PJM, NYISO Seeking Input on Replacing Con Ed-PSEG ‘Wheel’
PJM will hold a meeting Monday to seek stakeholder input on options for replacing the Con-Ed-PSEG “wheel.”
The decades-old agreement allows NYISO to move 1,000 MW from upstate generators through Public Service Electric and Gas (PSE&G) facilities in northern New Jersey to serve Consolidated Edison load in New York City. During a dispute with PJM over transmission costs, Con Ed announced last year that it has made other arrangements to serve its New York load and will stop using the wheel. The agreement is scheduled to end April 30, 2017, so a new protocol will need to be in place by May 1. (See PJM Plans for Changes in Tx Flows Without Con Ed-PSEG ‘Wheel’.)
The PJM meeting, beginning at 10 a.m., will review planners’ analysis of the system and lay out options the two grid operators are considering. A second meeting will be held at NYISO on Sept. 16.
The main question is how to handle eight phase angle regulators (PARs) that currently govern the direction of flows on lines connecting the grids. There are one each on the A, B and C lines that flow 1,000 MW from PSE&G into New York, in addition to three south of Waldwick on the J and K lines that flow 1,000 MW into PSE&G from upstate and two on the Branchburg-Ramapo 5018 line.
During Thursday’s PJM Planning Committee meeting, the RTO’s Mark Sims explained that the PARs have more physical limitations than HVDC ties, which can be more specific in regulating flow. The PARs can be set to certain “tap positions” to “bias” the flow but have a limit of 20 adjustments per PAR per day and 400 per month.
The determination of the new protocol will include an N-1-1 review. PJM and NYISO have agreed not to change their treatment of Rockland Electric Co.’s load, 80% of which is supplied by the 5018 line and the remaining 20% by several western ties across the border of New York and Pennsylvania.
The natural flow would send about 500 MW from NYISO into PJM via the J/K lines and then into New York City via the A/B/C lines, Sims said. Stakeholders have questioned allowing this because it appears to provide similar service to the “wheel” without the same transmission payments. Completely curtailing that natural flow threatens to “max out” the PARs’ thermal and voltage limits, Sims said.
“It’s not a real natural thing,” he said. “We don’t want to implement a protocol that immediately has RTEP violations that we need to fix … unless we go into that solution with eyes wide open.”
Among the “high-level” considerations that the grid operators are discussing are reducing the flow to the J/K lines by at least 6%, setting the PAR taps at neutral and adjusting them by agreed-upon percentages to reduce congestion. NYISO published a white paper on the process and will partner with PJM to publish another one in September that includes PJM’s perspective.
