Study On Mesoscale Numerical Simulation Of Wake Effect Of Wind Farm & Its Impact On Atmospheric Environment

As the explosive development of wind power in China,we need to perform a systematic assessment,including complex wind resources,wind power potential,and their feedback on the atmospheric environment.This will provide guarantees for developing the wind power industry in an efficient,sustainable,and friendly way.In this paper,based on the Weather Research and Forecasting?WRF?model and Community Multi-scale Air Quality?CMAQ?model,we established and validated the WRF-WFP-CMAQ coupled model framework,which WFP stands for the updated wind farm parameterization.Here we investigated the wake and atmospheric environmental responses of wind farms in various scales,which provides reasonable scientific research methods and practical data for the sustainable development of the wind power industry.Firstly,based on the WRF-WFP coupling model,the wake behavior and power output interference characteristics of adjacent wind farms are explored.Taking two adjacent large wind farms in Hami,Xinjiang as the research object,we examine the wake effect and power output characteristics of the whole field,and the wake flow and operation interference properties of the large wind farm to its adjacent wind farm are quantitatively evaluated.The sensitivity of the model to high grid resolution is analyzed,and a mesoscale simulation of adjacent wind farms at a high-level of 150 m is realized.As a result,it is found that the impact of large wind farms on the downstream wake is 20³0 km and the power generation loss ratio of the downstream wind farm is about 5.8%.Therefore,it is confirmed that the construction of large-scale wind farms in wind-enriched areas must maintain a reasonable buffer zone.Secondly,the Zhangbei wind power base in Hebei province in China is taken as the research target to explore the wake effect,power output characteristics of a large-scale wind power base,and its impacts on the atmospheric boundary layer.It is found that the intensity and range of wake effect are not only related to the characteristics of wind resources,but also closely related to the scale and topographic characteristics of wind farms,i.e.,for the wind farms in flat terrain,the largest speed losses in large-scale and small-scale farms are 11%and 8%,respectively,and the wake recovers 35 km and 20 km downstream;for the wind farms in mountainous terrain,the wake range of the wind farms in simple mountainous terrain and complex mountainous terrain is 6 km or less.In addition,the impact of the wind power base on the local atmospheric boundary layer is significant and continuous,but the impact on the further downstream areas is small and accidental.Finally,based on the well-validated WRF-WFP-CMAQ coupling model,the atmospheric environment effects of wind power in China are explored.The impact of meteorological elements and air pollutants and its atmospheric physical mechanism of the development scenario of the Chinese wind power industry in the past 10 years?2009²018?are evaluated for the first time.The study found that the impact of wind farms across the country on the atmospheric environment showed strong quarterly differences.For meteorological elements,the influence in winter is closely related to the distribution of wind farms and shows a local effect,and the influence in summer is caused by changes in the mesoscale atmospheric circulation and presents a north-south regional response.Chinese wind power does not produce additional air pollutants,but it promotes the redistribution of air pollutants,leading to regional north-south regional diffusion and transmission of air pollutants.At the same time,this effect increases year by year,especially in summer.In recent years,the increase in PM_2.5 in the Beijing-Tianjin-Hebei region is 6.76?g/m³,and the decrease in PM_2.5 in the Yangtze River Delta region reaches 5.25?g/m³.Therefore,the government needs to balance the development of wind power in different regions through administrative or economic means to mitigate the adverse impact of the wind power industry on the atmospheric environment,so as to achieve sustainable and environmentally friendly development of the wind power industry in China.