INTRODUCTION TO
GEOTHERMAL POWER STATION OF KYUDEN MIRAI ENERGY CO., INC.

1

Hatch o baru

／ 11 0 , 0 0 0 k W

Otake／ 1 4 , 5 0 0 kW

Yamagawa／ 3 0 ,0 0 0 kW

Ogiri

／ 3 0 ,0 0 0 kW

Takigami／ 2 7 , 5 0 0 kW

Hatchobaru Binary ／2 ,0 0 0 kW

Sugawara Binary／

5 , 0 0 0 kW

Yamagawa Binary／

4 , 9 9 0 kW

HISTORY OF GEOTHERMAL POWER DEVELOPMENT OF KYUDEN GROUP
The history of Kyushu Electric Power Group (Kyuden Group) 's geothermal development has begun in1949, when Kyushu Electric Power started survey and development in Otake and Hatchobaru areas.
After overcoming numerous difficulties, Otake Power Station (12,500kW) started to operate in August
1967 as the first hot water dominated and single-flash type geothermal power plant in Japan.
Furthermore, based on the achievements of Otake Power Station, Hatchobaru Power Station No. 1
Unit (55,000kW) was built in June 1977 as the first two-phase flow transportation pipeline system,
the first double-flash type geothermal power plant in the world. Hatchobaru No.2 Unit (55,000kW)
started to operate in June 1990, and has become one of the world's leading geothermal power plants
with total output of 110,000kW.
Yamagawa Power Station started commercial operation in March 1995, Ogiri Power Station in March
1996, and Takigami Power Station in November 1996.
Subsequently a 2,000kW binary cycle power facility was built at Hatchobaru. After pilot testing,commercial operation began in April 2006 as Hatchobaru Binary Power Station.
In June 2010, the rated output of Takigami Power Station was changed to 27,500kW.
In October 2020, we updated the power plant facility at Otake and increased the rated output to14,500kW. Herewith, Kyushu Electric Power's geothermal power generation facilities have capacity of
214,000kW.
On the other hand, Kyuden Mirai Energy Co., Inc. started to operate Sugawara Binary Power Station(5,000kW) in June 2015 as one of the largest binary power plants in Japan, which effectively utilize
low temperature geothermal fluid that cannot be used with conventional geothermal power plants.
Yamagawa Binary Power Station ( 4,990kW) started commercial operation in February 2018.
Then Kyuden Mirai Energy took over Kyushu Electric Power's geothermal business in April 2024 asresult of integration of the Kyuden Group's renewable energy business.
Kyuden Group is promoting the development and installation of geothermal power generation in order
to effectively utilize domestic energy and achieve carbon neutrality in 2050.

2Advantages in:･ Effective use of indigenous energy resource･ No necessity of fuel･ Semipermanent, stable use as renewable energy･ Clean energy, highly effective in controlling CO2
emissions･ Power can be generated stably regardless of weather ortime of day or night
Disadvantages in:･ Difficulties of construction of a large capacity power
station･ Necessity to pay much attention to the harmony withnatural surroundings, because the site for geothermal
power generation is often situated in natural beauties.

