For
Solar Panel and Storage Battery Installation in
Shibuya, Tokyo, trust
Kakeru Koumuten!

Kakeru Koumuten is a specialized exterior renovation company based in Aoba Ward, Yokohama City.
As a company strong in roofing work, we are entrusted with solar panel and storage battery installations that consider roofing and waterproofing!

“How to Choose a Solar Panel Contractor in Shibuya”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Shibuya”
We will also explain the above three points!

Installing solar panels carries risks such as “the occurrence of leaks” and other troubles.
To ensure a satisfactory solar panel installation, we recommend obtaining estimates from about three companies!

For Solar Panel and Storage Battery Installation in Shibuya, Tokyo, trust Kakeru Koumuten
Table of Contents (Tap to Open/Close)
  1. Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Shibuya, Tokyo
  2. Roof Inspection Before Installing Solar Panels
  3. Possible Subsidies and Grants Available in Shibuya
  4. Price List for Solar Panel and Storage Battery Installation
  5. Breakdown of Installation Capacity, Equipment, and Construction Costs
  6. Self-Estimate and Profit Simulation for Solar Power Generation
  7. Customer Testimonials
  8. Case Studies of Solar Panel Installations
  9. How to Choose a Solar Panel Installation Company in Shibuya, Tokyo
  10. Benefits of Introducing Solar Equipment
  11. Points to Consider When Introducing Solar Power Generation
  12. How to Choose Solar Panels
  13. Frequently Asked Questions About Solar and Storage Battery Installation in Shibuya
  14. If You’re Looking for a Solar Panel Installation Company in Shibuya, Contact Kakeru Koumuten
  15. Characteristics of Shibuya, Tokyo and Key Points for Solar Installation
  16. Service Area in Shibuya, Tokyo

Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Shibuya, Tokyo

Link banner to Kakeru Koumuten's strengths introduction page

The reasons why our company is entrusted with solar panel installation by customers in Shibuya, Tokyo include
one reason being that “Kakeru Koumuten serves Kanagawa and Tokyo as its service areas”,
and we have “strengths in solar panel installation that cannot be imitated by other companies”, which has received high praise from many customers.

In solar panel installation projects in Shibuya, we have absolute confidence in “cost, quality, and plans”,
so we would appreciate it if you could compare our estimates with those of other companies.

Because we are confident, we welcome estimates from any number of companies!

1. We Also Handle Exterior Renovations Aside from Solar Panel Installation!

Installation work of solar panels on the roofSolar panels installed on the roof
Troubles 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 you are knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to be knowledgeable about the roof to avoid maintenance and troubles after installation!

Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for rapid response to maintenance and urgent troubles after solar panel installation!

2.Facilities Specialized in Exterior Renovation

Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide low-cost, high-quality solar work and exterior renovations.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.

In-house Ownership of Scaffolding Materials

Entrance to the material storage areaCompany-owned scaffolding materials
To ensure safety during work on the roof, we own the necessary scaffolding materials for temporary scaffolding based on construction conditions and can assemble the scaffolding ourselves.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also cut costs on scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
Even in Shibuya Ward, where plateaus and valleys are intertwined, our own scaffolding team will plan the scaffolding according to the site.

Storage of materials in our large warehouse

Exterior of the material warehouse Interior of the warehouse storing materials
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, we canpurchase materials at a lower cost!
Additionally, we always have stock of roofing materials, so we canrespond quickly in emergencies!

Sorting and transporting waste materials in-house

Waste sorting spaceThe 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 remodeling dedicated showroom

Exterior renovation dedicated showroom exteriorShowroom interior
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on the roofing materials!
It is also possible to simulate the revenue and installation costs when introducing solar panels!

Since roofing and exterior wall work often accompany each other, we also provide samples of roofing materials and models that explain the structure in detail!

3.All Work Performed by Our Own Team

Diagram of the system for performing scaffolding, painting, and roof renovation by our own team

One of Kakeru Koumuten’s major strengths is all work performed by our own team.

By having a consistent system from inquiry to completion, Kakeru Koumuten can provide high-quality roof renovations at reduced costs.
Additionally, one representative will handle everything from the estimate to the completion of the work.
Since the person in charge does not change, whether it is the sales representative or the construction management representative, smooth communication is possible.

We can perform consistent in-house work from temporary scaffolding installation to exterior wall painting and roof renovation!

