Leave the installation of solar panels in Hamura City, Tokyo to Kakeru Koumuten Co., Ltd.!

For solar panel and battery installation in
Hamura City, 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 withsolar panel and battery installation considering roofing and waterproofing!

“How to Choose a Solar Panel Contractor in Hamura City”
“About the Costs of Solar Panel and Battery Installation”
“Subsidies Available for Solar System Installation in Hamura City”
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 obtainingthree or so estimates!

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

The reasons why our company is entrusted with solar panel installation by customers in Hamura City, Tokyo
One reason is that “Kakeru Koumuten serves Kanagawa and Tokyo as its service areas.” Additionally,
“We have unique strengths in solar panel installation that cannot be imitated by other companies,” which has received positive feedback from many customers.

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

1. We Also Handle Exterior Renovations Beyond Solar Panel Installation!

Troubles such as leaks that occur during solar panel installation may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if you are knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have knowledge 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 quick responses to maintenance and urgent troubles after solar panel installation!

2.Facilities Specialized in Exterior Renovation

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

In-house Ownership of Scaffolding Materials

To ensure safety during work on the roof, we own the necessary scaffolding materials for temporary scaffolding based on construction conditions, allowing us to set up scaffolding ourselves.
By conducting scaffolding work with our own scaffolding team instead of outsourcing, we can also reduce scaffolding construction costs.
We have scaffolding materials for approximately 50 single-family homes!
In Hamura City, our own scaffolding team will plan the scaffolding according to the site conditions.

Storage of materials in our large warehouse

We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, we canpurchase materials at a lower cost!
Additionally, since we always have a stock of roofing materials, we canrespond 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 remodeling dedicated showroom

In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on the roofing materials!
Simulations for potential earnings and installation costs when introducing solar panels are also available!

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 all work performed by our own team.

By having a consistent system from inquiry to completion, Kakeru Koumuten can provide high-quality roofing renovations at reduced costs.
Additionally, one representative will handle everything from the estimate to the completion of the work.
Since the same person will be in charge, whether it’s sales or construction management, smooth communication is possible.

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

4. Obtaining Various Permits and Skilled Workers

We have obtained construction industry permits and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal and painting technicians, and we are confident in our construction skills.
We can also handle large-scale roofing work for factories and other facilities!

5. Warranty and Aftercare

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

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

We are equipped to handle various roof troubles and situations.

If we cannot access the roof at high altitudes, we can utilize a drone for inspection!
During leakage investigations, we can also conduct surveys using a thermal imaging camera.

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

7. Human Resource Development

We create various roof models for skill enhancement and conduct practical training.
Since the installation 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.

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 Clear Materials and Simulations

At Kakeru Koumuten Co., Ltd., we provide 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.
We compile easy-to-understand materials that include important points and disadvantages for customers who may not be familiar with solar installations!

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.
It is crucial to confirm “whether it is safe to install them directly on the current roof” before installation, as this is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten Co., Ltd., which specializes in roofing work, has summarized the items to check before installation.

Fixing Methods and Checkpoints by Roofing Material

▶ Click here for roof renovations in Hamura City, Tokyo

Possible Subsidies and Grants in Hamura City, Tokyo

If you are introducing solar panels or storage batteries in Hamura City, Tokyo, there may be applicable systems from “the national government,” “Tokyo,” and “Hamura City.”
The following information is based on the official pages of each system as of October 7, 2026. The application status may change due to budget and recruitment periods, so please check the latest information before contracting or starting work.

Eligibility Conditions and Application Timing for Subsidy Programs

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

In Tokyo, subsidies are provided for installing solar power generation systems in residential homes through Cool Net Tokyo. The target is systems using certified solar modules installed newly in residential homes or on their premises, with a capacity of less than 50 kW. A pre-application before installation is required.

For existing homes, the subsidy amount is 150,000 JPY/kW for 3.75 kW or less (maximum 450,000 JPY), and 120,000 JPY/kW for over 3.75 kW. 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 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 JPY per kWh for storage battery packages (maximum 1,200,000 JPY/unit), and 60,000 JPY per kWh for additional storage battery units (maximum 720,000 JPY/unit), with additional amounts for participation in DR demonstrations.

The target is equipment registered with SII (Environmental Collaboration Initiative). If applying after October 1, 2026, only equipment listed in the Reiwa 8 year SII registered products will be eligible. This project is intended for simultaneous installation with solar power, but applications can 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

Hamura City “Reiwa 8 Year Environmental Consideration Project Subsidy System”

Hamura City is implementing an Environmental Consideration Project Subsidy System targeting solar power generation systems (energy creation menu) and storage batteries (rationalization menu). Subsidies are provided in the form of “eco-points” that can be used for consumption within the city. In Reiwa 8 year, the budget limit was reached at 5 PM on September 28, 2026, and applications have ended (as of October 7, 2026).

