Technology of RenewableEnergy
MASAYUKI FUKAGAWA* 1

KOUTARO FUJIMURA* 1

YOSHIAKI TAKEUCHI* 1

SHINJI ARINAGA* 1

YOSHINORI UEDA* 2Hachoubaru
Power Station

The Kyoto Protocol aimed at the prevention of global warming took effect from February 16, 2005, and moves for theintroduction of renewable natural energy are being intensified in Japan and other countries. This paper introduces thenatural energy equipment that Mitsubishi Heavy Industries, Ltd. (MHI) has developed, in particular devices that workon geothermal, solar and wind energy.
energy as an alternative to petroleum oil are growing
1. Introduction
all over the world. The industrialization of power genThe conditions affecting renewable natural energy
eration by geothermal energy on a large scale is inhave changed drastically during the past year or two.
progress in the US, the Philippines, Indonesia andSince April 2003, the law on special measures concernMexico (1) . Japan is well known as a volcanic country
with abundant geothermal energy. In 1924, a 1 kW
ing new energy used by electric utilities (Renewable
power generating test plant in Beppu started power genPortfolio Standard (RPS) Law) has been fully enforced,eration by geothermal energy for the first time in Japan.
making it mandatory for electric utilities to utilize aThis plant is now demonstrating its utility by producminimum fixed percentage of electric power generated
ing power domestically with a minimum of enviby new energy, etc. This new law is expected to achieveronmental pollution.
the result that by the year 2010, 1.36% of electric power
Power generation by geothermal energy is now at thesold will be generated by new energy.
stage of solving its main problem of how to generate inThe crude oil price, which showed an upward moveexpensive power efficiently from this energy offered byment in 1999, has continued to rise steadily since last
nature and of how to make it pay for itself economically.
year until the price of West Texas Intermediate (WTI)
In 1967, MHI constructed the Kyushu Electric Power(crude oil produced in Texas) exceeded $60 per barrel atCo., Inc. Otake Geothermal Power Station with a prothe crude oil futures market of the New York Mercantile
duction of 12.5 MW. This Otake Power Station, Japan'sExchange.
first hot water type geothermal power plant, served as
The LNG price that is linked to the crude oil price isthe foundation for the subsequent rapid development ofalso rising. In addition, the coal price which has hithgeothermal power generation in Japan.
erto remained stable is also moving up. These increases
In 1977 MHI constructed Japan's largest geothermalin petroleum fuel prices are largely due to political inpower plant producing of 55 MW for the Kyushu Elecstability, a fall in the crude oil surplus production
tric Power Co. Hachoubaru Power Station. At
capability of the Middle Eastern countries and a sharp
Hachoubaru, the double flash method was adopted toincrease in demand by BRICs such as China.
utilize the energy of the hot water which had previously
The Kyoto Protocol, which is intended to prevent globeen wasted, increasing the output by about 20% as combal warming, took effect on February 16, 2005.
pared with the former single flash method. Furthermore,
Accordingly, prospects for the introduction of renewable
the two-phase flow spouting from the production wellnatural energy are increasing in view of global environwas conveyed to the power plant without separating it
ment problems, and its uses are expanding to areas ininto hot water and steam, resulting in reduction of thewhich it may become economically viable, although thisconveyance pipeline facility and in further increase ofhas never been the ease before. Renewable natural eneconomy. This system, known as the Hachoubaru sysergy is, therefore, once again attracting attention intem, is now being adopted widely in newly constructedmany countries. This paper will deal in particular withThe photo aboveplants (Theabove).
the prospects for business utilizing geothermal, solar andAt present there are 418 geothermal power plants
wind power from among the natural energy-related busiin the world, of which 91 plants were constructed bynesses of MHI.
MHI with a high share of 21%. In July 2005, MHI de2. Geothermal energy
livered a 19.2 MW power plant to a site near Lake Taupo
Expectations for power generation by geothermalin New Zealand.
Mitsubishi Heavy Industries, Ltd.
Technical Review Vol. 42 No. 4 (Nov. 2005)*1 Nagasaki Research & Development Center, Technical Headquarters*2 Power Systems Headquarters

