Development of a pricing model for the reactive power supply via STATCOM capability of a real PV power plant

The study examines the extended reactive power provision outside the technical connection rules of an utility-scale PV power plant in the transmission grid and its monetary value. Various cost components of the provision are presented, valuation approaches are formulated, and their application in the transmission grid is examined. The basic valuation approach considers both plant specific and external costs affecting the development of the reactive power price. In particular, the specific active power losses of the provision and the additional wear of the inverters are considered. The analysis shows that the distribution of relative losses (MWh/Mvar) in the park differ due to the demanded dispatch patterns and represent the highest sensitivity in the development of costs. Due to insufficient data of additional costs of the park, the price for the reserve is not considered in the study, but the impact on the total price is described. In summary, the study provides a basic framework for understanding the costs and opportunities associated with providing reactive power from PV plant and demonstrates the potential for achieving a balanced cost-benefit ratio for both plant and grid operators. A field study investigation of the simulative observation is recommended in the context of further studies.