Effect of market changes on the required amounts of frequency regulation ancillary services in ERCOT

FSR Energy Seminar Series with Professor R. Baldick (University of Texas at Austin)

In US markets, there are multiple ancillary services, including frequency regulation and two or more types of contingency reserve. Frequency regulation is used to maintain supply-demand balance within each real-time market dispatch interval, which is either 15 or 5 minutes in duration, depending on the region. As a general principle, other things being equal, an increase in short-term load variability requires a larger quantity of frequency regulation to maintain the electrical frequency in the system within the standard limits. Due to the deployment of renewable energy sources like wind, the net load variation in the system increases. That is, as wind capacity increases, we would also expect that more frequency regulation would be procured in order to ensure system stability. The Electric Reliability Council of Texas (ERCOT) has experienced huge growth in wind over the last 20 years; however, the amount of frequency regulation ancillary service procured has decreased. We investigate why this has occurred, identifying a number of changes in the market design. The work highlights that electricity market designs can evolve to make better use of available resources.

Presenter: Prof. Ross Baldick (University of Texas at Austin)

The Seminar is organised by the Research Team of the Florence School of Regulation – Energy and open to all EUI members.