新能源发展所面临的气候挑战_来自英国的教训（英文）_黄伟.pdf

收稿日期：2023-03-23；录用日期：2023-04-26；网络出版：2023-05-13Received Date:2023-03-23;Accepted Date:2023-04-26;Online first:2023-05-13基金项目：国家自然科学基金项目（42242020）Foundation Item:National Natural Science Foundation of China(42242020)通信作者：宋长青，E-mail：Corresponding Author:SONG Changqing,E-mail:研究论文ARTICLEVol.14 No.3 Jun.2023 DOI:10.7515/JEE232002地 球 环 境 学 报地 球 环 境 学 报Journal of Earth EnvironmentJournal of Earth EnvironmentJEE引用格式：Citation:黄 伟,刘 言,马 辉,等.2023.新能源发展所面临的气候挑战：来自英国的教训 J.地球环境学报,14(3):305 314.Huang W,Liu Y,Ma H,et al.2023.Climatic challenges for renewable energy development:lessons from the UK J.Journal of Earth Environment,14(3):305 314.新能源发展所面临的气候挑战：来自英国的教训【封面文章】黄 伟1，刘 言2，马 辉3，高 磊1，杨晓帆2，宋长青2*1.兰州大学 资源环境学院 西部环境教育部重点实验室，兰州 7300002.北京师范大学 地表过程与资源生态国家重点实验室，北京 1008753.北京金风慧能技术有限公司，北京 100176Climatic challenges for renewable energy development:lessons from the UK【Cover】HUANG Wei1,LIU Yan2,MA Hui3,GAO Lei1,YANG Xiaofan2,SONG Changqing2*1.Key Laboratory of Western Chinas Environmental Systems,Ministry of Education,College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,China2.State Key Laboratory of Earth Surface Processes and Resource Ecology,Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China3.Beijing Gold Wind Smart Energy Technology Co.,Ltd.,Beijing 100176,China Abstract:Background,aim,and scope As global warming intensifies,utilizing renewable energy sources to reduce carbon emissions becomes increasingly important.However,the development of renewable energy faces challenges from climate,such as the low wind speed event that occurred in the North Sea in Sep.2021.This event severely impacted the United Kingdoms offshore wind power generation and led to instability in the European energy market.Materials and methods In this study,ERA5 reanalysis data were used to examine the spatiotemporal variations in wind speed and the atmospheric circulation patterns related to the event.Official statistics on cumulative installed capacity and offshore wind power generation were used to analyze the role of the expansion of installed capacity in response to low wind events.Results The interannual variability and a 摘 要：2021 年 9 月，由于大西洋北海地区风速突然下降，英国的海上风力发电量骤减，导致欧洲能源市场陷入混乱。风速的年际变化和长期逐渐减弱的趋势可能是造成这次事件的主要原因。此外，北海上一种持续 3 4 d 的阻塞高压也促成了低风速事件的发生。一个移动缓慢的暖脊显著地阻挡了西风气流，并割裂了北极极涡，导致北极和东欧地区的冷空气积聚。这种天气形势有可能引发寒潮，进一步增加电网的负担。然而，扩大风力发电机安装规模并不能有效应对此类事件。值得注意的是，中国的可再生能源发展也面临着与英国相似的挑战。因此，激进的可再生能源政策并不可取。为了更好地应对这些来自气候的挑战，可再生能源的发展需要从提高装备技术、发展混合能源系统以及开展更加精细的资源评估三个方面入手。以上结论对中国能源系统的转型具有重要的参考意义。关键词：低风速；大气阻塞；可再生能源；能源系统转型306地球环境学报第 14 卷DOI:10.7515/JEE232002DOI:10.7515/JEE232002long-term gradual decline in wind speed were found to be the physical causes of the low wind speed occurrence.A blocking high in the North Sea with a life span of 3 4 d also has a favorable impact on the likelihood of the low wind speed event.The anomalously warm ridge traveled slowly eastward,significantly blocking the westerly flow.The Arctic polar vortex was split by the warm ridge,resulting in the accumulation of cold air in northern Greenland and eastern Europe,and there was a decent possibility that a cold wave would emerge in Europe.Discussion The low wind speed events pose severe impacts on the UKs offshore wind power generation.Due to a highly consistent variation pattern of wind power resources across Europe,these impacts cannot be resolved by expanding the installed capacity.Chinas surface wind speed has been weakening over the past few decades as a result of climate change,principally because of a decrease in the power of the barometric pressure gradient.The impact of powerful El Nio events is also anticipated to enhance the interannual variability of wind speed in China.It is futile to solve the unpredictability and intermittency of wind resources by linking wind farms in various areas since on a broader time scale,the spatial variation in Chinas wind resources also displays similar patterns.As a result,China is experiencing difficulties with the growth of wind power similar to those in the UK.Conclusions Climate change has already posed challenges to the development of renewable energy,and these challenges will become increasingly severe as global warming continues.Therefore,it is essential to avoid aggressive approaches when deploying renewable energy policies.Recommendations and perspectives Addressing such events may require advancements in wind turbine technology,hybrid energy systems,and more refined wind resource assessments.Key words:low wind speed;atmospheric blocking;renewable energy;energy system transition1 IntroductionThe ongoing global warming,which is primarily attributed to greenhouse gas(GHG)emissions from the anthropogenic burning of fossil fuels,is causing increasingly frequent extreme weather and climate events worldwide(IPCC,2021).Thus,energy transition and GHG emissions reduction have become a matter of urgency for the whole world.Over the past decade,renewable power generation costs have fallen to very low