3

HISTORY OF GEOTHERMAL
POWER DEVELOPMENT

Electricity

Warm water

1904 Succeeded in power generation of 3/4 horsepower
utilizing natural steam at Larderello, Italy. (The world’s
first geothermal utilization for power generation)
1913 G e o t h e r m a l p o w e r g e n e r a t i o n o f 250 k W a t
Larderello. (The world’s first geothermal power
station)1919 Vice Admiral, Masuji Yamauchi succeeded in drilling asteam well at Beppu, Oita Pref., Japan.
1925 Dr. Heiji Tachikawa succeeded in power generation of
1.12 kW at Beppu. (Japan’s first geothermal power
generation)
1927 Dr. Tachikawa drilled a steam well at Otake, Oita
Pref., Japan.
1949 Kyushu Haiden (Kyushu EPC, presently) started
investigation and research of geothermal regions in
Oita Prefecture.
1951 Kyushu EPC carried out experimental power
generation of 30 kW at Beppu in cooperation with
Industrial Technology Institute.
1953 Kyushu EPC started investigation and research at
Otake district.
1958 A 6,500 kW power station started operation in
Wa i r a k e i , N e w Z e a l a n d . ( T h e w o r l d ’ s f i r s thydrothermal separation type geothermal power
station)1960 The Geysers No. 1 Unit in California, U.S.A. started
operation. (11,000 kW)
1966 Matsukawa Power Station in Iwate Pref. started
operation (23,500 kW). (Japan’s first full-scale
geothermal power station)
1967 Kyushu EPC commissioned Otake Power Station(12,500 kW). (The first geothermal power station by
public utility, in Japan)
1977 Kyushu EPC commissioned Hatchobaru No. 1 Unit
(55,000 kW)
1990 Kyushu EPC commissioned Hatchobaru No. 2 Unit
(55,000 kW)
1995 Kyushu EPC commissioned Yamagawa (30,000 kW)
1996 Kyushu EPC commissioned Ogiri (30,000 kW) andTakigami (25,000 kW)
2006 Hatchobaru Binary Power Station (2,000 kW) started
operation.
2010 Takigami Power Station output rating changed.
(25,000 kW to 27,500 kW)
2020 Otake Power Station renovated.
(12,500 kW to 14,500 kW)
2024 Renewable Energy Business integration(Kyushu Electric Power → Kyuden Mirai Energy)

Cooling
water

Otake Geothermal Power Station

We carried out integrated development at Otake and Hatchobaru Power
Stations: geothermal resource survey, exploration, drilling, engineering,
construction, operation and maintenance of power plants. On the other
hand, Ogiri and Takigami Power Stations were developed together withsteam supply developers: The developers developed resources andsupply steam to us while we purchase steam for power generation.
Yamagawa Power Station initially started jointly development in the same
way as Ogiri and Takigami, but we took over the steam supply facility in
February 2005 to run integrately from underground to aboveground.

Hatchobaru Binary Power Station4

Production Wells

Wellhead Silencer
Equipment that reduces the noise of
steam being blown out from theproduction well and released into theatmosphere when the steam turbine
is stopped, for example.

To use geothermal energy taken to the ground surface
from production wells for power generation, there aresome generation systems depending on characteristics
of geothermal fluid (pressure, temperature, flow rate,
etc.)

Where the geothermal fluid forms a steam and hot water mixture,
the fluid is led to a separator to separate the steam from the hotwater. Then, the steam is used to rotate the turbine for power
generation. This system was applied for Yamagawa, and Ogiri
power stations.

Where a temperature of hot water separated by the single flash
system is still high enough, this system can be applied. Applicationof this system increases the output by 15% to 25% though it
increases the investment to additional facilities compared with theSingle Flash System. This system was applied for Hatchobaru, andOtake power stations.

5Where the temperature of geothermal fluid is lower and no steam isavailable, low boiling medium is heated with hot water to produce
the steam for power generation. This system is applied atHatchobaru Binary, Sugawara Binary and Yamagawa Binary Power
Stations.

6

HATCHOBARU

Hatchobaru Geothermal Power Station has a total capacity of 110,000 kW, which is
the largest rated capacity of the geothermal power station in Japan.
This power station adopts a two-phase fluid transfer system where the steam andhot water from production wells are led in a mixed form to a steam separator
installed near the power station facilities. The mixed fluid is separated here into
primary (high pressure) steam and hot water, and the hot water is then expanded
under a reduced pressure in a flasher to generate secondary (low pressure) steam.
The primary and secondary steam taken out this way drives the turbine generator.
This system is called a double flash system.
The system was jointly developed and put into commercial use as a pioneer in theworld with Mitsubishi Heavy Industries, Ltd. This research and development wasawarded with The Prize of Japan Society for the Promotion of Machine Industry in
1980.
Hatchobaru is an unattended geothermal power station and controlled by theoperators stationed in Otake, about 2 km away from Hatchobaru. The operating
conditions including generator outputs, turbine revolutions, condenser vacuum,etc. are supervised and controlled with a tale-control system and data logger.

