NEWS
Expanding the Market with Low Head Water Turbines / Low Head Micro-Hydropower Generation Systems!
FEATURE
2024.12.18
Previously, we introduced Daikin Industries' micro-hydroelectric power generation system (※1). This was the first project of Daikin's Technology and Innovation Center (TIC), bringing together the collective strengths of the company to bear for this new business initiative. In this article, we will explore the improved low head water turbines / low head types, which enhance the energy efficiency of the system. For this interview, we spoke with three individuals involved in the project: Yoshitaka Yasui company director of DK-Power (※2), a TIC-initiated startup handling business development of this power generation system, including design, installation, and operations; Kaname Maruyama of TIC, who is in charge of fluid design, and Naoki Yamamoto of TIC, who oversees the project.
Developing a Micro-Hydroelectric Power Generation System from Scratch
― Could you tell us about your respective backgrounds?
Maruyama: I joined Daikin as a new university graduate in 2011 and have been involved in R&D development of fans used in air conditioners. Utilizing my knowledge in fluid design, I have also worked concurrently on the development of pumps, water turbines, and fans.
Yamamoto: I joined Daikin in 2019 after changing jobs. For about nine years, I had been involved in the development of turbine generators for thermal and nuclear power plants. Following the 2011 Great East Japan Earthquake, the nuclear power industry faced challenges, and after the 2015 Paris Agreement, the thermal power industry also experienced difficulties. This piqued my interest in renewable energy. When Daikin started looking for developers for its micro-hydroelectric power system, I saw it as an opportunity to utilize my previous experience and take on a new challenge in the field of micro-hydroelectric power generation. That's why I decided to join Daikin.
Yasui: I joined Daikin in 2006. During my university years, I researched condensation and humidity in an architecture lab. I wanted to deepen my knowledge of energy-saving design, so I focused on zero-energy buildings and renewable energy research at Daikin. As the commercialization of micro-hydroelectric power generation system has become feasible, I helped establish DK-Power and have been involved in the business from the start. Currently, I am responsible for all the technical aspects at DK-Power. I design power generation systems that meet the conditions of water utilities, make proposals for introducing the systems to these utilities, oversee the construction of power plants, and handle overall power generation operations, including maintenance after generation begins
― Could you tell us the lead-up to the development of the low head water turbines / low head type micro-hydroelectric power generation system?
Maruyama: I joined Daikin as a new university graduate in 2011 and have been involved in R&D development of fans used in air conditioners. Utilizing my knowledge in fluid design, I have also worked concurrently on the development of pumps, water turbines, and fans.
Yamamoto: I joined Daikin in 2019 after changing jobs. For about nine years, I had been involved in the development of turbine generators for thermal and nuclear power plants. Following the 2011 Great East Japan Earthquake, the nuclear power industry faced challenges, and after the 2015 Paris Agreement, the thermal power industry also experienced difficulties. This piqued my interest in renewable energy. When Daikin started looking for developers for its micro-hydroelectric power system, I saw it as an opportunity to utilize my previous experience and take on a new challenge in the field of micro-hydroelectric power generation. That's why I decided to join Daikin.
Yasui: I joined Daikin in 2006. During my university years, I researched condensation and humidity in an architecture lab. I wanted to deepen my knowledge of energy-saving design, so I focused on zero-energy buildings and renewable energy research at Daikin. As the commercialization of micro-hydroelectric power generation system has become feasible, I helped establish DK-Power and have been involved in the business from the start. Currently, I am responsible for all the technical aspects at DK-Power. I design power generation systems that meet the conditions of water utilities, make proposals for introducing the systems to these utilities, oversee the construction of power plants, and handle overall power generation operations, including maintenance after generation begins
― Could you tell us the lead-up to the development of the low head water turbines / low head type micro-hydroelectric power generation system?
Yamamoto: In hydroelectric power systems, the output energy (or power generation amount) is determined by the product of the water head and the flow rate. The greater the head or the higher the water flow, the larger the output. Traditionally, power generation has been done in areas with a large head and a low flow rate, generating outputs of 22kW to 75kW. This was because the vertical inline pump reverse turbine, a general-purpose pump running in reverse that we had been using, could not operate effectively under low head, high flow conditions due to its specifications. So, we decided to develop a new turbine to meet market demand.
Yamamoto: In hydroelectric power systems, the output energy (or power generation amount) is determined by the product of the water head and the flow rate. The greater the head or the higher the water flow, the larger the output. Traditionally, power generation has been done in areas with a large head and a low flow rate, generating outputs of 22kW to 75kW. This was because the vertical inline pump reverse turbine, a general-purpose pump running in reverse that we had been using, could not operate effectively under low head, high flow conditions due to its specifications. So, we decided to develop a new turbine to meet market demand.
Maruyama: Our initial market research revealed a high demand for the 22kW to 75kW range. However, further investigation identified a market for low head turbines / low head (effective head of 16.5m) with a 22kW output (annual power generation of 177MWh). This led us to take the step of developing a new system.
Newly developed low head water turbine / low head type micro-hydroelectric power system (22kW output).
