Status Report on DSWG Task 11: Retail DR/Dynamic Pricing Project Presentation to the ERCOT Demand Side Working Group Jay Zarnikau Frontier Associates LLC September 27, 2013

Background PUC Subst. Rule §25.505(e)(5): Load serving entities (LSEs) shall provide ERCOT with complete information on load response capabilities that are self-arranged or pursuant to bilateral agreements between LSEs and their customers. ERCOT sent electronic survey to all LSEs in June-July seeking customer counts on dynamic pricing/demand response contracts – ‘Your response to the survey will assist ERCOT have a better understanding of the amount of responsive Load and numbers of retail energy consumers actively responding to Load reduction signals’ 2

Background Quantify current customers in the ERCOT region subject to retail price response/demand response products Establish a benchmark for measuring growth in demand response Start by gathering tallies of customers who are contracted with their LSEs for various types of products: o Time of Use pricing o Critical Peak pricing/rebates o Real-Time pricing o Direct Load Control o 4CP response Survey did not ask for MWs or strike prices Some supplemental analysis is examining the impacts of solar photovoltaic programs on ERCOT’s system demand 3

Overall goal: By the end of this year, have a better estimate of the level of demand response activities in the ERCOT market that are taking place outside of ERCOT’s formal markets Determine ongoing activities and procedures, beyond this initial analysis. The Task 11 Subgroup Seeks to provide some help to the ERCOT staff in the analysis of this data 4 GOALS

Where We Are At: The subgroup had its third meeting/conference call on Monday, September 23 rd. Overall, the response from the load serving entities to the survey has been very good. Some of the REPs are likely to receive follow-up questions to help us identify specific pricing or curtailment “events” and some program features. Follow-up data requests are presently being designed. Analysis of the survey responses is getting started. 5

ERCOT Staff’s Approach to Quantifying Changes in Demand Associated with DR Actions For solar PV: Compare load shapes of consumers with solar PV to sets of otherwise- similar homes without solar PV (i.e., matching techniques). Very computer intensive. For demand response: Identify “events” (e.g., price spikes, critical peak prices called by a REP, curtailment requests). Look at load patterns for the same customer on previous days and compare with the load shape on the day of the event (an historical baseline approach). Perhaps also compare load shapes of customers on a program to otherwise-similar customers not on the program. 6

Next Steps Follow-up data requests are presently being designed. We are determining what analysis Varun Rai’s group at the University of Texas may want to assist with. (Whatever is done will probably supplement, rather than displace, what the ERCOT Staff is doing). The subgroup will meet again once the ERCOT Staff has completed some preliminary impacts analysis. Report to the stakeholders by the end of the year. 7

Summary Statistics 21 REPs submitting validated ESIIDs – 1 more with none – 15,826 ESIIDs with uncorrected errors Working with REPs to resolve Some are intentional deletions 177,451 ESIIDs with validated submissions – 18,385 will be excluded from analysis 1,780 ESIIDs became inactive/de-energized after June 15 and still not active 2,214 ESIIDs became inactive/de-energized after June 15 and went to different REP 956 ESIIDs became inactive/de-energized after June 15 and returned to same REP 13,322 ESIIDs stayed and went to different REP – 159,066 remain for analysis (so far) 8

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