DEVELOPMENTHISTORY
1964-66
1968
July 1973

July 1975
June 1977
July 1980

Dec. 1981
Hatchobaru Binary Power Station

Dec. 1981

Dec. 1986
June 1990
Apr. 2006
Apr. 2024

7

Drilled 2 exploration wells
between Otake andHatchobaru

Started production welldrilling

No.1 Unit development
approved by theGovernment's Power
Resource Development
and Coordination
Committee
No.1 constructioncommenced

No.1 commissioned
Applied permission of the
exploration to theGovernment fordevelopment of No.2 Unit
Started drilling of
exploration wells for No.2
Unit
No.2 Unit development
approved by theGovernment's Power
Resource Development
and Coordination
Committee
No.2 Unit constructioncommened

No. 2 Unit commissioned
Hatchobaru Binary Power
Station started operation
Renewable Energy
Business Integration(Kyushu Electric Power →Kyuden Mirai Energy)

●OUTLINE OF OTAKE AND HATCHOBARU GEOTHERMAL POWER STATIONS (Current as of August 2016)
Location
OutputCommissioned Date
Land area

TurbineSteam Pres.
Steam Temp.
Approx. Steam Flow
Rate
Type

Capacity
VoltageType
Cooling Method
No. of cells
Cooling
Capacity
Tower
Type
VacuumCondenser
Type
Capacity
Gas
Extractor
Type
Capacity
STEAM
PRODUCTION Separator No. of unit
FACILITIES
Type

POWER
STATION
FACILITIESGenerator*: Total processing steam flow

8

Otake
Hatchobaru No. 1
Hatchobaru No. 2
Oh-aza Yutsubo, Kokonoe-machi, Kusu-gun, Oita Pref.
14,500 kW
55,000 kW
55,000 kW
August 11, 1967
June 24, 1977
June 22, 1990
159,167 m2
1,948,109 m2
0.235 MPa (2.4 kg/cm2)
0.49 MPa/52 kPa (5.0 kg/cm2/0.53 kg/cm2) 0.59 MPa/29 kPa (6.0/0.3 kg/cm2)
136℃
158.1/111.4℃
164.2/106.4℃
120 t/h372/91 t/h

320/110 t/h

Single cylinder,
impulse, condensing
type

Single cylinder, double flow, impulse, mixed
pressure condensing type15,000 kVA
62,000 kVA
62,000 kVA
6,600 V
11,000 V
11,000 V
Horizontal, cylindrical revolving field typeAir cooled
Hydrogen cooled
Air cooled
3454,200 m3/h
13,140 m3/h
15,000 m3/h
Mechanical draft, counter flow double suction type91.6 kPa (687 mmHg)
91.6 kPa (687 mmHg)
91.5 kPa (686 mmHg)
Barometric jet type
Foundation unified, jet (direct contact) type1,570 kg/h
2,320 kg/h
3,460 kg/h
Vacuum Pump
Ejector + Motor driven blower
Diff. by well
413 t/h*
394 t/h*4
2
2
Vertical, cylindrical cyclone separator

9

YAMAGAWA

GEOTHERMAL
POWER STATIONOGIRIGEOTHERMAL
POWER STATIONTAKIGAMIGEOTHERMAL
POWER STATION

10

●Development History and Features

YAMAGAWA is characterized by its location at
the plain land area surrounded by agricultural
fields as compared with the other geothermal
power stations in Japan mostly located in mountainous area. In Yamagawa, the turbine inlet
pressure is set as high as 0.98 Mpa because thereservoir temperature is high.

Feb. 2005 Kyushu EPC takes over steam production
facilities
Apr. 2024 Renewable Energy Business Integration(Kyushu Electric Power → Kyuden Mirai Energy)●Development History and Features
1973 Nippon Steel Mining Co. (NSM) started
geothermal resource exploration.
1979 Nippon Steel Corp. (NSC) joined thegeothermal development undertaking.
1989 Kyushu EPC, NSM and NSC concluded abasic agreement for geothermal power
generation undertaking.
Feb. 1990 NSC and NSM coｰﬁnanced to establish
Nittetsu Kagosima Geothermal Co. and thecompany succeeded the geothermal
development.
Dec. 1993 The government approved the development.
Nov. 1994 Kyushu EPC started construction.
Mar. 1996 Commissioned.
Apr. 2013 Nittetsu Mining Co., Ltd. takes over thebusiness of Nittetsu Kagoshima Geothermal
Co., Ltd. through an absorption-type merger.
Apr. 2024 Renewable Energy Business Integration(Kyushu Electric Power → Kyuden Mirai Energy)●Development History and Features

Oct. 1993 Idemitsu Kosan Co., Ltd. established Idemitsu
Oita Geothermal Co. and the company
succeeded the resource development.

