Since its establishment in 2014, the NPO "Spatt Naruko Onsen Natural Energy" has been holding courses for residents and students of the next generation in Naruko and Nakayamadaira, one of Miyagi Prefecture's leading hot spring areas, in order to promote understanding and awareness of geothermal energy. As a supporting member, Baseload Power Japan provides support for these activities. We spoke with Professor Muramatsu from Tohoku University, who is one of the members of the NPO and gives lectures on renewable energy including geothermal energy.
--Please tell us how Spatt Naruko Onsen Natural Energy was established.
In the wake of the 2011 Great East Japan Earthquake, which forced all nuclear power plants to shut down, Tohoku University undertook a national project on research and development of alternative energy sources. The Tohoku region is rich in hot springs. Therefore, my team decided to develop binary power generation by utilizing geothermal energy, a local energy source.
Here in the Naruko and Nakayamadaira area, one of Miyagi Prefecture's leading hot spring areas, the geothermal potential is also very high. The source's composition does not contain a lot of scale, making it suitable for binary power generation. That is our encounter with the Nakayamadaira area. We developed a binary power generation system by utilizing one of unused wells at a hot spring inn. As a result, we confirmed that binary works in this area.
We considered to establish a non-profit organization to take over the operation of this binary power plant but decided against it due to the difficulty of profitability. However, as we proceeded with the project, we realized the importance of having local people correctly understand geothermal energy. For this reason, we steered the project toward activities to deepen geothermal understanding and increase awareness through the NPO.
--What are the challenges to binary power development in the hot spring region?
This is a correct understanding of local geothermal. Everyone is in favor of utilizing local heat, but they are still concerned about the impact on hot springs. For example, the heat source for hot springs is extracted from a layer 10 meters or even 100 meters deep underground, while the heat source for geothermal power generation is extracted from a deeper level of about 1,000 meters, so the impact on hot springs is said to be negligible. In addition, the cost and development period for flash-type large-scale geothermal power generation differs from that for binary power generation, which uses existing wells. In order for people to understand these factors, it is important for experts to provide detailed explanations. Currently, we are holding lectures such as classroom lectures, experiments, and site visits mainly for local residents and students, but in the future we would like to expand these lectures to include hot spring business operators.
--What are the keys to binary power generation operations?
I think it is economies of scale. Binary power generation has a lower output than large-scale geothermal power generation, so we feel that it is tough to operate at only one location, considering the investment cost. That is why we promote local understanding and operate power generation projects at multiple locations to achieve economies of scale.
--You mentioned that the hot spring water here in the Naruko and Nakayamadaira areas is suitable for binary power generation in terms of composition and temperature of the hot spring water. How should we revitalize the region by utilizing binary power generation?
Binary power generation not only produces electricity, but also allows for multi-stage use of heat. For example, the hot water used to generate electricity can be used not only for bathing, but also for heating, snow melting, greenhouse cultivation, and aquaculture. As the number of binary power plants increases, these cascade uses will also expand. I also believe that new businesses will be created using the heat.
With energy costs soaring, the government is now promoting local production for local consumption of energy. There is no reason not to use energy that is unique to your region. If energy costs are high in large cities such as Tokyo, it would be very efficient to start a business in a region with abundant thermal energy. If we can create such a structure, I believe it will help revitalize the region, which is suffering from a declining population.
…and that's why it's important to raise awareness of geothermal energy?
You are right, it is the current young generation that will lead the carbon neutral society in 2050. It is important for them to learn about environmental issues and geothermal heat, the heat of the region, while they are still young, and to develop the ability to think flexibly to create new businesses that make use of it. That is why we at Spatt Naruko Onsen Natural Energy believe that education should be a top priority issue, and every year we conduct on-site classes at Naruko Junior High School and Furukawa Reimei Junior and Senior High Schools.
--Finally, what are your expectations for a geothermal development company like Baseload Power Japan?
We want to set a precedent here. To that end, we want companies like Baseload Power to create many successful examples of binary power plants, not only in Japan but globally. If we can create many successful cases, including multi-stage use of heat, it will help raise awareness of geothermal power. I believe that this will lead to an increase in the number of communities and organizations entering the market. I believe that if development companies and local communities work together, we can create a carbon-neutral and vibrant community. For this reason, it is important for us to steadily implement geothermal education.
Professor Junji Muramatsu
Vice Director and Professor at Tohoku University. Studied chemical energy engineering at the Graduate School of Engineering, The University of Tokyo, and has been involved in research on beneficiation and smelting at Tohoku University since 1988, deepening his knowledge of mining and geothermal energy. Born in Aichi Prefecture, Japan