Ertan Hydropower Plant, Yalong River, China
The 3,492MW Ertan hydropower plant set several records during its
ten-year construction phase. The plant comprises a 240m concrete
arch dam and Asia's largest underground powerhouse, which is 280m
long by 25.5m wide and 65m high. The project also boasts one of the
world's longest diversion tunnels at 1,167m. Construction began in
1991 and the project was completed at the end of 1999, meaning that
Ertan also set a new record for speed of installation of a
hydroelectric project. It produced 3.9 billion kWh of power in its
first year of operation.
The site is located near Panzhihua on the Yalong River (a tributary
of the Yangtze) in Sichuan province. Sichuan is a mountainous inland
province in the south west of China with excellent hydro potential.
Its development was a top priority for the government, since the
region is poor and attracting foreign investment had proved
difficult compared to the successes of the booming coastal provinces.
YALONG RIVER HYDRO PROJECT
The gross capacity of the plant is 3,492MW (3,300MW net), well ahead
of all other hydro projects of the time. Total investment was an
estimated $3.4 billion. In addition to the large local work force,
the project has involved 700 technicians and specialists from the 47
countries involved.
China has the largest untapped hydropower potential in the world,
but less than 10% of potential hydro resources are currently being
exploited. Large and medium sized hydro power projects with a total
installed capacity of 5,314MW are helping China to achieve its
target of annually producing more than 5,000MW of hydro power. Ertan
is the largest project contributing to this total. The 1,517km-long
Yalong River is an excellent site because of its drop of more than
4,400m and potential to produce 33,400MW.
ARCH DAM AND POWERHOUSE
The main project components are a concrete double-curvature arch dam
(240m high and 775m long) and a huge underground powerhouse complex.
The underground complex includes a powerhouse cavern (281m x 26m to
31m x 66m) with six 550MW units, a transformer cavern (215m x 19m x
25m) and a surge chamber (201m x 19m x 69m). The project also has
the two largest diversion tunnels in the world (1,000m x 20m x 23m),
two spillway tunnels (each 850m x 13m x 13.5m) and a 500m-long
bridge.
The contract for all underground works and related structures was
awarded to a German-Chinese joint venture under the leadership of
Philipp Holzmann, Germany. The other partners are Hochtief, Germany,
and Changjiang Gezhouba Engineering Bureau, China. Austria's
Geoconsult provided consultancy advice following fatal rockburst
accidents during the underground construction work that were caused
by stresses in the hard and brittle rock.
HYDROPOWER GENERATING UNITS
Ertan was China's first hydropower plant to be built through
international bidding. Canada's General Electric Co (GE) won the
contract for the manufacture of the six generating units.
The contract called for GE to manufacture the first two 582MW
Francis turbines in Canada. The third and fourth was a joint project
of GE and Harbin Electrical Machinery Works in northeast China's
Heilongjiang Province, and the Shanghai-based Dongfang Electrical
Machinery Works. The fifth and sixth would then be produced by the
Chinese firms alone.
Dongfang in particular is an important partner for GE. In September
1999, Ertan unit five, the first Chinese domestic-made 550MW
hydropower generator, went into formal operation (the previous
largest hydro turbine built in China was 320MW). Dongfang and Harbin
have also formed a joint venture company with Austria's VA
Technologie for domestic hydro turbine production.
INTERNATIONAL CONSTRUCTION AND SUPPLIERS
Impregilo of Italy and Lyonnaise des Eaux of France also won joint
venture construction contracts worth around $600 million. Mitsubishi
Heavy Industries supplied switchgear. Harza Engineering, Lahmeyer
International, Electricité de France and the Advisory Group of
Norway provided consultancy services. Harza's contract included
design review, construction planning, cost estimates and tender
evaluation services. Siemens provided a Chinese language version of
its BFS plant management system for the Ertan plant, its first
implementation in a hydro plant.
SMEC, Australia, has developed procedures and corresponding computer
software to optimise the operation of the Ertan hydropower plant.
The software package includes a generation management system (GMS)
that operates with the Sichuan power grid. The power station
operators, EHDC, will use ETGMS to optimise the operation of up to
five hydro stations (including Ertan) for which it may be
responsible in the future. The software simulates the operation of
the entire Sichuan grid, with all existing and planned hydro and
thermal generating plants. This allows EHDC to make the most of the
water resources under its jurisdiction.
FINANCING
Ertan Hydroelectric Development Corporation's (EHDC) profits from
long-term contracted power sales to the local utility, Sichuan
Electric Power, are being ploughed back into further hydro
investment on the Yalong. This aims to start a cascade of
developments, freeing new projects from some of the elaborate
financing procedures required for Ertan.
Financing involved substantial equity from EHDC's three shareholders:
the State Development Investment Company, Sichuan Investment Company
and Sichuan Electric Power Company. Project loans came from the
World Bank, the State Development Bank of China and domestic banks.
The World Bank provided $780 million in long-term loans and $150
million in commercial loan guarantees. The State Development Bank
has used its government backing and high credit ratings to raise
funds for Ertan and other infrastructure projects, including Three
Gorges, in international bond and loan markets. The bank was founded
in 1994 to overcome the limits faced by stretched domestic banks in
high-capital-cost, long-term project lending.
DOUBTS AT ELECTRICITY CONSUMPTION
There was some foreign scepticism at the start of the project over
the potential electricity market in the region, and this may have
some justification. Annual per capita power consumption in Sichuan
is 600kW, which is less than 10% of that in the developed world.
The government of Sichuan province has however lifted its limits on
electric power consumption and has begun encouraging local
enterprises and urban consumers to use more electricity. Ertan plant
managers are now concerned at the low take-up of available power.
The first four operating units were capable of generating 10 billion
kW of electricity a year, but to date the plant has only signed 6.4
billion kW in contracts. The last two units will add 7 billion kW
more capacity and the plant may not meet its financial targets.
The 3,300MW Ertan Hydropower plant includes Asia's largest
underground powerhouse, and one of the world's longest diversion
tunnels.
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