People... walking under the bottom of the largest hydroelectric lake in Vietnam

In early June, Tuoi Tre Online was present at Son La Hydropower Plant (the largest hydropower plant in Vietnam with a capacity of 2,400MW).

The weather in the Northwest is very hot, up to 40 degrees Celsius. From the top of the dam, it is clear that the water level of the Son La hydropower reservoir is much lower than the normal allowable water level (215m).

Mr. Mai Duc Tiep (foreman of the operation workshop, Son La Hydropower Plant) said that more than 13 years in the profession is also more than 13 years since the first unit came into operation, this is the first time that the water level of Son La hydropower lake has reached a record low and must operate below the water level (175m).

"A few days before the peak heat, all 6 units were operating. In recent days, the units have almost stopped working, if they run, it is minimal because the lake is already at dead water level." - said Mr. Tiep.

In the operation center area of Son La Hydropower Plant, out of 6 units, only one unit runs on compensating power, and the remaining 5 units are ready to generate electricity.

"In the condition that the water level is dead, the water column of the unit is reduced, the turbine is at risk of vibration, the unit is reversed, and the temperature of the units is at risk of increasing, so the factory must arrange people to check equipment, enhanced check cycle. In normal conditions, we will check the unit once every 2 hours. Still, when operating below dead water level, it must be checked once every 1 hour or 30 minutes to detect abnormal signs to propose timely maintenance and repair promptly. The goal is how all 6 units are always ready to meet the grid power when required."- Mr. Tiep shared.

Mr. Khuong The Anh, general director of Son La Hydropower Company, said that since putting into operation, for the first time, both Son La and Lai Chau hydropower plants have operated below dead water level.

"In the past 3-4 days, Son La and Lai Chau hydropower plants have been almost idle, but 9 units are always ready to operate when required by the National Load Dispatch Center (A0) or if the factory installs a frequency limit warning that is dangerous to the system, the units actively operating to respond to system changes at any time. In times of water shortage like this, we do not need output but need to meet such situations," said Mr. The Anh.

And Mr. Doan Duy Quan, head of the Muong Lay hydrological station (Dien Bien), said that the water flow to Son La Lake in the section through Muong Lay decreased by 40-50% compared to the average of many years.

"The maximum water flow to the lake since the beginning of the year has been measured at 1,500m3/s, at this time it is just over 10m3/s. Since Son La Lake has accumulated water until now, this is the time when the water flow to the lake is smallest. Therefore, at this time, the water level of Son La Lake is only 175m, 10-15m lower than the average lowest water level of the years." Mr. Quan said, adding that the dry forecast will last until the end of June.