According to the city brochure (April of Reiwa 8), the solar power generation system covers half of the eligible expenses, with a maximum of 110,000 yen or 13,000 yen per kW for local businesses, and 55,000 yen or 6,000 yen per kW for businesses outside the city. The storage battery has a fixed amount, with 40,000 yen for local businesses and 20,000 yen for outside businesses for standalone units, and 70,000 yen for local businesses and 35,000 yen for outside businesses when combined with power generation equipment. The equipment to be installed must be unused, and lease contracts are not eligible.
Please check the official page and counter of the Hamura City Environmental Policy Division for information on the existence and content of the system in the following years.
👉 Here is the official page of Hamura City (Environmental Consideration Business Subsidy System)

Solar Panel Installation & Storage Battery Installation Price List

⇧ Service Menu | For costs related to solar panel installation & storage battery installation, click here

⇧ Service Menu | For costs related to solar panel removal & hot water heater removal, click here

Breakdown of Installation Capacity, Equipment, and Construction Costs

The costs for solar panels and storage batteries should be checked separately for “equipment costs (device costs)” and “construction costs”.
Even for the same “solar panel installation set,” the amount can vary significantly depending on the installation capacity, the grade of the equipment, and the condition of the roof.

Considerations for Installation Capacity (kW) and Battery Capacity (kWh)

The installation capacity of solar panels is determined by “the output of one panel (W) × number of panels”, with the unit being kW (kilowatt). Storage batteries are compared based on the amount of electricity they can store, represented in kWh (kilowatt-hour).
The amount of kW that can be installed on the roof varies for each house based on the shape, orientation, and size of the roof. Kakeru Koumuten Co., Ltd. creates layout diagrams from blueprints and on-site surveys to present the installation capacity.

On our pricing page, we list solar panels as approximately 800,000 JPY to 1,200,000 JPY for 3-5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6-10 kW. (These are just approximate amounts and can vary based on wiring length, scaffolding range, existing roofing materials, and panel layout.)
▶ Service Menu | Click here for costs of 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 by just looking at the amounts. Please check if the following items are clearly stated in each company’s estimate!

Self-Estimate and Profit Simulation for Solar Power Generation

With the simulator above,
you can get an estimated quote and a profit simulation for up to 30 years!
If you know the total installation capacity of the solar panels on the roof and the capacity of the storage battery, you can get an estimated quote and profit simulation!
*The simulation results are estimates. Actual profits will vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection or replacement.

Customer Voices

Case Studies of Solar Panel Installation

How to Choose a Solar Panel Installation Contractor in Hamura City, Tokyo

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

Therefore, when requesting solar panel installation and battery storage installation work, let’s confirm the following 4 points:

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

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Knowledge of roofs as well as solar panels

Improper installation of solar panels can be caused by a lack of knowledge and confirmation regarding roofs and waterproofing.
While knowledge of solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.

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

Confirm the existence of warranties and aftercare services

When choosing a solar installation contractor, let’s confirm the existence of warranties. It is important to check not only the duration of the warranty but also the coverage, exclusions, and cost conditions.

While the solar panels and battery storage units come with manufacturer warranties, also check for the existence of workmanship warranties in case leaks occur after installation!

For contractors that offer workmanship warranties, if leaks occur after installation, they may be able to respond under the warranty, provided it is within the warranty period and conditions.

Additionally, some contractors offer after-sales service separate from the warranty, so be sure to check if the contractor you are considering has after-sales service.
Since abnormalities or damage on the roof can occur in areas that are not visible, there is a possibility that customers may not notice them.
By conducting inspections in after-sales maintenance, we can detect abnormalities early, making it easier to prevent 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 installations is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovation is performed.)
We also conduct after-sales maintenance and send out DM every year!
After checking the DM, 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, as well as warranties and after-sales services.

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”
“Warranty and after-sales service”

and make a detailed comparison for your judgment! If the rank of auxiliary materials is low or if steps 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

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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 applied for 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’s subsidy, prior application before installation) before proceeding with the construction!

In the case of subsidies in Tokyo, after the completion of the work, an application for disbursement and performance report will be submitted, and it will be disbursed after examination! (The procedure varies depending on the system)

▶ Go to “Subsidies and Grants that May Be Applicable in Hamura City” within this article

Benefits of Introducing Solar Power Equipment

The benefits of introducing solar panels are as follows!

