EVN: Proposing solutions to operate the power system when there is high renewable energy

At a recent information session on the electricity supply situation in 2021 and the period 2021-2025, Vietnam Electricity Group (EVN) said that renewable energy sources are high, concentrated in a number of areas. Localities are causing difficulties in operating the power system. Therefore, it is necessary to have a solution soon to optimally operate the system.

Mr. Nguyen Duc Ninh – Director of the National Power System Dispatch Center (A0) said that in 2020, according to the Approval Decision of the Ministry of Industry and Trade (before COVID-19), Vietnam’s electricity demand still maintains high growth. The total planned electricity output for the whole year reaches 261 billion kWh. To meet electricity demand, EVN also plans to run about 3.4 billion kWh of oil-based electricity. However, due to the impact of the COVID-19 epidemic, the electricity consumption load decreased, leading to the exploited power sources being lower than planned. Actual electricity output reached just over 247 billion kWh, an increase of over 3%, a decrease of 14,350 billion kWh. In the first 4 months of 2021, electricity production grew by 7.92%; Commercial electricity increased by 6.74%.

EVN’s statistics show that, if in 2019 there were about 5,000MW of grid-connected solar power, by 2020 there will be nearly 5,000MW of grid-connected solar power and about 7,000-8,000MW of rooftop solar power and over 600MW of grid-connected solar power. wind is put into operation. According to the plan, in 2020, more than 10 billion kWh of renewable energy will be mobilized, but in reality, up to 12 billion kWh has been exploited.

To date, the total installed power capacity of the entire system has reached nearly 70,000 MW. Of which, solar power alone as of April 2021 has reached 18,783MW (9,583 MW of rooftop solar power and about 9,200 MW of farm solar power). And from now until the end of 2021, about 4,000-5,000 MW of wind power will be put into operation according to registered investor plans. It is expected that in 2021, the electricity output mobilized from renewable energy will reach about 32 billion kWh. Notably, grid-connected renewable energy sources are concentrated locally in some areas, leading to difficulties in operating the power system. Despite difficulties, EVN still ensures to mobilize power sources in the direction of prioritizing renewable energy, ensuring continuous power supply to loads.

To ensure the safety of the power system as well as economic efficiency, according to Mr. Nguyen Duc Ninh, cutting renewable energy sources is necessary. In the first 4 months of 2021, the amount of rooftop solar power cut was about 447.5 million kWh, accounting for 13.3%. It is expected that the whole year of 2021 will cut 1.25 billion kWh, accounting for 9% of total renewable energy output. Sharing more about the difficulties and effects on the power system when there are many renewable energy sources, Mr. Nguyen Van Ninh said, he has There is a state of excess power and overload on intra-regional lines and 500kV link lines; The load difference between peak and off-peak is large; Forecasting the generation capacity of renewable energy electricity is difficult due to large errors; Vietnam’s power system operates independently (unlike the interconnected power grid in the European region), while technical factors as well as ensuring the operation of a competitive electricity market and other regulations must still be met. Maintain traditional power sources.

According to statistics from the National Power System Dispatch Center, in the first 4 months of 2021, due to prioritizing the mobilization of renewable energy sources, thermal power plants had to start their generator sets more than 334 times. This number in 2020 is 192 times. With a coal, gas, or oil power project, each shutdown and restart costs up to tens of billions of dong, not to mention the risk of damage and reduced machine life. In fact, there was a problem with the generator set at the Phu My 2.2 plant; Ba Ria factory…

From actual operations, EVN has also developed solutions and reported to competent authorities, including requests to review, update, and adjust circulars and procedures to suit the operating conditions of the power system. high proportion of renewable energy, especially with a large penetration rate of rooftop solar power in the distribution grid, soon issue a mechanism for rooftop solar power, which encourages increasing the amount of self-use capacity as well as ensuring technical requirements.

EVN also reported to the Ministry of Industry and Trade/Prime Minister to approve the auction/tendering mechanism for wind and solar power projects – supplementing the Planning according to the 3-5 year implementation plan with appropriate scale at each location. time, each region in the future, avoiding grid overload and excess power. At the same time, propose an investment mechanism to build a battery storage system (BESS); Ancillary service mechanism in the power system to encourage power generation units to participate. Recommend early approval of additional planning for urgent power grid projects to serve the release of renewable energy. Overall review of the necessity of the avoidable cost mechanism and readjusting the avoidable cost calculation method in the context of renewable energy penetration at an increasingly high rate.

(According to evn.com.vn)