On evaluating cycling and movement of conventional generators for balancing services with large solar penetration

The increasing uncertainty caused by a higher penetration level of renewable energy points to the need for sufficient balancing services to ensure secure operation. It is thus necessary to quantify these services accurately and evaluate the cycling and movement of conventional generators that provide load following and regulation services for optimal planning and scheduling of multiple resources. This paper first introduces a systematic approach to calculating load following and regulation requirements with a large amount of solar integration. Then, two methods to quantitatively determine the cycling of conventional generators are proposed: (1) mileage and number of directional changes in balancing service, and (2) ramp statistics (or half-cycle) analysis. The proposed methods are tested on the Nevada (NV) Energy power system model. Simulation results demonstrate a significant impact of increased solar capacity on balancing service and cycling of conventional generators. Busy hours are identified for different study scenarios with various solar penetration levels. This study provides a basis for evaluating the wear and tear of conventional generators in the solar integration process in the Nevada power system.