― The previous system kept costs down by using commercial pumps.
This time, did you aim to improve performance by specifically designing a new propeller turbine?
Yamamoto: Yes. Our goal was to improve performance, so we designed and developed a propeller turbine from the ground up. Obviously, reducing costs was important to us. Just like the previous system, it is still intended for use in water pipelines at water utility facilities, but this new design permits power generation in areas with a smaller head.
The specific configuration of the micro-hydroelectric power system comes equipped with a permanent magnet synchronous generator and an integrated AC/DC converter controller mounted at the top of the system. The mechanical structure below the generator has been redesigned.
This time, did you aim to improve performance by specifically designing a new propeller turbine?
Yamamoto: Yes. Our goal was to improve performance, so we designed and developed a propeller turbine from the ground up. Obviously, reducing costs was important to us. Just like the previous system, it is still intended for use in water pipelines at water utility facilities, but this new design permits power generation in areas with a smaller head.
The specific configuration of the micro-hydroelectric power system comes equipped with a permanent magnet synchronous generator and an integrated AC/DC converter controller mounted at the top of the system. The mechanical structure below the generator has been redesigned.
Overall system configuration. The upper part remains unchanged, whereas the lower mechanism, vertical flow path, and propeller turbine have been newly designed.
In typical designs, the flow path inside the pump is horizontal, and the system is installed along that flow. However, in this case, we curved the flow path inside and changed the water flow from horizontal to vertical before allowing it to drop down and turn the propeller turbine. This is a significant difference from the previous design. By making the flow path vertical, we were able to efficiently channel the water and reduce the installation space for the system.
High-Efficiency Propeller Turbine Emerged from Thousands of Simulation Results
― If the flow path is curved to increase the water level, wouldn't that cause a pressure loss leading to an energy loss?
― Were there any other innovations?
Maruyama: Of course, pressure loss occurs when water flows through a curved pipe. However, a bigger issue was the axial flow hitting the propeller turbine as it curves, which caused a drift current. To eliminate this drift, we installed "guide vanes" to straighten the flow before the water enters the curved pipe. That was a key point.
Also, a great deal of thought was put into the propeller turbine design to improve energy efficiency. Since it was our first design, we conducted a large-scale parameter study, ran simulations repeatedly, and tested 2,000 to 3,000 patterns to find the optimal one. We were able to create a prototype right off the bat.
Maruyama: Of course, pressure loss occurs when water flows through a curved pipe. However, a bigger issue was the axial flow hitting the propeller turbine as it curves, which caused a drift current. To eliminate this drift, we installed "guide vanes" to straighten the flow before the water enters the curved pipe. That was a key point.
Also, a great deal of thought was put into the propeller turbine design to improve energy efficiency. Since it was our first design, we conducted a large-scale parameter study, ran simulations repeatedly, and tested 2,000 to 3,000 patterns to find the optimal one. We were able to create a prototype right off the bat.
Also, a great deal of thought was put into the propeller turbine design to improve energy efficiency. Since it was our first design, we conducted a large-scale parameter study, ran simulations repeatedly, and tested 2,000 to 3,000 patterns to find the optimal one. We were able to create a prototype right off the bat.
Yamamoto: Regarding costs, we designed the casing by combining existing standardized pipes. This enabled us to manufacture the system at a lower cost. The curved pipes that I mentioned earlier are also standard parts. One of the more surprisingly difficult aspects was designing a structure that simplified assembly. No matter how successful the simulations were, it was still challenging to convert the design into a tangible product.
Successful Implementation at Water Facilities Propels Nationwide Expansion
― Could you tell us about the business scheme for micro-hydroelectric power generation?
Yasui: The basic scheme involves renting the space to install the power generation system and the energy from the flowing water at the installation site from the water utility, and selling the electricity generated to an electric power company. A percentage of the income is then returned to the water utility. The business model operates with no financial burden on the water utility, allowing them to contribute to environmental conservation at zero cost.
Yasui: The basic scheme involves renting the space to install the power generation system and the energy from the flowing water at the installation site from the water utility, and selling the electricity generated to an electric power company. A percentage of the income is then returned to the water utility. The business model operates with no financial burden on the water utility, allowing them to contribute to environmental conservation at zero cost.
The low head type has already been implemented at an actual water utility facility. At the North Nasushiobara Water Purification Plant in Tochigi Prefecture, we utilized the water volume and water pressure entering the Orito Adjustment Pond to generate 177MWh annually, reducing CO2 emissions by about 98 tons. Since this was the first time for us to introduce the system to a water utility facility, it was a challenge to handle the large volume flow during installation and control, but after more than six months of operation since the system began generating electricity in the spring of 2024, it is running smoothly. The Tochigi Prefectural Water Bureau is extremely pleased with the environmental contribution made at no additional cost.
The micro-hydroelectric power plant at the Orito Adjustment Pond of the Tochigi Prefectural Water Bureau, where the water volume and water pressure from the North Nasushiobara Water Purification Plant are effectively utilized for power generation.
― Can you tell us about plans for future business development?
