Leave Your Solar Panel Installation in Taito, Tokyo to Kakeru Koumuten Co., Ltd.!
For solar panel and battery installation in
Taito, Tokyo,
Kakeru Koumuten is your trusted partner!
Kakeru Koumuten is a specialized exterior renovation company headquartered in Aoba Ward, Yokohama City.
As a company strong in roofing, we are entrusted with solar panel and battery installation considering roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Taito”
“Costs for Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Taito”
We will also explain the above three points!
Installing solar panels carries risks such as “the occurrence of leaks” and other troubles.
To ensure you have no regrets about your solar panel installation, we recommend obtaining estimates from about three companies!
Table of Contents (tap to open/close)
- Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Taito, Tokyo
- Roof Inspection Before Installing Solar Panels
- Subsidies and Grants Available in Taito, 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 Installer in Taito, 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 Taito
- If You’re Looking for a Solar Panel Installer in Taito, Contact Kakeru Koumuten
- Characteristics of Taito, Tokyo and Key Points for Solar Installation
- Service Area in Taito, Tokyo
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Taito, Tokyo
Regarding why our company is entrusted with solar panel installation by customers in Taito, Tokyo,
One reason is that “Kakeru Koumuten serves Kanagawa and Tokyo as its service areas.” Additionally,
“We have unique strengths in solar panel installation that cannot be imitated by other companies,” which has received positive feedback from many customers.
We would be grateful 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 Besides Solar Panel Installation!
Issues such as leaks that occur during solar panel installation may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if one is knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside their expertise, so caution is necessary.
It is reassuring to have someone knowledgeable about the roof to avoid maintenance and trouble after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent issues after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide low-cost, high-quality solar work and exterior renovations.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding based on construction conditions and can assemble scaffolding in-house.
By not outsourcing scaffolding work and using our own scaffolding team, we can also cut costs for scaffolding work.
We own scaffolding materials for approximately 50 single-family homes!
Even in urban areas like Taito Ward, our in-house scaffolding team will plan scaffolding according to the site.
Storage of Materials in Our Large Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you can purchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we can respond quickly in emergencies!
In-house sorting and transportation of waste materials
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior renovation dedicated showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on roofing materials!
We can also provide simulations for potential earnings and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also have samples of roofing materials and models that explain the structure, allowing for detailed explanations!
3.All work performed by our own team
One of Kakeru Koumuten’s major strengths is its complete in-house construction.
By having Kakeru Koumuten 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 same person will be in charge without changing roles such as sales or construction management, smooth communication is possible.
We can provide consistent in-house construction from temporary scaffolding installation, exterior wall painting, to roof renovations!
4. Various Permits and Skilled Workers
We have obtained construction industry licenses as well as permits for industrial waste collection and transportation!
We also have nationally certified sheet metal workers and painting technicians, and we are confident in our construction techniques.
We can also handle large-scale roof projects such as those for factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation, 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 a roof renovation is performed. The construction warranty is separate from the manufacturer’s product warranty, and the coverage and conditions vary based 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.
If you cannot access the roof due to height, 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 with a specialized brush.
We will respond according to the customer’s wishes.
7. Human Resource Development
To improve skills, we create various roofing models and conduct practical training.
Since the construction method changes depending on the shape and slope of the roof, we regularly conduct technical training so that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
At Kakeru Koumuten, we provide not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar construction guidebook” and a “profit and loss simulation” that takes into account loan interest rates and electricity costs.
The profit and loss simulation can be created for expected cumulative profits and losses over 20 to 30 years.
We compile easy-to-understand materials that include points to note and disadvantages for customers who are not familiar with solar construction!