Jun. 2010 Output rating changed(25,000 kW to 27,500 kW)
Apr. 2024 Renewable Energy Business Integration(Kyushu Electric Power → Kyuden Mirai Energy)

11

on atlturalermal
mouninlet
e the

N

C-pad
A-pad
A8-padB-pad
A6-pad
B5-padC-pad

C1-padE-pad

Power Station
D-pad

F-pad
0

12

250m

500m

Steam distribution pipe

●OUTLINE OF POWER STATIONName

YAMAGAWA

Location
OutputCommissioned Date
Land area
Steam Supplier (Developer)

POWER
STATION
FACILITIES(Current as of August 2016)

Steam Pres.
Steam Temp.
Turbine Approx. SteamFlow RateTypeCapacity
Generator Voltage
Type
No. of cells
Cooling
Capacity
Tower
Type
VacuumCondenser
Type
Capacity
Gas
Extractor TypeCapacity*
STEAM
PRODUCTION Separator No. of unit
FACILITIES
Type

OGIRI
TAKIGAMI
Makizono-cho
Yamagawa,
Kokonoe-machi,
Kirishima City andIbusuki City
Yusui-cho, Aira-gun, Kusu-gun, Oita Pref.
Kagoshima Pref.
Kagoshima Pref.
27,500 kW
30,000 kW
30,000 kW
November 1, 1996
March 1, 1995
March 1, 1996
418,400 m2
157,800 m2
297,600 m2
Kyuden Mirai Energy Nittetsu Mining
Idemitsu Oita
Co., Ltd.
Co., Inc.
Geothermal Co.
0.98 MPa (10.0 kg/cm2) 0.196 MPa (2.0 kg/cm2) 0.147 MPa (1.5 kg/cm2)
132.9℃
183.2℃
126.8℃
290 t/h

225 t/h

260 t/hSingle cylinder, single flow, impulse, reaction condensing type34,000 kVA
34,000 kVA
28,000 kVA
11 kV
11 kV
11 kV
Horizontal, cylindrical, revolving field type (air cooled)32
3
10,500 m3/h
7,000 m3/h
9,800 m3/h
Mechanical draft, counter flow double suction type88.1 kPa (661 mmHg) 90.5 kPa (679 mmHg) 90.5 kPa (679 mmHg)
Spray jet type + Tray type gas cooler (direct contact type)1,650 kg/h
798 kg/h
1,605 kg/h
1 series-2 stage
Ejector + Motor driven blower
Ejector275 t/h** × 2 series 440 t/h**
325 t/h**2 × 2 series
4
6
Vertical, cylindrical cyclone separator*: As of end of March 2010

13

14

■ Continuous monitoring
control system
Our geothermal power stations
operate at a stable output and there
is no need frequently operation byhuman operators. The geothermal
power stations generates withautonomous unmanned during
night-time and on holidays. The
operators operate them as needed.

LCD Monitor /Input Device

Hatchobaru
Printer

Otake Printer

Host
Computer

Central control room
surpervisory camera
×2

Turbine roomsupervisory camera
Station yard
surpervisory camera

LCD Monitor

15

17

Sugawara

Binary Power Station

Yamagawa

Binary Power Station

18

Sugawara Binary Power Station■ FEATURES

Sugawara Binary Power Station is the first 5,000kW-classgeothermal binary cycle power plant in Japan. We work
together with local government, Kokonoe Town to conduct
this geothermal power generation project.
Kokonoe Town provides us with steam and hot water fromtheir own geothermal wells while we purchase the geothermal
fluids and generate electricity by using the geothermal binary
cycle power plant.
We sell generated electricity to Kyushu Electric Power Co.,
Inc., with Feed-in Tariff system. Both we and Kokonoe Town
can make steady income while simultaneously contributing
to effective use of purely domestic energy and promotion of
global warming prevention.
Furthermore, with the cooperation of Kokonoe Town, we arealso working on co-existence with the local communities
by implementing hot spring monitoring as well as providing
explanations to the locals etc.
Pays fee forusing steam heat

Income on sellingelectricity

Kyushu ElectricPower Co., Inc.

