PJM, Stakeholders Review ELCC


PJM and stakeholders continued to look at effective load-carrying capability as a component of integrating renewable energy into the interconnection system at a special session of the Planning Committee on Monday.

Since September, the Planning Committee has been looking at effective load-carrying capability (ELCC). The methodology determines the contribution that an individual generator or a fleet of generators makes to overall system resource adequacy. Specifically, ELCC is a measure of the additional load the system can supply with the particular generator(s) of interest, without a change in reliability.

Patricio Rocha-Garrido, senior engineer – Resource Adequacy Planning, presented updated analysis and study results as a follow-up to his presentation at the regular Planning Committee meeting on Nov. 8. Monitoring Analytics, PJM’s independent market monitor, reviewed its wind and solar resource performance numbers.

Rocha-Garrido pointed out that PJM initially used inputs from the 2017 Installed Reserve Margin case because the 2018 case was not yet completed. Going forward, he said, PJM will use inputs from the 2018 IRM case but dramatic changes were unlikely.

PJM’s original objective was to calculate the effective load-carrying capability of wind resources to support a change to the current wind-capacity credit calculation. The change uses the median instead of the mean performance of wind units over peak summer hours to calculate ELCC.

He reviewed PJM’s analysis in more depth than previous presentations, going through the three ELCC allocation options and comparing those results to results under the current methodology, for both existing and new resources.

Tom Falin, director – Resource Adequacy Planning, said that based on the depth of the stakeholders’ questions and interest, it would be worth the effort to delve further into an ELCC approach, including how calculations might affect a resource’s capacity value and revenue stream.

Because of the number of open questions and the need for PJM to conduct more analysis to answer stakeholders, Falin said additional special sessions of the Planning Committee devoted to ELCC would be scheduled, as well as discussion at the Dec. 13 Planning Committee meeting.

Falin said PJM’s goal is to have the ELCC changes in place for the next base residual auction in August of 2019. This means the parameters for the auction would be posted around May 1, giving PJM and stakeholders time to refine the changes.

He added that PJM would go back and consider several other pending changes to Manual 21: Rules and Procedures for Determination of Generating Capability that are being reviewed in the stakeholder process to determine if those changes should move forward separately from the potential wind/solar changes.

Manual 21 provides uniformity for planning, operating, accounting and reporting purposes. The changes involve summer testing verification and have been discussed at the Planning Committee.