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 a roof renovation first. |
| 2. Condition of Substrate and Waterproof Sheet | If the sheathing or roofing (waterproof sheet) under the roofing material is damaged, it will affect the fixing strength of the fittings and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, Slope, and Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, will affect the power generation. We will create a layout diagram from the drawings and the site, and you can confirm it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels that can be installed (installation capacity) is determined by the shape and size of the roof. Since the number of panels that can be installed varies depending on the panel size, we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will check whether the method involves drilling holes in the roofing material for fixing or using fittings to secure the roofing material. The fixing method varies by technique, so please confirm the waterproofing treatment method for the fixing parts during the estimate. |
| 6. Weight of the Roof | The roof will become heavier due to the panels being installed. After investigating the existing roof, substrate, and load-bearing capacity, switching to lighter roofing materials may also be an option if necessary. |
| 7. Location of Equipment Installation and Wiring | We will confirm the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect the cost. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproof treatment of fixing parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay or replacement first. |
| Tile Roof | Fixed with brackets and methods suitable for the type of tile (even methods that do not drill holes in the tiles will secure to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lightweight roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you plan to renovate the roof 10 to 20 years after installation, there will be additional costs for the removal and reinstallation of solar panels. If the roof is deteriorating, renovating to a highly durable roofing material before installation may help reduce costs in the long run.
Kakeru Koumuten is strong in roofing work and can also handle the removal and reinstallation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Taito City, Tokyo
Possible Subsidies and Grants in Taito City, Tokyo
If you are introducing solar panels or storage batteries in Taito City, Tokyo, there may be systems available from “the national government,” “Tokyo,” and “Taito City.”
The following information is based on the official pages of each system as of October 7, 2026. The application status may change depending on the budget and recruitment period, 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 Metropolitan Government “Reiwa 8 Year Household Solar Power Generation Promotion Project” (Cool Net Tokyo) | New installation of certified solar modules in residential properties or their premises within the city, with systems under 50kW. Pre-application before installation is required. | Existing homes: 150,000 JPY/kW for 3.75kW or less (maximum 450,000 JPY), 120,000 JPY/kW for over 3.75kW New homes: 120,000 JPY/kW for 3.6kW or less (maximum 360,000 JPY), 100,000 JPY/kW for over 3.6kW (Additional costs for frame installation, waterproofing work, and renovation defect insurance, etc.) |
Pre-application: From May 29, 2026 Grant application and performance report: From June 30, 2026 to March 30, 2029 |
| Tokyo Metropolitan Government “Reiwa 8 Year Household Storage Battery Promotion Project” (Cool Net Tokyo) | New installation of storage batteries in residential properties, which must be SII registered equipment. This project is intended for simultaneous installation with solar power, but applications can be made for storage batteries alone. Pre-applications after October 1, 2026 will only be eligible for SII registered products for Reiwa 8. | Storage battery package: 100,000 JPY/kWh (maximum 1,200,000 JPY per unit) Storage battery unit expansion: 60,000 JPY/kWh (maximum 720,000 JPY per unit) (Additional incentives for participation in DR demonstrations, etc.) |
Pre-application: From May 29, 2026 Grant application and performance report: From June 30, 2026 |
| Taito Ward “Decarbonization Promotion Subsidy (for Housing)” Reiwa 8 Year | Applicable when introducing new unused equipment purchased within the ward (expansions of existing equipment and installations for properties intended for sale or transfer are not eligible). If the building is not owned by the applicant, consent from the owner is required. Pre-application before construction is necessary, and work will commence after receiving a confirmation email. | Solar power generation: 50,000 JPY per kW (maximum varies from 200,000 JPY to 500,000 JPY depending on building classification) Home storage batteries: 10,000 JPY per kWh (maximum 100,000 JPY) |
Pre-applications for Reiwa 8 have ended for both the first period (April 9 to 16) and the second period (August 18 to 24) (due to applications exceeding the budget, a lottery was held) The deadline for grant applications for those who have been accepted is February 15, 2027. |
| National “DR Household Storage Battery Project” (Reiwa 7 Year Supplement) | New installation of household storage systems that can be utilized for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 34,500 JPY per kWh (subsidy rate within 3/10; maximum 600,000 JPY per application). | The budget was reached on May 29, 2026, and the public recruitment has ended. (Applications can no longer be submitted.) |
| 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 for windows (openings) and the building structure; applications cannot be made for storage battery installation alone. Solar panels are not included as eligible facilities. | 蓄電池：96,000 JPY/戸 | Ends as soon as the budget limit is reached. Please check the official website for the application status. |
In Tokyo, the subsidy requires a pre-application before installation, while the subsidy in Taito Ward requires pre-application and notification of acceptance before construction. If construction starts before these applications, it may be excluded from eligibility, and applying does not guarantee approval. The pre-application for the 2026 fiscal year in Taito Ward has ended, so please check the official page for future recruitment details. Procedures differ by program, so please confirm before contracting and starting work.
