Hydropower dams ease above dead storage level after rains

Water levels at all hydroelectric reservoirs across Vietnam have now climbed above the threshold for safe electricity generation thanks to rains.

State-owned monopoly distributor Vietnam Electricity (EVN) said Tuesday that the levels are 282 m in the Lai Chau dam, 17 m above the dead water level; 179 m in Son La, 4 m above the threshold; 438 m in Ban Chat, 7 m above; and 96 m in Tuyen Quang, 6 m above.

In others such as Thac Ba, Huoi Quang, Ban Ve, and Tri An it is 0.5-3 m above the safety level.

The storage has risen following higher inflows after there were moderate to heavy rains in the past few days.

Between Monday night and Tuesday morning over 60 mm of rainfall was recorded in many places, including substantially higher levels in places such as Lai Chau Province.

According to the managements of the 1,200-MW Lai Chau and 2,400-MW Son La hydropower plants, the largest and third largest hydropower plants in Vietnam, the water levels are enough to generate electricity again though only for 90 hours and 50 hours before they drop back to dead levels.

Therefore, they do not plan to restart the plants and would wait for peak summer when power demand would surge, they said.

Seven others are down for the same reason, Tuyen Quang, Huoi Quang and Ban Chat in the north, Ben Va and Song Tranh 2 in the central region, and Dong Nai 3 and 4 in the south.

In the north, hydropower production, which accounted for 43% of supply until May, has slumped due to extreme weather which has dried up major dams.

By the end of May they only had enough water to generate 1.23 billion kWh of electricity, or enough to meet only four days’ demand based on a peak of 313.6 million kWh on May 22.

EVN said 11 hydropower plants in the region have shut down due to lack of water, summarily taking 5,000 MW out of the grid.

For over a month now many parts of the north have suffered power cuts amid unusually hot weather, many of them unannounced.

The National Center for Hydro-Meteorological Forecasting expects the hot weather to continue until the end of June.

By Gia Chinh – VnExpress.net – June 20, 2023