Author: Lin Chunting
In some places in Sichuan and Chongqing, people walk, play and ride electric bicycles on the river that exposes a large riverbed; the "real body" of the Leshan Giant Buddha sitting at the intersection of the three rivers is also displayed before people.
Sichuan, China's largest hydropower development and "West-East Power Transmission" base, shoulders the heavy burden of national energy and power supply security.
However, under the continuous interference of extremely high temperature and dry weather, the water supply to the "Land of Abundance" plummeted, and hydropower generation was "halved", and the support of electricity from outside the province was urgently needed.
On August 21, Sichuan launched the "Level 1 Emergency Response of Energy Supply Guarantee for Emergencies".
This is the highest level in the early warning classification level of local energy supply security, and it belongs to "particularly serious".
The highest historical records of electricity load in many provinces are also being refreshed.
While testing the huge and complex China's power system, the rare high temperature and dry weather also raised the following warnings: the global climate continues to warm, extreme weather disasters occur frequently, and the safety risk factor of the power system continues to increase.
Many people believe that increasing the diversity of power sources and developing new energy sources such as nuclear power and wind power can solve the problem of bias in the current energy structure. question.
An engineer from a state-owned power design institute said in an interview with a reporter from China Business News that at present, the energy and power industry is using energy storage and other means to enhance the elasticity and resilience of the power system in the face of extreme weather.
No one can escape
There are many rivers in Sichuan, mainly the Yangtze River system, and nearly 80% of the electricity is supplied by hydropower.
However, since July this year, the rainfall in the Yangtze River Basin has been 40% lower than the same period of the previous year, and the average rainfall in Sichuan is 51% lower than that in the same period of the previous year. Combined with factors such as insufficient coal transportation capacity from other provinces, the contradiction between local power supply and demand has become more prominent.
The State Grid has made a statement: it will play the role of resource allocation of the large power grid, organize cross-regional and cross-provincial mutual assistance, and maximize the power supply in Sichuan and Chongqing.
In addition to Sichuan and Chongqing, Shaanxi, Hubei, Anhui, Jiangsu, Zhejiang and other places experienced high temperatures of 40 to 43 °C for several consecutive days, breaking the highest local temperature records since meteorological records in many places.
In fact, high temperatures and droughts are not limited to China.
Like China, since the beginning of summer this year, Europe has experienced persistent high temperature weather, most of which are drier than before, and the precipitation in some countries has dropped to record levels.
The high temperature and drought have caused a significant increase in electricity demand, and at the same time have had a serious impact on electricity production, making the power shortage in Europe continue to worsen.
Taking France as an example, nuclear power accounts for about 70% of the country's total power generation, and most of the nuclear power plants are located inland. However, since the beginning of summer this year, the water level of the rivers used to cool the nuclear reactors has dropped to the lowest level in 20 years, and the nuclear power generation capacity has plummeted. drop.
Hydropower, France's second-largest source of electricity, is also implicated.
According to data from the French Electricity Transmission Network, France's hydropower generation in June was the "lowest level in history for the same period", and the power generation of some hydropower stations decreased by 60%.
The high temperature and drought have lowered the water level of the Rhine, the longest river in western Europe, and hindered the transportation of coal.
The unsecured coal supply has made some coal power plants in Europe unable to operate normally, exacerbating the shortage of power supply and rising electricity prices.
Among them, electricity prices in France and Germany are close to the highest level in history.
It can be seen from this that under extreme climates, any form of power supply may be impacted, and "no one can escape".
"How to improve the disaster resilience of the power system?" This is actually a world-class problem.
As far as China is concerned, Lin Boqiang, dean of the China Energy Policy Research Institute of Xiamen University, said in an interview with a reporter from China Business News that at present, China's power system is still dominated by fossil energy, accounting for nearly 84%, but it will be reversed in the future. , to focus on clean energy, and clean energy accounts for more than 80%.
"That is to say, the importance of thermal power will gradually decrease, and the proportion of wind power, hydropower, photovoltaics, and nuclear power will increase."
According to the "2030 Carbon Peak Action Plan" issued by the State Council, by 2030, the total installed capacity of wind power and solar power generation in the country will reach more than 1.2 billion kilowatts, which is about double the current level.
After 2030, the scale of these energy sources will increase.
However, like hydropower, renewable energy sources such as photovoltaics and wind power are inherently "depending on the weather", and power generation depends on solar energy and wind power respectively. These natural phenomena have natural fluctuations, intermittency and uncontrollability. The generation of this energy source becomes unpredictable.
