The Business Issues Committee on Wednesday approved additional Tariff language for the energy storage resource (ESR) participation model to address issues identified during software development for the ESR project.
The language spells out details regarding day-ahead margin assurance payments (DAMAP); the method for setting feasible day-ahead and real-time schedules; generator offer caps, mitigation and reference levels; and installed capacity (ICAP) supplier bidding requirements.
The revisions to MST Section 25 Attachment J clarify which of the two energy contribution formulas will apply to ESR schedule changes.
A portion of the attachment that applies to fast-start units also will be revised to specify that those units that increase their minimum generation bids in real-time will not be eligible for DAMAP, consistent with Tariff rules that apply to increasing incremental energy bids or start-up bids in real-time.
The ISO also is revising MST 4.4.2.1 to support the market software used to ensure feasible real-time schedules for ESRs.
The ISO’s real-time dispatch software will account for the energy level of all ESRs to prevent infeasible dispatch of both self-managed and ISO-managed resources. The ISO’s original Order 841 compliance filing stated that the software will reduce the ESR’s upper operating limit (UOL) or increase its lower operating limit (LOL) as needed to produce a feasible schedule. But during the software development, the ISO realized such adjustments are unnecessary and may be inefficient. (See FERC Partially Accepts NYISO Storage Compliance.)
Under the change, the software will determine feasible real-time schedules based on an ESR’s actual telemetered energy storage level.
The offer price capping logic in MST 23.7.2 will be revised so that offers to withdraw energy are capped at the lowest of the energy offer, the price allowed by the current capping logic or the price needed to account for the unit’s round-trip efficiency. The ISO said the change will prevent performance issues with security-constrained unit commitment (SCUC), real-time commitment (RTC) and real-time dispatch (RTD).
The current price capping logic will continue to be applied if a unit’s energy offer does not cross zero and will be applied to all energy segments that are greater than zero.
Revisions to MST 23.4.2.2 will allow adjustments to the mitigation of an ESR’s incremental energy curve if needed to account for the ESR’s round-trip efficiency.
Revisions to Section 23.1.4.3 will exempt ESRs from requiring a new unit reference level, specifying that they should be calculated using cost-based reference levels. “New unit reference levels are based on historical LBMPs and would not be representative of ESRs’ costs or operating parameters such as round-trip efficiency,” the ISO said in a presentation.
The ISO had proposed that ESR ICAP suppliers have a day-ahead market (DAM) bid/schedule/notify (B/S/N) obligation equal to the ICAP equivalent of unforced capacity (UCAP) sold, like other ICAP suppliers.
After making its Order 841 compliance filings in December 2018 and May 2019, the ISO realized that when an ESR uses the ISO-managed energy level bidding parameter and enters the DAM with an energy level insufficient to satisfy its obligation, the ESR could submit bids to inject energy that appear to satisfy the B/S/N commitment, but that would not provide the ISO with all the promised energy.
NYISO is proposing that all ESR ICAP suppliers must B/S/N the full range of the ESR, including both the ISO- and self-managed energy level bidding parameters.
The ISO said the language is needed to “harmonize” the physical and operating characteristics of ESRs with the purpose of the existing B/S/N requirements: to either make the energy backing the ICAP supplier’s capacity available or notify the ISO that the capacity is unavailable so the NYISO can respond to maintain reliability. “Without the proposed requirement for an ESR, an ESR could meet its Tariff obligation and yet not make that energy available, which is inconsistent with the purpose of the requirement,” the ISO said.
Failing to reflect an ESR’s anticipated charging in the DAM “could cause reliability issues in real-time by not having enough resources committed from the DAM to meet actual load, reserves, and the ESRs’ charging,” the ISO said.
The ISO will bring the Tariff modifications to the March Management Committee meeting and hopes to make them effective with its other Order 841 compliance changes, no later than Sept. 30.
BIC OKs BTM:NG Revisions to Load Forecasting Manual
The BIC also approved the first revisions since 2013 to the Load Forecasting Manual, reflecting the impact of behind-the-meter net generation (BTM:NG) in the installed capacity market forecast. A BTM:NG is a BTM generator that has excess capability after serving its host load at the same location.
If a BTM:NG resource does not require power to serve load from the hour of the NYISO or locality peak, the load of the resource will not be included in the actual and weather-adjusted load in the transmission district (TD).
If the resource does require power, its load will be deducted from the TD’s actual load and weather-adjusted load.
The forecast load of a BTM:NG resource will be based on a weather adjustment of its actual load, a projection of the load’s losses and a growth rate “consistent with” that of the transmission district in which it is located, the ISO said.
“This is a little different than other loads … We normalize [transmission district loads] as a whole. But we recognize that BTM:NG might have load characteristics much different than the average load in the area,” explained engineer Arthur Maniaci, the ISO’s principal forecaster.
The ISO said the changes will reflect the specific weather response of each resource and is consistent with the Tariff and ICAP Manual, using the top 20 hours of each resource from within the top 40 New York Control Area hours during summer. It also mirrors current NYISO demand response processes.
The changes were developed by the Load Forecasting Task Force in 2018 and 2019 and modified after feedback from the ICAP Working Group last year.
Working During the Coronavirus Pandemic
Several stakeholders had questions about the impact of the coronavirus pandemic on ISO operations.
Mark Seibert, manager of the Member Relations team, said the ISO will provide a secondary call-in number for meetings because of heavy loads on remote meeting services that resulted in some stakeholders getting busy signals in attempting to listen to the BIC meeting.
He also said that ISO staff who interact with stakeholders were directed to forward their work phones to their cell phones to remain accessible while working from home. Stakeholders should contact Seibert or Debbie Eckels in the Member Relations team if they have difficulty reaching an ISO official, he said.
Mike DeSocio, director of market design, said ISO employees are able to access the grid operator’s software systems remotely to allow continuity of operations. “Folks are able to get into the systems they need to get into and perform the work they need to perform, so we don’t expect any issues there,” he said.
— Rich Heidorn Jr.