Kakeru Koumuten will guide you on eligibility conditions for each program after confirming them.
Tokyo “2026 Fiscal Year Solar Power Generation Promotion Project for Households”
Tokyo is providing subsidies for those installing solar power generation systems in residential homes through Cool Net Tokyo. The target is systems using certified solar modules installed newly in residential homes or on their premises, with a capacity of less than 50kW. A pre-application before installation is required.
For existing homes, the subsidy amount is 150,000 JPY/kW for systems up to 3.75kW (maximum 450,000 JPY), and 120,000 JPY/kW for systems exceeding 3.75kW. Additionally, there are extra items for mounting frames, waterproofing work, and renovation defect insurance. The pre-application period is from May 29, 2026, and the application for grants and performance reports is from June 30, 2026, to March 30, 2029. For details on eligible equipment and conditions, as well as budget status, please check the official page.
👉 Cool Net Tokyo | Official page for solar power generation is here
Tokyo “2026 Fiscal Year Battery Storage Promotion Project for Households”
Tokyo is also providing subsidies for newly installed battery storage in residential homes. The subsidy amount is 100,000 JPY per kWh for battery storage packages (maximum 1,200,000 JPY/戸), and 60,000 JPY per kWh for additional battery units (maximum 720,000 JPY/戸), with additional amounts for participation in DR demonstrations.
The target is equipment registered with SII (Environmental Collaboration Initiative). If you apply for pre-application after October 1, 2026, only equipment listed in the 2026 fiscal year SII registered product list will be eligible. This project is intended for simultaneous installation with solar power, but applications can be made for battery storage alone. The application for grants and performance reports has started from June 30, 2026.
👉 Cool Net Tokyo | Official page for battery storage is here
Taito Ward “Decarbonization Promotion Subsidy (for Residential Use)”
Taito Ward is implementing the “Decarbonization Promotion Subsidy” (formerly Eco Subsidy) for those introducing energy-saving and renewable energy equipment in residential homes and businesses within the ward. The subsidy amount for the 2026 fiscal year is 50,000 JPY per kW for solar power generation systems (maximum varies from 200,000 JPY to 500,000 JPY depending on building classification), and 10,000 JPY per kWh for household battery storage (maximum 100,000 JPY). Only new, unused equipment purchased is eligible, and installations for existing equipment expansions or properties planned for sale or transfer are not eligible.
Starting from the fiscal year 2026, it is necessary to submit a pre-application before the construction and to receive an email confirming its acceptance before proceeding with the work. The pre-application period has ended for both the first phase (April 9 to 16) and the second phase (August 18 to 24), and due to the total application amount exceeding the budget, the order of acceptance was determined by lottery. Those whose pre-applications have been accepted must submit their grant application by February 15, 2027, after the completion of the construction and payment of construction costs. Please check the official page of the ward for information on future recruitment and details.
👉 Here is the official page of Taito Ward (Decarbonization Promotion Subsidy)
National Subsidy “DR Household Storage Battery Project (Support Project for the Introduction of Household Storage Systems for DR Resource Implementation)”
The government has been implementing the “DR Household Storage Battery Project” to support the installation of household storage batteries.
This program targets those who are introducing new storage systems of registered products that can be utilized for demand response (DR). In the fiscal year 2025 supplementary budget, the subsidy amount was determined based on a standard amount of 34,500 JPY per initial effective capacity of 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 excluding contracts or orders made before the grant decision.