Yasui: The previous system has been implemented in 60 municipalities (water bureaus) across the country. Thanks to this, we proudly consider ourselves to be number one in this field in Japan. However, to become the overwhelming No. 1 in Japan's micro-hydroelectric power sector, we believe that we need to continue increasing the number of power generation installations our systems.
Secretariat of the Headquarters for Water Cycle Policy (※3) sees a market potential that is more than 20 times the current market size. Furthermore, we expect that the low-head turbine/low-head type system that we have developed will contribute to the expansion of markets beyond water facilities. This is why we would like to make it an even better system.
Secretariat of the Headquarters for Water Cycle Policy (※3) sees a market potential that is more than 20 times the current market size. Furthermore, we expect that the low-head turbine/low-head type system that we have developed will contribute to the expansion of markets beyond water facilities. This is why we would like to make it an even better system.
Maruyama: While I am conducting research in areas other than micro-hydroelectric power, I feel strongly about applying the knowledge and experience gained from fluid dynamics to spread environmentally friendly products globally as a global company. I hope to actively expand into areas related to renewable energy that benefit the environment, not only in air conditioning but also more broadly.
― Lastly, would you give a message to young and mid-career engineers who are considering joining Daikin?
Yamamoto: You might think of Daikin as just an air conditioning company, but there are also departments like ours that focus on hydroelectric power generation. It's a company that truly allows you to challenge yourself in any area, so I hope you'll join us!
Maruyama: Yes, I feel that if you speak up, Daikin will give you the opportunity to take on responsibilities. The opportunities to be a part of the decision-making process are enormous, and if you have the drive and determination, you can be actively involved in many different areas. If you're interested, I hope you'll join us.
Yasui: Another attractive aspect of this job is that it's not just about technological development, but also about experiencing the entire process as you come into contact with customers and develop new business. I don't think many companies offer the opportunity to work on both technical development and new business development. The wonderful culture at Daikin of nurturing innovative ideas is perfect for those with a pioneering spirit who want to create new business ventures.
Yamamoto: You might think of Daikin as just an air conditioning company, but there are also departments like ours that focus on hydroelectric power generation. It's a company that truly allows you to challenge yourself in any area, so I hope you'll join us!
Maruyama: Yes, I feel that if you speak up, Daikin will give you the opportunity to take on responsibilities. The opportunities to be a part of the decision-making process are enormous, and if you have the drive and determination, you can be actively involved in many different areas. If you're interested, I hope you'll join us.
Yasui: Another attractive aspect of this job is that it's not just about technological development, but also about experiencing the entire process as you come into contact with customers and develop new business. I don't think many companies offer the opportunity to work on both technical development and new business development. The wonderful culture at Daikin of nurturing innovative ideas is perfect for those with a pioneering spirit who want to create new business ventures.
※1. The Comprehensive Strength of Daikin: TIC's First Business Achievement in Micro-Hydroelectric Power Generation Systems
※2. Company Information
Company Name: DK-Power Co., Ltd.
Representative Director: Tetsuya Matsuura
Location: 10 Suita-shi, Tarumi-cho 3-chome 21, Osaka, Daikin Industries Esaka Building
Established: 2017
URL: Company Information
Representative Director: Tetsuya Matsuura
Location: 10 Suita-shi, Tarumi-cho 3-chome 21, Osaka, Daikin Industries Esaka Building
Established: 2017
URL: Company Information
※3. Cabinet Secretariat Headquarters for Water Cycle Policy Secretariat
Yoshitaka Yasui
Director, DK-Power Co., Ltd.
Joined in April 2006. Originally from Osaka Prefecture.
Responsible for engineering related to renewable energy (hydroelectric power, solar power).
"I want to leverage my extensive field experience to produce as much clean energy as possible and contribute to improving the global environment."
Director, DK-Power Co., Ltd.
Joined in April 2006. Originally from Osaka Prefecture.
Responsible for engineering related to renewable energy (hydroelectric power, solar power).
"I want to leverage my extensive field experience to produce as much clean energy as possible and contribute to improving the global environment."
Kaname Maruyama
Chief Engineer, Technology and Innovation Center
Joined in April 2011. Originally from Yamaguchi Prefecture.
Responsible for high-efficiency and noise reduction technology for blowers.
"I want to continuously refine my technological expertise to contribute to society through technological development."
Chief Engineer, Technology and Innovation Center
Joined in April 2011. Originally from Yamaguchi Prefecture.
Responsible for high-efficiency and noise reduction technology for blowers.
"I want to continuously refine my technological expertise to contribute to society through technological development."
Naoki Yamamoto
Technology and Innovation Center
Joined in August 2019. Originally from Nara Prefecture.
Responsible for mechanical technologies related to micro hydroelectric power generation, overall system coordination.
"I aim to contribute to society from the perspective of energy by utilizing the experience and skills I have gained thus far."
Technology and Innovation Center
Joined in August 2019. Originally from Nara Prefecture.
Responsible for mechanical technologies related to micro hydroelectric power generation, overall system coordination.
"I aim to contribute to society from the perspective of energy by utilizing the experience and skills I have gained thus far."
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