Miya-chan,
Kokonoe-machi #3161

Kokonoemachi

Providessteam andhot water

Sugawara Binary
Power Station● DEVELOPMENT HISTORY
・1988
・2003
・2010

・2012
・2013

・2014

・2015

NEDO drilled the geothermal wells in
Kokonoe Town for research
NEDO transferred the wells to Kokonoe
Town free of charge
Kokonoe Town conferred with Kyushu
Electric Power Co., Inc. regarding
geothermal development in order toeffectively utilize of the wells
Well test and assessment for hot springs
carried out
We agreed with Kokonoe Town regarding
geothermal power generation project inthis area (Nov. 22)
Geothermal resources development debt
guarantee adopted by JOGMEC※2 (Apr.
10)
Construction work started (Apr. 21)
Test run started (Apr. 1)
Commercial operation started (Jun. 29)※1 : N e w E n e r g y a n d I n d u s t r i a l Te c h n o l o g y
Development Organization※2 : Japan Organization for Metals and Energy
Security

All electricity is soldunder a feed-in tariff(FIT) system

Yamagawa Binary Power Station■ FEATURES

Yamagawa Binary Power Station is one of the largest binary power plants in Japan. Until the time when it started tooperate, some of hot water could not be used for power generation and was returned to underground at Yamagawa. The
binary system can effectively utilize the unused energy of hot water.
We received "New Energy Award" in 2019 for recognition of our efforts to solve technical issues such as corrosion andscaling caused by high temperature and high concentration of hot water, and for the expected expansion of installation ofgeothermal power generation in the future.

● DEVELOPMENT HISTORY
・Aug. 2016
・May 2017
・Oct. 2017
・Feb. 2018

Civil engineering work
startedConstruction work of power
generation facility started
Test run started
Operation started

19

554-13 Sugawara, Kokonoe Town,
Oita Prefecture
Rated output
5,000kW
Commercial operation started inJun.29, 2015
Kyuden Mirai Energy Co., Inc. /Owner of power station / Owner ofKokonoe Town (2 Production wells
geothermal welland 2 Injection wells)
Turboden, a Mitsubishi Heavy
Manufacturer of main machine
Industries group, Italy
Pressure / Temperature
0.286MPaG / 142.4℃
Geothermal
fluid (outlet of
Steam flow rate
40.1t/hseparator)
Hot water flow rate
261.8t/h
Pressure / Temperature
0.953MPaG / 137.5℃
Working fluid
Flow rate
298t/h(inlet of turbine)
Working fluid type
N pentane (boiling point: 36℃)
Horizontal cylindrical rotating field
Type
type synchronous generator
Generator-1
Rotation speed
1,800minType
Vertical cylinder cyclone separator
Separator
Maximum pressure / Temperature 0.55MPaG / 162℃
Type
Mechanical-draft air coolingNumber of fans
27 units (3 units x 9 rows)
Condenser
Inlet temperature of air / Inlet
temperature of working fluid / Outlet 20℃ / 58.8℃ / 37℃
temperature of working fluid
Evaporator
Horizontal straight tube type (1 unit)
Heat
Preheater
Horizontal straight tube type (1 unit)
exchanger
Horizontal U-shaped tube type (1 unit)
Feed liquid heater
BS-4：142℃ / 18.7t/h / 811m
Production wellTemperature / Flow rate / BS-5：159℃ / 28.5t/h / 870m
Depth of well
BS-2：552m
Injection well
BS-2R1：589m
Power generation facility size
Approx. 47 m x 74 m
Length of Power line
Approx. 20 km
Plant control
Monitoring as needed● SYSTEM DIAGRAM OF SUGAWARA BINARY POWER STATION

Location● OUTLINE OF YAMAGAWA BINARY POWER STATION
Location

2303 Yamagawa Ogawa, Ibusuki
City, Kagoshima Prefecture
4,990kWFeb.23, 2018
Kyuden Mirai Energy Co., Inc.
Fuji Electric Co., Ltd.

