Combining about 33 GW of electrification load with a 70% carbon-free generating fleet sharply shifts the risks of blackouts to the winter from the summer, reinforcing the need for enough fossil-fueled and nuclear power plants to meet demand, the PJM Interconnection said in a report Tuesday.
The analysis shows an increasing need for resources that can quickly provide power as wind and solar taper during the afternoon while electricity use climbs, PJM said in the report, Energy Transition in PJM: Emerging Characteristics of a Decarbonizing Grid. The ramp in 2035 could be as high as 73 GW on some winter days, and natural gas- and coal-fired generation provided about half the ramping capacity under the modeling conducted by PJM, according to the report.
“Increased electrification and the shift to a winter peaking system will fundamentally change what it means to be reliable in PJM,” Glen Thomas, president of the PJM Power Providers Group, a trade organization, said Wednesday. “Decarbonization is important, but it must be done reliably, and reliability is going to be more challenging than it has been in the past.”
The PJM report builds on one issued in December by looking at issues such as electrification. The report’s findings should be seen as “guideposts” for future study and discussion, according to the grid operator.
The report is based on three 2035 scenarios: a 40% carbon-free "base" scenario, a 50% “policy” scenario that matched state energy goals in the PJM area, and a 70% “accelerated” scenario.
Carbon-free resources made up about 39% of the power produced in PJM in 2021, according to Monitoring Analytics, the grid operator’s market monitor.
Last year, gas-fired generation accounted for 37.9% of the power produced in PJM, followed by nuclear at 32.8%, coal at 22.2%, and wind, solar and hydroelectric at a combined 6.2%, Monitoring Analytics said in an annual market report released in March.
PJM system planners have long focused on getting through the hottest summer days, and generators and the market gave little attention to the winter, according to Mike Jacobs, a senior energy analyst at the Union of Concerned Scientists.
However, with electrification, PJM expects winter-time demand would increase 15% and summer load would climb 7%, making winter the grid operator's peak period, according to the grid operator's analysis.
“For the operations people to realize, we're tight in winter, just focuses the mind because right now winter has not been such a priority, and I think that's why we have had incidents in the winter that scare the pants off of people,” Jacobs said Wednesday, referring to Winter Storm Uri and the 2014 Polar Vortex.
Instead of peak power use occurring for a couple of hours in the late afternoon on a hot summer day, it would occur in the winter, starting around 6 pm and lasting longer, according to Thomas. “It’s a pretty fundamental shift,” he said, noting it has implications for how to meet the peak period.
That shift could affect how PJM plans to have enough power in the winter, Jacobs said, noting wind farms perform well in the winter while solar suffers.
With electrification, PJM in its latest report found that onshore and offshore wind’s effective load carrying capability, or ELCC – a measure of a resource’s reliability value – jumps to 22% and 45% from 6% and 15%, respectively. Solar’s ELCC falls to 6% from 32% and solar coupled with energy storage dips to 31% from 35% under the electrification scenario.
“These [PJM] reports say we need to get smarter about how we look at resource adequacy, and this attention to winter and using ELCC were critical steps to being able to have that conversation,” Jacobs said. “There's no doubt that we are going to need to make changes as we do this transition.”
Besides shifting PJM’s resource adequacy risk to the winter, electrification increases the role retail rate design and energy storage could play in managing high levels of renewable energy, according to the report.
The study indicates that market reforms are needed to incentivize operational flexibility, according to PJM.
Under a high renewable penetration scenario, energy storage supplied more than 80% of the reserve requirements. “There is an opportunity for PJM and stakeholders to explore the participation of renewable resources in the reserves market,” the grid operator said.
PJM said the study shows transmission, energy storage and emerging technologies will be needed to handle the evolving grid across its footprint, which spans 13 Mid-Atlantic and Midwest states and the District of Columbia.
Under the scenarios PJM studied, gas-fired generation fell by about 40% and coal-fired production dropped by about 35% from the base scenario to the accelerated scenario, driving carbon dioxide emissions down about 40%, PJM said in the report.
PJM said it plans to refine the study in future reports by assessing issues such as accelerated coal and gas plant retirements, dispatchable renewable resources and potential transmission expansion.