4. Various Permits and Skilled Workers

Construction industry permit displayDisplay of permits and qualifications obtained by Kakeru Koumuten
We have obtained construction industry permits and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal and painting technicians, and we are confident in our construction skills.
We are capable of handling large-scale roofing work for factories and other facilities!

5. Warranty and Aftercare

Link banner to Kakeru Koumuten's warranty information page

In addition to the manufacturer’s warranty, our solar panel installation work comes with our own workmanship warranty (leakage warranty)!
(The workmanship warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless a roof renovation is performed. The workmanship warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary depending on the warranty details.)
Aftercare maintenance is available annually, and we send out notification DM every year.
If you have any questions about the warranty, please click on the image above!

Maintenance of Solar Power Generation|Thorough Explanation of Importance, Frequency, and Cost Estimates!When introducing solar power generation, it is essential to consider...

6. Flexible and Prompt Response

Roof and solar panel inspection response

Our company is equipped to handle various roof troubles and situations.

If you cannot access the roof at high places, we can respond using a drone!
During leakage investigations, we can also conduct inspections using a thermal imaging camera.

If the power generation of the solar panels decreases due to dirt, we can also perform cleaning with a specialized brush.
We will respond according to the customer’s wishes.

7. Human Resource Development

Training session using models

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 conduct technical training to ensure that each staff member can handle various cases.

Company Overview神奈川で家の外装・屋根の工事、修理なら一番若くて親切な株式会社翔工務店にお任せください。 株式会社翔工務店はリフォームを通して美しく理想の生活空間を創るお手伝いをしています。外装改修、外壁塗装、雨樋修理清掃、屋根の塗装や重ね葺き葺き変えなどの部分的な修理まで、お客様のどのようなご要望にも全力でお応えします。...

8. Creation of Easy-to-Understand Materials and Simulations

Materials and simulation examples provided for solar panel installation

At Kakeru Koumuten Co., Ltd., we provide not only “estimates,” “layout diagrams,” and “power generation simulations” but also a “solar installation guidebook” and a “financial simulation” that takes into account loan interest rates and electricity costs.
The financial simulation can project cumulative income and expenses over 20 to 30 years.
Even customers who are not familiar with solar installations will receive clear documentation that includes important points and potential drawbacks!

We encourage you to obtain comparative estimates and review plans from other companies!

Roof Inspection Before Installing Solar Panels

Once solar panels are installed, they will remain on the roof for 20 to 30 years.
Confirming whether it is safe to install them directly on the current roof is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten Co., Ltd., which specializes in roofing, has compiled the items to check before installation.

1. Type of roofing material and age The method of securing the panels varies depending on the roofing material, such as slate, tiles, metal roofs, or flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first.
2. Condition of the substrate and waterproof sheet If the sheathing or roofing (waterproof sheet) beneath the roofing material is damaged, it can affect the fastening strength and waterproofing. We will also check for any signs of leaks.
3. Orientation, slope, and shade of the roof The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, can affect power generation. We will create a layout diagram from the drawings and the site, and you can confirm it through the power generation simulation.
4. Shape of the roof and available installation area The number of panels (installation capacity) that can be placed depends on the shape and size of the roof. The number of panels that can be installed varies based on their size, so we will compare the overall output of the roof.
5. Method of securing and waterproofing details We will check whether the panels will be secured by drilling holes in the roofing material or by using brackets to hold the roofing material. The method of securing varies by technique, so please confirm the waterproofing treatment of the fastening parts during the estimate.
6. Weight of the roof The roof will become heavier due to the panels. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may be an option if necessary.
7. Location of equipment installation and wiring We will confirm the installation locations for the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect costs.

Securing 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) Waterproofing treatment of fixing parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first.
Tile Roof Fixed with brackets and methods suited to the type of tile (even methods that do not drill holes in the tiles will 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 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, a method that does not drill holes may be chosen.
Flat Roof / Rooftop Fixed by installing a frame Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work.
If you perform roof renovations simultaneously, you may reduce future costs for the removal and reinstallation of solar panels!
If you carry out roof renovations 10 to 20 years after installation, additional costs for the removal and reinstallation of solar panels will apply. If the roof is deteriorating, renovating to a highly durable roofing material before installation may help reduce costs in the long run.
Kakeru Koumuten Co., Ltd. specializes in roofing work and can also handle the removal and reinstallation of solar panels in-house, so please consult us according to the condition of your roof!