Main transformer

SilencerSteamconveyingpipe

Evaporator
Condensed
water tank

● OUTLINE OF SUGAWARA BINARY POWER STATION

Two-phase fluid
conveying pipe

Steamseparator

SteamturbineCondensed
water pump

Hot watertank
Hot waterconveyingpipe
Production
well
BS-5
BS-4

Preheater
Injection Injection
well
well
BS-2
BS-2R1

Steamcondenser(Air coolingmethod)20

To factories, buildings,
stores, and generalhousesCoolingair
Two-phase fluid (geothermal
steam, hot water) system

Mediumpump

Geothermal steam system

Geothermal hot water system
N pentane system

Geothermal reservoir

Flow of electricity

We adopt “binary cycle” system in which n-pentane(lower boiling point than water) is heated andevaporated by the geothermal fluid supplied
from production wells, and the turbine is rotatedby n-pentane steam. Also, the geothermal fluid,which is the heat source, is supplied from the wellowned by Kokonoe Town. The air cooling system isadopted for cooling and liquefaction of n-pentane.

● SYSTEM DIAGRAM OF YAMAGAWA BINARY POWER STATION
Yamagawa Geothermal Power Station
system flow

Rated output
Commercial operation started in
Owner of power station
Manufacturer of main machine
Geothermal fluid
0.97MPaA / 178.6℃ / 584.7t/h(inlet of separator)
Pressure /Steam of geothermal fluid
0.38MPaA / 142.8℃ / 41.7t/h
Temperature /(inlet of evaporator)
Flow rate
Hot water of geothermal fluid
0.40MPaA / 143.6℃ / 543.0t/h(outlet of hot water tank)
Working fluid Pressure / Temperature / Flow rate 0.92MPaA / 122.1℃ / 330t/h(inlet of turbine)
Working fluid type
N pentane (boiling point: 36.1℃)
TypeThree-phase AC synchronous generator
Generator-1
Rotation speed
1,800minType
Vertical cylinder cyclone separator
Separator
Maximum pressure /0.48MPaA/160℃
Temperature
Type
Mechanical-draft air coolingNumber of fans
24 units (3 units x 8 rows)
Condenser
Inlet temperature / Outlet
60.6℃ / 44.5℃
temperature of working fluid
Evaporator
Horizontal kettle type (1 unit)
Heat
Horizontal shell and tube type (1 unit)
Preheater
exchangers
Feed liquid heater
Horizontal shell and tube type (1 unit)
Power generation facility size
Approx. 63 m x 88 m
Connected to line on the premises ofPower line
Yamagawa Power Station
Plant control
Monitoring as needed

Generator

Yamagawa Binary Power Station
system flow
Main transformer

Steamseparator

Generator

Hot water
tank

Steam
turbineSteamcondenser(Water-cooledtype)

Reinjection pump

Production
Well

Steam
separator

Evaporator

SteamturbineGenerator

Hot waterconveying pipe
Reinjection pump

Feed liquidheater
Hot watertank

Hot water pit

Preheater

Steamcondenser(Air coolingmethod)Coolingair

Injection
Well

Cooling towerFlash tankPentane pump
Two-phase fluid (geothermal steam, hot water) system
Geothermal steam system

Geothermal reservoir

Geothermal hot water system
N pentane system
Flow of electricity

We adopt “binary cycle” system in which n-pentane(lower boiling point than water) is heated andevaporated by the geothermal fluid, and the turbine
is rotated by n-pentane steam. Also, the geothermal
fluid, which is the heat source, is supplied from
Yamagawa power station. The air cooling system isadopted for cooling and liquefaction of n-pentane.

■ Conceptual Geothermal Structure

Production well21

(Hatchobaru)■ Drilling of Production Wells (Hatchobaru)■ Conceptual Drawing of Drilling Bit End

22

As of February 2020, the total capacity of geothermal
power stations operating in Japan is about 540 MW.
Of these, Kyuden Mirai Energy has 9 units in 6
stations for 224 MW, or about 41% of the capacity.
Though the geothermal power, to be said the 4th
power followed by Nuclear power, occupies a small
share in the energy mix in Japan, it has been playing
an important role as highly stable power supply
source by attaining a high capacity factor withoutanxiety of energy storage or supply.
Also, from the perspective of global warming
prevention, it is a natural energy source that is
highly effective in controlling CO2 emissions, and forthis reason there are high expectations for thedevelopment of geothermal power.

