New implications for the impact of extreme weather on systems with a high proportion of renewable energy



Extreme weather may become the new constant of global climate change

In the context of global warming, the frequency and intensity of extreme weather disaster events are increasing. The newly released Working Group I report of the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) (2021/8/9) states that human influences have unquestionably caused warming of the atmosphere, oceans and land, with widespread and rapid changes in the atmosphere, oceans, cryosphere and biosphere. The scale of the overall change in the climate system and its many aspects are unprecedented for centuries, if not millennia. Human-induced climate change is already affecting weather and climate extremes in every region of the globe. UN Secretary-General Antonio Guterres called for a global climate emergency at the Climate Ambition Summit on December 12, 2020.

The occurrence of extreme weather and climate events in the world also has the characteristics of mass and frequent occurrence. According to statistics, from 2000 to 2019, the global heat wave increased by 332%, heavy precipitation increased by 234%, droughts increased by 128%, storms increased by 140%, and wildfires increased by 146% compared to 1980-1999. In July this year, Henan continued to suffer heavy rainfall, and the peak rainfall in Zhengzhou reached 201.9 mm in one hour on the 20th, reaching the maximum rainfall in one hour in nearly 50 years. From 20 o 'clock on the 17th to 20 o 'clock on the 20th, three days of rainfall has approached the total amount of the past year. Severe floods in Zhengzhou and other places have caused heavy casualties and economic losses. Wu Guoding, vice governor of Henan province, said at a press conference on August 2 that 302 people had been killed and 50 were missing. Among them, 292 people were killed and 47 were missing in Zhengzhou. The extraordinary flood in Zhengzhou, Henan province, is just a microcosm of the natural disasters that have hit the world this year. In June, lightning ignited wildfires in Shasta Trinity National Forest in northern California, fueled by strong winds, high temperatures and dry weather. In mid-July, many European countries, including Germany, Belgium and the Netherlands, were hit by floods. Roads turned into rivers, houses collapsed, parked vehicles were washed away, and electricity and communications were cut. The torrential rains and floods are the worst natural disaster to hit Germany and other neighboring countries in nearly 60 years. During July and August, many parts of India were flooded by unusually heavy monsoon rains, and many places are battling deadly floods and landslides. Rare droughts this summer in the United States and Brazil, two of the world's biggest breadbaskets, led to a sharp rise in food prices, and data from the United Nations Food and Agriculture Organization show that the global food price index has risen nearly 40% year-on-year by May 2021.

Second, climate change may become a new variable to test energy security

Traditional energy sources usually refer to coal, oil, natural gas, hydropower and nuclear power. Its main feature is to rely on the energy generated by the combustion of its own substances as energy. Although its mining, transportation, storage and so on are affected by external conditions to a certain extent, but in general, the degree of impact is not high. However, the use of traditional energy will produce a lot of greenhouse gas emissions and air pollution, causing global warming and endangering human health. Renewable energy, especially wind and solar energy, depends on the conversion of wind and solar radiation resources in the atmosphere into electricity and other energy sources, and achieve new energy supply capacity. The advantage is that the use of renewable energy is zero carbon emissions and zero pollution. It can be seen that its dependence on wind resources and solar radiation resources is very high. This is a shortcoming in the utilization of renewable energy, which must be paid close attention to.

Extreme weather and climate events are often accompanied by abnormal changes in meteorological elements. For example, in the high temperature heat wave and static stable atmospheric environment, due to a large range of static wind environment, wind power generation is almost impossible in a certain period of time. Under the conditions of extreme cold and continuous rain without solar radiation, it will cause solar photovoltaic components to have no solar radiation for conversion. China's renewable energy development and utilization scale ranks first in the world, providing strong support for green and low-carbon energy transformation. The installed power generation capacity has achieved rapid growth. By the end of 2020, the total installed capacity of renewable energy in China has reached 930 million kilowatts, accounting for 42.4% of the total installed capacity, up 14.6 percentage points from 2012. The utilization level continues to improve, in 2020, China's renewable energy generation reached 2.2 trillion KWH, accounting for 29.5% of the total social electricity consumption, an increase of 9.5 percentage points over 2012, China's non-fossil energy accounted for 15.9% of primary energy consumption. However, at a time when renewable energy is increasingly becoming the backbone of a new energy mix with a high proportion, the new risks posed by climate change need to be paid close attention. China should learn from the lessons of relevant countries and strengthen its capacity to ensure climate resilience and energy security.

