Effect of Loss of Load Probability Distribution on Operating Reserve Demand Curve Performance in Energy-Only Electricity Market

Abstract

In energy-only electricity markets, the operational reserve demand curve is a scarcity pricing mechanism adopted to address the shortage of reserves and incentivize the generators. It is constructed based on the assumption of the normality of loss of load probability, which is estimated from reserve error data. In this Letter, the historical record of reserve error is collected and analyzed to test the assumption and find the fittest probability distribution. It is found that the normal distribution is generally not as good as other distributions like log-logistic, general gamma, and Weibull. Using a dynamic simulation framework, the installed reserve margins with different distributions are evaluated over a fifty-year period, demonstrating that the choice of distribution could significantly impact the subsequent pricing calculations and therefore the reserve margin in an energy-only electricity market. This work is of potential importance and immediate relevance to system reliability and resource adequacy in power systems.