Leave Your Solar Panel Installation Work in Edogawa, Tokyo to Kakeru Koumuten Co., Ltd.!
For solar panel and battery installation in
Edogawa, 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 Edogawa, Tokyo”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Edogawa, Tokyo”
We will also explain these 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 Why Kakeru Koumuten is Chosen for Solar Panel Installation in Edogawa, Tokyo
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Edogawa, Tokyo
- Pricing Table for Solar Panel and 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 Edogawa, Tokyo
- Benefits of Introducing Solar Equipment
- Points to Note When Introducing Solar Power Generation
- How to Choose Solar Panels
- Frequently Asked Questions About Solar and Battery Installation in Edogawa, Tokyo
- If You Are Looking for a Solar Panel Installer in Edogawa, Tokyo, Contact Kakeru Koumuten
- Characteristics of Edogawa, Tokyo and Key Points for Solar Installation
- Service Area in Edogawa, Tokyo
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Edogawa, Tokyo
Regarding why we are entrusted with solar panel installation by customers in Edogawa, Tokyo,
“Our Unique Strengths in Solar Panel Installation That Cannot Be Replicated 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 as many companies as possible!
1. We Can Also Handle Exterior Renovations Besides 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 someone knowledgeable about the roof 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 work and exterior renovations.
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, allowing us to assemble scaffolding ourselves.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also reduce scaffolding construction costs.
We have scaffolding materials for approximately 50 single-family homes!
Even if there are height differences on the site, our scaffolding team will plan the scaffolding according to the local conditions.
Storage of materials in our large warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, we canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we can providerapid response in emergencies!
Sorting and transportation of waste materials in-house
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly reduce waste disposal costs.
Exterior renovation dedicated showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on the roofing materials!
It is also possible to simulate the revenue and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also provide samples of roofing materials and models that explain the structure in detail!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is all work performed by our own team.
By maintaining a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof remodeling at reduced costs.
Additionally, one representative will handle everything from the estimate to project completion.
Since the same person will be in charge, whether for sales or construction management, smooth communication is ensured.
We can perform consistent in-house work from temporary scaffolding installation to exterior wall painting and roof remodeling!
4. Various Permits and Skilled Workers
We have obtained construction industry permits and 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 skills.
We can also handle large-scale roofing projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty, our solar panel installation work comes with our own workmanship warranty (leakage warranty)!
(The workmanship warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovation is performed. The workmanship warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty details.)
Aftercare maintenance is available annually, and we send out notification DM each year.
If you have any questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roof troubles and situations.
If you cannot access the roof at high altitudes, we can respond using a drone!
During leakage investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of the solar panels decreases due to dirt, we can also perform cleaning with a specialized brush.
We will respond according to the customer’s wishes.
7. Human Resource Development
We create various roof models for skill enhancement and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training so that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
At Kakeru Koumuten Co., Ltd., in addition to “estimates”, “layout diagrams”, and “power generation simulations”, we also provide a “solar installation guidebook” and a “financial simulation” that takes into account loan interest rates and electricity costs.
The financial simulation can project cumulative income and expenses over 20 to 30 years.
Even customers who are not familiar with solar installations will find our materials easy to understand, including important points and disadvantages!
We encourage you to obtain comparative estimates and review plans from other companies!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 to 30 years.
Confirming “whether it is okay to install them directly on the current roof” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten Co., Ltd., which specializes in roofing work, has summarized the items to check before installation.
| 1. Type of roofing material and age | The method of securing the panels varies depending on the roofing material, such as slate, tiles, metal roofs, or flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of the substrate and waterproof sheet | If the sheathing or roofing (waterproof sheet) beneath the roofing material is damaged, it can affect the fastening strength and waterproofing. We also check for signs of leaks. |
| 3. Orientation, slope, and shadows of the roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, can affect power generation. We create a layout diagram from the drawings and the site, and you can verify it with a power generation simulation. |
| 4. Shape of the roof and installable area | The shape and size of the roof determine the number of panels (installation capacity) that can be placed. The number of panels that can be installed varies depending on their size, so we compare based on the total output of the roof. |
| 5. Method of securing and waterproofing details | We check whether the panels will be secured by drilling holes in the roofing material or by using brackets to grip the roofing material. The method of securing varies by technique, so please confirm the waterproofing treatment of the fastening parts during the estimate. |
| 6. Weight of the roof | The roof will become heavier due to the panels. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may be an option if necessary. |
| 7. Location of equipment installation and wiring | We confirm the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring also affects costs. |
| 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. We also check the width of the front road and any steps on the site during the on-site survey. |
Fixing Methods and Confirmation Points by Roofing Material
| Roofing Material | Main Fixing Method | Pre-Installation Confirmation Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to roofing material and substrate with screws) | Waterproofing treatment of fixed parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suitable for the type of tile (even methods that do not drill holes in the tiles will fix to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lighter roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roofing material (depends on the combination of roofing material and brackets) | Whether the roofing material and brackets are compatible, installation conditions from the roofing material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a framework | Type and deterioration status of the waterproof layer, waterproofing around the framework. Consider in conjunction with the timing of waterproofing work. |
If you plan to renovate the roof 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 high-durability roofing materials before installation may help reduce costs in the long run.
