Report: Region’s electric grid can handle ‘extreme’ winter stress

The regional electric grid for Pennsylvania and parts of 12 other states can withstand prolonged periods of extreme stress — severe winter weather plus pipeline disruptions — despite the number of power plant retirements planned over the next five years, the grid operator said in an analysis Thursday.

But if significantly more at-risk power plants retire, there are plausible — if unlikely — scenarios with potential problems. A combination of stresses could trigger localized power outages five or more years in the future, the report found.

The analysis by Valley Forge-based PJM Interconnection comes as the Trump administration is considering emergency interventions to prop up financially struggling coal and nuclear plants.

Such plants, the administration contends, provide unique reliability benefits because they can store fuel on-site.

The PJM region — which covers 65 million people in 13 Mid-Atlantic states and the District of Columbia — has seen significant changes to its power generation mix in recent years. Inexpensive natural gas, energy efficiency measures and renewable energy have made it difficult for coal and nuclear plants to compete.

Planned retirements include FirstEnergy Solutions’ Beaver Valley and Bruce Mansfield nuclear and coalfired power plants in Shippingport and Exelon Corp.’s Three Mile Island nuclear power plant south of Harrisburg.

Despite the changes, “there is no imminent threat” to the reliability of the system, PJM said.

In a summary of findings to be released in detail in December, PJM said the regional grid as it is expected to look in 2023 would remain reliable “even in an extreme scenario, such as an extended period of severe weather combined with high customer demand and a fuel supply disruption.”

The stress test was meant to define the limits of the grid’s resilience.

It was undertaken to address concerns raised by policymakers that too much reliance on natural gas for electricity in five or 10 years could make the grid vulnerable if a series of worst-case scenarios converge.

In the most extreme of the more than 300 scenarios that PJM tested, “We do see a risk that we could get into situations where we couldn’t meet all demand under certain circumstances,” PJM President and CEO Andrew Ott said during a media briefing Thursday.

If many more than expected coal and nuclear plants retire, and natural gas plants that don’t have firm contracts for fuel are cut off during two weeks of severely cold weather, it could lead to power outages in isolated locations for hours or days, the analysis found.

The peak winter electric demandPJM modeled under its extreme scenario was greater than the historical peak from February 2015.

In response to those findings, the grid operator is exploring ways the market might begin to reward power suppliers for fuel security features — whether it is a coal plant with fuel stockpiles, a wind farm with battery storage or a natural gas plant that can run on oil and has a secure inventory of extra fuel.

“These are attributes we depend on in [operations] — fuel security — and we’re not paying for,” Mr. Ott said. “I don’t think that’s sustainable.”

PJM does not support government interventions that it sees as interfering with competitive markets, such as subsidies for specific power generating sources.

If PJM decides to propose market rule changes to address fuel security, it does not expect to do so until early 2020.