Leave Your Solar Panel Installation Work in Kita City, Tokyo to Kakeru Koumuten Co., Ltd.!
For Solar Panel and Storage Battery Installation in
Kita Ward, Tokyo,
trust Kakeru Koumuten!
Kakeru Koumuten is a company specializing in exterior renovations.
As a company strong in roofing work, we are entrusted withsolar panel and storage battery installations that consider roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Kita Ward, Tokyo”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Kita Ward, Tokyo”
We will also explain the above three points!
Installing solar panels can involve risks such as“the occurrence of leaks” and other troubles.
To ensure a satisfactory solar panel installation, we recommend obtainingcomparative estimates from about three companies!
Table of Contents (Tap to Open/Close)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Kita Ward, Tokyo
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Kita Ward, Tokyo
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installation Company in Kita Ward, 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 Kita Ward, Tokyo
- If You Are Looking for a Solar Panel Installation Company in Kita Ward, Tokyo, Contact Kakeru Koumuten
- Characteristics of Kita Ward, Tokyo and Points for Solar Installation
- Service Area in Kita Ward, Tokyo
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Kita Ward, Tokyo
Regarding why we are entrusted with solar panel installation by customers in Kita Ward, Tokyo,
“Our Unique Strengths in Solar Panel Installation That Cannot Be Imitated by Other Companies”
have received high praise from many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We Also Handle Exterior Renovations Other Than Solar Panel Installation!
Issues such as leaks that occur with 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 expertise in roofing 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 and exterior renovation work.
We have established five bases 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 related to scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
Even if there are height differences on the site, our in-house scaffolding team will plan the scaffolding according to the local conditions.
Storage of Materials in Our Large Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, allowing us torespond quickly in emergencies!
Sorting and Transporting Waste Materials In-House
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior Renovation Dedicated Showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on roofing materials!
We can also provide simulations of the revenue and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also have samples of roofing materials and models that show 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 a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof renovations at reduced costs.
Additionally, one representative will handle everything from the estimate to project completion.
Since the representative does not change, whether it’s the sales or construction management staff, smooth communication is possible.
We can perform consistent in-house construction from temporary scaffolding installation, exterior wall painting, to roof renovations!
4. Various Permits and Skilled Workers
We have obtained construction industry licenses and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal and painting technicians on staff, and we are confident in our construction techniques.
We can also handle large-scale roofing projects for factories and other facilities!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty for solar panel installation work, our own construction warranty (leakage warranty) is also included!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, a roof renovation may be required to provide the warranty. The construction warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty details.)
Aftercare is available annually, and we send out 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 for inspections!
During leak investigations, we can also conduct surveys using a thermal imaging camera.
If the power generation of solar panels decreases due to dirt, we can provide cleaning services using specialized brushes.
We will respond according to your preferences.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training so that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
Kakeru Koumuten provides not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar installation guidebook” and a “profit and loss simulation” that takes into account loan interest rates and electricity costs.
The profit and loss simulation can be created for projected cumulative profits and losses over 20 to 30 years.
Even customers who are not familiar with solar installations will receive materials that clearly outline 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 or 30 years.
Confirming “Is it safe to install directly on the current roof?” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, specializing in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing 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 fastening strength and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, Slope, and Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, will affect the power generation. We will create a layout diagram from the drawings and the site, and you can check it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels that can be installed (installation capacity) is determined by the shape and size of the roof. The number of panels that can be installed varies depending on the panel size, so we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will check whether the method involves drilling holes in the roofing material for fastening or using brackets to secure the roofing material. The fixing method varies by technique, so please confirm the waterproofing treatment method for 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, switching to lighter roofing materials may also be an option if necessary. |
| 7. Installation Location of Equipment and Wiring | We will confirm the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect the cost. |
| 8. Ease of Scaffolding Setup and Delivery 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 will also check the width of the front road and any steps on the site during the on-site survey. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproof treatment of fixing parts, cracks or deterioration of slate, condition of substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suited to the type of tile (even methods that do not drill holes in the tiles will 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/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, construction 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, additional costs for solar panel removal will apply. If the roof is deteriorating, it may be more cost-effective in the long run to renovate to a highly durable roofing material before installation.