In recent years, there have been cases in my country that wind turbines cannot operate normally due to freezing, and the supply of thermal coal is insufficient.
Building a new power system has thus become more urgent.
"Whether it is renewable energy or non-fossil energy, it is mostly in the form of electricity. Therefore, building a new power system with new energy as the main body is an important path for energy transformation." Li Junfeng, executive director of China Energy Research Association, told Yicai.com reporter said.
"In the future, a large number of energy storage facilities will need to be built to make up for the instability of renewable energy generation."
Energy storage! Energy storage!
With the increase in the penetration rate of new energy, the power system is changing from "centralized power generation" to "combined centralized and distributed power generation", and its main body has also begun to change from "source grid load" (ie "power source, power grid" , load") has become "source network load storage", and energy storage has become an important member of the new power system being constructed.
Energy storage has the dual attributes of power supply and load at the same time, which can solve the problem of rapid fluctuation of new energy output and improve the elasticity, controllability and resilience of the power system.
Specifically, on the one hand, energy storage can solve the problem of mismatch between power generation and electricity load during peak and valley periods by shaving peaks and filling valleys; on the other hand, it can participate in the provision of auxiliary power services to solve the volatility and intermittent nature of wind and solar power generation. The resulting grid volatility.
At present, China's energy storage is mainly based on pumped storage power stations.
The pumped-storage power station mainly uses the surplus electric energy to pump water during the trough period of electricity consumption, and discharges water to generate electricity during the peak period. It is known as the "regulator", "regulator" and "charging treasure".
According to the "Medium and Long-Term Development Plan for Pumped Storage (2021-2035)" announced by the National Energy Administration in 2021, pumped storage is currently the most mature technology, the most economical, and the most environmentally friendly power system with the most large-scale development conditions. Carbon clean and flexible adjustment of power supply, and the effect of cooperation with wind power, solar power, nuclear power, thermal power, etc. is better.
However, pumped hydro storage currently accounts for less than 2% of the country's total installed power capacity, making it difficult to meet the needs of the rapid development of new energy.
The Medium and Long-Term Development Plan for Pumped Storage (2021-2035) proposes to accelerate the development of pumped storage.
"In the future, we need to scientifically plan and build more pumped-storage power stations." Zeng Dewen, a former member of the State Grid Planning Expert Group, said in an interview with a reporter from China Business News.
A power grid insider told reporters that the two major power grid companies, State Grid and China Southern Power Grid, are making efforts to build pumped storage power stations.
In 2021, the State Grid proposed that during the "14th Five-Year Plan" period, it will invest 100 billion yuan to build a pumped-storage power station with an installed capacity equivalent to the total installed capacity of a Three Gorges Hydropower Station in new energy intensive development areas and load centers; Said that in the next ten years, a pumped storage power station with the same installed capacity will be built and put into operation, and a 15 million kilowatt pumped storage project will be built, with a total investment of about 200 billion yuan, plus a reasonable scale of new energy storage, which can meet the needs of 2030 Access and consumption of about 250 million kilowatts of new energy in the five southern provinces.
The so-called new energy storage refers to electrochemical energy storage batteries such as large-capacity liquid flow, lithium-ion, sodium-sulfur, lead-carbon batteries, and compressed air energy storage.
Like batteries, these new types of energy storage can store electricity and release it when needed.
The "14th Five-Year Plan for Modern Energy System" issued by the National Development and Reform Commission and the National Energy Administration proposed that to build a new power system, it is necessary to "accelerate the large-scale application of new energy storage technologies and vigorously improve the flexibility of power loads".
According to the "Guiding Opinions on Accelerating the Development of New Energy Storage" issued by the two ministries and commissions in 2021, by 2025, the new energy storage will be transformed from the initial stage of commercialization to large-scale development, with an installed capacity of more than 30 million kilowatts; by 2030 In 2018, the comprehensive market-oriented development of new energy storage will be realized.
"At present, the investment cost of the entire Chinese power system is mainly on the power supply side. The construction of power sources such as coal power plants, hydropower plants and nuclear power plants requires a lot of investment." Lin Boqiang told the reporter, "But in the future, it may be reversed, and the cost is mainly It is in the stability of the power system, including the system side of grid intelligence and energy storage."
The engineer of the above-mentioned state-owned electric power design institute told the first financial reporter that at present, the industry is increasing the planning of energy storage construction.
"The launch of more energy storage power stations is an important choice for the future power system to deal with extreme weather," he said.