However, the fiscal year 2025 supplementary budget reached its application amount on May 29, 2026, and the public recruitment has ended (the previous fiscal year’s supplementary budget also ended public recruitment on July 2, 2025). Applications are currently not being accepted, so 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.
👉 Here is the official site for the DR Household Storage Battery Project
Solar Panel Installation & Storage Battery Installation Price List
⇧Service Menu | Click here for costs related to Solar Panel Removal and Water Heater Dismantling
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and storage batteries should be confirmed by separating them into “Equipment Costs” and “Construction Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.
Considerations for Installation Capacity (kW) and Storage Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatt). Storage batteries are compared based on the amount of electricity they can store, expressed in kWh (kilowatt-hour).
The amount of kW that can be installed on a roof varies for each house based on the roof’s shape, orientation, and size. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panels at 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 only approximate amounts and may vary based on wiring length, scaffolding area, existing roofing materials, panel layout, etc.)
▶ Service Menu | Click here for costs related to Solar Panel Installation and Storage Battery Installation
Items to Confirm in the Estimate (Cost Verification)
When comparing estimates, it is common to compare different capacities and equipment 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 per panel (W), number of panels, total installation capacity (kW) are listed. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls the battery together. |
| 3. Storage 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 fixing method (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 the fixing points, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Application | How much support is included for applications to the power company, certification application 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 thermal water heaters or old panels and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether it is tax-inclusive or tax-exclusive, conditions under which additional costs may arise, details and duration of manufacturer warranty and workmanship warranty. |
If the capacity is different, both the amount and power generation will change. Kakeru Koumuten Co., Ltd. welcome competitive estimates, so if you bring estimates from other companies, we will explain the differences for each item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can obtain an estimated quote and a profit simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can get an estimated quote and profit simulation!
*The simulation results are estimates. Actual profits may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection or replacement.
Customer Voices
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installation
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh |
| Base Mounting Hardware Used |
| Niigata Manufacturing/Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Details |
| Fixed by catching the horizontal metal roof with catch type hardware (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| About 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the 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 grant amount, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Taito, Tokyo
There are many solar panel installation contractors available in Taito City, Tokyo, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and battery storage installation work, let’s confirm the following four points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the existence of warranties and aftercare maintenance
● Obtain estimates from multiple contractors (three companies is a guideline)
● Check if they provide support for subsidy applications
By confirming the above four points, you will be able to choose a reliable contractor.
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 installed on a severely deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring renovations for removal and reinstallation within a few years
・Misjudgment of the type of waterproofing leading to incorrect processing and resulting in leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the existence of warranties and aftercare maintenance
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 coverage, exclusions, and cost conditions.
While the solar panels and battery storage units come with a manufacturer’s warranty, it is also essential to check whether there is a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may cover the repairs under the warranty, provided it is within the warranty period and conditions.
Additionally, some contractors offer after-service separate from warranties, so be sure to check if the contractor you are considering has after-service.
Changes or damage on the roof can occur in areas that are not visible, so there is a possibility that customers may not notice them.
By conducting inspections during after-maintenance, we can check the hidden areas and easily prevent major repairs or failures by discovering abnormalities early!
Kakeru Koumuten Co., Ltd. provides a rain leak warranty as part of the workmanship warranty for solar panel installations. (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 a roof renovation.)
We also conduct after-maintenance and send out DM every year!
After checking the DM, if you wish, we will visit for after-maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting 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 from your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates,
“Check the items in the estimate”
“Type of solar panel”
“Warranties and after-services”
and make detailed comparisons to make your judgment! If the rank of auxiliary materials is low or if processes are skipped, costs can be reduced, so avoid making decisions based solely on price!
▶ Go to “Breakdown of Installation Capacity and Equipment/Construction Costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the grant may not be awarded.
Some systems require personal applications and cannot be handled by the contractor, and some require pre-application before installation, so it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Let’s complete the procedures specified for each system (for Tokyo’s subsidy, pre-application before installation; for Taito Ward’s grant, pre-application and notification of acceptance before construction) before proceeding with the construction!
