UNIVERSITY PARK, Pa. — A new planning tool under development at Penn State could help keep the lights on as the U.S. electric grid faces growing pressures from extreme weather, renewable energy and data centers, according to the U.S. Department of Energy. On the latest episode of “Growing Impact,” researchers discuss how the tool identifies unlikely but plausible combinations of events that could threaten grid reliability and inform smarter investments in transmission lines and power plants.
For decades, utilities planned the bulk power system around a handful of peak-demand moments each year, such as the hottest afternoon in August or the coldest night in January, according to Anirudh Subramanyam, team lead and assistant professor in Penn State’s Harold and Inge Marcus Department of Industrial and Manufacturing Engineering.
“If the grid could withstand those conditions, planners generally assumed it would perform reliably the rest of the time,” Subramanyam said.
That approach is becoming less effective as heat waves, cold snaps and wildfires occur in unexpected places and seasons, often interacting with other challenges such as fuel shortages, equipment failures or fluctuating renewable energy generation, the researchers said.
“Transmission planning is basically about where, when and what type of generation and transmission the grid should build over a 10- to 20-year horizon,” said Subramanyam. “We’re talking about billion-dollar investments and decades-long commitments, so we have to make sure we get it right.”
Most power outages are local, caused by downed distribution lines during storms, according to Mort Webster, professor in the John and Willie Leone Family Department of Energy and Mineral Engineering at Penn State.
In contrast, this project focuses on rare, high-impact events that can cascade across regions and trigger widespread blackouts, such as the 2021 Texas power crisis. During that event, an extended cold wave increased heating demand while freezing gas wells, wind turbines and inadequately winterized power plants hindered supply, leaving millions without electricity.
“In a case like this, it was a cascade of unlikely events that stacked up and tipped the system over,” Subramanyam said. “Those are exactly the kinds of scenarios we’re trying to help planners identify and prepare for.”
Federal regulators now require utilities and regional planners to consider a broader range of possible futures when developing long-term transmission plans. But weather conditions, electricity demand, fuel availability and equipment failures can combine in countless ways, making it impossible to evaluate every scenario.
Many planning approaches simplify uncertainty or focus on peak-demand periods, potentially overlooking threats to grid reliability. The Penn State team's method uses historical data and advanced modeling to identify a small number of plausible scenarios that could place the greatest stress on the grid. The goal is to identify recurring patterns that planners can study and prepare for.
“What we’re doing is simulating many different combinations of conditions and asking: Under which ones do we have trouble either generating enough power or moving it to where it’s needed?” Webster said. “From all of those, we can group the problematic cases into a few patterns that keep reappearing.”
The researchers said three trends are making grid planning increasingly complex: more volatile weather, growing reliance on variable wind and solar generation, and rapid growth of large data centers. Some data centers consume as much electricity as a small city, challenging long-standing assumptions about how and where demand will grow.
The challenge is not only predicting how much electricity will be needed, but where demand will emerge. New high-voltage transmission lines can take a decade or more to plan and build, requiring utilities to make investment decisions long before they know where future renewable energy projects or data centers will be located.
By focusing attention on the scenarios and patterns that matter most, Webster said, the tool could help improve grid reliability, support the transition to cleaner energy sources and ensure electricity remains available when people need it.
“Our project is essentially helping planners navigate that tradeoff between overbuilding and underbuilding,” Subramanyam said. “Ultimately, that means fewer large-scale blackouts and lower costs for consumers.”
"Growing Impact” is a podcast by the Institute of Energy and the Environment. It features Penn State researchers who have been awarded IEE seed grants and discusses their foundational work as they further their projects. The podcast is available on multiple platforms, including YouTube, Apple, Amazon and Spotify.