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 Edogawa, Tokyo
Subsidies and Grants That May Be Applicable in Edogawa, Tokyo
If you are introducing solar panels or storage batteries in Edogawa, Tokyo, there is a possibility that the systems from the “National Government,” “Tokyo Metropolitan Government,” and your local “Edogawa Ward” may apply.
The following information is based on the official pages of each system as of October 6, 2026. The application status may change depending on the budget, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| Program | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Tokyo “Home Solar Power Generation Promotion Project” | Individuals, corporations, or management associations installing a new unused solar power system (output less than 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 per kW for over 3.75kW to less than 50kW. New homes: 12,000 JPY per kW for 3.6kW or less (maximum 360,000 JPY), 10,000 JPY per 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 certificates issued by financial institutions during the performance report is mandatory. |
| Tokyo “Home Battery Installation Promotion Project” | Owners of eligible devices (batteries registered with SII, excluding national and local governments). Installation must occur between April 1, 2026, and March 30, 2027. 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 100,000 JPY per unit for participating in DR demonstration (150,000 JPY per unit if energy management devices are installed). Expansion of battery units: 60,000 JPY per 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 starting June 30. |
| Edogawa Ward “Renewable Energy Power Switching Subsidy (100% Renewable Energy Introduction Subsidy)” | Residents with an address in the ward who switch their home electricity to 100% renewable energy (or effectively 100%) and use it for over a year, with no delinquency in resident tax. | Flat 20,000 JPY. If any of the following are installed within 6 months before or after the switch: solar power generation equipment, stationary batteries, or high-efficiency water heaters, an additional 20,000 JPY will be added (maximum 40,000 JPY). |
For the fiscal year 2026, applications started on April 6. Will end once the budget is reached. As of October 6, 2026, the ward’s list page shows 150 subsidy approvals out of a planned 650. |
| Edogawa Ward (Subsidy for Installation Costs of Solar Power Generation Systems and Stationary Batteries) | As of October 6, 2026, the list of decarbonization subsidy programs for fiscal year 2026 does not include subsidies for the installation costs of solar power generation systems or stationary batteries. | ― | Please confirm the existence of the program with the ward’s contact office before signing a contract. |
| National “DR Home Battery Project” (Fiscal Year 2025 Supplement) | Newly installing home battery systems that can be utilized for DR (demand response) with registered products. | Calculated based on a standard amount of 34,500 JPY per kWh of initial effective capacity (subsidy rate within 30% and a maximum of 600,000 JPY per application). | The budget was reached on May 29, 2026, and the public recruitment has ended (the official site states there are no plans to reopen public recruitment, and applications cannot be made at this time). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but they must be combined with essential works such as insulation renovations of windows (openings) and the structure; applications cannot be submitted with only 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 application amount for renovations is displayed as 8% of the budget on the official website. Please check the application status on the official site. |
The Tokyo solar power and storage battery subsidies require prior application. Storage batteries applied for after October 1, Reiwa 8, will only be eligible if they are registered products under the national SII, and equipment requirements will change. The Edogawa Ward renewable energy power switching subsidy is combined with the power switch and the installation timing of solar power and storage batteries (within 6 months before and after). Eligibility conditions, application procedures, and the possibility of combining different systems vary by program, and applying does not guarantee issuance, so please confirm before contracting and 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 for the Introduction of Home Storage Systems for DR Resources)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those who are newly introducing registered storage systems that can be utilized for demand response (DR), and in the fiscal year 2027 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 items contracted or ordered before the grant decision being ineligible.