Kakeru Koumuten Co., Ltd. specializes in roofing work and can also handle solar panel removal in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Kita Ward, Tokyo
Potential Subsidies and Grants in Kita Ward, Tokyo
If you are introducing solar panels or storage batteries in Kita Ward, Tokyo, there is a possibility that the “National,” “Tokyo,” and your local “Kita Ward” systems 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 “Household Solar Power Generation Promotion Project” | Individuals, corporations, or management associations installing a new unused solar power system (output under 50kW, JET certification, etc.) in residential properties within Tokyo. The generated power must be used for residential purposes. Pre-application is required | Existing homes: 15,000 JPY per kW for up to 3.75kW (maximum 450,000 JPY), 12,000 JPY/kW for over 3.75kW to under 50kW New homes: 12,000 JPY/kW for up to 3.6kW (maximum 360,000 JPY), 10,000 JPY/kW for over 3.6kW |
For the fiscal year Reiwa 8, pre-applications are being accepted from May 29 (will end once the budget is reached). From the pre-applications of Reiwa 8, submission of certificates issued by financial institutions will be mandatory at the time of performance reporting. |
| Tokyo “Household Storage Battery Promotion Project” | Owners of eligible devices (storage batteries registered with SII) excluding national and local governments. Must be installed between April 1, Reiwa 8 and March 30, Reiwa 11. If applying after October 1, Reiwa 8, only products registered with the national SII for the fiscal year Reiwa 8 are eligible | Storage 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 devices are installed) Expansion of storage battery units: 60,000 JPY/kWh (maximum 720,000 JPY per household) |
For the fiscal year Reiwa 8, pre-applications are being accepted from May 29. Grant application and performance reporting will start from June 30. |
| Kita Ward “Subsidy for Introducing Renewable Energy and Energy-Saving Equipment” | Residents or businesses located within the ward (owner’s consent is required for rentals). Must introduce unused equipment. Grant application must be submitted before construction starts (generally at least 7 business days in advance) | Solar power generation (general use): 80,000 JPY per kW for outside ward contractors (maximum 200,000 JPY), 96,000 JPY per kW for inside ward contractors (maximum 240,000 JPY) Storage systems (general use): 10,000 JPY per kWh for outside ward contractors (maximum 100,000 JPY), 12,000 JPY per kWh for inside ward contractors (maximum 120,000 JPY) |
For the fiscal year Reiwa 8, the budget was reached at 15:15 on September 25, 2026, and applications are now closed (currently, applications cannot be submitted). |
| National “DR Household Storage Battery Project” (Reiwa 7 Fiscal Year Supplement) | Newly introducing household storage 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 maximum 600,000 JPY per application). | The budget was reached on May 29, 2026, and the public recruitment has ended (there are no plans to reopen public recruitment, and currently, applications cannot 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 renovation of windows (openings) and the structure; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities | Storage battery: 96,000 JPY per household | Budget will end as soon as the 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 reception status on the official site. |
The Tokyo solar power and storage battery subsidy requires prior application. For storage batteries applied for after October 1, 2026, only products registered with the national SII will be eligible, and the equipment requirements will change. The subsidy in Kita Ward requires an application for grant issuance before construction begins, and applications for the fiscal year 2026 have already closed. 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 or starting construction.
Kakeru Koumuten will provide guidance on eligibility conditions and application periods for each program after confirming them.
National Subsidy “DR Home Storage Battery Project (Support Project for the Introduction of Home Storage Systems for DR Resource Implementation)”
The 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). In the fiscal year 2025 supplementary project, the subsidy amount was determined based on a standard amount of 34,500 JPY per 1 kWh of initial effective capacity, 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 grant approval being ineligible.
However, the fiscal year 2025 supplementary applications reached the budget on May 29, 2026, and the public recruitment has ended. The official site also states that there are no plans for reopening public recruitment, and applications are currently not possible. Please check the official site for future public recruitment.
Additionally, there are currently no subsidies confirmed for the installation of solar panels on existing homes.
👉 Here is the official site for the DR Home Storage Battery Project
Tokyo “Promotion Project for the Introduction of Solar Power Generation in Homes”
This subsidy is for those installing unused solar power generation systems in residential homes in Tokyo. The simultaneous installation of storage batteries is not a condition.
