Cost/benefit and reliability studies on rapid-start units for energy/reserve contributions

This paper addresses the issues on high operation cost, start up and operation reliability of rapid-start units, such as open cycle gas turbines (OCGTs), for energy scheduling and online/offline reserve allocation in the deregulated electricity market. A probabilistic technique is presented in this paper to assess the un-realised reserve which has been allocated to the rapid-start generators that failed during starting up while considering their response time needed for reserve contribution. This is accomplished by modelling the process in term of expected energy not served (EENS) with an enumerated mathematical formulation. A study on the variation of OCGTs characteristics is performed and the results are compared with those of the 26-thermal unit system from IEEE-RTS integrated with 3 interruptible loads (ILs). Numerical results and discussions documented in this paper may be helpful to provide a guide for economic deployment of rapid-start units for energy and reserve contributions.