However, the fiscal year 2027 supplementary application amount reached the budget on May 29, 2026, and the public recruitment has ended. The official website also states that there are no plans to reopen public recruitment, and applications cannot be made at this time. 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 Households”
This subsidy is for those installing unused solar power generation systems in residential homes within Tokyo. The simultaneous installation of storage batteries is not a condition.
●Existing homes: For 3.75 kW or less, 150,000 JPY per kW (maximum 450,000 JPY); for over 3.75 kW to under 50 kW, 120,000 JPY per kW
●New homes: For 3.6 kW or less, 120,000 JPY per kW (maximum 360,000 JPY); for over 3.6 kW to under 50 kW, 100,000 JPY per kW
●There are also additions for the installation of rooftop frames and waterproofing work.
The target is to install unused panels with an output of less than 50kW that have obtained JET certification, in residential areas of Tokyo, for use in living spaces. The process involves prior application followed by a grant application after installation, and starting from the prior application for the fiscal year Reiwa 8, submission of a certificate issued by a financial institution during the performance report has become mandatory.
According to the official page of Tokyo, prior applications are being accepted from May 29, Reiwa 8. It will end once the budget is reached, so please check the official page for the application status.
👉 Here is the official page of Tokyo (Cool Net Tokyo)
Tokyo’s “Household Battery Introduction Promotion Project”
This is a subsidy for the installation costs of battery systems aimed at increasing self-consumption of electricity from solar power and improving energy independence during emergencies.
●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 per kWh (maximum 720,000 JPY per household)
The target is the owners of eligible equipment (excluding national and local public entities), and installation must be completed between April 1, Reiwa 8, and March 30, Reiwa 11. If applying for prior application after October 1, Reiwa 8, only products registered in the fiscal year Reiwa 8 by the national SII will be eligible.
The official page of Tokyo states that prior applications are being accepted from May 29, Reiwa 8. Please check the official page for detailed information, including conditions for combination with solar power generation.
👉 Here is the official page of Tokyo (Cool Net Tokyo)
Edogawa Ward “Renewable Energy Power Switching Subsidy (100% Renewable Energy Introduction Subsidy)”
This subsidy is for those who switch their household electricity to 100% renewable energy (or effectively 100%), and there are additional benefits when combined with the introduction of solar power generation equipment or stationary batteries.
●Power switching: Flat 20,000 JPY
●If any of the solar power generation equipment, stationary batteries, or high-efficiency water heaters are installed within six months before or after the switch: Additional 20,000 JPY (maximum 40,000 JPY)
The target is residents within the ward who will use the switched electricity for more than one year, and there should be no delinquency in resident tax. Applications for the fiscal year Reiwa 8 started on April 6 and will end once the budget is reached. According to the ward’s list page (checked on October 6, 2026), there are 150 subsidy approvals out of a planned 650. Applications are recommended to be sent by mail.
👉 Here is the official page of Edogawa Ward
Subsidy for Installation Costs of Solar Power Generation Systems and Stationary Batteries in Edogawa Ward
The list of decarbonization subsidy menu for the district for the Reiwa 8 fiscal year (confirmed on October 6, 2026) does not include subsidies specifically for the installation costs of solar power generation systems and stationary storage batteries. The list includes subsidies for renewable energy power switching, collective 100% renewable energy switching for apartment buildings, electric vehicles, and portable storage batteries. There may also be additional or resumed programs by the district, so please check with the district’s contact office for the latest information before making a contract.
👉 Click here for the Edogawa Ward Decarbonization Subsidy page
Solar Panel Installation & Storage Battery Installation Price List
⇧ Service Menu | Click here for costs related to solar panel removal & hot 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 “solar panel installation set,” the amount can vary significantly depending on the installation capacity, the grade of the equipment, and the condition of the roof.
Considerations for Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “output of one panel (W) × number of panels”, with the unit being kW (kilowatt). Storage batteries are compared in terms of the amount of electricity they can store, represented 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 to 5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6 to 10 kW. (These are just approximate amounts and may vary based on wiring length, scaffolding range, existing roofing materials, and panel layout.)