●Existing homes: 150,000 JPY per kW for up to 3.75 kW (maximum 450,000 JPY), 120,000 JPY per kW for over 3.75 kW and under 50 kW
●New homes: 120,000 JPY per kW for up to 3.6 kW (maximum 360,000 JPY), 100,000 JPY per kW for over 3.6 kW and under 50 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 50 kW that have obtained JET certification, for use in residential areas. The process involves making a prior application and then applying for the grant after installation. From the fiscal year 2026 prior application, it has become mandatory to submit a certificate issued by a financial institution during the performance report.
The official page of Tokyo states that prior applications have been accepted since May 29, 2026. It will end as soon as the budget is reached, so please check the official page for the reception status.
👉 Here is the official page of Tokyo (Cool Net Tokyo)
Tokyo “Home 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 (up to 1,200,000 JPY per household)
●Additional for DR demonstration participation: 100,000 JPY per unit (150,000 JPY per unit if energy management equipment is installed)
●Battery Unit Expansion: 60,000 JPY per kWh (up to 720,000 JPY per household)
The target is owners of eligible equipment (excluding national and local governments), and installation must occur between April 1, 2026, and March 30, 2027. If applying in advance after October 1, 2026, only products registered in the national SII for the fiscal year 2026 will be eligible.
According to the official Tokyo page, advance applications have been accepted since May 29, 2026. For detailed information, including conditions for combination with solar power generation, please check the official page.
👉 Click here for the official Tokyo (Cool Net Tokyo) page
Kita Ward “Subsidy for the Introduction of Renewable Energy and Energy-Saving Equipment”
This subsidy is for those who install solar power systems, battery systems, high-efficiency water heaters, etc., in residential areas within the ward. If you request construction from a local contractor, the subsidy amount is set higher than for contractors outside the ward.
●Solar Power Generation: 80,000 JPY per kW for outside contractors (up to 200,000 JPY), 96,000 JPY per kW for local contractors (up to 240,000 JPY)
●Battery System: 10,000 JPY per kWh for outside contractors (up to 100,000 JPY), 12,000 JPY per kWh for local contractors (up to 120,000 JPY)
The target is those who reside or have a business within the ward, and conditions include that the equipment must be unused and, in the case of rental properties, the owner’s consent is required. An application for the subsidy must be submitted before the start of construction (generally at least 7 business days in advance), and it is also a condition that the same type of subsidy has not been received in the same fiscal year. While it is possible to combine with other subsidies, the total amount of subsidies cannot exceed the eligible expenses.
However, according to the official Kita Ward page, the total amount of applications for fiscal year 2026 reached the budget amount at 15:15 on September 25, 2026, and acceptance has ended. Please check the official page for future implementation and details.
👉 Click here for the official Kita Ward page
Solar Panel Installation & Battery Installation Price List
⇧Service Menu | For Costs Related to Solar Panel Installation and Battery Installation, Click Here
⇧Service Menu | For Costs Related to Solar Panel Removal and Water Heater Removal, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and batteries should be checked separately as “Equipment Costs (Device Costs)” and “Construction Costs.”
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.
Considerations for Installation Capacity (kW) and 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). Batteries are compared based on the amount of electricity they can store, represented 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 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 factors such as wiring length, scaffolding range, existing roofing materials, and panel layout.)
▶ Installation Menu | Costs for Solar Panel Installation and Battery Installation
Items to Check in the Estimate (Cost Verification)
When comparing estimates, it is common to compare different capacities and equipment. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) should be listed. |
| 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 battery. |
| 3. Battery | Manufacturer, model number, capacity (kWh), range of use 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 the method of securing it (whether it involves drilling holes or clamping). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, and whether there is a monitor to check power generation. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at the fixed points, and whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | How much support is included for applications to the power company, certification for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If roof work and exterior painting are done simultaneously, check that the same scope and quantity are not double-counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters or old panels and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether the price includes tax or is tax-excluded, conditions under which additional costs may arise, and details and duration of manufacturer and workmanship warranties. |
If the capacities differ, both the price and 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 get an estimated quote and income simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can obtain an estimated quote and income simulation!
*The simulation results are estimates. Actual income may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection and replacement.
Customer Feedback
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installations
| Construction Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh |
| Base Mounting Hardware Used |
| Niigata Manufacturing / Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed using catch type hardware gripping the horizontal metal roof (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimates are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that grants are available, and I would like to know how much will be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of the grant, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Kita Ward, Tokyo
There are many solar panel installation companies that serve Kita Ward, Tokyo, and you may be unsure which company to choose.
