Massive blackout in China and a perspective for Vietnam’s power system


Massive blackout in China and a perspective for Vietnam’s power system

From the causes of China’s electricity shortage recently, Vietnam has noticed what needs to be determined about the current and future power structure?

China has the world’s leading power system in all aspects. Electricity output in 2020 will reach 7,620 billion kWh, far ahead of the second largest country, the United States with 4.009 billion kWh. Installed capacity as of May 2021 is 2,240 GW, nearly double the total installed capacity of 1,226 GW in the United States. The length of the UHV ultra-high voltage transmission line (800 kV and 1,000 kV, DC and AC), including the line under construction, extends 41,000 km from West to East, from North to South, connecting 7 power regions China. Unlike developed countries, China’s electricity output is still increasing continuously.

But every giant has a weakness. In less than 12 months, that weakness has been exposed twice. The weakness was first revealed through a string of power cuts during the cold winter peak of late December 2020 to early 2021 in Hunan, Jiangxi and Zhejiang. The second time at the end of September 2021 in a series of provinces in the Northeast, down to Guangdong and to the west, Yunnan.

Since September 10, 2021, the external grid power supply to Liaoning has dropped sharply, forcing the province to switch to “orderly” electricity use measures – that is, to turn off the load with a reduction of 4,169 MW. . Tens of thousands of households are also included in this plan. From September 10 to 22, 2021, the province had to make 6 power cuts as planned due to a shortage of 5-10% of capacity and 3 times of power cut due to a lack of 5% of capacity.

In Heilongjiang province, year-to-date, economic activity has continued to improve and electricity demand has increased rapidly. From January to August this year, electricity consumption in the province reached 71.3 billion kWh, up 9.16% over the same period last year, while the electricity growth forecast for the whole country is only around 6-7. %. Heilongjiang prepares for winter, famous for its “ices” in Harbin forcing a series of thermal power plants to shut down for maintenance in preparation for the long harsh winter. At the same time, the weather forced the renewable energy power source to reduce its generating capacity, forcing from September 10, Heilongjiang had to switch to a planned power cut. From September 10 to 22, Heilongjiang had to cut power 13 times. Meanwhile, in the Northeast, the evening outdoor temperature has dropped to 1 degree Celsius, people are starting to need heating.

On September 23, 2021, the Northeast electricity system was reduced in both hydroelectricity capacity due to lack of water, almost lost renewable energy in the evening, so the three Northeast provinces are Liaoning, Jilin and Hei. Long Giang was forced to cut off emergency power from 16:30 to 21:30. Liaoning cuts 440 MW of load, Jilin cuts off 360 MW and Heilongjiang cuts off 200 MW to save the Northeast power system because the frequency has dropped lower than 49.80 Hz. The emergency power cut upsets people’s lives, causes traffic jams due to loss of signal lights, people get stuck in elevators, damages production and even causes accidents in production due to power outages. suddenly. The Northeast has not lost power for 20 years, so people are subjective and do not take precautions. But if the power is not cut off, the Northeast electricity grid will be broken.

While the Northeast begins with winter, in Guangdong it is still summer, a hot summer that makes the need to run air conditioners soar. In addition, the electricity load increased sharply due to the surge in Guangdong’s production. Peak load in January to March was only 100 GW, but in September increased to 135 GW. Meanwhile, electricity not only did not increase in time, but also decreased because the price of natural gas and coal increased, and it was also more difficult to buy. Thermal power companies also have no incentive to generate electricity. The peak compensation generator sets are malfunctioning again.

Since the beginning of September, a series of manufacturing plants in Guangdong have received requests to cut power consumption, especially during peak hours. They don’t know when the request will be removed. Even in Dongguan (Dongguan), the world’s manufacturing hub, power cuts are required to cut power for up to four days for a normal factory and five days a week for an energy-intensive factory. , making it difficult for production to meet year-end orders.

It is true that the increase in load is unexpected, but how can a country with a installed capacity of 2,240 GW lack electricity when the peak load reaches 1,200 GW? – That is, the peak load is only 53.6% compared to the installed capacity of the system? Most people will blame the lack of coal to produce electricity.

But if we look at the total coal production in the graph, we see that the supply of coal has not decreased compared to 2019. So the lack of coal is only a small part of the reason for the lack of electricity. It is hard to even expect China to consume more coal as the Chinese leadership has pledged to peak CO2 emissions by 2030. The power shortage event occurred due to a coincidence of many causes including coincidence. naturally and of course.

According to the commitment, China will peak CO2 emissions by 2030 and then reach carbon neutrality in 2060, solar and wind renewable power sources increase rapidly. Assuming the coal fuel supply does not increase compared to 2019, the renewable power source (solar and wind power) with a installed capacity of 550 GW must meet the increased load. But because it is an inactive source, at the peak at dusk, it is considered that 260 GW of solar power does not exist. There were times when the wind was only blowing at 10% of normal, meaning that there were times when 290 GW of wind power capacity was only 29 GW (January 7, 2021). So 550 GW of renewable electricity is actually only 29 GW that is sustainable all the time.

