Proceedings of the 19th Annual Meeting of Particle Accelerator Society of Japan
October 18 - 21, 2022, Online (Kyushu University)

PASJ2022 WEOB05

STUDY ON SUSTAINABLE ENERGY MANAGEMENT SYSTEM IN ILC,PART-II
M. Yoshioka†, Iwate University, Morioka, Japan and Iwate Prefectural University, Takizawa, Japan
T. Kano, Iwate Prefectural University, Takizawa, Japan
S. Narita, Iwate University, Morioka, Japan
H. Odaira, Iwate Prefectural Office
S. Hirai and R. Ueda, NTT FACILITIES, INC., Solution Business Department, Tohoku Branch
Y. Kawabata, TOBISHIMA CORPORATION, Civil Engineering Division
J. Sawai, Sumitomo Mitsu Construction Co., Ltd. Civil Engineering Division
Abstract
This paper is part 2 of the paper submitted to the 2020
Annual Meeting of the Particle Accelerator Society of Japan. The previous paper summarized and introduced thebasic concept of Green ILC activities in the Tohoku regionand specific activities in line with this concept. Since then,both domestic and international policies have been announced with the specific goal of achieving carbon neutrality by 2050. Naturally, Green ILC activities must also bebased on these targets in accordance with this policy. Ouractivities have been organized into the following three categories. (1) Promotion of energy-saving technologies. (2)Increasing the ratio of renewable energy in cooperation
with local communities and improving energy management technologies such as waste heat energy recovery. (3)Additional efforts to enhance absorption of global warminggases derived from ILC operations in cooperation with local communities. In order to achieve this goal, it is important to operate our agriculture, forestry, and fisheries industries in a smarter way, and the construction and longterm operation of the ILC must serve these goals. This paper will report in detail on item (3) in particular.

INTRODUCTION
A major change that has occurred in the two years since
the presentation of Part 1 of this paper [1] at the 2020 Annual Meeting of the Particle Accelerator Society of Japan(Hereafter referred to as PASJ) is that the goal of achievingcarbon neutrality by 2050 has been clearly stated bothworldwide and also in Japan. Assuming that the ILC will
be operational in the late 2030s, that is only a decade or so
before the above goal. Therefore, it is essential to proceedwith ILC construction based on the 2050 carbon neutrality
target. For this purpose, it is necessary to show numericaltargets, i.e., visualization of CO2 emission and absorption.
The starting point for activities related to Green ILC isto know how much CO2 would be emitted through operation of the ILC facility. For this purpose, it is necessary toknow the conversion factor of how much CO2 is emitted
according to the amount of electricity used by operating theILC. The local power companies publish the conversion
coefficients every year. The preliminary value for FY2021announced by Tohoku Electric Power Company is 0.482

kg-CO2/kWh [2]. Assuming ILC peak power of 120 megawatts and annual power use of 700 million kWh (depending on operating hours), the annual CO2 emissions from theILC would be 337 kilotons. The basis for calculating theconversion coefficient between electricity consumption
and CO2 emissions is composited from the types of power
generation facilities. The coefficient becomes smaller as
the ratio of renewable energy improves. The details of thisare also shown in the reference [2]. The path to a realization of a carbon-neutral ILC can be briefly summarized as
reducing emissions by 337 kilotons and increasing CO2 absorption, which can be summarized as below.
(1) Promote the development of energy-saving technologies and return the benefits of these technologies to society. Further development of superconducting accelerating
cavities and improving the power efficiency of klystrons
are examples.
(2) Efforts to increase the ratio of renewable energy anddevelopment of waste heat energy recovery technology.
However, it is difficult to reduce CO2 emissions to zeroby these two efforts alone. In addition, the following third
effort is needed:(3) We inevitably need a mechanism to absorb CO2.
Of the three efforts summarized above, (1) would be aninternal effort of the ILC itself. However, (2) and (3) cannot be achieved without cooperation with the local community. Therefore, Green ILC activities must be closelycoordinated with local communities. Then, who will increase CO2 absorption? It would be the primary industry ofagriculture, forestry, and fisheries. Among these industries,forests would be the trump card for increasing CO2 absorption.

