Transmission lines’ poor capacity is exacerbating Vietnam’s power crisis.
EVN faces a range of challenges to keep the nation powered up
Several independent hydropower producers in the Central Highlands’ Kon Tum province last week complained they could not sell their products to local buyer Kon Tum Power Company, an affiliate of the Electricity of Vietnam (EVN), because of transmission lines’ weak capacity.
Nguyen Ngoc Tuong, general director of Tan Phat - investor in the 8.1 megawatt Dak Ne hydropower plant, said the company was recently required to reduce output and even stop generating by the Kon Tum Power Company as transmission lines were overloaded.
The VND230 billion ($11 million) Dak Ne plant was commissioned in September, 2010 and is capable of producing nearly 38 million kilowatt hours of power annually. It was the first hydropower project in the Central Highlands registered with the clean development mechanism (CDM) defined in the Kyoto Protocal.
Kon Tum has 50 small- and medium-sized hydropower projects which will have an accumulative capacity of 500MW in 2015.
The major 110kV transmission line in the province is loading power from the majority of independent power producers and from the 100MW Plei Krong hydropower plant invested by EVN.
Kon Tum Power Company director Nguyen Duc said the line was loaded 1.5 times higher than its designed 100MW capacity.
“We require local producers to cut their output, even in peak times,” Duc said.
Nguyen Bo, general director of the Kon Tum Industry and Trade Department, said that the authorities had already proposed EVN build a 220kV transmission line to ensure power resources reach the grid.
According to the National Power Transmission Corporation (NPT), transmission grid weakness was a countrywide phenomena, particularly this year when the output would increase 17.6 per cent to 117.6 billion kWh. Power output in the dry season will particularly grow 18.3 per cent to 56 billion kWh.
The national 220-500kW lines are always overloaded in the dry season, especially the 500kV north-south line and the Hanoi and Ho Chi Minh City grids.
That situation also resulted in high losses over the past years, which recorded at 10.25 per cent in 2010 and around 10 per cent in 2009.
According to the NPT, capital shortages had hindered new transmission line construction projects.
Some 45 projects worth some VND899 billion ($43.2 million) have not arranged investment capital, including the upgrade of the 500kV Pleiku transformer station, the 500kV Vinh Tan-Song May line, the 220kV Thuong Tin-Mai Dong line and the 220kV Ha Dong-Thanh Cong line.
EVN’s deputy general director Duong Quang Thanh said the company had planned to build major transmission lines this year to increase national grid’s loading capacity. They comprise the 220kV Buon Kuop-Dak Nong line, the 220kV Dak Nong-Phuoc Long-Binh Long line and the 500kV Pleiku-My Phuoc-Cau Bong line.
Hydropower plants in Vietnam, particularly those in the north, have been still in serious short of water to enable their full generation capacity.
Thanh said major hydropower plants’ reservoirs were operating moderately for water reserves, enabling better generation in April-June, the peak dry season time. Hydropower plants are planned to produce a total of 11.5 billion kWh in dry season, coal-fired power plants 12.2 billion kWh, gas-to-power plants 23.8 billion kWh, FO & DO oil-to-power plant 4 billion kWh and imported power 2.5 billion kWh.