installation Menu | Costs for Solar Panel Installation and Battery Installation
Items to Check in the Estimate (Cost Confirmation)
When comparing estimates, it is common to compare different capacities and equipment just by 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 of one panel (W), number of panels, total installation capacity (kW) are written. |
| 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 is a method that drills holes or a method that clamps and secures). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, presence of a monitor to check power generation. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at fixed points, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | How much support is included for applications to the power company, certification applications for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If roofing work and exterior painting are done simultaneously, check that the same scope and quantity are not double counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters or old panels and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether the price is tax-inclusive or tax-exclusive, conditions under which additional costs may arise, and details and duration of manufacturer and workmanship warranties. |
If the capacities are different, the amounts and power generation will also vary. Kakeru Koumuten Co., Ltd. welcome comparisons of estimates, so if you bring estimates from other companies, we will explain the differences by item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can get an estimated quote and a financial simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can obtain an estimated quote and financial simulation!
*The simulation results are estimates. Actual financial results may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection and replacement.
Customer Feedback
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installations
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh class |
| Base Mounting Hardware Used |
| Niigata 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 |
| 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 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 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 Shinagawa, Tokyo
There are many solar panel installation contractors available in Shinagawa, Tokyo, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and battery storage installation work, let’s check the following 4 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 (3 companies as a guideline)
● Check if they provide support for subsidy applications
By confirming the above 4 points, you will be able to choose a reliable contractor.
Knowledge about roofs as well as solar panels
Improper installation of solar panels can sometimes be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles due to insufficient verification of roofs and waterproofing
・Solar panels installed on a severely deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring removal and reinstallation within a few years
・Misjudging the type of waterproofing and performing incorrect treatment, leading to leaks
and more
By understanding the condition and type of the existing roof before installing solar panels, unnecessary expenses and unexpected troubles can be avoided.
▶ 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, let’s confirm the presence of warranties. It is important to check not only the duration of the warranty but also the scope, exclusions, and cost conditions.
While the solar panels and battery storage come with a manufacturer’s warranty, it is also important to check for the presence of a workmanship warranty in case leaks occur after installation!
For contractors that provide 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 offer aftercare services separate from warranties, so be sure to check if the contractor you are considering has aftercare services.
Since abnormalities or damage on the roof can be in areas that are not visible, you may not notice them yourself.
By conducting inspections of these hidden areas during aftercare maintenance, early detection of abnormalities can help 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 without performing roof renovations.)
We also conduct aftercare maintenance, and we send out annual direct mail!
After checking the direct mail, if you wish, we will visit you 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 construction content, costs may vary, and warranties and after-services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check:
“Confirmation of estimate items”
“Types of solar panels”
“Warranties and after-services”
and make a detailed comparison! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making decisions based solely on price!
▶ To “Breakdown of installation capacity, equipment, and construction costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for 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.
Since there are systems that require prior application, such as the Tokyo Metropolitan subsidy, it is reassuring to have a contractor who can support you in preparing necessary documents and understanding the procedure flow.
Complete the procedures specified for each system (for the Tokyo Metropolitan subsidy, prior application is required) before proceeding with the construction!
For the Tokyo Metropolitan subsidy, after installation, you will need to submit a grant application and performance report, which will be reviewed before the grant is awarded! (The procedure flow varies by system.)
▶ To “Subsidies and grants that may be applicable in Shinagawa Ward, Tokyo” in this article
Benefits of Introducing Solar Equipment
The benefits of installing solar panels are as follows!
Benefit 1: Economic Benefits
The biggest advantage of introducing solar panels is the economic benefit!
The selling price for 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 costs rise, the ability to cover your consumption with solar power becomes appealing!
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 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 2026 fiscal year. After the fifth year, it is often more advantageous to use the electricity at home (self-consumption) rather than selling it, making the combination with a storage battery an option.
👉 Ministry of the Environment and Energy | 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 criteria, you may be able to utilize subsidies!
Reducing the actual burden through subsidies is a significant advantage!
In Shinagawa Ward, you may be eligible for programs from the national government, Tokyo, and Shinagawa Ward. Currently, applications for the 2026 fiscal year for residents of Shinagawa Ward are suspended (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 do 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 a heat insulation effect!
(Note that 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 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 reinstalling the solar panels.
If the existing roof is deteriorating, it is reassuring to renovate it with durable roofing materials before installing solar panels!
Additionally, 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 request a simulation considering maintenance costs before introducing solar panels!
Point 2 The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix brackets to the roofing material or substrate with screws, waterproofing of the fixed parts is crucial.