levels,making it possible for renewable projects to replace coal-fired plants on a large scale(IRENA,2021).China has been vigorously promoting the development of renewable energy to fulfill its responsibility for GHG emissions reduction.According to the National Energy Administration report,renewable energy-generating installations in China are expected to account for more than 50%of the global total by 2025.However,many renewable energy resources are climatically dependent,and hence climate change itself may impact the renewable energy supply(Gernaat et al.,2021).The UKs wind power generation drastically reduced in Sep.2021,according to a Wall Street Journal story,as a result of a sharp drop in North Sea wind speeds.Under the pressure of the resulting reduced energy supply,the UK was forced to increase its thermal power generation to make up for the electricity shortage.The imbalance between supply and demand also led to high global fossil fuel prices.The electricity price in the UK more than doubled in Sep.,almost seven times that for the same period in 2020.As a result of this impact,the electricity markets of other European countries also featured price increases.This low wind speed event wreaked chaos in European energy markets,and thus it is important to determine whether it was a rare anomaly or a cyclical climatic event against the background of global warming.Analysis of the relevant atmospheric circulation patterns and clarifying the causes of this extreme event may help the renewable energy power network to respond effectively to the challenges imposed by climate change,in the context of Chinas vigorous development of renewable energy policies.第 3 期黄 伟，等：新能源发展所面临的气候挑战：来自英国的教训307DOI:10.7515/JEE232002DOI:10.7515/JEE2320022 Material and methods2.1 Research dataPrevious research on wind power has determined that ERA5 generally performs better than other reanalysis data products,providing continuous hourly wind speed data at 100 m height,which is suitable for modern wind turbines(Olauson,2018).To investigate the fluctuations in wind speed at 100 m height in the North Sea(50 60N,4W 12E)in Sep.from 1979 to 2021,ERA5 monthly averaged data on single levels(https:/cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels-monthly-means?tab=overview)were used.The Copernicus Climate Change Service(C3S)operational energy dataset(https:/cds.climate.copernicus.eu/cdsapp#!/dataset/sis-energy-derived-reanalysis?tab)offers climate and energy information for the European energy market.Based on the hourly wind speed at 100 m height,it was utilized to select the five days in Sep.2021 with the lowest wind speed.Further research on the circulation patterns connected to this low wind speed occurrence in Sep.2021 employed temperature and geopotential from ERA5 hourly data on pressure level(https:/cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-pressure-levels?).The amount of wind energy produced is significantly influenced by installed capacity in addition to wind speed.This study also assembled official data on Sep.offshore wind power cumulative installed capacity and energy generation in the UK from 2010 to 2021(https:/www.gov.uk/government/organisations/department-for-business-energy-and-industrial-strategy)to order to establish the relationship between installed capacity and wind power output and to examine it with wind speed variability.2.2 MethodsThis research first calculates the regional average wind speed in the North Sea region for each Sep.from 1979 to 2021 to generate a time series incorporating the wind speed trend and variability.This allows us to analyze the wind speed variation in the North Sea region over a longer period.The linear regression coefficients of the time series are computed to represent the general trend in wind speed.To evaluate the stability of the time series,the Pettitt test(Pettitt,1979)was applied.It is the most commonly used test for change point detection because of its sensitivity to breaks in the middle of any time series(Jaiswal et al.,2015).The period of wind speed variation is also determined using the power spectrum analysis.To further explore the spatial characteristics of wind speed variation in the North Sea,this study additionally investigated the spatial distribution of wind speed linear regression coefficients.The mean circulation pattern of the five days in Sep.2021 with the lowest wind speed is used as the circulation pattern for a typical low wind speed event.A composite analysis is conducted by comparing this pattern with the climatological circulation pattern(the mean circulation field of Sep.1979 2021)to analyze the atmospheric circulation characteristics during low wind speed events(the typical low wind speed process minus the climatological circulation pattern).3 Results and Discussion3.1 Long-term wind speed variationThe results showed that since 1979,the regional average wind speed at 100 m height throughout the North Sea in Sep.has a pronounced pattern