An annual survey conducted by the regional power grid operator Midcontinent ISO concludes that the 15-state grid has enough capacity to meet its reliability requirements from 2019 to 2023.
MISO joined utility regulators from MISO states, known collectively as the Organization of MISO States, or OMS, to conduct the annual survey. Representatives of 97% of the region's power demand responded to the survey.
The 2018 survey forecasts that the grid will have a 600 MW surplus in 2019 above its 17.1% planning reserve margin. That surplus widens to about 6,600 MW if potential new capacity and potentially unavailable resources are included, according to a MISO presentation on the survey resultspresentation on the survey results. New capacity includes power plants in development, while unavailable capacity includes potential retirements and capacity that could be unavailable under future market conditions.
The supply balance could be short after 2019, the results show, but only if significant sums of potentially unavailable capacity is taken offline and potential new capacity is not added. By 2023, the region could be short of meeting its minimum reserve requirements by 4,500 MW when looking only at projected committed capacity. The shortfall turns to a 6,000-MW surplus when including potential capacity.
In the presentation, MISO staff indicate that supply balance by year largely depends on the availability of its resources, demand growth changes, and fuel mix changes. Between the 2017 to 2018 surveys, MISO staff assumed demand will still grow, but at a slower pace, assuming a 0.3% annual growth rate rather than the 0.5% annual rate assumed in the 2017 survey.
"While we continue to see decreasing demand in the MISO footprint, the story continues to be the evolving generation portfolio," John Bear, MISO's CEO, said. "As the MISO footprint continues to transform, we must learn to adapt in areas such as our transmission planning studies, market-based solutions that focus on speed and flexibility, and enhancing coordination with our neighboring seams partners."
As part of the survey, MISO staff found that natural gas and other gases will continue to outpace coal as the largest single resource in the region's fuel supply mix. Natural gas' share is expected to increase from 59.9 GW in 2019 to 66.4 GW by 2023, while coal is expected to decline from 57.5 GW in 2019 to 53.3 GW in 2023. Other resources include nuclear, demand response/behind-the-meter generation — expected to surpass nuclear by 2023 — renewables including wind and solar, and an "other" category.
Since the 2017 survey, MISO staff noted two changes to supply. The 2018 survey assumed a higher reserve requirement of 17.1%, up from the 15.8% in the 2017 survey. MISO staff also observed a 4,600-MW drop in available supply.
Consistent with the 2017 OMS-MISO survey results, certain zones in MISO may not have enough supply within their zones but will be able to import excess supply across the region to cover their deficits, MISO staff said in the presentation. By 2023, the survey results show possible deficits in Zone 4, which covers central and southern Illinois; Zone 7, which denotes Lower Michigan; and Zone 6, which covers Indiana and a part of western Kentucky.
