ERCOT, MISO, PJM and SPP last week filed a joint brief in the appeal of EPA’s power plant rule seeking more flexibility on compliance, arguing it is needed to ensure reliability. (See Republican-led States Sue EPA over Power Plant Emissions Rule.) 

The four grid operators submitted comments similar to those they made while the agency was working on the rule. (See EPA Power Plant Proposal Gets Mixed Reception in Comments.) 

“Without additional modification, the compliance timelines and related provisions of the rule are not workable and are destined to trigger an acceleration in the pace of premature retirements of electric generation units that possess critical reliability attributes at the very time when such generation is needed to support ever-increasing electricity demand because of the growth of the digital economy and the need to ensure adequate backup generation to support an increasing amount of intermittent renewable generation,” they wrote. EPA’s final rule would strain their ability to maintain the reliability of the electric grid, they argued. 

The grid operators had proposed a “reliability safety valve” that would help mitigate their concerns, but EPA did not include that in the final rule, nor did it explain why, they noted. The grid operators had wanted EPA to provide upfront, clear criteria on the “remaining use of life and other factors” and enforcement discretion; the creation of a subcategory of generators needed for reliability; offering states guidance on how to use a reliability valve; and the creation of “regional reliability allowances” that generators could use in emergencies to avoid penalties under the rule. 

Instead, they argued, the final rule unreasonably discounts that existing fossil generators will need to decide whether to commit to installing untested technology or retire their units years before the compliance deadline with state compliance proposals due in 2026. That could accelerate earlier retirements of generators, the grid operators said. 

The rule requires 90% carbon capture and storage for coal plants that want to run after Jan. 1, 2039, as well as for new and modified natural gas units with capacity factors of 40% and above. Both categories of plants would need to install CCS systems by Jan. 1, 2032. 

“None of EPA’s projected time frames reflect historical rates of adoption of CCS technology for electrical generation purposes, nor does EPA adequately consider the risks that the technologies will not mature in time for [electric generating unit] owners to deploy them,” the grid operators said. 

EPA’s rule did include a short-term reliability mechanism, which requires the declaration of an energy emergency alert 2 before any compliance mitigation can take place. 

“This short-term reliability mechanism that EPA did adopt in the rule thus unduly places the grid — and customers — at greater risk before any short-term relief would be available,” the grid operators said. They “should not have to wait until the heightened level of emergency that an EEA2 declaration represents; they should be able to take proactive measures to address reliability issues upon earlier evidence of deteriorating grid conditions as evidenced by declaration of an energy emergency alert 1.” 

Compliance flexibility should kick in at EEA 1 because at that point, grid operators can still call on emergency generation. By waiting until an EEA 2, grid operators cannot act until they are in a real-time emergency. 

For longer-term issues, states can ask for extended deadlines or lower technology standards, but the grid operators would like to see EPA offer more guidance on that process. 

EPA is not responding to the initial briefs until next month, but the RTOs’ comments did generate some response from others. The Clean Air Task Force and Natural Resources Defense Council filed lengthy comments on grid reliability, arguing the rule was designed to give utilities and system operators the flexibility they need to maintain grid reliability. 

“While EPA has considered reliability issues in its proposal, FERC is the agency with direct jurisdiction over electric reliability,” the organizations said. “As discussed above and as recognized by FERC, the electric grid is undergoing changes unrelated to the EPA proposal, and the proposed regulations are only incremental to these existing forces. FERC and the electric utilities have the responsibility and many tools available to them to ensure reliability as these grid changes occur.”