This year’s hydroelectricity will no longer generate electricity at full capacity like the rainy season in 2020 when the Tam Hiep Hydropower group achieved a record of generating electricity. Climate change makes the water to the lake irregular, more year on year, less year on year. Therefore, the installed capacity of hydropower can only be partially trusted.

Thus, only thermal power and nuclear power can actively mobilize to meet the increased load. Part of the thermal power plant is in the maintenance period to prepare for non-stop generation for the winter when the demand is high. Another part does not want to run the machine because the price of coal is too high, making the price of electricity higher than the price of electricity sold. Thus, the lack of coal is only one part. The new coal price is the main part. Shanxi 5,000 kcal standard coal in April 2020 was priced at 467 yuan/ton, it increased to 865 yuan/ton in August and exceeded 1,000 yuan/ton in September 2021. Natural gas prices also skyrocketed. With that fuel price, the more power generation, the more loss. Thermal power, therefore, does not guarantee full availability of the installed 1,260 GW.

China’s nuclear power has an installed capacity of 51 GW, which is a respectable number even in the eyes of a nuclear power like France. However, that number is too small compared to the peak load of 1,200 GW.

China continues to pursue dual goals: Reduce CO2 emissions per unit of GDP and limit the increase in CO2 emissions to reach neutrality by 2060. The central government will force provinces that have not reached the double reduction level yet. above must be reached this year, including by cutting production. The government always promises that the current electricity capacity is enough to ensure that domestic electricity is not cut off.

Many Chinese articles have begun to speak about the need to ensure proactive power supply and increase electricity prices. Guangdong province has raised industrial electricity prices by increasing peak and off-peak hours since October 1, 2021. Domestic electricity remained at the average price of 0.542 yuan/kWh (about 1,950 VND/kWh).

While the cause of the increase in coal prices is new, the imbalance due to the high amount of renewable electricity has caused a shortage of electricity for China since December 2020 and is not surprising – despite the weather. always unexpected turn of events. Of course, when the economy moves towards carbon neutrality, there are many times when there is still a headache with the frenzy of renewable electricity. Although China already has 36 GW of stored hydropower (the world’s leading large capacity), and an East-West super high-voltage transmission system, it is still not enough to balance 550 GW of renewable energy capacity.

In addition, stored hydroelectricity has a “political” role as a buffer for nuclear power. In order to increase electricity storage, retail electricity prices must also increase.

Conclusions and perspectives associated with Vietnam’s power system

The causes of power outages in China over the past time can be summarized as follows:

1. The sudden increase in electricity consumption caused by China not only increased production to meet its own Covid-19 recovery, but also partially met the recovery of the whole world.

2. Sudden increase in electricity consumption due to weather.

3. The high price of coal and gas fuels while the retail price of electricity remains unchanged, making thermal power unprofitable, even at times suffering losses when generating electricity.

4. Coal supply has been stable over the past few years and cannot increase dramatically according to electricity load. China’s climate commitment does not allow coal resources to increase forever, but to decrease.

5. Commitments on climate change force some provinces to cut down on electricity use in order to achieve the CO2/GDP emission ratio. They are not allowed to increase total emissions.

6. The high percentage of renewable electricity, but not enough storage makes the total installed capacity seem redundant but cannot meet the load when needed.

7. Climate change makes hydroelectricity water unstable, only a part of capacity can actively generate electricity.

8. The low retail price of electricity, not following the market, and the price difference at peak hours are not enough to encourage businesses to use electricity more rationally.

In each province and electricity region, the combination of those causes is different, there is a decrease in this group of causes compared to another group of causes.

From the above-mentioned causes of China’s power shortage, the Vietnamese power system needs to pay attention when determining the power source structure, especially to take into account the reasonable capacity ratio of renewable energy in the whole system for each period. period, the issue of energy storage, as well as noting the unexpected factors of climate change (impact on both power generation capacity, electricity consumption load), the possibility of increasing retail prices electricity and the operation of the competitive retail electricity market.


References:

China National Statistics Office. http://www.stats.gov.cn/english/

General Administration of Customs of China. http://www.customs.gov.cn/Electricity Council of China. https://www.cec.org.cn/

Reuters. China power crunch spreads, shutting factories and dimming growth outlook. https://www.reuters.com/world/china/chinas-power-crunch-begins-weigh-economic-outlook-2021-09-27. September 27, 2021.English.

The Paper. https://www.thepaper.cn/newsDetail_forward_14706796, Xinhua News Agency Investigation: Why are many places “cutting off power cuts”? Can the subsequent power supply be guaranteed? September 28, 2021. Chinese.