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Basically, solar cells may be considered to have abright future. As demand increases, the supply of silicon ingot for poly-crystalline silicon is beginning tofall short. This concern is beginning to become reality
as the price of poly-crystalline silicon has risen from
3 000 yen per kg in 2004 to approx. 5 000 yen this year.
If the poly-crystalline silicon price continues to rise,
the advantages of cost reduction mentioned above may
be outweighed possibly slowing down the spread ofsolar cells in the world. As countermeasures, the development of thinner cells and improved efficiency
thereof are in progress with a view to efficient utilization of materials.
MHI has developed a technique to produce a thin film
silicon solar cell having the world's largest surface area
(1.1 m x 1.4 m), and started its commercial production
two years ago in Isahaya City, Nagasaki Prefecture. This
type of solar cell has been installed not only in domestic
public and commercial buildings/facilities and private
residences but also in overseas countries such as Germany, Australia and the Middle East.
The main characteristic of MHI's solar cell production is the manufacture of solar cells directly from gas
using plasma and chemical reaction. The thin film silicon solar cells produced by this method requireapproximately 1/1 000 of the amount of silicon required
for the micro-crystalline type solar cell, so that the abovementioned material shortage problem is no longer
significant.
In addition, compared with the crystalline type, thethin film type excels in temperature characteristics during the summer and generates more power annually. Inview of this advantage, delivery of thin film type solar
cells including those from MHI is increasing in Germany,
where power generated by photovoltaic modules is bought
Fig. 1
at higher prices (Fig.
1).
In order to encourage introduction of solar cells, New
Energy and Industrial Technology Development Organization (NEDO), together with the IndustryGovernment-University, is making efforts toward further cost reduction.

3. Solar energy
In 1999 Japan's photovoltaic module production was
the highest in the world, and since then it has increased
to almost half of the world's annual production (approx.
700 000 kW). The world's annual total production also
increased by approximately 60% during the period from2003 to 2004, supporting the expansion of the solar cellmarket. The world's total capacity of solar cell facilities
in 2003 was approx. 1.8 million kW, of which Japan occupied 48%, Germany 23% and the US 15%. Thus, Japanoccupies top place in the world for solar cell facility production.
This outstanding accomplishment is the result of theJapanese Government's systematic research and development, verification testing and institutional
encouragement for the introduction of renewable natural energy, as well as manufacturers' untiring efforts toimprove efficiency and reduce costs. For instance, thepower generation cost per kWh in 1994 was approx. 140
yen, but ten years later in 2004 it was reduced to approx.
46 yen, or to one-third. The cost reduction attained has
dramatically changed the conventional concept that"solar cells are friendly to the environment but badfor economy." This cost reduction has contributed not
only to an increase in solar cell facilities in Japan but
also to the adoption of solar cell facilities in many
places throughout the world.
Solar cells are now spreading fast not only to developed countries where accommodations forinterconnection to existing systems have already beendeveloped technically and institutionally but also to developing countries in Asia and Africa, for example, andPacific Ocean island countries which are not yet covered by power transmission networks, as a convenientand clean power source. In particular, technical and economical assistance by developed to less developed
countries is indispensable to the spread of solar cells
in countries of the latter category. Such assistance wasonce referred to as an ideal model for Official Development Assistance (ODA) activities.

Fig. 1 400 kW solar cell power plant in Germany
Approximately 4 000 thin film type 1.1 m x 1.4 m photovoltaic modules produced by
MHI are working satisfactorily.

Mitsubishi Heavy Industries, Ltd.
Technical Review Vol. 42 No. 4 (Nov. 2005)

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2004, the Agency for Natural Resources and Energy alsoannounced the "New Energy Industry Vision" so thatwind power generation is now attracting attention fromthe viewpoint of domestic industry cultivation(6).
Since the start of operation of the 40 kW wind powerturbine at its Koyagi Plant of Nagasaki Shipyard &Machinery Works in 1980, MHI has been going ahead
with its wind turbine development and supply on its own
proprietary technology and had delivered 1 820 units ofwind turbine with a total capacity of 1 038 MW to eight
countries of the world by April 2005. This amount exceeds the accumulation of wind power turbines
introduced in Japan. MHI's market shares in 2004 are
32% (the highest) in Japan, and 31% (second-highest) in
the United States (3).
Wind power turbine design has generally been basedon IEC 61400-1, but this standard was originally basedon performances in flat European coastal areas wherestable westerly winds prevail. This discrepancy with theJapanese climate has begun to cause equipment troubles.
In particular, the accident involving collapse of a windturbine on Miyako Island, Okinawa Prefecture caused
by Typhoon No. 14 in September 2003 was viewed withconcern by the Ministry of Economy, Trade and Industry
and the Ministry of Land, Infrastructure and Transport,
and accordingly promotion of standardization toward"Japan type wind turbines," as shown in Table 1 herein,
as well as related research and development were decided upon.
MHI, the only Japanese manufacturer of large typewind power turbines, is cooperating in activities such as
improvement of the reliability of wind power turbines
and is at the same time developing and offering wind
power turbine technology suited to Japan's climate suchas Smart-Yaw, which is typhoon-resistant, and active
tower vibration restriction through control of fluctuating wind load.