Therefore, when requesting solar panel installation and battery storage installation work, let’s check the following four points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the existence of warranties and aftercare services
● Obtain estimates from multiple companies (three companies are a guideline)
● Check if they provide support for subsidy applications
By confirming the above four points, you will be able to choose a reliable company.
Have knowledge not only about solar panels but also about roofs
Defective installation of solar panels can sometimes be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient verification of roofs and waterproofing
・Solar panels were installed on a severely deteriorated roof, resulting in leaks
・Solar panels were installed on a roof with a short lifespan, necessitating a renovation to detach and reattach the solar panels 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 unforeseen 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 company, make sure to check for warranties. It is important to confirm not only the duration of the warranty but also the coverage, exclusions, and cost conditions.
While the solar panels and battery storage come with a manufacturer’s warranty, also check for the existence of a workmanship warranty in case leaks occur after installation!
If the company offers a workmanship warranty, they may cover any leaks that occur after installation within the warranty period and conditions.
Additionally, some companies provide aftercare services separate from warranties, so be sure to check if the company you are considering has aftercare services.
Since abnormalities or damages on the roof may not be visible, you might not notice them yourself.
By conducting inspections of hidden areas during aftercare, you can more easily detect abnormalities early, preventing major repairs or breakdowns!
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 unless roof renovation is 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 vary, and warranties and after-sales services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request your preferred contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates,
“Check the estimate items”
“Type of solar panels”
“Warranties and after-sales services”
let’s carefully compare and make a judgment! If the rank of auxiliary materials is low or if processes are skipped, costs can be reduced, so avoid judging solely based on price!
▶ 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 if there are deficiencies in the documents, the grant may not be awarded.
Since there are systems that require prior application, such as the Tokyo Metropolitan subsidy, it is reassuring to have a contractor who supports the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for the Tokyo Metropolitan subsidy, prior application is required) before proceeding with the construction!
For the Tokyo Metropolitan subsidy, after installation, you will need to submit a grant application and performance report, and it will be awarded after review! (The flow of procedures varies by system)
▶ Go to “Subsidies and grants that may be applicable in Kita 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 consumption with solar power becomes attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
Furthermore, the selling price (FIT) for residential use (under 10kW) will be set as “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year” for certifications after October 2025, and the same price will apply for the 2026 fiscal year. After the fifth year, it is generally more advantageous to use it at home (self-consumption) rather than selling it, making the combination with a storage battery a viable option.
👉 Ministry of the Environment | For purchase prices, periods, etc., click here
Advantage 2 Subsidies can be utilized!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
Reducing the actual burden through subsidies is a significant advantage!
In the case of Kita Ward, there may be eligibility for programs from the national government, Tokyo, and Kita Ward. The subsidies for the 2026 fiscal year in Kita Ward have ended (please check the 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 do have operational noise.)
Advantage 4 Heat insulation effects are expected!!
By installing them on the roof or rooftop, the panels block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the temperature of the roof, providing expected heat insulation effects!
（This does not improve the building’s insulation performance itself）
Benefit 5: Electricity can be used even during power outages!!
If a storage battery is installed, it is possible to use electricity even during emergencies such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capabilities, you may be able to use electricity from a dedicated outlet during daytime power generation.
（The devices, output, and duration that can be used during a power outage vary depending on the model and wiring method）
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1: Maintenance costs can be incurred
A particularly overlooked maintenance cost is for the roof where solar panels are installed.
If you perform roof remodeling 10 to 20 years later, there will be costs for removing and reinstalling the solar panels.
If the existing roof is deteriorated, it is reassuring to remodel it with durable roofing materials before installing the solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to deterioration of the storage battery.
It would be reassuring to ask for a simulation considering maintenance costs before introducing solar panels!
Point 2: The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but in methods that fix hardware with screws, etc., to the roofing material and substrate, 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, 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 outputs and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
Choosing Method 1: Compare by Total Output of the Roof
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and it is always better to generate more power!
Solar panels vary in size and output depending on the manufacturer.
A panel with an output of 350W and a panel with an output of 400W may seem like the higher output panel is better at first glance.
However, if the size of the panel does not fit well with the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different 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 a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual power generation (kWh) will vary depending on conditions such as the roof’s orientation, slope, and shading.
Choosing Method 2: Compare by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases over 10 or 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or power generation itself.
Choosing solar panels while considering the degradation rate, rather than just the initial output, will help you avoid regrets!