▶ For installation menu and costs for solar panel and storage battery installation, click here
Items to Confirm in the Estimate (Cost Confirmation)
When comparing estimates, it is common to compare different capacities and equipment based solely on price. 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 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 the storage battery. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range usable during power outages (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of the hardware suitable for the roofing material and method of fixing (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 for fixed parts, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | Extent of support included for applications to the power company, certification applications for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If it is simultaneous with roof work or exterior painting, check that the same scope and quantity are not double-counted. |
| 9. Removal and Disposal | Whether the removal of existing solar water heaters or old panels and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether prices are tax-inclusive or exclusive, conditions under which additional costs may arise, details and duration of manufacturer warranties and workmanship warranties. |
If the capacities differ, both the price and the power generation will change. Kakeru Koumuten Co., Ltd. welcome comparisons, so if you bring estimates from other companies, we can explain the differences item by item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can obtain an estimated quote and a profit simulation for up to 30 years!
If you know the total installation capacity of the solar panels on the roof and the capacity of the storage battery, you can get an estimated quote and profit simulation!
*The simulation results are estimates. Actual profits may vary based on conditions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection or replacement.
Customer Voices
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installations
| Work Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh |
| Base Mounting Hardware Used |
| Niigata Manufactured / Aluminum Catch-Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed by catching the horizontal metal roof with catch-type hardware (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that grants are available, and I would like to know how much can be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels 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 grant amount, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Edogawa, Tokyo
There are many solar panel installation contractors available in Edogawa Ward, 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 existence 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
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 were installed on a severely deteriorated roof, resulting in leaks
・Solar panels were installed on a roof with a short lifespan, necessitating a renovation for removal and reinstallation within a few years
・Misjudging the type of waterproofing led to incorrect treatment and subsequent leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the existence of warranties and aftercare services
When choosing a solar installation contractor, let’s confirm the existence 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 units come with manufacturer warranties, it is also essential to check for the existence of a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may be covered under the warranty if it is within the warranty period and conditions.
Additionally, some contractors provide aftercare services separate from warranties, so be sure to check if the contractor you are considering has aftercare services.
Since abnormalities or damage on the roof may not be visible, you might not notice them yourself.
By conducting inspections during aftercare, you can more easily detect abnormalities early, preventing significant 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 is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovations are performed.)
We also conduct aftercare maintenance and send out annual DM!
If you check the DM and wish to proceed, we will visit for aftercare maintenance!
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”
“Type of solar panel”
“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!
▶ Go 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 solar panel installations and battery installations, but if the order of procedures is incorrect or there are deficiencies in the documents, the subsidy may not be granted.
Since there are systems like the Tokyo subsidy that require prior application, it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for the Tokyo subsidy, prior application is required) before proceeding with the construction!
For the Tokyo subsidy, after installation, you will need to submit a grant application and performance report, which will be reviewed before the grant is issued! (The flow of procedures varies by system)
▶ Go to “Subsidies and grants that may be applicable in Edogawa Ward, Tokyo” 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 generated electricity, 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 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 likely to be more advantageous to use it at home (self-consume) rather than selling it, making the combination with a storage battery a viable 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 conditions, you may be able to utilize subsidies!
The reduction of the actual burden amount due to subsidies is a significant advantage!
In Edogawa Ward, you may be eligible for programs from the national government, Tokyo, and Edogawa Ward (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 such as power conditioners may have operational noise.)
Advantage 4 Heat insulation effects are expected!!
By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, this can help reduce the temperature rise of the roof, providing expected heat insulation effects!
(Note that this does not improve the 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 functionality, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1: Maintenance costs can be incurred
A particularly overlooked maintenance cost is for the roof where the solar panels are installed.
If you perform roof remodeling 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 remodel it with durable roofing materials before installing solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It would be reassuring to ask for a simulation that considers maintenance costs before introducing solar panels!
Point 2: The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix hardware 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 hardware, and it cannot be used with all metal roofs.)
Catch-type base metal fittings for horizontal metal roofs
Note 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load capacity, switching to 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 roof output
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and it is always better to generate more power!
The size and output of solar panels vary by manufacturer.
A panel with 350W output and a panel with 400W output 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,” resulting in different numbers of panels that can be installed on the same roof due to size differences.
400W×15 panels = 6kW (total output of the roof)
350W×20 panels = 7kW (total output of the roof)
As shown above, even if the output of one panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual power generation amount (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 the warranty and does not represent the actual degradation rate or power generation amount.
Choosing solar panels while considering the degradation rate, rather than just the initial output, will help you avoid 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.
For output warranties, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies widely!
Since a longer warranty is generally better, let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Edogawa, Tokyo
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Edogawa, Tokyo. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Edogawa, Tokyo?
The cost varies depending on the installation capacity, equipment, and roof condition. In the above construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines for different capacities are available on the solar panel and storage battery installation pricing page. We will create a layout diagram from the drawings and on-site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Edogawa, Tokyo?
