Proceedings of the 17th Annual Meeting of Particle Accelerator Society of Japan
September 2 - 4, 2020, Online

PASJ2020 WEPP57

STUDY ON A SUSTAINABLE ENERGY MANAGEMENT SYSTEM FOR THE ILC
Masakazu Yoshioka #, A, B, C), Tohru KanoB), Shinya NaritaC), Hisashi OdairaD), Sadayoshi HiraiE), Yasuo KawabataF),
Junji SawaiG)
A)
Tohoku University
B)
Iwate Prefectural University
C)
Iwate University
D)
Iwate Prefectural OfficeE)
NTT FACILITIES, INC., Solution Business Department, Tohoku Branch,F)
TOBISHIMA CORPORATION, Civil Engineering Division
G)
Sumitomo Mitsu Construction Co,.Ltd. Civil Engineering Division

Abstract
A large accelerator facility is also a large power load facility. In that sense, Japan's largest facility was TRISTAN and
KEKB of KEK with a maximum contracted power and annual power consumption of 96 MW and 500 million kWh,respectively. Electricity was received from the commercial grid and the end thermal energy was released into the air
with a cooling tower. However, in recent years, sustainable energy management of large-scale accelerator facilities has
become a prerequisite for their acceptance by society worldwide. Since the ILC would use more power than TRISTAN,
its facility design should be based on that idea. In this paper, we discuss not only electric power used in the ILC but also
the general and comprehensive management of electric power and thermal energy based on the characteristics of theentire region where the facilities are to be located. Energy sources including electricity will be comprehensively
considered, such as commercial grids, co-generation, seasonal solar heat utilization, heat utilization of unused biomass,
geothermal, hydropower, and wind power. Finally, we propose a new energy management system that would be set inmotion by ILC.

1. Introduction
In April 2020, ICFA announced that it will set up aninternational team for realizing a pre-laboratory for the
ILC, which will be hosted by KEK, and at the beginningof August it was announced that the International
Development Team (IDT) had been organized. In June
2020, it was also announced in the European particle
physics strategy [1] that "the timely realization of theelectron-positron International Linear Collider (ILC) in
Japan would be compatible with this strategy and, in thatcase, the European particle physics community would
wish to collaborate”. Japan-US talks on academicgovernment-industry levels have been ongoing since 2013,
but at the LCWS2019 in Sendai in November 2019, State
Department officials announced that they would commit
to the ILC together with the Department of Energy [2].
In summary, as a strategy for energy frontier physics
around the world, CERN will develop and prepare the
Future Circular proton-proton Collider FCC at the centerof mass energy of 100 TeV while operating the High
Luminosity LHC until around 2038, and operate it fromthe mid-2050s. Regarding the ILC, with the IDT at thecenter, we aim to establish the ILC pre-laboratory by theend of next year and to start operations at the ILC after
the mid-2030s.
The European strategy includes items relevant to thepresent paper. It requires that future accelerator facilities
be based on the concept of energy sustainability. The
passage is quoted below: “The environmental impact ofparticle physics activities should continue to be carefully
studied and minimized. A detailed plan for the___________________________________________# masakazu.yoshioka@kek.jp

minimization of environmental impact and for the saving
and re-use of energy should be part of the approval
process for any major project”. Needless to say, the ILC
should also be based on this idea. Since around 2014, wehave called this concept “the Green ILC” and haveconducted various R&Ds regarding the construction ofsustainable research facilities based on the characteristicsof the ILC candidate site. The purpose of this paper is toreport the overall picture of those activities.

2. Overview of Green ILC
Looking at the accelerator as a power load facility,
TRISTAN had the highest peak power at an accelerator
facility in Japan, with a maximum contract power of 96
MW. The maximum value of annual electric power
consumption was KEKB with 500 million kW hours.
The ILC is expected to have a peak power of 120 MW
and an annual usage of about 700 million kW hours
depending on its annual operational time, which ismore than our previous experiences. In summary fromthe viewpoint of energy flow, we would first accept
electricity from commercial grids and privatecogeneration, which would also serve as a backup
power source. The input power would eventually
become thermal energy in the accelerator, detector andutility equipment. Cooling equipment would heat up
the water in the cooling water system, and that hot
water would be dissipated from cooling towers
installed in the ground. Next, we will summarize eachstep of the Green ILC concept.
The 1st step is to optimize the beam performance(luminosity) per power consumption in the parameter- 410 -

Proceedings of the 17th Annual Meeting of Particle Accelerator Society of Japan
September 2 - 4, 2020, Online

