Monday, February 18, 2019

MISO Plans for New Uninstructed Deviation Rules

By Amanda Durish Cook

MISO will this March begin testing new rules to deal with generators’ uninstructed deviations from dispatch orders, stakeholders learned last week.

The RTO announced its plan to move ahead with implementing a new deviation threshold during a Jan. 25 conference call — coincidentally the same day FERC approved its filing in a delegated order (ER19-199). The new standard will be based on comparing real-time performance with day-ahead offer ramp rates.

During the call, MISO said it was preparing for the new thresholds despite not yet receiving FERC approval. Hours later, FERC issued a brief order approving MISO’s proposal just in time to meet the RTO’s requested decision date. The commission said it did not receive any “adverse comments” to the filing.

Jason Howard | © RTO Insider

MISO Market Quality Manager Jason Howard said the RTO is on track to start testing the new threshold by the first week of March and have a full implementation by mid-spring.

“As long as we don’t see something or run into any issues of this testing phase … we’ll implement this by May 1,” Howard said.

MISO will test the new system using singular past operating days with forecast data from market participants, Howard said. He said MISO is using singular operating days instead of running full weeks of data because the testing represents “a significant amount of work” for RTO staff. The testing approach will be similar to that used prior to implementing five-minute market settlements.

MISO’s proposal calculates a generator’s uninstructed deviation with a tolerance based on the minimum of five times the real-time ramp rate or 12% from the average set point instructions. Currently, generators in MISO are flagged after they deviate by more than 8% from dispatch signals over four consecutive intervals.

The proposal eliminates the RTO’s current “all or nothing” eligibility for make-whole payments, instead allowing generators to collect full payments when they respond to dispatch instructions at a performance rate of 80% or higher over an hour, while excluding payouts when performance rates fall below 20%. Units operating between those two thresholds would earn make-whole payments in proportion to performance. The change means that a generator that fails four or more consecutive five-minute dispatch intervals within an hour by either providing excessive or deficient energy will not automatically lose its eligibility for make-whole payments.

Additionally, MISO only plans to assess excessive or deficient energy charges on dispatchable intermittent resources during intervals when the market participant’s forecast is provided or when the resources are economically dispatched below the RTO’s forecast.

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