Potential new products and models to improve an RTO's ability to manage uncertainty

Abstract

A Regional Transmission Organization is charged with operating the system in a reliable and cost effective fashion. To achieve this goal, the RTO must be able to deal with uncertainties in available resources and demands. Sources of uncertainty include but are not limited to increasing penetration of renewable resources such as wind, changes to scheduled interchange with other regions as participants respond to conditions, and uncertainty in the RTO's load forecasts. The RTO must plan to operate the system in a fashion that allows it to maintain the power balance, meet reserve requirements, and enforce transmission constraints in a cost effective fashion as conditions change. The level of uncertainty and variability with which the RTO must plan to deal is increasing. For example, the increasing penetration of renewable resources such as wind generation increases the uncertainty to which the RTO must be able to respond. To manage the increasing uncertainty, Midwest Independent Transmission System Operator (MISO) is investigating the development of a market product to procure rampable capacity that is able to respond to the uncertain changes in net load that may materialize on a moment to moment basis. MISO has been developing dispatch approaches that would ensure that it maintains adequate rampable capacity to meet random changes in net load in its Real-Time market. It has also recently begun work on extending the methods to allow it to develop schedules its Day-Ahead Market that procure rampable capacity in the Day-Ahead time frame that will be available to respond to random variations in net load in the Real-Time market. In addition to the dispatch algorithms, MISO has been investigating ways to extend unit commitment algorithms to ensure that sufficient rampable capacity will be available in its Day-Ahead and Real-Time dispatch processes. We provide an overview of the Day-Ahead and Real-Time Security Constrained Economic Dispatch (SCED) processes that MISO is investigating to ensure that the dispatch maintains sufficient rampable capacity to meet uncertain changes in net load. The Day-Ahead Security Constrained Unit Commitment (SCUC) process can also be extended to ensure that MISO commits resources with sufficient rampable capacity to meet rampable capacity requirements in the Day-Ahead and RealTime dispatch processes.