▶ Click here for roof renovations in Shibuya, Tokyo

Potential Subsidies and Grants in Shibuya, Tokyo

If you are introducing solar panels or storage batteries in Shibuya, Tokyo, there is a possibility that you may be eligible for programs from “the national government,” “Tokyo,” and “Shibuya City.”
The following information is based on the official pages of each program as of October 7, 2026. The application status may change depending on the budget and application period, so please check the latest information before contracting or starting work.

Eligibility Conditions and Application Period for Subsidy Programs

Program Main Eligibility Conditions Subsidy Amount Application Period & Status
Tokyo Metropolitan “Reiwa 8 Year Household Solar Power Generation Promotion Project” (Cool Net Tokyo) New installation of certified solar modules on residential properties or their premises in Tokyo, 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 mounting, waterproofing, 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 “Reiwa 8 Year Household Storage Battery Promotion Project” (Cool Net Tokyo) New installation of storage batteries in residential properties in Tokyo, with 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 household)
Expansion of storage battery units: 60,000 JPY/kWh (maximum 720,000 JPY per household)
(Additional incentives for participating in DR demonstrations, etc.)
Pre-application: From May 29, 2026
Grant application and performance report: From June 30, 2026
Shibuya Ward “Renewable Energy Power Utilization Promotion Subsidy [For Households]” Individuals registered as residents in the ward must switch to 100% renewable energy-derived electricity and continue using it for more than three months. Installation of solar panels or storage batteries is not eligible. 30,000 Hachipay points From May 1, 2026 to February 28, 2027
(Ends when the budget is exhausted)
National “DR Household Storage Battery Project” (Reiwa 7 Year Supplement) New introduction 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 1kWh (subsidy rate within 3/10; maximum 600,000 JPY per application) The budget was reached on May 29, 2026, and the public offering has ended. (Currently, applications cannot be made)
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 storage battery installation alone. Solar panels are not included as eligible facilities. Storage battery: 96,000 JPY per household Ends when the budget limit is reached. Please check the official website for application status.
Please pay attention to the “order of procedures” for subsidies!
In Tokyo, a pre-application before installation is required for subsidies. If construction begins beforehand, it may not be eligible for Tokyo’s subsidies, and applying does not guarantee approval. The official page for Shibuya Ward does not confirm any local grants for the installation of solar panels or storage batteries. Procedures and eligibility may vary by program, so please check before contracting or starting work.
Kakeru Koumuten Co., Ltd. will guide you on the eligibility conditions for each program after confirming them.

Tokyo “Reiwa 8 Fiscal Year Household Solar Power Generation Promotion Project”

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 that are newly installed 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 yen/kW for up to 3.75kW (maximum 450,000 yen), and 120,000 yen/kW for systems exceeding 3.75kW. Additionally, there are supplementary items such as installation of 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 “Reiwa 8 Fiscal Year Household Storage Battery Promotion Project”

Tokyo is also providing subsidies for newly installed storage batteries in residential homes. The subsidy amount is 100,000 yen per kWh of storage battery package (maximum 1,200,000 yen per household), and for additional storage battery units, it is 60,000 yen per kWh (maximum 720,000 yen per household), with additional amounts for participation in DR demonstrations.

The target is equipment registered with SII (Environmental Collaboration Initiative). If applying for pre-application after October 1, 2026, only equipment listed in the Reiwa 8 fiscal year SII registered products will be eligible. This project is intended for simultaneous installation with solar power, but applications can also be made for storage batteries alone. The application for grants and performance reports has been accepted since June 30, 2026.
👉 Cool Net Tokyo | Official page for storage batteries is here

Shibuya Ward “Renewable Energy Electricity Utilization Promotion Subsidy [For Households]”

The subsidy related to renewable energy for households confirmed on Shibuya Ward’s official page is a system for switching electricity contracts. Individuals registered as residents in the ward must switch to electricity sourced 100% from renewable energy within the fiscal year and continue using it for more than three months after the switch, among other conditions, with a subsidy amount of 38,000 Hachipay points.

