How will the two largest hydroelectric plants in Nghe An operate if the reservoir reaches dead water level?

Ban Ve Hydropower Plantbuilt on the Nam Non River. The main dam blocking the river is located in Ban Ve, Yen Na Commune, Tuong Duong District. The capacity of Ban Ve Reservoir is more than 1.8 billion m^3,in which the useful capacity from elevation 155m - 200m is 1.3 billion m³water.

However, due to prolonged drought and the need to regulate production water, the water levellake bedBan Ve Hydropower Plant has reached an alarming level. At this time (June 14), the water level in the Ban Ve Hydropower Reservoir has dropped significantly, only 1 meter higher than the designed dead water level of the Ban Ve Hydropower Plant.

Reporters' observations on June 13 showed that the Ban Ve Hydropower Reservoir is dropping to a deep level. People living in the Ban Ve Reservoir area said that the water level in the reservoir has never been as low as this year. Photo: Xuan Hoang

Currently, the lake water level is only 156.6m, nearly 20m lower than the same period and the remaining useful capacity is just over 80 million m³.

Mr. Hoang Van Ngoc - Deputy Director of Ban Ve Hydropower Company said: When the reservoir reaches the dead water level of 155m, Ban Ve Hydropower Plant can only generate electricity with the discharge flow equal to the return flow. Accordingly,water flowabout the lake now reaches more than 100 m³/second.

According to regulations, only in special cases due to the need to meet energy security, or provide irrigation water for downstream areas, can the reservoir below the dead water level be continued to be exploited, but with low power capacity. However, at this time, only 1 unit is operating, the other unit must be stopped, because if both units are operating at the time of dead water level, it will affect the equipment.

Therefore, in the second half of June and the end of the dry season, if the weather continues to be extremely hot, there will be a shortage of water supply downstream and a risk of not being able to supply enough electricity to the system.

“Early this June, there was a time when the water flow into the lake only reached 35m³/second, the lowest since the plant began operating. However, it has been raining in the upstream area these past few days, so the water supply has improved. However, the weather is unpredictable, if the heat continues, the operation of the power plants will be difficult," Mr. Ngoc worried.

According to Ban Ve Hydropower Company, the current water level of the reservoir is only 1 meter higher than the dead water level, so the operation of generators is affected, reducing capacity.In the photo:Workers of Ban Ve Hydropower Company at the Central Control Room. Photo: Xuan Hoang

At the FactoryHua Na Hydroelectric Power Plant(Que Phong) Although the water level in the lake has improved compared to half a month ago, operations are still difficult.

Mr. Doan Van Truong - Deputy Director of Hua Na Hydropower Company said: At the end of May, the water in the reservoir had dropped to the dead water level. At that time, both generators were still operating, but the capacity only reached a minimum of 70/90 MW/generator.

Panoramic view of the downstream area of ​​Ban Ve Hydropower Dam from above taken on June 13. Photo: Xuan Hoang

"These days the water flow on the Chu River flowing into the lake has improved by more than 150 m.³/second, so as of this morning, June 14, the water in the reservoir is 2.9m higher than the dead water level, but much lower than the same period last year. However, the plant still has to operate at minimum capacity at the dead water level to supply power to the grid. However, the generators operating at the dead water level will affect the equipment," said Mr. Truong.

According to the forecast of the North Central Hydrometeorological Station, the severe heat in the North Central region may last for many days to come, affecting the operations of hydropower plants./.