4. Wind energy

24
22
20
: New introduction18: Aggregate total
16
14
12
108
6420
1997 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07 '08 '09

1201101009080706050403020
100

Aggregate total (GW)New introduction (GW/year)

Of all renewable energy type power generation methods, wind power generation excels in economy and heads
the class in successful large-scale introduction. In 2004,
6 747 units of large-size wind turbines with a total capacity of 8 154 MW were constructed in the world,
reaching an accumulation total of 73 884 units with aFig. 2
total capacity of 47 912 MW (Fig.
2)(3).
In Denmark, 20% of power demand has already been
generated by wind power, and in Germany the figure is6%. Wind power in Europe has grown sufficiently to sustain a not insignificant part of total power demand. Inthe United States also, a strong wind power generation
introduction promotion system (production tax credit(PTC) by which the 1.8 cents/kWh tax is returned depending on the quantity of power generation) has been
extended until the end of 2007, and a large boom on a
3 000 MW/year scale is taking place.
In Japan too, regular introduction of wind farms having tens of units with capacities of tens of thousands ofkW has begun, starting with the construction of theTomen Power Tomamae wind farm in October 1999
Fig
(FigFig.. 3 ). As of the end of 2004, 924 units of wind power
turbines with a total capacity of 926 MW were operating
at 315 locations (4). Recently, more wind power turbines
have been introduced to the metropolitan district, sometimes presenting familiar background scenes in movies
and TV dramas and CMs. At present, the restriction oninterconnection to the existing power transmission network is a cause of concern, but after 2007, when themoratorium by the RPS Law is to be removed, until 2010,
introduction of wind power is expected to move quickly
toward the Government's target of 3 GW.
Further in the future, the introduction is expected toincrease to 10 GW including offshore wind power generation by 2020, and up to 20 GW in 2030 (5) . In JuneYear
Fig. 2 Progress of introduction of world wind power generation(3)Fig. 3 Kamaishi wide region wind farm, the largest in Japan
42 900kW: Mitsubishi MWT-1000A wind turbine 43 units.

Mitsubishi Heavy Industries, Ltd.
Technical Review Vol. 42 No. 4 (Nov. 2005)

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Table 1 Standardization of wind power generation
Accident information and statistics
concentration

NEDO Wind Power Generation Utilization Ratio
Upgrading Investigation Committee establishedin March 2003

Major accident reporting mademandatory

Notice from Nuclear and Industrial Safety Agency
in November 2004

Japan type wind power generation
guideline compilation project

Publicly invited by NEDO Research and Developmentin June 2004

Wind power plant anti-winddesign/engineering guideline

Expected to be prepared by Japan Society of Civil
Engineers by end of 2005

5. Conclusion
MHI intends to remain aggressively involved in theintroduction of renewable natural energy technology fromthe global viewpoint of environmental problems such as
greenhouse gas (CO2), and will lead Japan with reduced
energy resources to becoming the world's most advanced
natural energy technological country.
References(1) Mitsubishi Geothermal Power Plants,electrick,T.IEE Japan,1998(2) Proccedings of 22nd Symposium on Photovoltaic power system, Japan Photovoltaic Energy Association(2004) .
(3) World Market Update 2004•CBTM Consult Aps•CMarch2005(4) Introduction of wind power generation systems in Japan (onlyin Japanese), New Energy and Industrial Technology Development Organization (NEDO) Home Page
URL: http://www.nedo.go.jp/intro/pamph/fuuryoku/(5) Wind Energy Road Map•@(only in Japanese), Wind Energy
Road Map Development Subcommittee (NEDO report) (2005)(6) New energy industry vision•@(only in Japanese), Agency for
Natural Resources and Energy (ANRE) , Japan (2004)

Masayuki Fukagawa

Koutaro Fujimura

Shinji Arinaga

Yoshinori Ueda

Yoshiaki Takeuchi

Mitsubishi Heavy Industries, Ltd.
Technical Review Vol. 42 No. 4 (Nov. 2005)

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