CHINA ERTAN HYDROPOWER PLANT
|Ertan 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 1167m.
Construction began in 1991. The Ertan power plant produced 3.9 billion
kilowatt hours of power in the first year of operation since August 1998,
when its first generating unit went into operation. Completed at the end
of 1999, it has set a new record for speed of installation of a
hydroelectric project. 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 is a top priority for the government,
since the region is poor and attracting foreign investment has proved
difficult compared to the successes of the booming coastal provinces.
Ertan Hydroelectric Project in Yalong River is a large hydropower
station under construction so far in China. Total installed capacity is
3,300MW with an annual output of 17 billion kwh. The double curvature arch
dam with height 240m ranks 3rd among similar
type of this dam in the world, the scale of the underground powerhouse
ranks 4th in the world. Total reservoir
storage capacity is 5.8 billion cu.m.
The gross capacity of the plant will be 3,492MW (3,300MW net), well ahead of all other recent foreign hydro projects as well as those in China. Total investment will be 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'S HYDROPOWER REOURCES
China has the largest untapped hydropower potential in the world. 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, will help China achieve its target of annually producing more than 5,000MW of hydro power for the first time. The largest project contributing to this total is the Ertan power plant on the river Yalong. The 1,517km-long Yalong is thought to be an ideal place for power stations because of its drop of more than 4,400m and potential to produce 33,400MW.
ERTAN HYDROELECTRIC DEVELOPMENT CORPORATION
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 would 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 that stretched domestic banks faced in high-capital-cost, long-term project lending.
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 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 the available power. The first four operating units were capable of generating 10 billion kilowatts of electricity a year, but to date the plant has only signed 6.4 billion kilowatts in contracts. The last two units will add 7 billion more capacity and the plant may not meet its financial targets.
DOUBLE-CURVATURE ARCH DAM POWERHOUSE COMPLEX
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 (281x26?1x66m) with six 550MW units, a transformer cavern (215x19x25m) and a surge chamber (201x19x69m). The project also has the two largest diversion tunnels in the world (1000x20x23m), two spillway tunnels (each 850x13x13.5m) 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.
MANUFACTURE OF 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, while the third and fourth would be 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.
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.
SOFTWARE AND GRID OPERATIONS
SMEC, Australia, has designed procedures and developed corresponding computer software to optimise the operation of the Ertan hydropower plant. The software package includes a generation management system (GMS) that operates in conjunction 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.