CO2 EMISSION
CO2 emissions by industry type for each basic municipality are estimated by the Ministry of the Environment
and published on its website [3]. Since the proposed ILC
site is in Ichinoseki City (hereafter referred to as IC), Iwate
Prefecture, we checked the data for IC from [3]. It is 871
kilotons in FY 2018. We encourage all participants in thisconference to check the actual situation in the area where
their facility is located. As mentioned in the previous section, the annual CO2 emissions from the ILC in operation____________________________________________† masakazu.yoshioka@kek.jp- 88 -Proceedings of the 19th Annual Meeting of Particle Accelerator Society of Japan
October 18 - 21, 2022, Online (Kyushu University)

PASJ2022 WEOB05

cedar
Japanese red pine
OthersFigure 1: CO2 emissions from the ILC added to the IC datafor FY 2018.
would be 337 kilotons. Figure 1 shows the CO2 emissions
from the ILC added to the IC data for FY 2018.
Adding the emissions from ILC to the 2018 IC data, thetotal CO2 emissions are 1,210 kilotons, in which ILC's contribution amounts to 27.9%.

CO2 ABSORPTION BY FORESTS AND REALIZATION OF A CARBON-FREE SOCIETY TRIGGERED BY THE ILC
Estimations by the Forest Utilization Division,Forest Development Department, Forestry
AgencyEach tree in a forest absorbs CO2 from the atmospherethrough photosynthesis, and grows by storing carbon while
generating oxygen. The Forest Utilization Division of theForest Development Department of the Forestry Agency
has estimated the amount of CO2 absorption by forests,
which is summarized below [4]. The amount of CO2 absorbed and stored by each tree is different, so to simplify
the discussion, we will limit this summary to cedar forests.
It is estimated that a properly managed 36–40-year-old cedar planted forest fixes approximately 302 tons of CO2 /ha.
Such artificial cedar forests are estimated to absorb about
8.8 tons/year/ha of CO2. Since the ILC emits 337 kilotons
of CO2/year, 38,000 hectares of such managed artificial cedar forests would be needed to absorb this amount. Trees
absorb the most CO2 when they are growing. Therefore,forests must be properly maintained. At the same time, thiswill lead to proper management of the forest industry.

CO2 Absorption Analysis by IC Forests
We first analyse forests in the IC: the total forest area in
the IC is 66291 hectares, of which planted forests accountfor 31392 hectares, or 47.4 %. Most natural forests are
hardwoods, with a small amount of red pine. The species
composition of planted forests is shown in Fig. 2.

Japanese cypress
Japanese larch

Figure 2: Composition of planted forests in IC by species.
Cedar is the most abundant, followed by red pine. Thesetwo species make up most planted forests.
Based on the forest management status in the IC, H.
Kikuchi, advisor to the Agriculture and Forestry Divisionof the IC, estimated the annual sequestration of CO2, considering tree species, age, and forest management status [5].
The result is an annual CO2 sequestration of 303.53 kilotons. Dividing this by the total forest area of the IC yields
an average absorption rate of 4.58 tons/year/ha. This value
is only 52% of the calculation by the Forestry Agency mentioned above. This means that there is much room for improvement. This absorption is also less than the amount of
CO2 released by the ILC and is only 25% of the total CO2
emissions of the IC when the ILC is in operation.
So far, we have clarified the figures for CO2 emissions
and absorption in the IC. Based on these visualized figures,
we must now consider how to reduce the amount of CO2
emitted and increase the amount of CO2 absorbed.
We propose to explore a path to achieve carbon neutrality with a clear numerical target.