The application period is from May 1, 2026, to February 28, 2027, and will end as soon as the budget is exhausted. Applications must be made via smart application, and a continuation report must be submitted within three months of the switch (by February 28, 2027). This is not a system aimed at the installation of solar panels or storage batteries themselves, so please confirm it as a separate system from construction subsidies.
👉 Here is the official page of Shibuya Ward (Subsidy for Promoting Renewable Energy Power Use [for Households])

National Subsidy “DR Household Storage Battery Project (Support Project for Introducing Household Storage Systems for DR Resources)”

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 newly introducing registered products’ storage systems that can be utilized for demand response (DR), and for the fiscal year 2025 supplementary budget, the subsidy amount is determined based on a standard amount of 34,500 yen per initial effective capacity of 1 kWh, with a subsidy rate of up to 30% and a maximum of 600,000 yen per application. There are also conditions such as that contracts or orders made before the grant decision are not eligible.

However, the supplementary budget for fiscal year 2025 reached the budget limit for grant applications 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 possible, so please check the official site for future public recruitment.

Furthermore, there are currently no subsidies confirmed for the installation of solar panels for existing homes.
👉 Here is the official site for the DR Household Storage Battery Project

Solar Panel Installation & Storage Battery Installation Price List

Construction menu for solar panel installation and storage battery installation
⇧ Construction Menu | For costs related to solar panel installation and storage battery installation, click here

Solar Panel Removal and Hot Water Heater Dismantling Service Menu
⇧Service Menu | Click here for costs related to Solar Panel Removal and Hot Water Heater Dismantling

Estimate Guidance

Breakdown of Installation Capacity, Equipment, and Construction Costs

The costs for solar panels and storage batteries should be confirmed by separating them into “Equipment Costs (Device Costs)” and “Construction Costs.”
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.

Understanding Installation Capacity (kW) and 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 (kilowatts). Storage batteries are compared based on the amount of electricity they can store, represented in kWh (kilowatt-hours).
The amount of kW that can be placed on the roof varies for each house based on the roof’s shape, orientation, and size. Kakeru Koumuten will create a layout diagram based on the drawings and on-site survey to present the installation capacity.

On our pricing page, we list solar panels as approximately 800,000 JPY to 1,200,000 JPY for 3-5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6-10 kW. (These are just estimated amounts and can vary based on wiring length, scaffolding range, 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 by only looking at the amounts. Please check if the following items are clearly stated in the estimates from each company!

1. Solar Panels Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) should be specified.
2. Power Conditioner Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Check if it is a type that controls with a battery.
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 method of securing it (whether it is a method that drills holes or a method that clamps and secures).
5. Wiring and Electrical Work Wiring route and length, work around the distribution board, presence of a monitor to check power generation.
6. Roof Reinforcement and Waterproofing Details of waterproofing treatment at the fixed parts, 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 roof work and exterior painting are done simultaneously, check that the same scope and quantity are not counted twice.
9. Removal and Disposal Whether the removal of existing solar thermal water heaters or old panels and disposal costs for waste materials are included.
10. Tax Classification and Warranty Whether prices are tax-inclusive or tax-exclusive, conditions under which additional costs may arise, details and duration of manufacturer warranty and workmanship warranty.
Tips for Comparison: “Installation Capacity (kW)” and “Equipment Model Number” should be aligned for comparison!
If the capacity differs, both the amount and power generation will change. Kakeru Koumuten Co., Ltd. welcome competitive quotes, so if you bring estimates from other companies, we will explain the differences for each item!

Self-Estimate and Profit and Loss Simulator for Solar Power Generation

Self-Estimate and Profit and Loss Simulator for Solar Power Generation

With the simulator above,
you can get an approximate estimate and a profit and loss 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 approximate estimate and profit and loss simulation!
*The simulation results are approximate. Actual profits and losses will vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection and replacement.

Customer Feedback

Examples of Solar Panel Installation

BEFORE

Metal roof before solar panel installation

AFTER

Roof after 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 class
Base Mounting Hardware Used
 Niigata Manufactured / Aluminum Catch Type Hardware
Fixing Method & Waterproofing Arrangement
 Fixed by gripping the horizontal metal roof with catch type hardware (Catch Method)
Price Range
 2,200,000 JPY~2,300,000 JPY
 ※Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY
 Estimated recovery period for construction costs: about 8 to 9 years (self-consumption)

 ※The grant amount and recovery estimate are based on the system and calculations at the time of construction, and may differ under the current system.
Construction Period
 Approximately 3 days
Completion Month
 April 2025
Inquiry Details
I am considering the installation of solar panels and storage batteries.
I heard that grants are available, and I would like to know how much will be provided.

