Worried about power shortage, why still release flood?

The current power system's operation mainly depends on coal power, accounting for 60% - Photo: D.Tuyen

In mid-June, entering the peak of the dry season, hot weather occurred in many provinces and cities, causing electricity consumption to continuously exceed its peak. According to the Electricity Regulatory Authority (Ministry of Industry and Trade), the maximum load capacity from June 10 to 16 reached the highest value since the beginning of the year in the North.

Too much water, hydroelectric power plant must release flood water

Recorded on June 14, the total system capacity reached 48,954MW, electricity output was 1,019 million kWh, of which the North alone had 504.9 million kWh, the largest load output since the beginning of the year with an average daily output of 945.6 million kWh.

Since the beginning of the year, the national load has increased by about 11.5% compared to the same period in 2023 (the North increased by 11.1%, the Central region by 10.2%, the South by 12%). According to the Electricity Regulatory Authority, the national power dispatch system has recently increased the exploitation of Son La, Hoa Binh, Tuyen Quang, and Ban Chat reservoirs to gradually bring the water levels of the reservoirs back to pre-flood levels.

However, since June 11, Tuyen Quang lakes have had to open 1-2 bottom spillway gates. On June 15, from 1pm, Son La lake had to open a bottom spillway gate and closed it at 6pm the same day. This development is different from before when since April, the electricity industry said it had to store and save water, "reserve" it to prioritize power generation during the peak of the dry season.

The remaining output in the reservoir as of 0:00 on June 16 of the entire system was 7,973.3 million kWh, 2,987.3 million kWh higher than the annual plan. Water inflow to hydroelectric reservoirs in the North was 109 - 230% higher, such as Ban Chat, Thac Ba, Tuyen Quang, Trung Son and Bac Ha, but the remaining reservoirs had low water flow, only reaching 33 - 92%.

Meanwhile, lakes in the Central region have water levels much lower than average from 7 - 84%, while the South has water levels lower than average (except Dong Nai 2 and Da Nhim lakes).

Speaking to Tuoi Tre, an electricity expert said that because the design of the reservoirs is quite safe and flexible, with both bottom and surface discharge gates, when the water comes in, the reservoirs will operate depending on the situation. In the context of a tense dry season electricity supply, storing and saving water for power generation during the peak dry season will be the top priority.

According to this person, large hydroelectric plants such as Hoa Binh, Son La, Thac Ba... have reservoirs so they can store water in the lake. "With small hydroelectric plants without reservoirs, when the water comes in, it will not be stored again, so the investor is forced to release flood water when there is heavy rain or sudden water flow, to ensure the safety of the project's operations," this person explained.

In fact, in the North, the capacity of small hydroelectric plants is about 4,500 MW, equivalent to large hydroelectric plants, so the overflow situation when the water level suddenly rises is a normal principle to ensure the safety of the project.

Lots of water to run the machine, still worried about power shortage

Although the water level in the lakes has improved and there is water discharge, according to electricity experts, during the peak of continuous heat, electricity supply will face many difficulties because the available capacity of hydroelectric plants will decrease sharply according to the water level in the lakes.

For example, with Hoa Binh Lake, if the water level is sufficient, the capacity reaches 1,920 MW, but this number drops to only 1,400 MW if the water level in the lake decreases due to heavy use. However, according to this person, hydropower no longer accounts for a large proportion. The balance depends on coal-fired thermal power.

In fact, to proactively operate, many coal-fired power plants have also accelerated coal imports even before the peak period. Nghi Son Thermal Power Company - one of the largest coal-fired thermal power plants with a capacity of 600 MW of the Power Generation Corporation 1 (GENCO 1) - said that the electricity output produced and mobilized by the company is higher than the plan approved by the Ministry of Industry and Trade.

According to a representative of this enterprise, to meet the increased demand for mobilizing resources in the first four months of the year, the enterprise signed a coal supply contract with the Vietnam National Coal - Mineral Industries Group (TKV) and the Dong Bac Corporation with a higher output of 109,000 tons, ensuring an additional generation of 250 million kWh compared to the assigned plan.

Up to now, the amount of coal in inventory in the months has ensured progress, met operational needs and maintained inventory levels higher than the minimum inventory level.

With 20 plants with a total installed capacity of 7,150 MW, accounting for 8.9% of the total capacity of the entire system, ensuring the operation of GENCO 1's power plants (under EVN) plays a very important role. According to GENCO 1's representative, coal-fired thermal power plants must always be prepared and improve operational reliability to the highest level to maximize power mobilization.

This enterprise also proactively requires the chairmen and general directors of affiliated power units to uphold the spirit of responsibility as leaders and increase discipline. Absolutely comply with operating procedures, inspect and supervise to promptly identify risks to avoid incidents in mobilizing power sources, prepare materials and human resources to operate the system...

Must ensure enough electricity during hot weather

According to the Ministry of Industry and Trade, from now until the end of June, coal-fired thermal power plants will still be mobilized according to system demand, ensuring operation and repair for optimal mobilization along with gas turbine plants.

Hydropower plants are also exploited according to the actual hydrological situation, flexibly mobilizing to ensure available capacity to meet the peak of hot weather in the Northern region. Maximum mobilization of Tuyen Quang, Son La, Hoa Binh, Ban Chat hydropower plants due to good water flow and increased flood prevention capacity.

The Ministry also directed power generation units to proactively report and provide accurate information on the operation status of generators, causes of incidents, repair time, coal inventory, expected progress and coal import plan to send to A0.

Absolutely do not let the situation happen where the plant is ready to generate electricity but lacks coal fuel and cannot generate enough capacity, so that there is a basis for planning operations for the remaining months of 2024.

Source: https://tuoitre.vn/lo-thieu-dien-vi-sao-van-xa-lu-20240621093505885.htm