Capacity Value of PV Generation and Its Impact on Power System Planning: A Case Study in Northwest of China

Conventional effective using hours and capacity analysis of power plants can not clearly describe the peak-shaving potential of PV generation for its intermittency. This paper presents the capacity value of PV generation in Province A of northwest of China based on the output power at maximum load intervals. The statistical results show that the capacity credit of PV generation in Province A is less than 2% with a 90% probability. This low capacity credit is attributed to the characteristics of the output of PV station and the load in Province A. This capacity credit should be considered for power system planning. The practical planning of the power system to accommodate the PV generation is considered based on peak-valley-load difference analysis. The study results demonstrate that other effective peaking-shaving power supplies are needed in Province A. Also, future plan of flexible conventional power supplies to balance the fluctuation of PV generation have to be adopted since the maximum peak-valley-load difference rate in Province A keeps constant for PV power penetration within 10% and increases linear with penetration over 10%.