Our Proposal

We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement when solar panels are placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of the grant, so we explained it to the customer along with the estimate!

How to Choose a Solar Panel Installation Contractor in Shibuya, Tokyo

There are many solar panel installation contractors available in Shibuya, Tokyo, and you may be unsure which one to choose.

Therefore, when requesting solar panel installation and battery installation work, make sure to check the following 4 points.

● Knowledge of roofs as well as solar panels

● Confirm the presence of warranties and aftercare services

● Obtain estimates from multiple contractors (3 companies is a guideline)

● Check if they provide support for subsidy applications

By confirming the above 4 points, you will be able to choose a reliable contractor.

Which Solar Power Installation Company is Best? Introducing How to Choose Without Regret!When considering the introduction of solar power generation, the mos...

Knowledge of roofs as well as solar panels

Defective installation of solar panels may be caused by a lack of knowledge and confirmation 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 checks on roofs and waterproofing

・Solar panels installed on a severely deteriorated roof, leading to leaks
・Solar panels installed on a roof with a short lifespan, requiring removal and reinstallation within a few years
・Incorrect treatment due to misjudging the type of waterproofing, 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 unforeseen troubles.

▶ Go to “Roof Check Before Installing Solar Panels” in this article

Confirm the presence of warranties and aftercare services

When choosing a solar installation contractor, 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 units come with a manufacturer’s warranty, also check for the presence of a workmanship warranty in case leaks occur after installation!

For contractors that offer a workmanship warranty, if leaks occur after installation within the warranty period and conditions, they may be able to address the issue under the warranty.

Additionally, some contractors offer after-sales service separate from warranties, so be sure to check if the contractor you are considering has after-sales service.
Changes or damage on the roof may occur in areas that are not visible, so there is a possibility that customers may not notice them.
By conducting inspections during after-sales maintenance, even in areas that are not visible, it becomes easier to detect abnormalities early and prevent major repairs or failures!

Kakeru Koumuten Co., Ltd. provides a rain leak warranty as part of the workmanship warranty for solar panel installations. (The warranty for solar panel installations is 10 years, and depending on the condition of the roof before installation, a roof renovation may be required to provide the warranty.)
We also conduct after-sales maintenance and send out annual DM!
Please check the DM, and if you wish, we will visit for after-sales maintenance!

About Kakeru Koumuten Co., Ltd. WarrantyKakeru Koumuten Co., Ltd. provides a simple explanation of our roof construction, exterior wall painting, and sealing work guarantees!! We do not require any advance or interim payments!!...

Obtain estimates from multiple contractors (3 companies as a guideline)

When requesting solar panel installation, be sure to obtain estimates from multiple contractors.

Even for the same manufacturer and the same construction content, costs may vary, and warranties and after-sales 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-sales services”

and make a detailed comparison to make your judgment! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making judgments based solely on price!

▶ Go to “Breakdown of Installation Capacity, Equipment, and Construction Costs” in this article

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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 subsidy may not be granted.
There are systems that require personal applications and cannot be handled by the contractor, as well as systems that require prior application before installation, so it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Complete the procedures specified for each system (for Tokyo subsidies, a prior application before installation is required) 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 Shibuya Ward” within this article

Benefits of Introducing Solar Power Equipment

The benefits of introducing solar panels are summarized in the following five points!

Benefit 1: Economic Benefits

Household budget illustration

The biggest benefit of introducing solar panels is the economic advantage!
Although the selling price of electricity has decreased compared to ten years ago, you can gain benefits by reducing the electricity you buy from power companies through self-consumption of the generated power!
As electricity prices rise, the ability to cover your consumption with solar power becomes attractive!
If you plan to use the generated power at night, installing a storage battery is essential!

Furthermore, the selling price (FIT) for residential use (under 10kW) will be set at “24 yen/kWh for the first four years, and 8.3 yen/kWh from the fifth to the tenth year” for certifications after October 2025, and the same price will apply for the 2026 fiscal year. After the fifth year, it is likely to be more advantageous to use it at home (self-consume) rather than selling it, making the combination with a storage battery an option.
👉 Ministry of the Environment and Energy | For purchase prices, periods, etc., click here

Benefit 2 You Can Utilize Subsidies!

Illustration of a person happy to reduce costs

The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the requirements, you may be able to utilize subsidies!
The reduction of the actual burden amount through subsidies is a significant benefit!
In the case of Shibuya Ward, there may be national and Tokyo metropolitan systems applicable (the official page of Shibuya Ward does not confirm any unique grants for the installation of solar panels or storage batteries).

