Transmission overload forces power stations to cut output

Several small- and medium-sized hydropower plants in the Tay Nguyen (Central Highland) provinces of Kon Tum and Gia Lai have scaled back production because the only 110kV power line that transmits electricity from these plants to the national power grid is overloaded.

Kon Tum now has about 50 small- and medium-sized hydropower projects that are estimated to supply a total of 500MW to the national grid by 2015.

Many of these projects have been supplying electricity to the national grid for about one year under contracts signed with the national power utility Electricity of Viet Nam (EVN).

However, for several months now, EVN’s Kon Tum branch has asked several small- and medium-sized plants to take turns to stop or reduce production because of transmission overload.

Nguyen Ngoc Tuong, general director of the Tan Phat Joint Stock Company, said his company’s Dac Ne hydropower plant, which has a capacity of 8MW, has been asked by the EVN to reduce production.

“The plant’s investment capital is a bank loan. If the plant does not produce electricity, it faces the risk of bankruptcy in the future because it cannot repay the loan,” Tuong said.

Tran Minh Tien, member of the Board of Directors for the Dak Psi Hydropower Company which has one of its projects generating power for the national power grid, said under the contract signed with the EVN, the latter would buy all the power produced by the plant.

However, the EVN was now restricting production of the 30MW plant, he said.

When approving hydropower plant projects, competent agencies must clarify the transmission capacity so that investors could decide whether or not they should invest in such ventures or decide the scale of investment they could make, Tien said.

The 14-MW Dac Doa hydropower plant in Gia Lai is expected to begin producing electricity at the end of this quarter, but its investor is worried that the plant will not be able to supply power to the national grid.

Many hydropower plant investors in Kon Tum and Gia Lai are also consumed by the same worry.

Nguyen Duc, director of Kon Tum Electricity, said: “Small- and medium-sized hydropower plants in Kon Tum now rely on just one 110kV power line running from Kon Tum to the 500kV transformer station in Gia Lai’s Pleiku City, but this is overloaded now.”

This 110kV power line had a capacity of 100MW, but it had to transmit up to 160MW, Duc said.

“In this situation, Kon Tum Electricity has to require hydropower plants to reduce production, including during peak hours.”

Nguyen Bo, director of the Kon Tum Department of Industry and Trade, said the province had petitioned the EVN to build a 220kV power line to ensure that all power produced in the province could be supplied to the national grid.

“However, this is only at the survey stage,” Bo said.

For the time being, the 110kV power line would continue to be overloaded, he said.

However, the Lao Dong (Labour) newspaper has reported that the EVN’s Plei Krong hydropower plant is still supplying its entire production capacity of 100MW to the 110kV power line.

The original plan envisages that electricity from the Plei Krong plant will be supplied to the national grid via a new transmission line built specifically for the purpose.

Since this power line has not been built, small- and medium-sized hydropower plants that do not belong to the EVN are having to suffer losses. – VNS

Tags: Vietnam electricity, Vietnam energy, Vietnam power shortage