120 likes | 129 Views
This presentation discusses the current structure of section 3.19 in terms of annual, monthly, and daily constraints, highlighting approval processes and proposing improvements to address identified issues.
E N D
Presented to CMWG 10/14/2011 Steve Reedy, Manager, CRR Competitive Constraints/ Protocols 3.19
Current Structure of section 3.19 Annual Monthly Daily • Annual • Study any constraints proposed by TAC/WMS • ~36 Million possible • TAC must approve 1 month before Annual Auction • September TAC Meeting • Board approves changes CMWG
Current Structure of section 3.19 Annual Monthly Daily • Monthly • Study any constraints that passed annual • TAC must approve updates before Monthly Auction • i.e. for an October CC change, TAC approves in September CMWG
Current Structure of section 3.19 Annual Monthly Daily • Daily • Study any constraints that passed annual and that month • No TAC approval needed CMWG
TAC Approval Deadline Causes Problems If approval is not to be “rubber stamp”, we need to build in time for discussion/debate 1 CMWG meeting, 2 WMS meetings, 2 TAC meetings? TAC September 1st TAC August 4th WMS July 13th WMS June 15th CMWG June 14th Analysis complete by June 14th, Analysis starts May 15th Difficult to guess as to what constraints will cause congestion next year on May 15th Very little NOMCR/outage information available on May 15th CMWG
Why are CCT results needed before the annual auction? • “The competitive constraints will determine which constraints are in SCED step 1 and thus significantly affect the clearing price in real time, thus I need to know that information to place in my pricing model for the next two years of CRRs” • TRUE & FALSE • TRUE -“The competitive constraints will determine which constraints are in SCED step 1” • FALSE – “The constraints in SCED step 1 significantly affect the clearing price in real time” CMWG
SCED/CCT decision tree Does constraint pass CCT? N Y Use mitigated curve -verifiable costs ~marginal costs Is constraint actually competitive? (i.e. no market power exists) Y N Six of one DME can exercise market power and use non-marginal cost offer curve DME cannot exercise market power and uses marginal cost offer curve Half a dozen of another CMWG
When does CCT status affect prices? • The only time a CCT competitive designation affects prices is when a constraint has been designated competitive, but a DME CAN exert local market power. • This is an “N-2” occurrence • CCT has failed • IMM has failed • A good assumption in calculating values for annual auction is that all units offer in at marginal costs. CMWG
Proposal: Designate Competitive Constraints throughout the year • ERCOT proposes competitive status of new constraints to each meeting of WMS; • WMS recommends to TAC • TAC approves • In effect next week • Daily test still done (can toggle status to non-competitive) • Annual revisiting of constraints previously determined to be non-competitive CMWG
Implementation proposal • ERCOT submits NPRR to change as previously described/NPRR approved • ERCOT will study all constraints that have been active (binding with non-zero shadow price) in SCED. • Step 1 : all constraints in history that have been binding in SCED • Recommend competitive status on all to WMS by May meeting • TAC approve as early as June 2012 meeting • Step 2 : ERCOT to study all new active constraints that have come up since last WMS meeting and recommend competitive status at each WMS meeting. • Step 3 : June of each year ERCOT to restudy all constraints currently designated as non-competitive CMWG
Problems with Current CCT • Current CCT finds Odessa Auto constraint “competitive” • This appears to be due to the choice of the “From Bus” of the constraint as the reference bus for the analysis. • Using this reference bus causes the algorithm to include many units (including units in Houston and San Antonio) as units that could provide counterflow. • In reality, SCED would not move a unit in Houston to solve an Odessa constraint. • I propose that we change CCT such that it uses the same reference bus that SCED uses; a distributed reference bus. • Would require a protocol change CMWG
Problems with CCT CCT included wind units in market share calculation for Odessa constraint Practical experience suggests that wind units would be extremely unlikely to attempt to economically withhold and drive up local prices. As such, perhaps wind units should not be included in market concentration calculations. This would also require an NPRR CMWG