PRESENT STATUS OFGEOTHERMAL POWER IN JAPAN

Mori

Onuma
Sumikawa
UenotaiWasabizawa
Yanaizu-Nishiyama

Matsuohachimantai
Matsukawa
Kakkonda No. 1, 2

OnikobeSugawara Binary
Okuhida-Onsengo Nakao

Otake
Waita

LegendMinamiaso Yunotani: Existing geothermal power station

Ogiri
Medipolis Ibusuki
Yamagawa
Yamagawa Binary

Note: Power stations in blue are owned by Kyuden Mirai Energy.
Power stations in black are owned by other companies.

Takigami Binary Suginoi
Hatchobaru No. 1, 2Hatchobaru Binary

Ogiri Geothermal Power Station

23

IcelandRussiaGermany

FrancePortugal

Italy

Austria

Romania

USA
TurkeyChina
Japan
MexicoTaiwanEthiopia

ThailandEl Salvador

Philippines

GuatemalaCosta Rica
Nicaragua

Papua New Guinea
Kenya

Indonesia

Australia
New Zealand● Geothermal Power Stations in Japan(As of February 2020)

Company name (Upper line:Power Station Rated Output
Name
Location
Commissioned in
Owner / Lower line:Steam Suppller )
(kW)
Mori
Mori, Hokkaido
Hokkaido EPC
25,000Nov.26,1982
Tohoku Sustainable &Hachimantai, Iwate Pref.
Matsukawa
23,500
Oct.8,1966
Renewable Energy Co., Inc.
Iwate Geothermal Power Co.,
Matsuohachimantai Hachimantai, Iwate Pref.
7,499
Jan.29,2019
Ltd
Tohoku EPC
Shizukuishi, Iwate Pref. Tohoku Sustainable &Kakkonda
30,000Mar.1,1996
Renewable Energy Co., Inc.
Onuma
Kazuno,Akita pref. Mitsubishi Materials Corp.
10,000Jun.17,1974
Tohoku EPC
Sumikawa
Kazuno,Akita pref.
50,000Mar.2,1995
Mitsubishi Materials Corp.
Tohoku EPC
Uenotai
Yuzawa, Akita Pref. Tohoku Sustainable &28,800Mar.4,1994
Renewable Energy Co., Inc.
Wasabizawa
Yuzawa, Akita Pref. Yuzawa Geothermal
46,199
May.20,2019
Electric Power Development Co.,
OnikobeOsaki, Miyagi Pref.
14,900
Apr.2,2023
Ltd.
Yanaizu, Fukushima Tohoku EPC
Yanaizu-Nishiyama
30,000May.25,1995
Pref.
Okuaizu Geothermal Co., Ltd.
Okuhida-Onsengo
Takayama, Gifu Pref. Nakao Geothermal Power
1,998
Dec.1,2022
Nakao
Oguni, Kumamoto Pref. Waitakai LLC
1,995
Jun.16,2015
Waita
Minamiaso,
Minamiaso Yunotani Chinetsu
Minamiaso Yunotani
2,168
Mar.3,2023
Kumamoto Pref. Co., Ltd.
Suginoi
Beppu, Oita Pref. Suginoi Hotel
1,900
Apr.1,2006
Kyuden Mirai Energy Co., Inc.
Takigami
Kokonoe, Oita Pref. Idemitsu Oita Geothermal Co.,
27,500Nov.1,1996
Ltd.
Idemitsu Oita Geothermal Co.,
Takigami Binary
Kokonoe, Oita Pref.
5,050
Mar.1,2017
Ltd.
Otake
Kokonoe, Oita Pref. Kyuden Mirai Energy Co., Inc.
13,700Oct.5,2020
55,000Jun.24,1977
Hatchobaru
Kokonoe, Oita Pref. Kyuden Mirai Energy Co., Inc.
55,000Jun.22,1990
2,000
Apr.1,2006
Kyuden Mirai Energy Co., Inc.
Sugawara Binary
Kokonoe, Oita Pref.
5,000
Jun.29,2015
Kokonoe Town
Kyuden Mirai Energy Co., Inc.
Kirishima, Kagoshima Pref.
30,000Mar.1,1996
Ogiri
Nittetsu Mining Co., Ltd.
30,000Mar.1,1995
Ibusuki, Kagoshima Pref. Kyuden Mirai Energy Co., Inc.
Yamagawa
4,990
Feb.23,2018
1,580
Feb.18,2015
Medipolis Ibusuki Ibusuki, Kagoshima Pref. Medipolis Energy Co., Ltd.
Source: "The Current State of and Trends in Geothermal Power 2020" by Thermal and Nuclear Power Engineering Society The geothermal power
plants with rated output of 1,000kW or more are listed.