Benefit 3 Environmentally Friendly!

Environmentally friendly solar power illustration

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 Shielding Effect!!

Illustration of heat shielding by solar panels

By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the temperature rise of the roof, so a heat shielding effect can be expected!
(Note that this does not improve the insulation performance of the building itself.)

Advantage 5 Electricity can be used even during power outages!!

Illustration of a house that can use electricity during a power outage

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 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.)

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What Points Should Be Noted When Introducing Solar Power Generation?

Next, we will explain the “3 Points to Note” when installing solar panels!

Illustration of a person explaining points to note

Point 1 Maintenance Costs are Required

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 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 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 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 fastening points is crucial.
In methods that involve making holes in the roof, there is inevitably a risk of leaks.
Of course, we will ensure proper 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 fastener for horizontal metal roofsCatch-type base fastener for horizontal metal roofs

Note 3: The roof will become heavier

With the addition of 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.

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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 in the limited area, and the more electricity generated, the better!

Solar panels come in various sizes and outputs depending on the manufacturer.
A panel with 350W output and a panel with 400W output may seem that the higher output panel is better at first glance.
However, if the size of the panel does not fit well with the roof, “20 panels of 350W can be installed, while only 15 panels of 400W can be installed,” indicating that the number of panels that can be installed may differ even 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). The 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 reduction after long-term use varies by product. The manufacturer’s output guarantee value serves as a standard for warranty purposes and does not indicate the actual degradation rate or the amount of electricity generated.
Choosing solar panels while considering both the initial output and the degradation rate will lead to a decision without 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 differ by manufacturer.
Regarding output warranties, some manufacturers offer a 30-year warranty, while others provide a 10-year warranty, making it quite varied!
Generally, the longer the warranty, the better, so be sure to check the warranty periods and conditions of the manufacturers you are considering!

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Frequently Asked Questions about Solar Power and Storage Battery Installation in Shibuya Ward

We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Shibuya Ward. (Tap to open the answers)

How much does it cost to install solar panels and storage batteries in Shibuya 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 for different capacities are available on our 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 power and storage battery installation in Shibuya 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) will be eligible from pre-applications made after October 1, 2026. The national DR household storage battery project has ended its public recruitment.

Since the application status may change, please refer to the subsidy and grant section and consult with us before signing a contract.

Can I apply for subsidies even after the construction is completed?

In many cases, procedures are required before construction. Tokyo’s subsidies require pre-application before installation, and if you install first, you will be ineligible. The 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 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 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. If deterioration is progressing, we can also propose methods such as roof overlay (cover method) or complete replacement before installation.

My roof is old. Should I do a roof renovation first?

It depends on the condition of the roof. If a roof renovation is needed within 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the remaining lifespan of the roof is short, renovating with durable roofing materials before installation may help reduce total costs.

Please consult us about the installation process 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 is designed for simultaneous installation with solar panels, but you can also apply for just the storage battery. 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, we create a layout diagram from the drawings and site survey, and provide you with the installation capacity and power generation simulation.

Even in residential areas of Shibuya Ward, the shading from neighboring houses and surrounding buildings varies from one house to another. 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 if roofing work is done simultaneously or depending on the roof’s shape and installation capacity.

Additionally, there will be a separate period for applying for subsidies and to the power company, so please consult us as soon as possible.

What is the current selling price (FIT)?

For residential use (under 10 kW), the price 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, with the same prices applying for the 2026 fiscal year.

The idea is to recover initial costs quickly in the first 4 years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that takes into account loan interest rates and electricity costs.

Can you handle maintenance and inspections after installation?

Yes, we can. Kakeru Koumuten sends out annual after-maintenance DM notifications and visits customers who wish to have inspections. We can also clean solar panels with a special brush if the power generation decreases due to dirt.

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 renovate a roof that already has 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 water heater removal pricing page.

Get a free estimate for solar panels and storage batteries in Shibuya

Estimates are completely free. We welcome competitive estimates!

If you are looking for a solar panel installation contractor in Shibuya, please consult Kakeru Koumuten

Our company handles many exterior renovations, including solar panel installations, roof work, and exterior wall work in Shibuya, Tokyo.
We receive requests from a wide range of customers, including renovation companies and real estate agencies!