Choosing Method 3: Compare by Warranty Period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
For output warranties, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies widely!
A longer warranty is always better, so let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Kita City, Tokyo
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Kita City, Tokyo. (Tap to reveal the answers)
How much does it cost to install solar panels and storage batteries in Kita City, 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.
For cost estimates by capacity, please refer to our solar panel and storage battery installation pricing page. We will create a layout diagram from the drawings and site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Kita City, Tokyo?
As of October 6, 2026, Tokyo’s “Solar Power Generation Promotion Project for Households” (for existing homes, 15,000 yen per kW for systems under 3.75kW, with a maximum of 450,000 yen) and “Storage Battery Promotion Project for Households” (100,000 yen per kWh for storage batteries, with a maximum of 1.2 million yen per household) are accepting pre-applications starting May 29, 2026, as listed on the official Tokyo (Cool Net Tokyo) page. In Kita City, there is a subsidy for the introduction of renewable energy and energy-saving equipment (for solar power generation, 80,000 yen per kW for outside contractors, with a maximum of 200,000 yen; for contractors within the district, 96,000 yen per kW, with a maximum of 240,000 yen), but the budget for the fiscal year 2026 was reached on September 25, 2026, and applications have closed. The national DR household storage battery project has also ended its public recruitment.
Since the application status may change, please refer to the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies even after the construction is completed?
This depends on the system. Tokyo’s subsidies require pre-application. Conditions such as whether you can 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 by construction method, and when using a method that fixes 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 propose methods such as roof overlay (cover method) or replacement before installation.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed within 10 to 20 years after installation, 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 on how to proceed with the installation after checking the roof’s condition through a 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 Tokyo Metropolitan Government’s subsidy for storage batteries (for Reiwa 8, it is 100,000 yen per kWh, with a maximum of 1.2 million yen per household) aims to increase self-consumption of electricity generated by solar power. You can compare “solar only” and “solar + storage battery” in a financial simulation for consideration.
How many kW can be installed on my roof? Is it okay for north-facing roofs or those with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and site survey, and provide you with the installation capacity and power generation simulation.
In the Kita Ward, the area is divided into highlands on the west side and lowlands on the east side, with many slopes, so the height differences of the site and the shadows cast by surrounding buildings will differ for each house. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
For the above construction example (4.3 kW solar panels + storage battery), it took about 3 days. The duration may vary if roofing work is done simultaneously or depending on the shape of the roof and installation capacity.
Please note that additional time is required for subsidies and applications to the power company, so please consult us as soon as possible.
What is the current selling price (FIT) for electricity?
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 for the 5th to 10th years, and the same price will apply for the 2026 fiscal year.
The idea is to recover initial costs more quickly in the first four years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that takes into account loan interest rates and electricity prices.
Can you provide maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-service maintenance notices via DM and visits customers who request inspections. We can also clean solar panels with a specialized brush if the power generation decreases due to dirt.
Since it is difficult to check areas on the roof by yourself, please feel free to consult us if you have any concerns.
Can you also renovate roofs that already have solar panels installed?
It is possible. Kakeru Koumuten Co., Ltd. can detach and reattach solar panels in-house, allowing us to perform roof overlay (cover method) or re-roofing after removing the panels, and we will handle everything consistently until they are reinstalled. The removed panels can be stored in our own warehouse.
For costs, please refer to the solar panel detachment and hot water heater removal pricing page.
If you are looking for a solar panel installation company in Kita-ku, Tokyo, please consult Kakeru Koumuten
Our company handles many exterior renovations, including solar panels, roof work, and exterior wall work in Kita-ku, Tokyo.
We receive requests from many customers, including renovation companies and real estate agencies!
Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received great feedback from numerous customers.
We continue to update our construction performance every year, and we will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay (cover method) and re-roofing but also partial roof repairs, exterior painting, and exterior wall cover methods.
We are also happy to handle small jobs like partial repairs and rain gutter cleaning!
In urgent cases like leak repairs, we may be able to provide emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult us!
“I want to know recommended solar panels”, “I want to keep costs down as much as possible”, “I just want an estimate for now”, we will provide the best solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in our customers’ shoes and will propose the best construction plan!
We are confident that we will not lose in terms of cost, quality, and organization compared to other companies in exterior construction!