As of October 6, 2026, Tokyo’s “Promotion Project for Solar Power Generation in Households” (for existing homes, 15,000 yen per kW for up to 3.75kW, maximum 450,000 yen) and “Promotion Project for Storage Battery Installation in Households” (100,000 yen per kWh, maximum 1.2 million yen per household) are accepting pre-applications starting May 29, 2026, as listed on the official Tokyo (Cool Net Tokyo) page. Edogawa Ward has a renewable energy power switching subsidy (20,000 yen, an additional 20,000 yen for the installation of solar power or stationary storage batteries), but the list of subsidy programs for the fiscal year 2026 does not include installation cost subsidies for solar power generation systems or stationary storage batteries. 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?
This depends on the system. Tokyo’s subsidies require pre-application. Conditions such as whether you can sign a contract or start construction before applying vary by system, so please confirm before signing a contract.
The order of procedures also varies by system, so please check before signing a contract or starting construction.
Can solar panels be installed on a slate roof? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate. The fixing method varies depending on the construction method, and if the method involves fixing brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is essential.
Kakeru Koumuten Co., Ltd. is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation. If deterioration is progressing, we can also suggest methods such as roof overlay (cover method) or complete 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, there will be additional costs for removing and reinstalling solar panels. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with durable roofing materials before installation.
Please consult us about the installation process after checking the condition of the roof during the on-site survey!
Should I install a storage battery together with the solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it in your home rather than selling it.
Additionally, the subsidy for storage batteries in Tokyo (for Reiwa 8, it is 100,000 yen per kWh, with a maximum of 1,200,000 yen per household) is aimed at increasing self-consumption of electricity generated by solar power. Edogawa Ward’s renewable energy power switching subsidy also adds 20,000 yen for the introduction of solar power and stationary storage batteries. You can compare “solar only” and “solar + storage battery” in a financial simulation.
How many kW can I install on my roof? Is it okay for north-facing or shaded roofs?
The capacity that can be installed varies depending on the shape, direction, 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.
Edogawa Ward is a city with many parks and trees, and the shading from surrounding buildings and trees varies from house to house. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
For the above construction example (solar panels 4.3 kW + storage battery), it took about 3 days. The duration may vary if roof work is done simultaneously or depending on the shape of the roof and installation capacity.
Please note that there will be an additional period for applying for subsidies and to the power company, so please consult us early.
What is the current selling price (FIT)?
For residential use (under 10 kW), the selling price from certifications after October 2025 will be 24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year, 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 handle maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-maintenance notices via DM and visits customers who wish to have inspections. We can also clean solar panels with a special brush if the power generation 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 Co., Ltd. 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 detachment and water heater removal pricing page.
If you are looking for a solar panel installation company in Edogawa, Tokyo, please consult Kakeru Koumuten
Our company handles many exterior renovations, including solar panels, roof work, and exterior wall work in Edogawa, Tokyo.
We receive requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten promises “high-quality renovations at low cost”, and we have received great feedback from numerous customers.
We continue to update our construction performance each year, and we will strive to improve quality to satisfy even more customers in the future.
Our company can perform not only roof overlay work and re-roofing but also partial roof repairs, exterior painting, and exterior wall cover methods, all with our own team.
We are happy to assist with small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leak repairs, we may be able to provide emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult us!
“I want to know about 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 specific requests.
We will never propose unnecessary work focused on profit!
We always stand in the customer’s position and propose the best construction plan!
We are confident that we will not be outdone by other companies in terms of cost, quality, and organization for exterior work!
We are confident, so we welcome competitive quotes!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Characteristics of Edogawa, Tokyo and Points for Solar Work
Edogawa Ward has a total area of 49.09 square kilometers, stretching approximately 13 km north to south and 8 km east to west, with 498 parks surrounded by water and greenery. Located at the estuary surrounded by the Edogawa and Arakawa rivers and the sea, about 70% of the ward’s area is a lowland called the zero-meter zone, which is below high tide level. We have summarized the characteristics of Edogawa Ward, Tokyo, and points to consider when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Edogawa Ward, Tokyo, and points for solar installation
■ About 70% of the ward is lowland. Check for flooding risks at installation sites
Edogawa Ward has been affected by ground subsidence due to past groundwater extraction, and the entire area is considered at risk of flooding from storm surges. Depending on where power conditioners and storage batteries 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 flood hazard map and consult with us regarding the installation location and height, in conjunction with the manufacturer’s installation conditions.