Kakeru Koumuten promises “high-quality renovations at low cost”, and we have received positive feedback from many 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 optimal solutions for your specific requests.
We will never propose unnecessary work focused on profit!
We always stand in our customers’ shoes and propose the best construction plans!

We are confident that we will not be outdone by other companies in terms of cost, quality, and organization for exterior work!
We 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 Shibuya, Tokyo and Points for Solar Work

Shibuya, Tokyo, is a ward located in the southwestern part of the 23 wards of Tokyo. According to the official page of Shibuya, the area is 15.11 km2, with about one-tenth occupied by green spaces such as Meiji Shrine, Yoyogi Park, and part of Shinjuku Gyoen. The terrain corresponds to the Yodobashi Plateau of Musashino, with valleys formed by the Shibuya River and others.
Below are summarized the residential environment of Shibuya and points to consider when installing solar panels and storage batteries. (Tap to open)

View the characteristics of Shibuya, Tokyo and points for solar work

■ In areas where plateaus and valleys are intertwined, confirm the installation locations of storage batteries and power conditioners along with flood risk

Shibuya Ward features a mix of plateaus and valleys such as the Shibuya River, resulting in varying elevation levels. On the ward’s flood hazard map and flooding records page, you can check flood expectations and past flooding incidents. When deciding on the installation locations for storage batteries and power conditioners, it is advisable to check the flood risk for your residence on the hazard map and consider the height and position of the installation for peace of mind.

■ Tokyo’s annual sunshine duration is approximately 1,927 hours

According to the Japan Meteorological Agency’s average values (1991–2020), Tokyo receives about 1,927 hours of sunshine annually.
The power generation varies by season, so it is important to conduct an annual power generation simulation and choose the capacity of the storage battery to match the times when electricity consumption is high.

■ In areas with closely situated houses, check for shadows from neighboring houses and buildings

In places where houses are closely built, the shadows cast by neighboring houses and 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.

■ On slopes and narrow roads, plan scaffolding and equipment delivery carefully

In residential areas with elevation differences or narrow front roads, careful planning for scaffolding and equipment delivery may be necessary. Kakeru Koumuten will respond to site conditions with our own scaffolding team and scaffolding materials.

■ Check the roof condition according to the age of the building

For houses that have been built for several 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 prior application to Tokyo Metropolitan Government

Subsidies from the Tokyo Metropolitan Government require a prior application to Cool Net Tokyo before installation. The official page for Shibuya Ward does not confirm any local grants for solar panel and storage battery installations, so it is important to check the procedures and timelines for the Tokyo Metropolitan Government’s system in advance, in conjunction with the timing of the construction.

Our company serves Kanagawa Prefecture and Tokyo, and we handle many exterior and solar construction projects in Shibuya Ward, Tokyo.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us about any sudden troubles!

Service Area in Shibuya Ward, Tokyo

Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and all of Tokyo.

List of Areas in Shibuya Ward, Tokyo

Uehara, Shibuya Ward / Uguisudani-cho, Shibuya Ward / Udagawacho, Shibuya Ward / Ebisu Nishi, Shibuya Ward / Ebisu Minami, Shibuya Ward / Ebisu, Shibuya Ward / Oyama-cho, Shibuya Ward / Kamiyama-cho, Shibuya Ward / Sakuragaoka-cho, Shibuya Ward / Sasazuka, Shibuya Ward / Sarugakucho, Shibuya Ward / Shibuya, Shibuya Ward / Shoto, Shibuya Ward / Shinsen-cho, Shibuya Ward / Jingumae, Shibuya Ward / Jinnan, Shibuya Ward / Sendagaya, Shibuya Ward / Daikanyama-cho, Shibuya Ward / Tomigaya, Shibuya Ward / Dogenzaka, Shibuya Ward / Minamidai-cho, Shibuya Ward / Nishihara, Shibuya Ward / Hatagaya, Shibuya Ward / Hachiyama-cho, Shibuya Ward / Hatsudai, Shibuya Ward / Higashi, Shibuya Ward / Hiroo, Shibuya Ward / Honmachi, Shibuya Ward / Maruyama-cho, Shibuya Ward / Moto-Yoyogi-cho, Shibuya Ward / Yoyogi Kamiyama-cho, Shibuya Ward / Yoyogi, Shibuya Ward

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For roof, gutter and exterior construction and repairs in Kanagawa,
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!