To address long-term questions of fuel security, grid operator PJM Interconnect says it will examine fuel security vulnerabilities and establish criteria to assess areas that could face future fuel security issues.

The initiative is intended to help ensure fuel security for electricity generation on its power system serving 65 million people.

PJM says that its grid remains reliable even with the resource retirements analyzed to date and investment in new natural gas-powered generation sources. It says the potential for "continued evolution of the fuel mix" toward natural gas underscores concerns raised by PJM in a March 2017 report about the need to examine the long-term resilience of the grid.

In that report, PJM concluded that the system could remain reliable with the addition of more natural gas and renewable resources, but that “heavy reliance on one resource type” raises potential resilience risks beyond existing reliability standards.

PJM says its latest assessment will involve three phases:

• Identify system vulnerabilities and determine attributes such as on-site fuel requirements, dual-fuel capability or others that ensure that peak demands can be met during extreme scenarios.

• Model those vulnerabilities as constraints in PJM’s capacity market, similar to existing transmission constraints, allowing for proper valuation of needed attributes in the market.

• PJM will continue to work with the U.S. Department of Homeland Security, the U.S. Department of Energy, the Federal Energy Regulatory Commission, states, stakeholders and others to ensure that the results are consistent with identified security needs in the PJM footprint, including service to key military installations and other identified security concerns.

Similar Issue in MISO

Similar reliability issues are in play in the adjacent MISO region where coal-fired generation's share has fallen from 80 percent to 50 percent, and natural gas has grown from an 8 percent share to around 30 percent. MISO grid operators also must contend with wind generation, which accounts for as much as 9 percent of total installed capacity, up from virtually zero a decade ago.

The PJM grid was challenged in late December and early January by a cold snap. Between Dec. 28, 2017, and Jan. 7, 2018, PJM experienced one of its top 10 winter peak demand days. On Jan. 5, 2018, demand reached 137,522 megawatts, the sixth highest overall winter peak demand.

During the cold snap, the grid and the generation fleet performed well, PJM said, with excess reserves and capacity available even during peak demand.

Stress Test

The intent of PJM's most recent vulnerability assessment is to stress test the system under various fuel supply disruption scenarios, to better understand potential future reliability concerns. PJM anticipates completing the study within the next six months, and the results will be discussed with PJM stakeholders, including state and federal agencies.

PJM Interconnection was founded in 1927, and operates the electric power grid in all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and the District of Columbia.