In methods that involve making holes in the roof, the risk of leaks inevitably arises.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and fixing the solar panels using the catch method is also an option. (The catch method has compatibility conditions between the roofing material and brackets, and it cannot be used with all metal roofs.)
Catch-type base brackets specifically 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 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!
How to Choose 1: Compare by Total Roof Output
When installing solar panels on the roof, it is important to know how much electricity can be generated in a limited area, and generating more electricity is always better!
The size and output of solar panels vary by manufacturer.
A 350W output panel and a 400W output panel may seem like the higher output panel is better at first glance.
However, if the size of the panel does not fit well with the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” 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 calculations are for 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 by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases over 10 years and 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or electricity generation itself.
By considering the degradation rate as well as the initial output, you can choose solar panels without regrets!
How to Choose 3: Compare by Warranty Period
Solar panel warranties include “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
For output warranties, some manufacturers offer a 30-year warranty while others may only provide 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 Shinagawa, Tokyo
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Shinagawa, Tokyo. (Tap to open answers)
How much does it cost to install solar panels and storage batteries in Shinagawa, Tokyo?
The cost varies depending on the installation capacity, equipment, and condition of the roof. In the above construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines by capacity are published on our solar panel and storage battery installation pricing page. We will create a layout diagram from the drawings and site survey and provide a free estimate!
Are there any subsidies available for solar and storage battery installation in Shinagawa, Tokyo?
As of October 7, 2026, Tokyo’s “Promotion Project for Solar Power Generation in Households” (for existing homes, 15,000 yen per kW for systems under 3.75kW, with a maximum of 450,000 yen) and “Promotion Project for Storage Battery Installation in Households” (100,000 yen per kWh for storage batteries, with a maximum of 1.2 million yen per household) are accepting pre-applications starting May 29, 2026, as listed on the official Tokyo (Cool Net Tokyo) page. In Shinagawa, there is the Shinagawa Zero Carbon Action Grant (for solar power generation, 50,000 yen per kW with a maximum of 200,000 yen for residents, and for storage batteries, 30,000 yen per kWh with a maximum of 300,000 yen), but the quota for residents in the 2026 fiscal year has exceeded the planned number, and applications are currently suspended, as stated on the official Shinagawa page. The national DR household storage battery project has ended its public recruitment.
Since the application status may change, please refer to the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies after the construction is completed?
It varies by program. Tokyo’s subsidies require pre-application, while Shinagawa’s grants allow applications after installation is completed. Conditions such as whether you can contract and start construction before applying differ by program, so please check before signing a contract.
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 requires checking the condition of the roofing material and substrate. The method of securing varies by construction method, and when securing 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 suggest methods such as roof overlay or replacement if deterioration is progressing.
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 10 to 20 years after installation, there will be additional costs for dismantling the solar panels. 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!
Should I install the storage battery together with the 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 Tokyo Metropolitan Government’s subsidy for storage batteries (for the 2026 fiscal year, 100,000 yen per kWh, with a maximum of 1,200,000 yen per household) aims to increase self-consumption of electricity generated by solar power. In Shinagawa Ward, storage battery systems are also included in the subsidy program (the application for the 2026 fiscal year for residents of the ward is currently closed). You can compare “solar power only” and “solar power + 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 based on the blueprints and on-site survey, and we will provide you with the installation capacity and generation simulation.
Shinagawa Ward is a region where the land formation differs between plateaus, lowlands, and coastal areas, and the shape and orientation of the roof, as well as the shadow cast by surrounding buildings, vary from house to house. You can check the expected generation amount through the generation simulation.
How long will the construction period be?
In the above construction example (solar panels 4.3 kW + storage battery), it took about 3 days. The duration may vary if roof work is performed simultaneously or depending on the roof shape and installation capacity.
Please note that there will be an additional 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 (less than 10 kW), the selling price from certifications after October 2025 will be 24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year, and the same price will apply for the 2026 fiscal year.
The idea is to recover initial costs quickly in the first 4 years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that takes into account loan interest rates and electricity costs.
Can you provide maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-maintenance notices via DM and visits customers who wish for inspections. We can also clean solar panels using a special brush if the generation amount decreases due to dirt.
It is difficult to check areas on the roof by yourself, so 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 detach and reattach solar panels in-house, allowing us to remove the panels, perform roof overlay (cover method) or re-roofing, and then reinstall them consistently. The removed panels can be stored in our 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 Shinagawa, Tokyo, please consult Kakeru Koumuten Co., Ltd.
Our company handles a variety of exterior renovations, including solar panels, roof work, and exterior wall work in Shinagawa, Tokyo.