■ A city with many parks and trees. Check shadow patterns on-site
Edogawa Ward has 498 parks and approximately 6.98 million trees. In properties surrounded by trees and neighboring houses, the shadow patterns falling on the roof can change depending on the time of day and season, so it is important to check the panel layout on-site. Kakeru Koumuten Co., Ltd. will create a layout diagram from the blueprints and on-site survey, and you can confirm it with a power generation simulation.
■ Areas close to rivers and the sea. Confirm installation conditions based on manufacturer standards
In locations near rivers and the sea, installation conditions for panels, frames, and fittings (handling in salt damage areas) may be specified for each product. The response may vary depending on the distance from the coast, so please check the manufacturer’s installation conditions when requesting a quote.
■ Roof types and ages vary from house to house. Check the roof and waterproofing before installation
Even within the same ward, roof types, ages, and sunlight exposure vary from house to house. Kakeru Koumuten Co., Ltd. will confirm the type and condition of the roof and the site situation before installation, and propose methods for securing, waterproofing details, and scaffolding plans.
■ The annual sunshine hours at the Tokyo Observatory are approximately 1,927 hours
Meteorological Agency’s average values (1991–2020) indicate that the annual sunshine hours at the Tokyo Observatory are approximately 1,927 hours, with January (about 193 hours) having the most and June during the rainy season (about 124 hours) having the least. (This is a reference value, not based on observations within Edogawa Ward.)
The power generation in Edogawa Ward can also be affected by shadows from surrounding trees and buildings, so it is important to conduct annual power generation simulations and choose the capacity of the storage battery to match the times when electricity is used the most.
Our company handles many exterior construction and solar power projects in Edogawa 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 Edogawa Ward, Tokyo
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Edogawa Ward, Tokyo
Ichinoe, Edogawa Ward / Ichinoe Town, Edogawa Ward / Ukita Town, Edogawa Ward / Edogawa, Edogawa Ward / Osugi, Edogawa Ward / Okunomiya Town, Edogawa Ward / Kamishiozaki, Edogawa Ward / Kamishinozaki, Edogawa Ward / Kitakasai, Edogawa Ward / Kitakoiwa, Edogawa Ward / Kitashinozaki, Edogawa Ward / Komatsugawa, Edogawa Ward / Shikanbone, Edogawa Ward / Shikanbone Town, Edogawa Ward / Shinozaki Town, Edogawa Ward / Shimoshinozaki Town, Edogawa Ward / Seishin Town, Edogawa Ward / Chuo, Edogawa Ward / Nakakasai, Edogawa Ward / Shinbori, Edogawa Ward / Nishiichinoe, Edogawa Ward / Nishikasai, Edogawa Ward / Nishikoikwa, Edogawa Ward / Nishikomatsugawa Town, Edogawa Ward / Nishishinozaki, Edogawa Ward / Nishimizue, Edogawa Ward / Ninoe Town, Edogawa Ward / Harue Town, Edogawa Ward / Higashikasai, Edogawa Ward / Higashikoikwa, Edogawa Ward / Higashikomatsugawa, Edogawa Ward / Higashishinozaki, Edogawa Ward / Higashishinozaki Town, Edogawa Ward / Higashimatsumoto, Edogawa Ward / Higashimizue, Edogawa Ward / Hirai, Edogawa Ward / Funabori, Edogawa Ward / Motoichishiki, Edogawa Ward / Matsue, Edogawa Ward / Matsushima, Edogawa Ward / Matsumoto, Edogawa Ward / Mizue, Edogawa Ward / Minamikasai, Edogawa Ward / Minakoiwa, Edogawa Ward / Minamishinozaki Town, Edogawa Ward / Tanigawachi, Edogawa Ward / Rinkai Town, Edogawa Ward
・Trust Kakeru Koumuten for exterior wall painting in Edogawa, Tokyo!
・Trust Kakeru Koumuten for roof renovations in Edogawa, Tokyo!
・Trust Kakeru Koumuten for exterior renovations in Edogawa, Tokyo!
・Kakeru Koumuten Co., Ltd. construction achievements
・Kakeru Koumuten Co., Ltd. aftercare services
・Kakeru Koumuten Co., Ltd. construction menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of 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 installing solar power generation? Key points for site selection included!
・Check out our solar power generation estimates here!
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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!
