Assessment Of China’s Wind And Photovoltaic Power Excess Capacity And Evaluation Of Environmental Benefit

Overcapacity will not only cause energy waste,but also cause serious environmental pollution.With the transformation of China’s energy consumption mode,overcapacity of renewable energy industry also becomes more obvious.Therefore,more and more researches have been done on the excess capacity of renewable energy but focusing more on qualitative studies.Under such circumstances,this study aims to construct a renewable energy overcapacity assessment model to evaluate the national and provincial overcapacity degree of China’s wind and photovoltaic power industries.The corresponding environmental benefit is also investigated.Main findings are as follow.First,the overcapacity assessment model for wind power and photovoltaic power of China and Chinese provinces has been established based on capacity utilization rate.And data envelopment analysis method is used to verify the national overcapacity results by software DEAP 2.1.Second,the spatial and temporal characteristic of excess capacity of China are uncovered.（1）From temporal perspective,the overcapacity situation of photovoltaic power industry is more severe than wind energy.The peak period was concentrated around year 2015 and 2016,but the overcapacity trend became relieved with time passing by.The capacity utilization rate reached 80.94%and 81.75%respectively in 2018,which returned to the normal levels.（2）From the spatial perspective,the phenomenon of overcapacity of wind power concentrated mainly in the"Three North Regions",while the photovoltaic industry concentrated mainly in the southwest area.（3）Although the phenomenon of downstream overcapacity of the renewable energy industry has gradually been controlled,the middle stream excess capacity was still very severe.Besides,for provinces with large renewable energy install capacity,they are more downstream overcapacity-dominated style.While for regions with slow development of renewable power installation,they are more middle stream overcapacity-dominated type.Third,this study uses the IPCC emission factor method to calculate the reduction effect of carbon dioxide emission,air pollutant and water resource for wind and solar power industries from life cycle perspective.The potential environmental benefits from reducing overcapacity is further investigated.The results show that the total carbon emission reduction of wind and solar energy in 2018 reached 348.76 and 104.07 Mt CO₂respectively,and the potential carbon emissions reduction were 72.66 and31.38 Mt CO₂,respectively.Finally,five control strategies for overcapacity were put forward by combining current renewable energy excess capacity situation and renewable energy development and power market operation.For example,improve the intermittent power supply from the technique,simplify the energy approval process,improve power consumption capability,adjust energy structure,and encourage the synergistic effect of the electrolytic hydrogen industry and renewable energy.