
Awarded for the use of biomass energy in Kosuge Village

Kosuge-no-yu, a hot spring facility in Kosuge Village, Yamanashi Prefecture, received the “New Energy Foundation Chairman's Prize” at the 2024 New Energy Grand Prix and the “Encouragement Prize” at the R6 Decarbon Challenge Cup, making it a double winner in recognition of its efforts in the use of log wood boilers with other renewalble facilities. We have been working on the project for six years, from the start of the survey to its design, installation, and operation.
We are very happy to have received this third-party recognition.
The key players who made this achievement possible can be divided into two groups: before and after the introduction of the wood-fired boiler.
First of all, I would like to thank Mayor Mr Funaki, the Kosuge Village Office, and the staff of Minamoto Co, who made the decision to introduce the system, and Mr. Sekiguchi of Minamoto Co and Forest Adventure Kosuge, who worked with us from the research stage,
Mr. Murakami, Manager of Kosuge-no-yu, Mr. Shizawa of Yamanashi Woody Biomass Council, Mr. Oshima of Natural Flame who supported us from basic design to implementation design and installation work (power and piping system), Mr. Ogawa of Wood Biomass Laboratory who strongly supported us from hardware subsidy application to construction management.
At the construction stage, the following companies were involved: Maruichi Construction, who took care of the yard work; Mr Mori from Mori no Nakamatachi Co , who was in charge of installing the wood boiler, hot water storage tank and solar water heater; Osadagumi Construction, Kashiwa Equipment and Akiyama Electric, who were in charge of removing the existing heat pump equipment, the wood boiler building, hot water piping and electrical work.
After the boiler introduction, the event was made possible thanks to the efforts of the forestry owners who transported the logs to the Kosuge Tree Station, the forestry entities such as the Kita-Tsuru Forest Association and Aoyagi Forestry, the forestry owners who shipped the logs by light truck, and the staff of Minamoto Co, especially the manager of Kosuge no yu, Mr. Murakami, who always responded with love to the operation of the log wood boiler.
As Little Tree Co, I started a study (to ensure economic feasibility and supply chain) for the introduction of a firewood boiler in 2018, and provided support for the basic design in 2019, the implementation design in 2020, and the installation work in 2021 with Wood Biomass Energy Labo,Co.
Since the start of operations in 2022, I have played a role as an advisor to the Kosuge Village Regional Forestry Administration in managing the forest for a stable supply of thinned wood, setting up maintenance projects, analyzing utility cost reduction data for log wood boiler, responding to inspections, and connecting with the use of forest space being promoted as part of a local development project. Once again, I would like to express my gratitude to all of you. Thank you very much.
The following is a summary of the New Energy Grand Prize award.


The advantage of renewable energy is that it is produced in the place where it is used (on-site) by local and decentralised.. This can be seen as a raison d'être when compared to existing centralised energy systems.
In 2011, when we supported Kirikiri, Otsuchi-cho, Iwate Prefecture, which was affected by the Great East Japan Earthquake, in our activities to provide hot bath facilities where evacuees could bathe, using the damaged wood as fuel for wood boilers, we became acutely aware that energy is not 'everyday' and 'natural’.
At this time , energy were not being carried out in the same way natural as in the past : fossil fuels were not being delivered due to road cuts, power lines and poles had collapsed and electricity was still not being supplied. We realised that the 'everyday life' that we normally take for granted and enjoy is actually supported by energy brought in from outside the region and the magnificent infrastructure that supports it.
I had the opportunity to present this at the World Sustainable Energy Days in Wells, Austria in 2012, WSED NEXT, an opportunity for young renewable energy researchers to showcase their initiatives around the world.
When a catastrophic event occurs, their daily lives are shattered in an instant. What do we do then? How do we get the energy we need to survive? Humans cannot survive without energy.
In such circumstances, by focusing on the natural resources (woody biomass, solar, solar thermal, hydropower, wind power, etc.) that are available in the surrounding area and introducing appropriate energy conversion equipment, heat and electricity could be generated sustainably, even in times of disaster.
Conversely, because of the resources that are around and nearby, energy can be produced without having to rely on energy transported from outside, even if the supply infrastructure is disrupted.
Of course, such energy is not only used in times of disaster, but continues to supply energy in normal times. This is the characteristic and advantage of renewable energy.
Even if it is difficult to be self-sufficient in all the energy consumed in a region, by combining existing energy with renewable energy and concentrating renewable energy in disaster centres and other places where energy is needed in an emergency, the gap that occurs between the daily and emergency energy supply can be levelled.


A point that was evaluated as an initiative this time was the mix of multiple renewable energy devices, with the log wood boiler at the core.
In order to combine three types of equipment - wood-fired boilers, photovoltaic power generation/storage batteries and solar heat - at Kosuge no Yu, the evacuation centre in the event of a disaster, and to provide evacuees with bathing opportunities through independent operation, the wood-fired boilers and pumps can be operated off-grid using electricity charged to storage batteries, even during power outages.
Some other points to emphasise are listed below.
・The use of previously unused thinned wood from TMG's water source forest maintenance.
・The Minamoto Co purchases thinned wood brought in by local forestry companies and mountain owners, and processes it into firewood.
・The Minamoto Co has achieved a 45% reduction in utility costs in the second year, compared to the 50% reduction it had planned to achieve within five to ten years.
・The Minamoto Co is also working with local development initiatives such as the Kosuge no Yu Bon Odori dance, forest space utilisation and inspection tours.
We will continue to promote these initiatives, from upstream to downstream, from forests to energy, from supply to demand, aiming for comprehensive village circulation and local economic development, and will work hard together with our valuable collaborators and supporters. Hardware and systems are important, but what is more important is the software and human resources - motivated people and organisations that can run towards the goal together. Without both of these wheels in place, success will not be achieved. That is what Kosuge Village has. I think that is the charm of Kosuge Village.
I am now able to work across the spectrum from forestry to energy, thanks to our 10 years of experience in Doshi Village, including the introduction and operation of the Doshi no Yu log wood boiler and forest management and maintenance under the Forest Management Plan, as well as thanks to Doshi Village for providing us with such opportunities.
We will continue to work towards building an OPEN FOREST, a trinity of forestry, wood utilisation (material and energy) and forest space utilisation.
A three-minute video has been created as a document for the second round of the Decarbonisation Challenge Cup, arranged from the video created at the time of the introduction and reflecting the results so far. It is posted below.
The following is an introduction video to the log wood boiler made at the time of installation. It was filmed by myself and edited by a friend from Doshi Village, and produced jointly.

Finally, the winners of the New Energy Awards and the Decarbonisation Challenge Cup are listed on each pages.


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