Extreme cold weather in December and January has PJM Interconnection performing a contingency analysis of the relationship between its natural gas and electricity systems.

The analysis was triggered by cold weather alerts issued on 10 days between Dec. 27 and Jan. 17, according to Brian Fitzpatrick, PJM senior lead fuel supply analyst.

In the midst of the bomb cyclone, PJM experienced one of its top 10 winter peak demand days — 137,522 MW on Jan. 5 — but neither temperatures nor customer demand reached levels experienced in the polar vortex of 2014, according to a previous report by the regional transmission organization. PJM’s electricity grid performed well during the cold snap, but a major increase in related uplift charges shows the need to reform pricing for energy and reserves, according to that report.

A risk assessment performed since then by PJM found no reliability issues, and the grid operator concluded that it needs no additional reserves.

However, it did identify about 70 potential gas contingencies, most related to loss of local distribution companies and compressor stations off the Texas Eastern Transmission and Transcontinental Gas Pipe Line systems, Fitzpatrick said during a meeting of PJM’s operating committee Tuesday.

PJM is requesting hydraulic modeling from interstate pipelines and working to identify the timing and impacts associated with potential loss of generation. The committee expects to present refined contingency lists through 3Q2018, Fitzpatrick said.

While natural gas-related outages made up a large percentage of the total forced outages in PJM during the winter 2017-2018 cold snap, the actual number of gas outages was lower than in 2014.

Total forced outages on Jan. 7, 2014 were 40,200 MW, 22% of PJM’s total capacity, with 9,700 MW from gas plant outages and 9,300 MW from gas supply outages. On Jan. 7, 2018, total forced outages in PJM were 23,751 MW, 12.1% of total PJM capacity, with 8,096 MW from gas plant outages and 5,913 MW from gas supply outages. Coal outages were also down significantly, falling from 13,700 MW in 2014 to 6,935 MW in 2018.

The grid operator said recently that it has ample resources to match the demand expected to be created this summer, when forecasters predict temperatures will be hotter than normal.

PJM’s system, spread over 13 states and Washington, DC, has increasingly seen an increase in natural gas-fired power generation in recent years, driven largely by the low prices created by Appalachian shale production. From 2010-2016, the system was 33% coal-fired, 33% natural gas, 18% nuclear and 6% renewables. That’s compared to 2005, when coal and nuclear resources generated 91% of the electricity on the PJM system.

Natural gas continued to gain in PJM’s annual capacity auction held last month.

PJM recently began a process to analyze long-term fuel security as part of an ongoing effort to ensure that the nation’s largest grid remains reliable and resilient to the broader changes underway in wholesale power markets.