24● World Geothermal Power Facilities (in MW)
Country
USA
Philippines
Indonesia
MexicoNew Zealand
Italy
IcelandKenya
Japan
TurkeyCosta Rica
El Salvador
Nicaragua
RussiaGuatemalaPapua New Guinea
Portugal
China
Germany
FranceEthiopia
Austria
Australia
ThailandRomania
TaiwanTotal

Output3,450.0
1,870.0
1,340.0
1,017.0
1,005.0
916.0
665.0
594.0
519.0
397.0
207.0
204.0
159.0
82.0
52.0
50.0
28.0
27.0
27.0
16.0
7.3
1.2
1.1
0.3
0.1
0.1
12,635.1

Source: "The Current State of and Trends in Geothermal Power 2015”
by the Thermal and Nuclear Power Engineering SocietyAs it uses the underground heat resource, the geothermal power
dose not require fuel and is a clean energy source not polluting
the air. Geothermal power stations are built surrounded byabundant natural environment but we transformed the land areafor development as small as possible by adopting the centralized
power generation and steam supply facilities.
It is said, in this view point, that the geothermal power is an environmental friendly power source. To make best use of the favorable specialty of geothermal power, Kyuden Group has been
trying to downsize the ground facilities as small as possible, andpaying special attentions to coloring of the facilities. It has taken
positive steps in coordination with the surroundings by promoting
the greening in the premises of the power stations.

View of Kuju Mountain Range from Handa Plateau, Kokonoe-machi, Oita Pref.

■ KUJUIn kokonoe-cho, there are 4 geothermal power stations :HATCHOBARU, OTAKE, TAKIGAMI and SUGAWARABINARY. Kuju area nearby is one of the best sceneryspots in Kyushu where the 1,700m class volcanoes arerenowned their beauty in shape. Yamanami Highway,
crossing these areas on a plateau, is also known as acomfortable driving course surrounded by natural
beauty and scenery. Whenever you visit Handa and Kuju
Plateaus , beautiful flowers and birds welcome andrefresh you gently. Here also available many well-known
hot spas like Sujiyu, Makinoto, Chojabaru and many
more.

25

Kirisima-azalea and Mt. Takachiho■ KIRISHIMA
Mt. Karakuni-Dake, rising at the north-east of Kagoshima Pref. and the surroundings are called"Kirishima" generally and included in "Kirishima-Yaku National Park". This region has a lot of hotspas called "Kirishima Spa Villages" and there are about 130 hot spa resources used for bathing
and drinking. OGIRI is located in between Makizono-cho and Kurino-cho of this region.
You can enjoy different beauties of scenery in each season; fresh greens in spring, Kirisimaazalea in early summer, red-and-yellow leaves in autumn, and silver thaws in winter. This area
forms its own world in Kyushu displaying the magnificent scenery. In the surroundings, there aremany tourist spots including Mt. Takachiho famous for a Japanese mythology.

Sand Spa in Yamagawa and Mt. Kaimon■ IBUSUKI
The Yamagawa Power Station is located in the area known as Ibusuki, facing Kagoshima Bay at
the southern tip of the Satsuma Peninsula. The greater part of this area is covered by KirishimaYaku National Park and is a beautiful coastline and hot spring location.
The most famous Ibusuki Hot Spa and the others in this region provide unique hot spa bathing; tohave your body buried in the hot sand. Fresh seafood also raised this region's reputation.

26

INTRODUCTION TO
GEOTHRMAL POWER STATION OF KYUDEN MIRAI ENERGY CO., INC.

KYUDEN MIRAI ENERGY CO.,INC.

2024.04