NERC Summer Assessment Sees ‘Elevated’ Reliability Risks In The West, MISO

by Peter Maloney
APPA News
May 21, 2022

Parts of western North America face an “elevated or high risk” of energy shortfalls this summer because of predicted above-normal temperatures and drought conditions and electric reliability in the Midcontinent ISO (MISO) is at “high risk” because of capacity shortfalls, according to the 2022 Summer Reliability Assessment released by the North American Electric Reliability Corp. (NERC).

The expected continuation of western drought conditions poses several threats to electric reliability, NERC said. Below normal snowpack can result in lower-than-average output from hydro generation in a region that depends on energy transfers to balance electric supply and demand.

In particular, the California-Mexico (CA/MX) assessment area and the Southwest Reserve Sharing Group (SRSG), depend on “substantial electricity imports” to meet demand on hot summer evenings and at times when wind and solar resources are low.

Texas, the Southwest Power Pool (SPP), and Saskatchewan, in particular, are at elevated risk of energy emergencies during extreme conditions, the NERC report said, pointing out that in addition to putting a strain on electrical equipment, high temperatures also contribute to high demand.

The report also noted that continuing drought conditions over the Missouri River Basin could adversely affect SPP thermal generators that use the Missouri River for cooling.

Drought conditions can also exacerbate wildfires, NERC said, noting that government agencies are warning of the potential for above-normal wildfire risk across much of Canada, the U.S. South Central states, and Northern California. Wildfires can affect the reliability of transmission lines and the smoke from wildfires can cause diminished output from solar power resources, NERC said.

NERC also warned that the risk of unexpected tripping of solar photovoltaic resources during grid disturbances continues to be a reliability concern. In May and June of 2021, Texas experienced widespread solar loss events like those previously observed in California and four additional solar loss events occurred between June and August 2021 in California. During these events, widespread loss of solar resources was coupled with the loss of synchronous generation, unintended interactions with remedial action schemes, and some tripping of distributed energy resources, NERC said.

NERC also singled out the risks facing MISO, saying the region is at “high risk” because it faces capacity shortfalls in its north and central areas during both normal and extreme conditions because of generator retirements and increased demand.

Load serving entities in four of 11 MISO zones entered the annual planning resource auction (PRA) in April 2022 without enough owned or contracted capacity to cover their requirements, and peak demand projections have increased by 1.7 percent since last summer due in part to a return to normal demand patterns that were altered during the pandemic.

Even more impactful, NERC said, is the drop in capacity in the most recent PRA. MISO will have 3,200 megawatts (MW), representing 2.3 percent, less generation capacity than in the summer of 2021.

In addition, at the start of the summer, MISO will be without a transmission line connecting its northern and southern areas as restoration continues on a four-mile section of a 500-kilovolt (kV) transmission line that was damaged by a tornado in December 2021.

MISO system operators “are more likely to need operating mitigations, such as load modifying resources or non-firm imports, to meet reserve requirements under normal peak summer conditions,” NERC said. If there are extreme temperatures, higher generation outages, or low wind conditions MISO’s north and central areas will be exposed to “higher risk of temporary operator-initiated load shedding to maintain system reliability,” the NERC report said.

Supply chain issues and challenges commissioning new resources are also a concern in areas where those resources are needed for reliability during summer peak periods, NERC said. The report identified CA/MX and SRSG as areas that have “sizeable amounts of generation capacity in development and included in their resource projections for summer.”

In addition, coal-fired generators are having difficulty obtaining fuel and non-fuel consumables as supply chains are stressed, NERC said.

While no specific reliability impacts are foreseen, coal stockpiles at power plants are relatively low compared with historical levels, and some operators report challenges in arranging replenishment due to mine closures, rail shipping limitations, and increased coal exports, the report said.

Outside of MISO and the Western Interconnection, all other regions have sufficient resources to manage normal summer peak demand and are at low risk of energy shortfalls from more extreme demand or generation outage conditions, the report said.

The entire electric system, however, faces cyber security threats from Russia and other potential actors amid heightened geopolitical tensions in addition to ongoing cyber risks. “Russian attackers may be planning or attempting malicious cyber activity to gain access and disrupt the electric grid in North America in retaliation for support to Ukraine,” the NERC report said.

The Electricity Infrastructure Sharing and Analysis Center (E-ISAC) continues to exchange information on cyber threats with members and post communications and guidance from government partners.

E-ISAC members are “encouraged to check in regularly to receive updates and to actively share information regarding threats and other malicious activities with the E-ISAC to enable broader communication with other sector participants and government partners,” NERC said in its summer assessment.