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Three Types (Pelton, Screw, Undershot) of Small Hydropower Generator

Three Types (Pelton, Screw, Undershot) of Small Hydropower Generator

Bamboo Chemical Laboratory, Ltd.

3 Types of Small Hydroelectric
Generators with 10kW Power in
maximum for Various Head at Low Initial Cost

Our small-scale hydroelectric power generators that utilize river water can be optimally selected and applied corresponding the locational conditions such as water flow and head. The range of power generation output is 10kW or less generated by relatively small-capacity turbine. Since our small-scale generators can be decentralized in immediate surroundings of rivers and canals, the equipment can be installed at a lower cost compared to large-scale types. In addition, the capital investment is more easily estimated than large-scale types.

Major Features and Advantages

① Three types of products are highly reliable equipment configurations and suitable for introduction and operation.
② The total generation efficiency is equal to or higher than conventional products.
③ The safety system can always work and automatically retract the turbine generator so as not to be damaged in
  abnormal conditions.
④ Onsite incidental work is minimal, and equipment costs are lower than conventional equipment by other companies.


Pelton type (horizontal axis)

Pelton type (vertical axis)

Screw type

Undershot type

Technology Data

Possible applications

Among the three types of generators, the Pelton type for high head generates power by the water pressure derived from height difference between the water intake and the turbine, and flow rate. It takes water from a high place in the river, supplies water to the Pelton turbine generator installed at a low position with a pressure pipe over a long distance.

In addition, the screw type and undershot type for low head are installed immediately to an existing weir (or additional head work might be required) with a width of 2 to 5 meter and a head of 1 to 3 meter, and utilize water falling from the weir to drive the water wheel to generate electricity.

The choice for low head between the screw type or the undershot type is determined by the locational conditions to be considered for installation and the effect on the water.

The following conditions are basic specifications.
・ Pelton type small hydropower generator has 30 meters head or more, flow rate of 5 L/sec or more
・ Screw type small hydropower generator has one meter head or more, flow rate of 200 L/sec or more
・ Undershot wheel type small hydropower generator has one meter head or more, flow rate of 800 L/sec or more

Competitive advantage

In general, in developing countries, there are many small and medium-sized irrigation canals in familiar places, so there are many places where such small and inexpensive generators are highly recommended to install.

The initial cost and operation cost at the site are relatively inexpensive compared to conventional products. The initial cost per kW is 1.7 million yen which is almost 70% of the initial cost of the conventional product.

The estimated initial and operation cost are as follows;
・ Water turbine generator 5 kW type set costs 8.5 million JPY

The cost of this turbine generator depends on the power generation capacity and condition of installation.
・ Operating cost is about 100,000yen/year for wear and tear parts for maintenance.
・ The wear and tear parts at the initial stage only will be delivered when the equipment is installed.


                                                    Table 1 Introduction of small hydropower generation

Features ——-Highly reliable configuration and generation efficiency
Our technologies include low head handling, cost savings, and a height adjustment mechanism for undershot hydropower generators.
Please refer to the attached brochures in detail.
Horizontal axis Pelton type hydropower generator
Vertical axis Pelton type hydropower generator
Screw type hydropower generator
Undershot type hydropower generator

Technical maturity / Past record of introduction

The company has so far installed 23 small hydropower units of the three types. In 2020, the company will install one unit of undershot type in Japan.
                                               Table 2 Installed generators of domestic and international

Information on patent related to this technology

Screw type
Patent No. 6020988
The company are currently applying for a patent on the undershot water type.

Company Data


Bamboo Chemical Laboratory, Ltd.
(A venture from National Institute of Technology, Anan College)

Address 265-1 Aoki, Minobayashi-cho, Anan-shi, Tokushima, 774-0017 Japan
Capital 6 million JPY (as of 31 January, 2020)
Contact person

Mr. Masayuki TSURUHA (Representative)
Tel : +81-0884-49-4234   Mobile : +81-90-7579-6510

Number of employees 4 (as of 31 January, 2020)
Date of company foundation 10 October, 2010
The type of business

Engineering and manufacturing of equipment for production


International operation

Number of employees for international operation 
Overseas offices
City, Country Name of Company
(if applicable)

Modality of business transaction

In addition, after we conclude a partner agreement with a local company which has a certain level of technology and skills that can deal with the actual local circumstances.
We conclude a partner agreement with another company, including on-site investigation, feasibility study, local installation work, operation confirmation and operation.
A local company will be in charge of business under the guidance of engineers dispatched from us. 

Export of product
Basically, we manufacture in Japan and export our products of standard hydroelectric generators, and conduct on-site preliminary surveys, technical guidance on installation and operation by engineers dispatched from our company.


Schematic illustration of the technology

Message to customers
We are pleased to provide you with a system that generates electricity by utilizing water power in your country.
In particular, we are sure that our three types of small hydropower equipment will definitely help you.
We hope that you can select the method that suits your location from these three methods.

Our product concepts are
①Small-scale decentralized type that can be easily introduced.
②High equipment reliability and high efficiency of power generation
③Low initial investment: 1.5-2 million Japanese yen/kW

We look forward to your order. If you have any questions, or wish for a consultation, please do not hesitate to contact us by telephone / email of the contact information on the previous page.

Contact Person(s)

Mr. Masayuki TSURUHAE-mail:

*Please mention that you saw UNIDO's website when making the first contact with the company.

Registered Category

  • Energy Technologies : Renewable energy