PASJ2020 WEPP57

settings of all ILC devices. This has already been
incorporated by the efforts of the accelerator designers
such as utilization of superconducting equipment, nanobeam collision scheme, and polarized beam collision.
In the 2nd step, the energy efficiency of all accelerator
equipment would be improved, and ongoing development
research, for instance, on the Q value improvement of thesuperconducting cavities and the efficiency improvementof the klystron and modulator power supply would becontinued.
The 3rd step would be to select a sustainable source ofelectricity as the ILC’s power source. The Tohoku regionis advantageous in this respect. ILC's peak electricity is
0.5 to 1% of the electricity generated in all of the Tohoku
region, while sustainable electricity such as hydro,
geothermal, wind, solar, and biomass exceeds 20% of theelectricity produced in the Tohoku region. Therefore, itwould be easy to limit electricity contracts to sustainablesources. But this is not our endeavor. We must consider
more active sustainable energy management methods.
The 4th step would rely on the efforts of ourselves andthe region where the ILC would be located. First, we will
position “The Global Village Vision” formulated by
the Global Village Planning Committee [3] as our higherlevel philosophy. In that vision, the following four items
are listed as problems to be aware of: (1) a fragmentedinternational society, (2) the appearance of a huge capital
market due to economic globalization and changes in theworld's social and economic systems, (3) technologicaldevelopment and its shadow such as 5G, IoT and AI, (4)global warming issues.
The vision also emphasizes the following items based onJapan's view of nature, society, history and culture, andabundant natural environment: (1) Satoyama culture(culture of the “hilly heartland” - ie, villages in thevicinity of mountains) since the Jomon period (prehistoricculture up to about 1000 BCE), (2) World Heritage Site
Hiraizumi's idea of the pure land, (3) a history of forminga recycling-oriented society since the Edo period(1603~1868), (4) the abundance of various forests, the sea,
and food culture, (5) a history of incorporating different
cultures and different civilizations. On that basis, we will
gather wisdom and tackle the global issues mentioned
above. Below, based on this higher-level philosophy,
individual efforts based on the characteristics of the
Tohoku region are described.

3. The “Green ILC” concept rooted in the
Tohoku region
First, we have established a collaborative system ofindustry, government, and academia to base our activities.
"Academia" refers to Iwate University and Iwate
Prefectural University, "Government" means the Iwate
Prefectural Government and the Iwate Industry Promotion
Center, and "Industry" means the working groupcompanies under the Advanced Accelerator Association
Promoting Science and Technology project promotion

subcommittee (hereafter referred to as AAA) [4] as well
as local companies, chambers of commerce, etc.
The Tohoku ILC Project Development Center(hereinafter referred to as “Center”) was established in
response to the establishment of the IDT in KEK
mentioned above. When the Center was established, there
were a total of 22 organizations at the moment; Tohoku
University, Iwate University, Iwate Prefectural University,and Iwate Prefecture, Miyagi Prefecture, and municipal
governments in both prefectures. Specific activities will
be carried out by establishing "committees", but regarding
the Green ILC, we would like to form "committees" withthe above-mentioned groups that have alreadyaccumulated activity results as members.
It should be mentioned that electricity is, of course,
important for considering sustainability, but we should
also consider the use of heat from hot and cold water. The
specific activities are summarized below.
3.1

Exhaust heat recovery from the ILC and thecreation of businesses derived from it
The equipment of the ILC device is cooled withcooling water. The temperature of the hot water depends
on the equipment design, but generally it is low at around
60 ℃, and it is normally dissipated into the air at thecooling tower. Research on such low-energy, low-grade
heat energy recovery technology is being conducted at
Iwate University, National Institute of Advanced
Industrial Science and Technology (AIST), Takasago
Thermal Engineering Inc., and other industry-academia
joint research. Details will be reported at the previous andthe present conferences [5-8]. This technology is also
useful for recovering exhaust heat from factories, hotsprings, refuse incinerators, etc. that are mostly discarded
in today’s society, without needing to wait for its
application to the ILC.
3.2 Connecting the ILC with the local forestry industry
The Tohoku region and the area where the ILC is
located have high percentages of their area covered with
forests, with an active forestry industry. Therefore,
linking the ILC to the forestry industry is important forregional development. At the same time, it will also
incorporate the ILC as part of a sustainable energy cycle
within the region.
The 1st step is to build wooden structures to house theILC-related facilities such as laboratories and offices, aswell as housing for researchers, engineers and theirfamilies. This is a policy in line with the promotion ofwooden construction of housing and large public facilities
as part of the national basic policy. There are no
particular technical issues regarding the construction ofwooden houses. Issues related to town development andplanning will be described later. On the other hand,research and development is required to make large
facilities such as ILC-related laboratories with wooden
structures. About this issue, we have already published apaper at the previous PASJ meeting [9]. Details are- 411 -