of interannual variation with a gradually decreasing trend of 0.3 m s1(10a)1.Based on the Pettitt test using 1989 as the abrupt change point,the time series can be divided into two segments,with the latter segment having a lower mean and higher variance than the former one.This phenomenon supports the previous findings that increased global warming causes weaker winds(Zha et al.,2021)and more extreme events(Diffenbaugh et al.,2017)(Fig.1a).This downward trend is consistent for the whole North Sea(Fig.1b).Additionally,spectral analysis indicates that this change in wind speed has significant periodicities of about 6 a.We speculate that the low wind speed event was the result of the trend of continuously weakening wind speed in Sep.over the past nearly 50 a and its periodic interannual variation.308地球环境学报第 14 卷DOI:10.7515/JEE232002DOI:10.7515/JEE232002a:time series of regional average wind speed at 100 m height in the North Sea from Sep.1979 to 2021.The fitted linear trend is also shown.The year 1989 is indicated by the vertical dashed line(abrupt change point).The average wind speed from 1979 to 1989 and 1989 to 2021,respectively,is shown by the red and blue dashed lines.b:spatial distribution of the linear trend of wind speed variation at 100 m height in Sep.in the North Sea region from 1979 to 2021.The color fill indicates the value of the linear trend,and the stippled area indicates the significance at the 90%level.Fig.1 Characteristics of wind speed variation in the North Sea3.2 Circulation patterns of the low wind speed eventSince the circulation patterns of typical low wind speed processes are very similar in the vertical direction(Fig.2),this study focuses on the 500 hPa circulation pattern,which is more significant for weather forecasting.It is evident that the westerly circulation is divided into two branches in the Atlantic Ocean,and that there are strong meridional fluctuations in both branches.The North Sea and its southern land area are sandwiched between the two branches,and the wind speed is weaker than in the other surrounding areas.At the same time,a huge warm ridge extends from the northern part of the North Sea,splitting the Arctic polar vortex into two parts,where the cold low pressure over Greenland splits again and a cold low-pressure center approaches the warm ridge from western Iceland.The ridgeline of the warm ridge crosses the North Sea and corresponds to stable weather with low wind speeds in the North Sea.The observed circulation pattern closely resembles the Atlantic blocking activity pattern proposed by Rex(1950).The blocking high is a crucial weather system in the North Atlantic region and exerts a significant influence on weather patterns in North America and Europe.It not only results in reduced wind speeds but can also cause extreme weather events,such as cold waves and blizzards,in Europe(Rex,1951;Kautz et al.,2022).Therefore,we analyzed the changes in the circulation pattern for Sep.4 6 and 13 14 to determine whether this characteristic pattern is caused by Atlantic blocking activity.During the evolution of the 500 hPa circulation field from Sep.4 6,it can be observed that the blocking high continued to move northward since Sep.4.When the cold low-pressure system over Greenland moved southward,it was blocked and squeezed by the blocking high and began to split.The split cold low-pressure system continued to develop on Sep.5 6 and finally cut off the warm ridge in the afternoon of Sep.6.Before the warm ridge was cut off,it had a significant blocking effect on the westerly flow.The wind speed gradually returned to normal only after the warm ridge left the North Sea region.This low wind speed process corresponds to the collapse of the warm ridge in the vigorous stage after being cut off by the cold low-pressure air on both sides of the ridge(Fig.3).Compared to the circulation changes from Sep.4 6,the evolution of the circulation pattern from Sep.13 14 is relatively more complex(Fig.4).It can be seen that there are two high-pressure systems within the Arctic Circle on Sep.13,one of which controls the eastern Atlantic,resulting in low wind speeds in the North Sea region,while the other high-pressure system is located at 40 50E and is about 第 3 期黄 伟，等：新能源发展所面临的气候挑战：来自英国的教训309DOI:10.7515/JEE232002DOI:10.7515/JEE232002to be cut off by cold low-pressure systems on both sides.The two high-pressure systems surround the cold low-pressure system in the east.Although the high pressure on the east side was cut off by the cold low-pressure system on the afternoon of Sep.13,its remaining high-pressure center merged with the high pressure on the west side on Sep.14 and continued to develop.During this process,the high-pressure system over the North Atlantic was continuously compressed by cold low-pressure systems from the west of Iceland,but the blocking situation did not collapse.The reason for the end of the low wind speed event in the North Sea was that on Sep.14,a warm ridge in