Benefit 1: Economic Advantage

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

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

Benefit 2: You Can Utilize Subsidies!

The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the conditions, you may be able to utilize subsidies!
The reduction of the actual burden amount due to subsidies is a significant advantage!
In the case of Hamura City, there may be applicable systems from the national government and Tokyo (the application for Hamura City’s environmental consideration project subsidy program for the 2026 fiscal year has ended).

Benefit 3 Environmentally Friendly!

Solar power generation has low carbon dioxide emissions and can reduce dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices such as power conditioners do have operational noise.)

Benefit 4 Expect Heat Insulation Effects!!

By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, this can help reduce the temperature of the roof, providing expected heat insulation effects!
(Note that this does not improve the building’s insulation performance itself.)

Benefit 5 Power can be used even during power outages!!

If a storage battery is installed, it becomes possible to use electricity even during emergencies such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capabilities, 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 “three points to note” when installing solar panels!

Point 1 Maintenance costs can be incurred

A particularly overlooked maintenance cost is for the roof where solar panels are installed.
If you perform roof renovations 10 to 20 years later, there will be costs for removing and reattaching the solar panels.
If the existing roof is deteriorating, it is reassuring to renovate it with durable roofing materials before installing solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.

It would be reassuring to ask for a simulation that considers maintenance costs before introducing solar panels!

Point 2 The risk of leaks increases depending on the roofing material

The fixing methods for slate roofs and tile roofs vary by construction method, but when using screws or other fasteners to secure the roofing material and substrate, waterproofing of the fixed areas becomes crucial.
If the method involves making holes in the roof, there will inevitably be a risk of leaks.
Of course, we will ensure proper waterproofing, 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 metal fittings for horizontal metal roofs

Note 3: The roof will become heavier

To install solar panels, the roof will become heavier. After investigating the existing roof, substrate, and load-bearing capacity, switching to a lighter roof may be one 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.
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 better to generate more power!

The sizes and outputs of solar panels vary by manufacturer.
While a 350W output panel may seem less impressive than a 400W output panel, the actual performance can differ based on how well the panel size fits the roof. For example, “20 panels of 350W can be installed” while “15 panels of 400W can be installed,” meaning the number of panels that can be installed on the same roof can vary 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 can be higher!

It is important to consider the total output of the roof rather than just the output of a single panel!
*The above calculations are for total output (kW). The actual generated power (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 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.
By considering the degradation rate along with initial output, you can choose solar panels without 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.
Regarding output warranties, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies widely!
Since a longer warranty is generally better, let’s check the warranty periods and conditions of the manufacturers you are considering!

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Frequently Asked Questions about Solar and Storage Battery Installation in Hamura City

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

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

Our company handles a wide range of exterior renovations, including solar panels, roof work, and exterior wall work in Hamura City, Tokyo.
We have received requests from many customers, including renovation companies and real estate agencies, who have contacted us!

Kakeru Koumuten promises “high-quality renovations at low costs”, and we have received positive feedback from numerous customers.
We continue to update our annual construction achievements and will strive to improve quality to satisfy even more customers in the future.

Our company can perform all exterior renovations, including roof overlay work, roof replacement work, partial roof repairs, exterior painting, and exterior cover methods, all with our own team.
We are also happy to assist with small jobs such as partial repairs and rain gutter cleaning!

In urgent cases such as leak repairs, we may be able to provide emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult with us!

“I want to know about recommended solar panels“, “I want to keep costs as low as possible“, “I just want an estimate for now“, and other specific requests will be met with optimal solutions.
We will never propose unnecessary work that prioritizes profit!
We always stand in the customer’s position and will propose the best construction plan!

We are confident that we will not be outdone in terms of cost, quality, and organization compared to other companies in exterior work!
We are confident, so we welcome competitive estimates!
Estimates are completely free, and if we are found to be inferior to other companies, you are free to decline!

Characteristics of Hamura City, Tokyo, and Points for Solar Work

Hamura City is located in the western part of Tokyo, along the Tama River. The official page of Hamura City provides a flood hazard map and a landslide hazard map (disaster prevention map Hamura).
We have summarized the residential environment of Hamura City and points to consider when installing solar panels and storage batteries below. (Tap to open)

Our company serves Kanagawa Prefecture and Tokyo, and we handle many exterior construction and solar projects in Hamura City, 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 Hamura City, Tokyo

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

We welcome inquiries via LINE as well◎

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