In the case of subsidies in Tokyo, the process involves submitting a grant application and performance report after the completion of the work, which will be granted after a review! (The procedure varies depending on the system)
▶ Go to “Subsidies and Grants That May Be Applicable in Taito Ward” within this article
Benefits of Introducing Solar Power Equipment
The benefits of introducing solar panels are as follows!
Benefit 1: Economic Benefits
The biggest benefit of introducing solar panels is the economic benefit!
Although the selling price of electricity has decreased compared to ten years ago, you can gain benefits by reducing the electricity purchased from power companies through self-consumption of generated electricity!
As electricity costs rise, the ability to cover consumption with solar power becomes attractive!
If you plan to use the generated electricity at night, the installation of a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) will be set at “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year” for certifications after October 2025, and the same price will apply for the 2026 fiscal year. After the fifth year, it is likely to be more advantageous to use it at home (self-consume) rather than sell it, making the combination with a storage battery a viable option.
👉 For purchase prices and periods, visit the Agency for Natural Resources and Energy
Benefit 2: Subsidies Can Be Utilized!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
Reducing the actual burden amount through subsidies is a significant advantage!
In the case of Taito Ward, in addition to national and Tokyo metropolitan systems, there is a possibility of being eligible for Taito Ward’s decarbonization promotion subsidy (solar power generation systems and home storage batteries) (the ward’s subsidy requires a prior application before construction, and the application for the 2026 fiscal year has ended).
Benefit 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 do have operational noise.)
Advantage 4 Expect heat insulation effects!!
By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, it can suppress the rise in roof temperature, so heat insulation effects can be expected!
(Note that this does not improve the building’s insulation performance itself.)
Advantage 5 Electricity can be used even during power outages!!
If a storage battery is installed, it becomes possible to use electricity even during emergencies such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capability, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1 Maintenance costs can be incurred
A particularly overlooked maintenance cost is for the roof where solar panels are installed.
If you perform roof renovations 10 to 20 years later, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorating, it is reassuring to renovate it with durable roofing materials before installing solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It would be reassuring to 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 method of securing slate roofs and tile roofs varies depending on the construction method, but when using screws or other fasteners to secure the roofing material and substrate, waterproofing treatment at the fixed points becomes crucial.
In methods that involve making holes in the roof, there is inevitably a risk of leaks.
Of course, we will ensure thorough waterproofing treatment, but if you are concerned about making holes, one option is to replace the roofing material with a metal roof and secure the solar panels using the catch method. (The catch method has compatibility conditions between the roofing material and the fasteners, and it cannot be used with all metal roofs.)
Catch-type base fasteners for horizontal metal roofs
Note 3: The roof will become heavier
To accommodate the solar panels, the roof will become heavier. After investigating the existing roof, substrate, and load-bearing capacity, replacing it with a lighter roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary widely.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
Choosing Method 1: Compare by Total Output of the Roof
When installing solar panels on the roof, it is important to consider how much electricity can be generated within the limited area, and the more electricity generated, the better!
Solar panels come in various sizes and outputs depending on the manufacturer.
For example, a 350W output panel and a 400W output panel may seem that the higher output panel is better at first glance.
However, if the size of the panels does not fit well with the roof, “20 panels of 350W can be installed, while only 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 represent total output (kW). Actual electricity generation (kWh) will vary based on conditions such as roof orientation, slope, and shading.
Choosing Method 2: Compare by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases over 10 years and 20 years.
The degree of output decline after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or power generation amount.
Choosing solar panels while considering the degradation rate, not just the initial output, will help you avoid regrets!
How to Choose 3: Compare by Warranty Period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
Some manufacturers offer a 30-year warranty for output, while others provide a 10-year warranty, so it’s quite varied!
A longer warranty is always better, so be sure to check the warranty period and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar and Storage Battery Installation in Taito Ward
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Taito Ward. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Taito Ward, 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 by capacity are published on the solar panel installation and storage battery installation pricing page. We will create a layout diagram from the drawings and on-site survey and provide a free estimate!
