Starting up rapid-start units for reserve contributions in a system with interruptible loads

This study presents the effect of starting reliability of rapid-start units (RSUs), such as open-cycle gas turbines (OCGTs) and hydro generators, for energy scheduling and reserve allocation. A method that explicitly integrates unit starting reliability into the expected energy not served (EENS) formulation for non-spinning reserve (NR) contribution is proposed. A unit commitment objective function is used to incorporate the various types of energy/reserve providers and to schedule energy and reserve simultaneously. These providers are conventional thermal units, OCGTs, hydro units and interruptible loads. An EENS model that considers these energy/reserve providers and accounts for their response times is presented pictorially. A penalty cost formulation for RSUs that failed to start up for NR contribution is proposed. This work emphasises the importance of modelling units of varying starting reliability. These results could be used to assist independent system operators and generation companies when selecting energy/reserve sources for power generation and reserve contribution.