Mr. Pham Van Vuong - Director of Hoa Binh Hydropower Company said that from early 2023 until now, the hydrological situation has been unfavorable. Hence, the water inflow to the reservoir is very poor. In the context of high power demand, the upper terraced plants of the Da River such as Lai Chau Hydropower and Son La Hydropower Plants have sometimes been below the dead water level, unable to generate electricity. Even the Tuyen Quang hydropower reservoir in the Red River basin, which is considered to be quite abundant in water, every year always "fulfills" early in terms of power output, but this year, it is also affected by drought. In the context that other hydropower plants are limited in operation due to severe drought, the "burden" of frequency and pressure regulation is also placed on Hoa Binh Hydropower Plant to ensure the safety of the national power system.
Hoa Binh Hydropower Reservoir - photo taken on June 13, 2023
With 8 units (each with a capacity of 240MW), under normal conditions, generating enough capacity, Hoa Binh Hydropower Plant contributes 9,832 billion kWh/year to the national power system. However, from the beginning of the year until now, the total output of electricity generated to the grid of the new Hoa Binh Hydropower Plant is about 3.5 billion kWh, only reaching about 37% of the plan in 2023. The main reason is due to the dry situation. drought, the water flow to the reservoir is very low. Even in recent days, despite rain in many northern provinces and cities, the water flow to the reservoir is very low - only about 200m3/s.
Mr. Tran Van Hoa - Deputy Director of the company added, Hoa Binh Hydropower Plant plays an important role in pressure and frequency regulation, this responsibility is even higher when Son La and Lai Chau Hydropower Plants stopped generating electricity due to a lack of water. In particular, if one of the thermopower plants in the power system encounters a problem, or the renewable energy source is generating high levels, but there is a rain or a passing cloud that causes a sudden decrease in capacity, then Hoa Binh Hydropower Plant shall promptly increase capacity to ensure the safety of the national power system.
Mr. Do Quang Binh - Head of Operation Shift of Hoa Binh Hydropower Plant said that the favorable feature of hydropower is that it can be restarted quickly, almost immediately (within 1-3 minutes). Therefore, the units of Hoa Binh Hydropower Plant always operate in flexible mode, always in a state of readiness to meet the constantly changing operation. “Under normal conditions, A0 only makes about 10 calls to the plant a day on average, but in the peak hours of this year's hot season, more than 30 calls are made per day, when the maximum generation is required, or when the minimum one is required to ensure the safety of the system as well as perform the water storage," said Mr. Do Quang Binh.
For Hoa Binh Hydropower Plant, the biggest difficulty in operation today is that the units have to be adjusted continuously, sometimes with a maximum capacity of 240MW, but later it can go to zero, and then continue to start up. One day the start-up, increase in capacity, or decrease in capacity can be conducted many times, etc. The capacity adjustment depends on the power system, meeting the system's requirements. However, the change in the capacity increase or decrease, the stoppage, or the start-up of units many times in a short time will raise the risk of breakdown, damaging as well as affecting the equipment life. Therefore, employees of Hoa Binh Hydropower Company are always on duty, regularly checking and monitoring to ensure the safety of the power units.
According to Mr. Pham Van Vuong - Director of Hoa Binh Hydropower Company, Hoa Binh Reservoir is currently at a water level of approximately 102m, 22m higher than the dead water level. If the maximum capacity is required, after about 12-13 days, the reservoir will return to the dead water level (80m), then the task of frequency regulation for the national power system will be impossible.