Are there any subsidies available for solar and storage battery installation in Taito Ward?
As of October 7, 2026, Tokyo’s subsidies for solar power generation and storage batteries (Cool Net Tokyo) are accepting pre-applications. For storage batteries, only SII registered devices (registered products for Reiwa 8) are eligible from pre-applications made after October 1, 2026. The decarbonization promotion subsidy in Taito Ward (50,000 yen per 1kW of solar power, 10,000 yen per 1kWh of storage battery, with a maximum of 100,000 yen) has ended for pre-applications for Reiwa 8 (first and second half). The national DR household storage battery project has also closed 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?
For many programs, procedures must be completed before construction. Tokyo’s subsidies require pre-application before installation, and if you install first, you will be excluded from eligibility. Taito Ward’s grants also require pre-application and acceptance email before construction, and starting work beforehand will make you ineligible. Procedures differ by program.
Since the order of procedures varies by program, please confirm before signing a contract or starting construction.
Can solar panels be installed on slate roofs? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate beforehand. The method of securing it varies depending on the construction method, and in methods that fix hardware to the roofing material or substrate, waterproofing treatment of the fixed parts is crucial.
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 and suggest methods such as roof overlay (cover method) or complete replacement if deterioration is advanced.
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 to a highly durable roofing material before installation.
Please consult us on how to proceed with the installation after checking the condition of the roof through a site survey!
Is it better to install a storage battery together with solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price of electricity 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 is designed for simultaneous installation with solar panels, but applications can also be made for storage batteries alone. You can compare “solar panels only” and “solar panels + 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 Co., Ltd., we create a layout diagram from the drawings and site survey, and we will provide you with the installation capacity and power generation simulation.
Even in the urban area of Taito Ward, the shadow cast by surrounding buildings varies from house to house. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
In the above construction example (solar panels 4.3 kW + storage battery), it took about 3 days. The duration may vary depending on whether roofing work is done simultaneously and the shape and installation capacity of the roof.
Additionally, there will be a separate period for applications for subsidies and power companies, so please consult us as soon as possible.
What is the current selling price (FIT)?
For residential use (less than 10 kW), the rate for 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 in 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 Co., Ltd. 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 Co., Ltd. sends out annual aftercare maintenance DM notices and visits for inspections upon request from customers. We can also clean solar panels using a special brush if the power generation is reduced due to dirt.
The roof is a part that is difficult to check by yourself, so if you have any concerns, please feel free to consult us.
Can you also handle renovations for roofs that already have solar panels installed?
Yes, it is possible. 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 Taito City, please consult Kakeru Koumuten
Our company handles a wide range of exterior renovations, including solar panel installation, roof work, and exterior wall work in Taito City, Tokyo.
We have received many requests from customers, including renovation companies and real estate companies, who have contacted us!
Kakeru Koumuten promises “high-quality renovations at low cost”, and we have received positive feedback from many customers.
We continue to update our annual construction performance, 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 wall cover methods.
We are also happy to handle small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leak repairs, we may be able to provide emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult us!
“I want to know recommended solar panels“, “I want to keep costs down as much as possible“, “I just want an estimate for now“, and other specific requests will be met with optimal solutions.
We will never propose unnecessary work focused on profit!
We always stand in the customer’s shoes and propose the best construction plans!
We are confident that we will not be outdone in terms of cost, quality, and organization compared to other companies in exterior work!
We welcome competitive estimates with confidence!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Characteristics of Taito City, Tokyo and Points of Solar Work
Taito Ward, Tokyo, is located in the eastern part of the 23 wards of Tokyo and is the smallest ward by area among them. On the official page of Taito Ward, a hazard map summarizing flood risks from the Kanda River, Sumida River, and Arakawa, as well as internal flooding, storm surges, and landslide disasters, is available.
