Competitive cross-voltage level procurement of reactive power considering reliable capacity from wind and photovoltaics

Transition toward high shares of power production from wind and photovoltaics (PV) brings about a substantial increase in controllable reactive power (Q). The capability to provide Q independent of active power production (24/7) is available at comparably low or even zero investment cost. Yet, this capability is not required by network connection codes and only rarely utilized, even if available. In a first step, we take an overall economic perspective and review the economic competition of 24/7 Q provision from variable renewable power plants (VRPP) with alternative Q resources. Technical restrictions to be respected are discussed, as well as the reliability requirements related to investment‐planning relevant Q provision. Competitiveness is significantly influenced by Q utilization rate and connecting voltage level. For practical implementation of 24/7 Q procurement from VRPP, its value needs to be assessed. We review possible approaches from overall economic perspective. We conclude that in operational decisions, VRPP Q should be valued at marginal cost, whereas in Q investment planning decisions, full cost should be considered. We derive the pros and cons of making 24/7 Q provision a mandatory part of network connection codes. For system operators (SOs) to integrate available capacity, regulatory acknowledgment of related revenue impact should be considered. We present possible solutions. Summarizing, the contribution presents the status quo in research on cross‐voltage level, investment‐relevant Q provision by VRPP. Using the presented methodology for value assessment, areas for further research are systematically pointed out.