Back Cast of Interim Solution B+ to Improve Real-Time Scarcity Pricing: White paper.

The Public Utility Commission of Texas (PUCT) has requested that ERCOT perform a back cast of an interim proposal that will approximate Real-Time co-optimization of energy and Ancillary Services (AS). This interim proposal has been described as the “Interim Solution B+” and is intended to be a more appropriate method of pricing scarcity during conditions of low operating reserves in Real-Time. This back cast approximates the pricing outcomes and estimates what the market impacts may have been if “Interim Solution B+” had been in place for the years 2011 and 2012. This analysis builds off of the previous “Interim Solution B” back cast that was filed by ERCOT on February 13, 2013.