Collaboration between ILC and the Community
to Achieve Carbon Neutrality
There are two central challenges with the Green ILC activities in cooperation with the local forest industry basedon the premise of achieving carbon neutrality by 2050. (1)To increase the amount of wood used in the construction ofILC-related facilities such as laboratories, offices, etc. asmuch as possible. (2) To increase the use of wood as muchas possible in the town planning process triggered by theILC as shown in Fig. 3. A further generalization would be
to increase affinity with the local forest industry in ILCrelated town planning.
For item (1), we have already compared the constructionof a laboratory with a floor area of 6,000 m2 in a mixed
wood/RC structure with a steel/RC structure in joint research between private industry and Iwate University andthe results were reported at the PASJ conference in 2018
[6]. In this case, we considered the use of locally sourced
lumber (red pine produced in northern Iwate), with- 89 -

Proceedings of the 19th Annual Meeting of Particle Accelerator Society of Japan
October 18 - 21, 2022, Online (Kyushu University)

PASJ2022 WEOB05

Figure3: Community-driven town planning triggered by the construction of the ILC.
sawmilling and construction carried out by a local company. It was found that there were no technical problems at
all in constructing such a large experimental hall with amixed wood/RC structure. In the case of the steel frame,
the only option is to procure material from outside the prefecture. A comparison of construction costs showed that amixed wood/RC structure was slightly more advantageousthan a steel frame/RC structure. In addition, the economic
ripple effect and the amount of induced employment aremuch more favourable for the wood/RC mixed structure. Itis important not only to evaluate the economic ripple effects of the project, which was done in 2018, but also tolook at it from the perspective of the balance between CO2emission and absorption. The volume of red pine logs usedin this estimation is 3.8 km3. According to data from theIwate Prefecture Ministry of Agriculture, Forestry, andFisheries [7], conifer log production in the prefecture is1,238 km3, so the volume of logs used in this estimation isequivalent to 0.3% of the total production in the prefecture.
That's how effective it is in expanding the use of red pine.
On the other hand, when steel frames are used, CO2 emissions must be taken into account not only during steel production, but also during import of raw materials from overseas and transportation within Japan. In other words, increasing the use of wood and reducing the use of steel
frames has a dual effect in terms of reducing CO2 emissions.
The basic policy regarding item (2) is summarized as follows. The ILC is Japan's first large-scale international re-search institute. Referring to the case of CERN, we estimate that the number of ILC-related researchers, engineers,business people, and their families will eventually increase
to several thousand. The number of people will vary foreach phase of the ILC design, construction, and operation.
In addition, the number of spin-off companies are expected
to continue to increase, so the population surrounding theILC facility is expected to grow even more from several
thousand people. Town planning to accommodate thesepeople coming from other countries and staying for long or
short periods of time is an important challenge. It should
be considered that one of the characteristics of the area surrounding the ILC is that it is a vast region blessed with various types of excellent natural environments. Moreover, itis equipped with infrastructure such as highways, publicroads, Shinkansen trains, and airports. In order to take advantage of the diverse hobbies and interests of foreign residents and the unique environment described above, wepropose a decentralized town planning approach. An example is shown in the figure above.
The first step is to make one community unit the size of
200-300 houses. Also, ILC-related people and local residents will be able to live together. It must respond to theregion's declining birthrate and aging population. Allhouses will be constructed of wood, with high airtightness
and thermal insulation, and an energy centre will be set up
in one location to distribute hot and chilled water to eachhouse. The heat source of the energy centre will be de-- 90 -Proceedings of the 19th Annual Meeting of Particle Accelerator Society of Japan
October 18 - 21, 2022, Online (Kyushu University)

PASJ2022 WEOB05

signed to take advantage of local resources, such as biomass, solar power, and hot springs. A design code shouldbe established for the residential design to achieve a lush
greenery unified streetscape. All building materials will belocally sourced, and local companies will be employed fordesign, construction, and maintenance. Assuming a woodusage of 25 m3 in an average wooden house (120 m2), thetotal usage for 300 houses would be 7.5 km3. Assumingthat logs required would be twice that of sawn lumber, thetotal amount of logs would be 15 km3, which is four times
that of the large laboratory described in the previous section.
The communication environment will incorporate thelatest technology to meet the "Digital Rural City National
Concept" which is the basic policy of the Japanese government aimed at bridging the urban-rural divide through digital technology [8].

