Reactive Power and Thermal Constraints on Utility Scale Solar Electricity Generation in Saudi Arabia: A Reproducible Parametric Study of Net Export Capability

This paper examines how reactive power requirements, connection impedance, auxiliary demand, and reduced inverter capability can limit the active power export of utility-scale solar photovoltaic plants in Saudi Arabia. A deterministic parametric model is developed to assess net export capability at the point of interconnection while accounting for inverter apparent power limits and network effects.For an illustrative 100 MW solar plant with 110 MVA of nominal inverter capacity, the study shows that retaining 95% of inverter apparent power capability limits net export to 94.57 MW when 33 MVAr must be supplied at the grid connection point. The corresponding minimum nominal inverter rating required to maintain 100 MW export is calculated as 115.72 MVA. The study also evaluates the effect of external reactive power support and demonstrates how reactive injection and absorption can produce different capacity outcomes due to the electrical characteristics of the connection path.The work provides a transparent and reproducible screening method for early-stage assessment of solar plant capability, inverter sizing, and grid connection requirements before detailed network and manufacturer-specific studies are completed. The numerical results are scenario-based and are not presented as measurements from an operating Saudi solar installation.