Recently, Sichuan issued a new power restriction order: in order to ensure the safety of the power grid and the use of electricity for people's livelihood, it has been decided to implement a total production shutdown of all industrial power users in Sichuan Power Grid from August 15 to 20, for a total of five days.

At this point, the situation of power supply and demand in Sichuan has changed from the "shortage" of power during the peak period in July to the situation of "double shortage" of electricity throughout the day. It is expected that the maximum electricity load in the province will increase by 25% over the same period last year, and the situation of power supply is very grim.

In fact, with the increase of high temperature days this summer, China has once again ushered in the peak period of power consumption, and some areas have introduced the policy of off-peak power consumption. As we all know, Sichuan is rich in water resources, the proportion of hydropower supply is very high, hydropower installed capacity and hydropower generation both steadily ranked first in the country, and it is also the largest province in hydropower transmission.

But the lack of electricity this summer happened in Sichuan.

Extreme weather is the main cause of power shortage.

Hydropower accounts for as much as 70% of Sichuan's power structure. Coal and electricity account for only about 20%. Sichuan has the second largest hydropower station in the world-Baihetan Hydropower Station, with a total installed capacity of 16 million kilowatts and an average annual generating capacity of 60.2 billion kilowatts. This family alone can meet the daily electricity consumption of 90% of the people in Sichuan. In addition, there are 13 large hydropower stations, including Xiluodu Hydropower Station and Wudongde Hydropower Station, with an installed hydropower capacity of 89.47 million kilowatts and a generating capacity of 353.14 billion kilowatt hours, both ranking first in the country.

In the power consumption structure of Sichuan Province, residential electricity accounts for 40%, and industrial electricity accounts for 60%. Industrial electricity consumption is dominant.

It is not only a major province of hydropower, but also in the flood season at present. Why did Sichuan become the protagonist of power shortage?

This mainly comes from the same effect of weather and electricity structure.

First of all, on the supply side: the lack of water in the flood season is the main reason for the power shortage in Sichuan Province this year.

Hydropower in China has obvious seasonal characteristics of "abundant in summer and dry in winter". Generally speaking, the flood season in Sichuan is from June to October, and the dry season is from December to April of the following year. But the climate this summer is extremely unusual. After entering the flood season (June to October), the water inflow in Sichuan Province is extremely serious. In July, the inflow from the major rivers in the province, such as the Dadu River and the Minjiang River, generally decreased by more than 40% compared with the historical average for many years. The installed scale of hydropower in Sichuan Province is about 89 million kilowatts, in which there are a large number of radial small hydropower with no regulating capacity, and the dry water seriously affects the output of this kind of small hydropower in flood season, resulting in a substantial decline in hydropower generation.

7Months later, the electricity of natural water from Sichuan increased from 9. 5%.Billion kilowatt-hours dropped to 4.5100 million kilowatt-hours, a decrease of up to 50%And still at an average daily rate of 2%The speed continues to decline. The once-in-a-century high temperature water has been evaporated on a large scale, and it is difficult to reverse the straight decline in hydropower production.

Secondly, on the demand side:The extreme high temperature weather is serious this year. Data from the Sichuan Provincial Climate Center show that the number of high temperature days in the province since July this year is the highest since 1961. The high temperature weather promotes the rapid rise of residential electricity demand and promotes a significant increase in the peak demand load in the province. Electricity sales in Sichuan reached 29.087 billion kilowatt-hours in July, an increase of 19.79 percent over the same period last year, setting a new record for monthly electricity sales.The maximum load of Sichuan power grid is close to 60 million kilowatts, an annual increase of 14% over the same period last year.The average daily electricity consumption of residents was 344 million kilowatt-hours, an increase of 93.3 percent over the same period last year, nearly doubling.

On the one hand, the hydropower supply is greatly reduced, and on the other hand, the power load is growing faster than expected, resulting in a persistent gap between power supply and demand. At the same time, the rigid outward transmission and lack of regulation capacity in the power consumption structure also aggravate the shortage of supply and demand in the province.

There is a deep contradiction between electricity transmission and seasonal regulation.

In terms of electricity transmission, Sichuan Province, as a major province of power transmission from west to east, a large number of rigid contracts need to be carried out in the flood season.Sichuan State Grid Electric Power Company explained: according to the national strategy of "power transmission from west to east", large cascade power stations such as Xiangjiaba, Xiluodu, Jinping and Baihetan in Sichuan are all developed and consumed by the state as a whole. Its electricity is distributed throughout the country as a whole, and there is a fixed proportion of distribution within and outside the province, and the excess electricity is not given priority to be consumed in Sichuan. Therefore, according to the distribution of electricity in Sichuan, nearly 1 stroke 3 of electricity needs to be exported, and priority is given to eastern China, which is dominated by Jiangsu, Zhejiang and Shanghai. At present, the external power transmission capacity of Sichuan Province has reached 30.6 million kilowatts. In the first half of this year, Sichuan Power Grid has delivered a total of 1.35 trillion kilowatt-hours of electricity to East China, Northwest China, North China, Central China, Chongqing and Tibet.

In addition, there are seasonal differences and runoff regulation contradictions that can not be ignored in hydropower.During the flood season, the huge supply of electricity exceeds the demand, and there is often "abandoned water". When it comes to the lack of electricity generation in the dry season, there is often a "power shortage".

Of course, Sichuan Province also has certain means of seasonal regulation, but the overall regulation ability is weak.

