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Summary of Potential Issues with NPRR385 Price Floor. ERCOT. NPRR 385 Negative Price Floor Proposal. NPRR385 proposes the implementation of an administrative Real-Time Settlement Point Price floor of negative $251/MWH for Resource Nodes, Hubs and Load Zones.
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Summary of Potential Issues with NPRR385 Price Floor ERCOT QMWG
NPRR 385 Negative Price Floor Proposal • NPRR385 proposes the implementation of an administrative Real-Time Settlement Point Price floor of negative $251/MWH for Resource Nodes, Hubs and Load Zones. • Since NPRR385 was filed there have been numerous discussions of potential issues that this presentation attempts to capture and provide some historical analysis
Issues Raised Related to NPRR385 • EDF and others expressed the concern that implementing an LMP negative price floor in RT Settlement can motivate inappropriate economic behaviors. • For example, it is possible to execute a bid/offer strategy between DAM and RT that allows a trade entity to extract money from the ERCOT Markets with essentially no risk (refer to the EDF example posted to the RDTF list server) • There have been both DAM and Real-Time prices below -$251 (see Appendix for Real-Time Price history) • Concern about the application of the negative price floor at the Load Zone and Hub Settlement Points in RT. • These Settlement Points are highly liquid Settlement Points for transactions including those in the DAM and, most likely, in commercial transactions that may not be conducted through ERCOT. • Consideration of changes to Control Room procedure to assist in relief from negative LMPs • ERCOT drafting procedure for consideration
Issues Raised Related to NPRR385 • Consideration of setting Shadow Price Cap based on both positive and negative price events– • Shadow Price Caps are applicable whenever a constraint is binding. Constraint Shadow Prices are limited by the Cap value. Consequently, the LMP affected by a binding export constraint will be affected by the value of the Shadow Price Cap utilized in the RN RTLMP calculation. • Consideration of setting a Separate Shadow Price Cap for “Generation Export” Constraints • This alternative is the same as the above but implies a need to identify a class of “Generation Export” constraints that can be assigned a Shadow Price Cap unique to the negative price event. • Consideration of applying the same LMP cap (−$251.00) in both the CRR/DAM/RT to enforce an arbitrage free requirement between these markets. • Implementation of a negative LMP floor in the CRR Auctions, DAM and RT will require reviews of impacts to system and potential market behavior • Consideration of using an appropriate Settlement adjustment to limit the exposure to negative prices based on the a threshold amount for the RT-LMP and the Resource’s down ramp rate limitations.
Negative SPP in RTM @ Load Zones and Hubs12/1/2010 – 10/04/2011
Summary of Negative RT-SPP Less Than −$251/MWH by Generation Resource Type