GLOBAL PERSPECTIVES
According to a recent book by Bill Gates, total global
warming gas emissions are 51 billion tons/year [9]. The
breakdown in order of emissions is as follows: manufacturing, including cement and steel production (31%), electricity (27%), agriculture and livestock (19%), transportation and traffic (16%), and heating and cooling (7%). On
the other hand, according to data compiled by the Japan
International Research Center for Agricultural Sciencebased on data from the Food and Agriculture Organizationof the United Nations, the total area of forests in the worldin 2020 will be 4.06 billion hectares, which is decreasing
every year [10]. Of course, there are many other mechanisms besides forests, such as the oceans, land, and othereffect, that can be used to absorb global warming gas froma global perspective. These must be studied by experts
from various fields. However, from a local perspective, asdiscussed above, the authors believe that it is important todevelop a healthy forestry industry and make efforts toachieve carbon neutrality in each region as much as possible.

SUMMARY
There is no doubt that anthropogenic global warming is
progressing rapidly beyond the natural cycles of the past
due to the sun's activity cycle and the cyclic variation of tiltof the earth's orbit and axis of rotation. We believe that thesimultaneous loss of the Arctic and Antarctic ice sheets isextremely serious, and that the world's goal of achievingcarbon neutrality by 2050 is a reasonable and urgent decision. In this case, it is necessary to consider both global andlocal perspectives as discussed above.
We propose that the goal from a local perspective should
be to achieve a balance between CO2 emissions and absorption in each region. Such considerations should be especially relevant when building large power load facilities
such as the ILC. As noted above, such efforts will not pro-

duce results for the ILC alone. Collaboration with the community is essential. In order to achieve this goal, it is important to make efforts with clear numerical targets.

ACKNOWLEDGMENT
In completing this manuscript, we have benefited fromthe cooperation of many companies, organizations, and individuals. We are cooperating with the Project Promotion
Subcommittee of the Advanced Accelerator AssociationPromoting Science & Technology, AAA in town planning.
In the forest industry, we received a lot of information from
Iwate Prefecture's Niwa Lumber, Shibata Sangyo, Maruhi
Lumber, and Yamagata Prefecture's Shelter. Mr. Hiroshi
Kikuchi of Ichinoseki City's Agriculture and Forestry Division provided detailed information on the city's forest resources and the difficult task of estimating CO2 fixationand absorption. Mr. Norihiro Kodama of Hachimantai
Smart Farm, Inc. gave an information on high-density automated basil cultivation using hot spring exhaust heat. Finally, we received information through study sessions withthe following many municipalities: Ichinohe Town, IwateTown, Hachimantai City, Hanamaki City, Kitakami City,
Nishiwaga Town, and Ichinoseki City.
The authors would like to express their deepest gratitude
to all of them.

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Adachi et al., “ECONOMIC RIPPLE EFFECT BY UTILIZING LOCAL WOOD IN THE CONSTRUCTION OFWOODEN DETECTOR PREPARATION BUILDINGFOR THE ILC EXPERIMENT”, Proceedings of the 15th
Annual Meeting of PASJ, August 7-10, 2018, Nagoya,pp.1243-1247.
[7] Iwate Prefecture, Agriculture, Forestry and Fisheries Department Report, November 2019.
[8] Cabinet Secretariate, June 2022, https://www.cas.go.jp/jp/seisaku/digital_denen/index.html[9] Bill Gates, “How to Avoid a Climate Disaster: The Solutions
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