We have summarized points to consider when installing solar panels and storage batteries in Taito Ward’s residential environment below. (Tap to open)
View the characteristics of Taito Ward, Tokyo, and points for solar construction
■ Check the installation location of storage batteries and power conditioners against the hazard map
The flood and landslide hazard map of Taito Ward allows you to confirm the assumptions regarding floods (Kanda River, Sumida River, Arakawa), internal flooding, storm surges, and landslide disasters. When deciding on the installation location for storage batteries and power conditioners, it is reassuring to check the flooding assumptions for your residence on the hazard map and consider the height and position of the installation.
■ Tokyo’s annual sunshine hours are approximately 1,927 hours
The Japan Meteorological Agency’s average values (1991-2020) indicate that Tokyo receives about 1,927 hours of sunshine annually.
Since power generation varies by season, it is essential to conduct annual power generation simulations and choose the capacity of storage batteries to match the times of high electricity usage.
■ In urban areas with closely spaced buildings, check the shadows cast by surrounding structures
In places where residences and stores are closely built, the shadows cast by surrounding buildings vary for each house depending on the roof’s orientation and height. Since solar panels generate less power when shaded, Kakeru Koumuten creates layout diagrams based on blueprints and the actual site conditions, allowing you to confirm through power generation simulations.
■ In areas with narrow front roads, plan scaffolding and equipment delivery carefully
In places where the front road is narrow, careful planning for scaffolding and equipment delivery may be necessary. Kakeru Koumuten will respond to the site conditions with our own scaffolding team and scaffolding materials.
■ Check the roof condition according to the building’s age
For buildings that have been around for many years, it is important to check the condition of the roofing materials and substrate before installing solar panels. Depending on the roof’s condition, installing them simultaneously with roof renovations can help reduce future costs for removing and reinstalling solar panels.
■ Subsidies require procedures before construction in both Tokyo and Taito Ward
For Tokyo’s subsidies, a pre-application to Cool Net Tokyo is required before installation. Taito Ward’s decarbonization promotion subsidy also requires a pre-application and an acceptance email before construction. It is essential to check the procedures and timelines for each system in advance, in line with the construction schedule.
Our company serves Kanagawa Prefecture and Tokyo, and we handle many exterior and solar construction projects in Taito 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 for any sudden troubles!
Service Area in Taito Ward, Tokyo
Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Taito Ward, Tokyo
Taito Ward, Akihabara / Taito Ward, Asakusa / Taito Ward, Asakusabashi / Taito Ward, Ikenohata / Taito Ward, Imado / Taito Ward, Iriya / Taito Ward, Ueno / Taito Ward, Ueno Park / Taito Ward, Ueno Sakuragi / Taito Ward, Kaminarimon / Taito Ward, Kita Ueno / Taito Ward, Kiyokawa / Taito Ward, Kuramae / Taito Ward, Kojima / Taito Ward, Kotobuki / Taito Ward, Komagata / Taito Ward, Shitaya / Taito Ward, Sensoku / Taito Ward, Taito / Taito Ward, Torigoe / Taito Ward, Nishi Asakusa / Taito Ward, Nihonbashi / Taito Ward, Negishi / Taito Ward, Hashiba / Taito Ward, Hanakawado / Taito Ward, Higashi Asakusa / Taito Ward, Higashi Ueno / Taito Ward, Matsugaya / Taito Ward, Misugis / Taito Ward, Minowa / Taito Ward, Moto Asakusa / Taito Ward, Yanaka / Taito Ward, Yanagibashi / Taito Ward, Ryusen
・Exterior wall painting in Taito, Tokyo, is entrusted to Kakeru Koumuten!
・Roof renovations in Taito, Tokyo, are entrusted to Kakeru Koumuten!
・Exterior renovations in Taito, Tokyo, are entrusted to Kakeru Koumuten!
・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 comparison estimates and key points!
・Top 12 solar power generation manufacturers! Features and selection points are also introduced!
・What are the installation costs for solar power generation? Tips for reducing costs are thoroughly explained!
・What are the best locations for installing solar power generation? Key points for site selection are also introduced!
・Here is the introduction to solar power generation estimates!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!