Proceedings of the 17th Annual Meeting of Particle Accelerator Society of Japan
September 2 - 4, 2020, Online

PASJ2020 WEPP57

described in the literature, but we used a model where redpine produced in northern Iwate Prefecture is processed
into laminated wood in the central Iwate Prefecture, and alocal construction company takes charge of theconstruction. As a result, it was found that wooden
structures were superior to steel structures in terms of
direct cost, primary and secondary economical ripple
effects and the increase of employment.
The next step is to promote using scrap wood chips forheating in ILC-related facilities. In the Tohoku region,
there are many examples where sawmill wood is used for
papermaking and heat production. Wood chips and bark
will be generated more frequently if we make ILC-related
facilities with wooden structures, and those scraps can beutilized in heat production.
Finally, it was proposed we use aerial laser surveying
technology in order to create forest industry policy over awide area. Originally, this technology was developed withjoint research between Asia Air Survey Co., Ltd. and
Iwate University with the aim of confirming details on thecondition of the ground surface with high accuracy inorder to study ground facilities for the ILC. By removing
tree information from the survey data, the bare surface
conditions can be obtained. The accuracy is about 20 cm,
depending on the number of data points. Conversely,
the removed digital data contains a huge amount of
information related to trees, and tree species and treeheight can be identified. This will be applied to the forest
industry. For details, please refer to the reference [10].
3.3 Utilization of solar heat
Although solar power generation comes to mind as a useof solar energy, it should be noted that the efficiency of
converting energy into electric power is 20% or less. As
mentioned above, in the Tohoku region, more than 20%
of total power sources are sustainable power sources
including solar light, and it can be considered that thewaste heat recovery explained in the previous section will
be utilized as local energy in local industries. Therefore,
we consider the use of heat from solar energy as a further
heat source. We investigated the case of Denmark, which
is an advanced region using solar heat [11]. There, solar
panels with a thermal output of 27 MW (installation area:
3.7 hectares) and an underground pit-type heat storagetank with a capacity of 62,000 cubic meters cover 40% of
the heat source of 3,700 communities. With this method,
it is possible to store thermal energy over the seasons.
When this system is introduced to Japan, there will beitems that require new technological development: thesloshing problem on the water surface due to earthquakes
in a large-capacity underground pit-type heat storage tankand the deterioration problem of the heat insulation effectof soil due to aquifers. If these problems are solved, it will
be one of the most effective heat sources in mountainous
areas such as the ILC candidate site.

3.4

The Green ILC concept and community
development and planning - building an energy
recycling society based on the Global Village
VisionUp to this point, an overview has been given for each
item of technological development. In this section, I will
explain how to put them all together and use them in the
town planning concept set in motion by the ILC.
The total number of researchers and engineers working
at ILC research facilities will gradually increase throughthe phases of preparation, construction, and operation.
Taking into account the example of CERN, aninternational research institute, I think that ILC could
have a total scale of 5,000 people. When factoring incompanies engaged in operation and maintenance work,
the creation of new industries through technology transfer,and the increase in joint researchers, the related
population will eventually reach the tens of thousands.
On the other hand, the population in the area where the
ILC is located is currently undergoing a sharp natural
decline. For example, in the earliest case, the ILC is
expected to start operating by 2035, and by that time thepopulation will have decreased by 16%. Compared to theamount of population decline, the increase in ILC-related
population would only have a small impact on that
number. However, we propose that ILC should be used tocreate new towns for this rapidly changing society.
We will consider arranging hundreds of units in a
distributed manner as a basic concept for town
development. The reasons are summarized below.
(1) Looking at the communities where research andstudy cities and universities in Western countries arelocated, it is rare that related people live in a concentrated
manner. Rather, they often blend in with the area and live
in a dispersed manner.
(2) Population increase related to ILC would not occur atonce but gradually.
(3) The local natural environment is generally good, andthe vast mountainous areas and plains are spread out. In
addition, depending on the area, there are seas, mountains,rivers, snow, hot springs, swamps, etc., and people will beable to live in places that most suit them.
(4) Currently, transportation infrastructure such as
expressways and Shinkansen trains is already in place,and will continue to be improved. Therefore, for example,
the range of travel within one hour is wide.
(5) In addition, local community development should be
adapted in line with the declining birthrate and aging of
the population so that new residents can be mixed withlocal residents.
(6) The hundreds of community houses based on theGreen ILC concept will be based on highly airtight andinsulated whole wooden structures that coexist with trees
and nature. There, construction work will be kept to aminimum by taking advantage of the local topography
and natural environment. We will establish a core green
space in the community, and develop smart agriculturethat makes use of the IoT in the surrounding area. Design- 412 -

