The Crowding-out Effect Caused By Wind Power Increase And The Method To Evaluate The Beneift Of Wind Power

With the swift development of economy and society, the problems ofsustainable energy supply and environmental protection have drawn specialattention. Large-scale thermal power replaced by wind power can effectively reducethe consumption of fossil fuels and avoid the greenhouse gases and pollutantemissions produced by thermal power generation. So wind power has become animportant alternative energy.The output of wind turbines depends on the natural wind speed, which hasuncertainty, volatility and incomplete controllability. When the capacity of windpower is more than a certain proportion, the fluctuations of wind power willproduce many adverse impacts on safety and economic operation of the grid.Especially for the grid based on thermal units peaking, wind power increase willforce thermal power peaking units to decline the output, to deviate from the bestoperation point and to operate inefficiently. When the downward spinning reservecapacity is burned out, the wind power increase will cause coal-fired increase andthe cost rise of thermal units operation, and then reduce the energy savings andemission reductions benefits and economy benefits. Therefore, on the basis ofmeeting a given electricity load demand and considering the operation cost of thethermal power peaking responding to wind power fluctuations, it is an importantfoundation for the generation control of the power system with large-scale windpower to assess the effectiveness of wind power integration on power system.In this paper, the thermal power peaking grid with large-scale wind power isstudied. The characteristics of wind power and the influence of power grid peakingare analyzed. During the load valley period, when the downward spinning reservecapacity is burned out, the wind power increase will cause the increase of theoperation cost of thermal power peaking units and the pollutant emission. Theconcept of “crowding-out effect” is proposed, its occurrence mechanism is described. From the angles of the energy savings and emission reductions andeconomic benefits, the wind power efficiency evaluation model is constructed tocarry out the quantitative evaluation of the benefits of wind power integration intopower system.Finally, the effectiveness of the method was verified by a numerical example.The coping strategy of improving wind power efficiency and effectively restrainingthe "crowding-out effect" is given. The benefit of the power system and the impactof the price of energy consumption and CO2emissions on the energy savings andemission reductions benefits of wind power are analyzed, when the strategy isadopted.