Extreme weather events, especially extreme temperature events such as heat waves and extreme cold, often require a large amount of energy reserves and deployment support. Extreme weather and climate events caused by climate change will make the future energy supply and demand present an extremely complicated situation. In early 2021, the extreme blizzard weather in Texas, United States, caused a large area of power and water supply systems to be paralyzed, resulting in several days of water and power cuts for residents, and even some people died of cold and hunger at home. Texas is known as the "energy capital" of the United States because of its oil industry, but residents in the state have been left without reliable electricity for days during the cold wave, leaving them without power and unable to heat their homes. The Wall Street Journal has commented that "Texas's over-reliance on wind energy makes the grid more vulnerable to severe weather." Half of the state's wind turbines froze during the cold wave, causing the wind's share of electricity to drop from 42 percent to 8 percent. Natural gas and coal generation have increased to make up for the shortfall, but this is still not enough to meet soaring electricity demand. According to the Wall Street Journal, subsidies for renewable energy, which politicians from both parties have been promoting for decades, have made the power grid unstable. Coal and nuclear are more heavily regulated than wind, which has led to the closure of uncompetitive coal plants in places like Texas. Over the past decade, coal-fired power plants that have gone out of service in the United States could have provided electricity to about 60 million homes. In addition, many nuclear power plants have been shut down. However, the more dependent the grid is on intermittent renewable energy such as wind and solar, the less stable it is when supply and demand change dramatically, and the Texas grid collapse shows the risks and limitations of renewable energy.

The instability of renewable energy output is another shortcoming of green energy. There is no doubt that the power crisis in Texas provides an important warning for our country's future power supply. In the context of comprehensive carbon reduction, how to avoid the problem of short-term power shortage is one of the key points worth paying attention to. The key to carbon reduction lies in the energy transition, which is to replace the existing fossil energy with clean energy. Under the guidance of the goal of "reaching the peak of carbon and carbon neutrality", China's energy and power industry will be transformed from fossil energy to renewable energy. However, compared with traditional fossil fuels, clean energy sources (such as solar and wind) are often less sustainable during extreme weather events. During heat waves, for example, wind power is almost impossible due to the wide range of quiet wind conditions. During the extremely cold period, the fan may freeze, the solar photovoltaic can not be output, the supply of clean energy will decrease significantly, and there must be a strong energy supply and storage system and network as well as the support of traditional energy reserve emergency supply capacity. The limited time of renewable energy storage is another short board of green energy. Limited by energy storage equipment, the existing energy storage time of renewable energy is only 2-4 hours. But power outages caused by extreme weather, such as the cold snap that caused the Texas blackout, can last up to a week, tend to last longer. Renewable energy storage and pumping can no longer participate in the supply and regulation of electricity when the storage or storage capacity is released within a few hours. If you want to rely on energy storage to form weekly adjustment capacity, you need a powerful energy storage equipment, and the existing 2-4 hours of energy storage time is a qualitative difference.

Third, building a climate resilience system is a governance strategy that remains unchanged and responds to changes

To sum up, in the process of planning and implementing China's carbon neutrality, we should fully consider the climate resilience of energy supply.

First, it is necessary to raise the awareness of the whole society on the importance of building a resilient climate energy supply system, and implement the concept of climate-resilient energy supply redundancy in various actions. It is necessary to strengthen guidance and incorporate the resilient climate energy supply capacity into the security development indicator system as an important indicator for the construction of resilient societies, resilient cities, resilient industries, and resilient sectors. In the context of climate change, the setting of the redundancy amplitude of climate-resilient energy supply should be studied and used as an important redundancy index for building a climate-resilient system. Second, irresistible factors (such as prolonged and frequent extreme weather events) should be taken into account in international negotiations and nationally determined Contributions (NDCS). Third, in the process of building a multi-energy complementary new integrated energy system, we must ensure the synergistic role of coal and electricity, the "ballast stone" of energy supply. Fourth, in the process of green transformation, climate resilience and redundancy protection should be included as a task in collaborative governance work. Traditional energy systems must not be dismantled. Fifth, we need to promote the construction of a smart energy system, promote the digitalization, informatization, and intelligent transformation and upgrading of the entire energy and power industry chain, strengthen the supply-side response capacity, and realize the coordination and interaction of load and storage of the source network. Sixth, it is necessary to study and formulate new mechanisms and systems for risk identification, prediction, early warning and emergency response in the post-epidemic era and the era of carbon peak carbon neutral climate emergency response. Dealing with risk in an uncertain future world as a matter of routine. Do a good job of risk emergency prevention of green energy vulnerability, and effectively respond to possible risks by legalization, institutionalization, systematization and standardization.