The first is thermal power regulation.The installed capacity of thermal power in Sichuan Province is less than 20 million kilowatts, accounting for 18% of the installed capacity in Sichuan Province and supporting about 16% of the power consumption. According to the 14th five-year Plan of Sichuan Energy, by 2025, thermal power will be about 23 million kilowatts. But in July this year, the maximum load of Sichuan power grid reached an extreme peak of 59.1 million kilowatts. The peak in previous years will also reach 4000-50 million kilowatts. Therefore, the regulation effect of thermal power is very limited.

The second is the self-regulation of water and electricity.Hydropower stations also have reservoirs of different sizes, which may be subject to seasonal water regulation, so that electricity can be generated during low water periods. However, the reservoir capacity of hydropower stations is often small, and the regulation capacity is very poor. Therefore, the leading reservoir is needed. The construction of the leading reservoir is built in the upstream of the power station in the basin, with small installed capacity but huge storage capacity. In order to achieve the seasonal control of traffic. According to the data of Sichuan province, the installed capacity of reservoir power stations with seasonal regulation capacity is less than 40% of the total installed capacity of hydropower.

The third is the shortage of foreign transmission network.Sichuan UHV power grid is not perfect, the maximum can only undertake 500 kV power transmission, which makes it impossible for Sichuan to expand power transmission capacity from other provinces or cities in the short term. Hydropower stations such as Ganzi and Aba have a surplus of electricity that cannot be sent to Chengdu.

The problem of power shortage may continue, but the impact is weaker than last year.

At present, under the extreme weather of high temperature for a long time, which is rarely seen in history, the power gap in Sichuan may be about 10 million kilowatts. Under measures such as ensuring the maximum utilization of thermal power resources, power support outside the province, and giving priority to the use of electricity for people's livelihood, the gap will be alleviated to some extent. But based on the analysis of the causes of the former stage,If the temperature and weather conditions do not improve, it may be difficult to make up for the power shortage in the short term.

According to the forecast of Sichuan Provincial Meteorological Bureau, there will be a precipitation weather process in the northern part of the western Sichuan Plateau and the western part of the basin around August 18, and the high temperature in the basin will continue, reaching 3942 ℃ or more in most parts of the basin. It is expected that the high temperature in the basin will end around the 22nd. However, the average precipitation of the whole province from mid-August to early September is still less than that of the same period of normal year, and the average temperature is higher than that of the same period of normal year. In August, the average temperature of the whole province will be the highest in history.

Yunnan, Hubei, Guizhou and other provinces, which are also major hydropower provinces, are also facing the impact of hydropower supply, which may lead to the problem of power shortage. At present, some other provinces and cities are also beginning to promote orderly power consumption measures. It includes Zhejiang, Anhui and Jiangsu in East China, as well as Yunnan and Shandong, where power cuts were serious last year.

In terms of impact, it should be weaker than the impact of power cuts in the same period last year.

In May last year, Yunnan Province launched the first shot of power cuts, when Yunnan Power Grid issued a notice saying that the main reservoirs were overdrawn and thermal power was not enough to store coal, and emergency off-peak power cuts began for local state power companies. After entering September, there has been a further increase in the number of provinces with power cuts, with Guizhou, Jiangsu, Shandong, Anhui and other provinces issuing notices of temporary power cuts and off-peak power consumption. In addition to restricting the use of electricity by "two high" enterprises in the three northeastern provinces, the impact of power cuts also affects residents and enterprises that do not implement orderly power consumption measures.

In addition to the active power cuts in the provinces marked red or yellow in the double-controlled barometer of energy consumption last year, another important reason was the helplessness of the provinces with a serious shortage of coal.If last year's power cuts were mainly due to "lack of coal", then this year's power cuts are mainly "lack of water." Although thermal power accounts for less in Sichuan, the proportion of thermal power in the country is very large, more than 60%.

According to CITIC's expectation, according to the scale of domestic hydropower generation in the flood season last year was 650 billion kilowatt hours, if the electricity generation in this year's flood season is reduced by 20%, the impact of the decline in hydropower output on domestic power generation is about 1.6%.

At present, the power coal price has fallen from the high level and the coal inventory of the power plant has been significantly improved compared with last year, and the obvious rise in transaction electricity price will help to enhance the willingness of thermal power enterprises to generate electricity. Thermal power generation in July has accelerated by 11 percent from last year's high base.

At the same time, the growth rate of electricity demand has also slowed down.The cumulative growth rate of electricity consumption of the whole society has dropped from 10.3% at the end of last year to the current 3.4%, which is also conducive to the convergence of the overall power gap. So the overall impact is weaker than the power cuts in the same period last year.

As far as Sichuan province is concerned, Sichuan is the largest photovoltaic industry base in China, one of the three major power equipment manufacturing bases in the country, and the largest electronics industry production base in the west. The status of the industrial chain is very important.

At present, Foxconn, Ningde era, BOE and other leading enterprises in Sichuan factories are short-term shutdown or production restrictions. The impact depends on the duration of power cuts, and if it lasts for two weeks, it may have an impact on the production of related industries.

The impact of short-term shutdown on the output of silicon in photovoltaic industry is about 12000 tons; the output of electrolytic aluminum is about 30 000 tons; it also has a certain impact on zinc and semiconductors, but the impact on lithium carbonate and chemical products is relatively limited.

At the same time, in the context of "tight balance" between power supply and demand, nuclear power which belongs to "base load power" and thermal power with high flexible regulation properties are expected to thicken their performance under the boost of demand. The importance of power grid construction, energy storage, virtual power plants and other industries to strengthen transmission balance and reorganize energy peak-cutting and valley-filling demand industries will also be further enhanced.