We are confident, so we welcome competitive estimates!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Characteristics of Kita-ku, Tokyo and Points of Solar Work
Kita Ward has an area of 20.6 square kilometers, making it the 11th largest among the 23 wards. The terrain is distinctly divided into a highland area on the west side and lowland on the east side, with a height difference of about 25m in some places. We have summarized the characteristics of the terrain in Tokyo’s Kita Ward and points to consider when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Tokyo’s Kita Ward and points for solar construction
■ Terrain divided into highlands and lowlands. Check scaffolding, delivery, and shadows for each site
According to the ward’s materials, the areas of Ukima, Akabane Higashi, and Oji Higashi are almost flat, while Akabane Nishi, Oji Nishi, Takinohigawa Nishi, and Takinohigawa Higashi have significant height differences and many slopes. In areas with slopes or height differences, careful planning of scaffolding and delivery routes for equipment such as panels and storage batteries may be necessary. Additionally, the way shadows fall on the roof can change due to slopes and height differences with neighboring houses, so it is important to confirm the panel layout on-site. At Kakeru Koumuten, our own scaffolding team plans the scaffolding according to the site, creates layout diagrams from blueprints and on-site surveys, and you can check the power generation simulation.
■ Lowlands anticipating Arakawa River flooding. Confirm flood risk for equipment installation locations
According to the ward’s materials, flooding is anticipated in the lowland areas if the Arakawa River floods, with deep flooding expected in areas close to the river. Depending on where the power conditioner and storage batteries are installed, separate from the panels on the roof, the impact during flooding may vary. You can check the flood risk for your residence on the ward’s flood hazard map (Arakawa, Sumida River, Kanda River, Shakujii River, storm surge), and please consult with us regarding the installation location and height in conjunction with the installation conditions of the manufacturer you are using.
■ Roof types and ages vary from house to house. Check the roof and waterproofing before installation
Even within the same ward, the types of roofs, ages, and shapes of the sites vary from house to house. At Kakeru Koumuten, we will check the type and condition of the roof and the site situation before installation and propose methods for securing and waterproofing, as well as scaffolding planning.
■ The annual sunshine hours at the Tokyo Observatory are about 1,927 hours
Japan Meteorological Agency’s average values (1991–2020) indicate that the annual sunshine hours at the Tokyo Observatory are approximately 1,927 hours, with January (approximately 193 hours) being the month with the most sunshine, and June during the rainy season (approximately 124 hours) having the least. (This is a reference value, not based on observations within Kita Ward.)
The power generation in Kita Ward can also vary due to the height differences of surrounding buildings and land, so conducting annual power generation simulations and selecting battery capacity to match peak electricity usage times are key points.
Our company handles many exterior construction and solar power projects in Kita 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 Kita Ward, Tokyo
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Kita Ward, Tokyo
Kita Ward Akabane Kita / Kita Ward Akabane Dai / Kita Ward Akabane Nishi / Kita Ward Akabane Minami / Kita Ward Akabane / Kita Ward Iwabuchi-cho / Kita Ward Ukima / Kita Ward Oji Honcho / Kita Ward Oji / Kita Ward Kamijujō / Kita Ward Kamanakazato / Kita Ward Kamiya / Kita Ward Kishi-machi / Kita Ward Kirigaoka / Kita Ward Sakae-machi / Kita Ward Shimo / Kita Ward Showa-machi / Kita Ward Jujo-dai / Kita Ward Jujo Nakahara / Kita Ward Takinogawa / Kita Ward Tabata Shin-machi / Kita Ward Tabata / Kita Ward Toshima / Kita Ward Nakazato / Kita Ward Nakajujō / Kita Ward Nishi-gaoka / Kita Ward Nishi-gahara / Kita Ward Higashi Jujo / Kita Ward Higashi Tabata / Kita Ward Horifune
・For exterior wall painting in Kita, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・For roof renovations in Kita, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・For exterior renovations in Kita, Tokyo, trust Kakeru Koumuten Co., Ltd.!
・Kakeru Koumuten Co., Ltd.施工実績
・Kakeru Koumuten Co., Ltd. after maintenance
・Kakeru Koumuten Co., Ltd.施工メニュー・料金表
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of getting multiple estimates and key comparison points!
・12 major manufacturers of solar power generation! Features and selection tips included!
・What are the installation costs for solar power generation? Tips for reducing costs explained in detail!
・What are the best locations for installing solar power generation? Key points for site selection included!
・Find out more about 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!
