The Midcontinent Independent System Operator (MISO) region could face electricity shortages this summer, according to a recent assessment by the grid operator.
MISO in late April projected a summer peak forecast of 124 gigawatts (GW) compared with 119 GW of projected regularly available generation within the ISO’s territory because of forecasted warmer-than-normal temperatures in the region.
“Under typical demand and generation outages, MISO is projecting insufficient firm resources to cover summer peak forecasts,” MISO said in a presentation during a late April workshop on summer readiness.
The projected shortfall would have to be filled with increased, non-firm imports and possibly emergency resources, it said.
“The seasonal assessment aligns with the cleared resources identified in the 2022-2023 Planning Resource Auction, which indicated capacity shortfalls in both the north and central regions of MISO and leaving those areas at increased risk of temporary, controlled outages to preserve the integrity of the bulk electric system,” J.T. Smith, MISO’s executive director of market operations, said in a statement.
Severe weather poses one of the key threats to the MISO region. “There is evidence that severe weather events that impact electric reliability have been increasing since the early 2010s,” a January 2022 MISO report found. “For example, in January 2021 the Electric Power Research Institute found that hurricanes are increasing in intensity and duration, extreme heat events are increasing in frequency and intensity, and cold events are increasing in frequency.”
At the same time, MISO today “operates with less excess capacity than in the past because MISO’s large footprint has facilitated the sharing of reserve capacity, a direct benefit to customer rates,” the report said. “Nevertheless, many thermal resources have recently retired from service due to economic, regulatory, and environmental pressures, and the aging thermal assets that remain in service may be more prone to unplanned outages and face supply chain issues.”
MISO said it is possible to reliably operate its system with substantially lower levels of thermal resources, but “we need to ensure that the resources that replace them provide the commensurate capabilities needed to ensure reliable operations,” it said.
Looking forward, MISO also is concerned that the growing trend toward electrification – of transportation and heating, for instance – “could transform the region’s grid from a summer-peaking to a winter-peaking system, and that uncontrolled vehicle charging and daily heating and cooling load could result in two daily power peaks in nearly all months of the year.”
In preparation for the summer season, MISO said it has implemented training sessions and is conducting exercises with member companies “to prepare for the worst-case scenarios and to implement lessons learned and best practices,” but added, “during real-time operations, unplanned outages and other variables may require additional actions to maintain grid reliability.”
“We closely monitor the many challenges the summer season can bring and coordinate with our members and other grid operators for situational awareness,” Jessica Lucas, MISO’s executive director of system operations, said in a statement.