PJM, MISO, ERCOT and SPP Submit Second Round of Joint Comments on EPA Emissions Rule


PJM and three other grid operators have submitted a second round of joint comments in response to the proposed EPA rule on New Source Performance Standards for Greenhouse Gas Emissions.

The Joint ISOs/RTOs (PJM, MISO, ERCOT and SPP) provide electric service to an estimated 154 million customers in all or part of 30 states and the District of Columbia. Their Dec. 20 Joint Comments (PDF) followed comments the same group submitted last summer and were in response to a supplemental request by EPA for comments focused on identifying reliability mechanisms to be considered in the Final GHG Rule.

The previous comments stated that the proposed Rule may exacerbate the already concerning retirement rate of generation needed for reliability given the increasing amount of renewable resources on the grid.

Flexibility for Reliability Today and Tomorrow

In the near term, this most recent filing proposes that the EPA consider a suite of “reliability safety valves” to address potential immediate needs for unit-specific relief, enabling generators to operate during system emergencies.

To address longer term regional reliability challenges, the comments also propose targeted relief to help each region continue to meet target reserve margins, specifically:

“(T)he Joint ISO/RTOs continue to believe that the proposed Rule and associated implementation timelines would accelerate the retirement of generators with the attributes needed to support grid reliability….Without waiving our previously stated concerns with the Rule, the Joint ISO/RTOs propose herein several ‘reliability safety valve’ options that could arise during Rule implementation. The Joint ISOs/RTOs certainly hope that none of these reliability assurance mechanisms will need to be utilized. However, in our view, it would be imprudent to adopt a rule that does not contain measures to ensure reliability.”

Addressing Immediate Need Concerns

To allow for the continued operation of units required for grid reliability, the comments propose two options:

  1. For immediate and near-term unit-specific relief, the Joint ISO/RTOs recommend expansion of existing permit conditions for affected units to allow for automatic and timely operation – as needed – for grid reliability.  A pre-approved, automated process would enable rapid response to address immediate-term, near-term and potentially, longer-term reliability issues.
  2. A proposed approach already employed in the EPA’s Clean Power Plan would allow a unit to operate for reliability for an initial period of up to 90 days, after which a state would need to revise its plan to account for and offset emissions.

Maintaining Regional Resource Adequacy

The Joint ISO/RTOs offered several “reliability safety valve” options for EPA consideration to support longer-term grid reliability requirements on a forward basis. These include (a) options that are focused on federal rule provisions and enforcement mechanisms (b) options that can be addressed in the first instance within state compliance plans and (c) market-based options through the creation of a bank of regional reliability allowances that can be “paid back” in the future in the form of reduced emissions once the reliability issue is resolved.

Reliability Check-ins

These Supplemental Comments reiterate the grid operators’ call for established “check-ins” on a regularly scheduled basis to address both reliability issues stemming from Rule implementation, as well as to monitor the progress of deployment of the extensive clean energy infrastructure that the rule presupposes.

Such check-ins with grid operators, at least on a two-year basis, would help ensure that technologies such as carbon capture and hydrogen co-fired generation are developing as anticipated by the EPA.  These reviews would be in addition to, not a replacement for, the more targeted “reliability safety valves” also proposed. These proposals, the grid operators added, may be combined in various ways to achieve the goal of preserving reliability while meeting the environmental goals of the proposed EPA rule. The Joint ISOs/RTOs expressed appreciation for continued engagement with the EPA and readiness to continue to work with all parties with these shared goals.