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PASJ2020 WEPP57

codes will be set for residential buildings, materials andcolors will be unified, and building sizes will be limited.
(7) When creating a community, we will not implementa style of selling and withdrawing. We will create amanagement system, thoroughly implement area
management, and make it a management structure that isable to grow. We will prepare various types of houses
such as detached houses, terraced houses, multi-family
houses so that they can respond to changes in the lifestyleand income of residents. There, we will create a 5th
generation town that incorporates cutting-edge
technologies such as IoT and AI so that we can respond to
future technological changes.
(8) Establish an energy center in the community.
Electricity will be received collectively, and cold and hot
water can be supplied and distributed to each house. Asan energy source, in addition to electric power and fossil
fuel, hot spring heat, geothermal heat, unused biomass,solar heat utilization and unused exhaust heat are usedaccording to the characteristics of the region.
(9) For the purpose of moving to established towns andmarkets and commuting to ILC-related facilities, we will
also consider introducing fully automatic electric vehicles
and eVTOL, which is likely to be put into practical use in
the near future.

heat (Green ILC)”, LCWS2016, Morioka, 4-9, December
2016,
https://agenda.linearcollider.org/event/7371/timetable/#all[6] T. Kokubo and M. Yoshioka, “A PROPOSAL ON USING
EXHAUST HEAT OF THE ILC WITH ADSORPTIONTHERMAL STORAGE TECHNOLOGY”, Proceedings ofthe 14th Annual Meeting of Particle Accelerator Society ofJapan, August 1-3, 2017, Sapporo, pp.1273-1277.
[7] G. Mitoya and M. Yoshioka, “PROPOSAL OF REGIONAL
THERMAL
ENERGYCIRCULATIONMODELTRIGGERED BY GREEN ILC”, Proceedings of the 14th
Annual Meeting of Particle Accelerator Society of Japan,
August 1-3, 2017, Sapporo, pp.1278-1281.
[8] A. Sasaki et al., “Study of Utilizing Waste Heat from A
Large-scale Accelerator with Adsorption Thermal Storage
Materials”, this meeting (THOT01).
[9] H. Adachi et al., “ECONOMIC RIPPLE EFFECT BYUTILIZING LOCAL WOOD IN THE CONSTRUCTION
OF WOODEN DETECTOR PREPARATION BUILDINGFOR THE ILC EXPERIMENT”, Proceedings of the 15th
Annual Meeting of Particle Accelerator Society of Japan,
August 7-10, 2018, Nagoya, pp.1243-1247.
[10] H. Terazawa et al., “Studying the utilization of UAV laser
survey and a Red Relief Image Map (RRIM) in theconstruction of a large accelerator”, This meeting (WEPP56).
[11] Sustainable energy policies across the country of Denmark
are advanced; “Dronninglund Solar thermal plant”,

4. Summary
The basis of the Green ILC concept is to make the ILC
with a regional energy circulation system that is closely
linked to the characteristics of the region surrounding it.
In other words, it should be a model of regional planning
in Japan, set in motion by the ILC, while making use ofvarious technologies based on the Global Village Vision
as a higher philosophy. We believe that this concept is anecessary condition for social acceptance when locatinglarge accelerator facilities, not limited to ILC.

Acknowledgment
This paper is based on the work of a working group
under the Project Promotion Subcommittee of the AAA.
It also refers to the contents of regional study groups
related to ILC that are established in various areas of
Iwate Prefecture. Finally, we also referred to the joint
research results of Iwate University and privatecompanies. We extend our deepest thanks to those groups.

References[1] TheEuropeanparticle

physics

strategy

in

2020;

https://europeanstrategy.cern/european-strategy-forparticle-physics[2] M. Pavek, “Remarks for Elinda Pavek at Linear Collider
Board Meeting, “US-Japan Cooperation in Science andTechnology””, LCWS2019, Sendai, 28 Oct.-1 Nov. 2019,https://agenda.linearcollider.org/event/8217/timetable/[3] Earth Village Vision Committee, “Earth Village Vision, A
proposal from Japan to the world”, December 2019,https://www.kok.or.jp/project/global_village_vision.html[4] AAA. Advance Accelerator Association Promoting Scienceand Technology; https://aaa-sentan.org/en/[5] J. Sawai, “Energy flow management and utilization of waste- 413 -

https://www.dronninglundfjernvarme.dk/media/2984/broc
hure_dronninglund_2015_booklet_eng_web_.pdf