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 positive 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 can perform all exterior renovations, not only roof overlay work and re-roofing but also partial roof repairs, exterior painting, and exterior cover methods.
We are also happy to handle small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leak repairs, we may be able to provide emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult with us!
“I want to know recommended solar panels”, “I want to keep costs as low as possible”, “I just want an estimate for now”, we will provide optimal solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in the customer’s position and will propose the best construction plan!
We are confident that we will not lose in terms of cost, quality, and organization compared to other companies in exterior work!
We are confident, so we welcome competitive quotes!
Estimates are completely free, and if our company is inferior to others, you are free to decline!
Characteristics of Shinagawa, Tokyo and Points for Solar Work
The area of Shinagawa Ward is 22.84 square kilometers. The terrain consists of part of the Musashino Plateau’s southeastern area, lowlands, and reclaimed land located to the east, with a coastal area facing Tokyo Bay. We have summarized the characteristics of the terrain in Shinagawa, Tokyo, and points to be careful of when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Shinagawa, Tokyo and points for solar work
■ A mix of plateaus, lowlands, and reclaimed land. Check scaffolding, delivery, and shadows for each site
According to district materials, low-lying areas are said to spread around Gotanda and Osaki along the Meguro River, and near the coast in Shinagawa and Oi. Land use is said to be approximately 57% residential land, and in plots where the distance to neighboring houses is close, the shadow cast by neighboring houses, the space for scaffolding, and the equipment delivery routes differ for each house. At Kakeru Koumuten, our own scaffolding team plans the scaffolding according to the site, creates layout drawings from blueprints and site surveys, and you can confirm this through a power generation simulation.
■ Check the flood and storm surge hazard maps. Pay attention to the installation location of equipment.
Shinagawa Ward has created hazard maps for floods (Shinagawa Ward Flood Hazard Map, Shinagawa Ward Tamagawa Flood Hazard Map) and storm surges (Storm Surge Flood Hazard Map). Depending on where the power conditioner and storage battery are installed, separate from the panels on the roof, the impact during flooding may vary. Please check the flooding assumptions for your residence on the ward’s hazard map and consult with us regarding the installation location and height, in accordance with the installation conditions of the manufacturer you are using.
■ Roof types and ages vary from house to house. Check the roof and waterproofing before installation.
Even within the same ward, the types of roofs, their ages, and the shapes of the plots vary from house to house. At Kakeru Koumuten, we will check the type and condition of the roof and the situation of the plot before installation, and propose the fixing methods, waterproofing details, and scaffolding plans.
■ The annual sunshine hours at the Tokyo Observatory are about 1,927 hours.
According to the Japan Meteorological Agency’s average values (1991-2020), the annual sunshine hours at the Tokyo Observatory are about 1,927 hours, with January (about 193 hours) being the most sunny and June during the rainy season (about 124 hours) being the least sunny. (This is a reference value, not based on observations within Shinagawa Ward.)
The power generation amount in Shinagawa Ward can also be affected by the shadows of surrounding buildings, so conducting an annual power generation simulation and selecting the capacity of the storage battery according to the times of high electricity usage are key points.
Our company handles many exterior construction and solar projects in Shinagawa Ward, Tokyo.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us about any sudden troubles!
Service Area in Shinagawa Ward, Tokyo
Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Shinagawa Ward, Tokyo
Shinagawa Ward Ebara/Shinagawa Ward Oi/Shinagawa Ward Osaki/Shinagawa Ward Katsushima/Shinagawa Ward Kamiosaki/Shinagawa Ward Kitashinagawa/Shinagawa Ward Koyama/Shinagawa Ward Koyamadai/Shinagawa Ward Togoshi/Shinagawa Ward Nakanobu/Shinagawa Ward Nishi-Oi/Shinagawa Ward Nishi-Gotanda/Shinagawa Ward Nishi-Shinagawa/Shinagawa Ward Nishi-Nakanobu/Shinagawa Ward Hatanodai/Shinagawa Ward Higashi-Oi/Shinagawa Ward Higashi-Gotanda/Shinagawa Ward Higashi-Shinagawa/Shinagawa Ward Higashi-Nakanobu/Shinagawa Ward Hiratsuka/Shinagawa Ward Hirocho/Shinagawa Ward Futaba/Shinagawa Ward Minami-Oi/Shinagawa Ward Minami-Shinagawa/Shinagawa Ward Yashio/Shinagawa Ward Toyocho
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・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of comparative estimates and key points!
・Top 12 solar power generation manufacturers! Features and selection tips included!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
・What are the best locations for solar power installation? Key points for site selection included!
・Check here for solar power generation estimates!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!
