Theoretical and practical considerations in implementing and using a reliability unit commitment (RUC) in restructured electricity markets

In this presentation the theoretical foundation of the RUC process and key important considerations in implementing RUC are presented. The paper also provides a description of the general sequential approach in which the IFM process is executed first and then the RUC process is completed. A brief exposition of the merits of the simultaneous approach where the day-ahead market (DAM) and RUC clear simultaneously has been offered. The reasons for performing RUC after the DAM were also presented. The additional RUC commitment and capacity cost could be allocated to under-scheduled load. There is a "clear" cost-causation for the additional commitment. The RUC cost could service as deterrence for load under-scheduling. However, one can dispute the efficiency of this incentive as a deterrent for load under-scheduling. Another important issue is the application of the LMP in the RUC awards. One can make the case that this is not appropriate. In this presentation, pricing issues of the RUC awards has been presented. Finally, other practical issues, such as the modeling of fast startup units, combined cycle units, treatment of market power mitigation in RUC and settlement rules are also discussed in the presentation