Railways Could Be Key “Utility Player” for Backup Power
To meet electricity demand and build capacity for backup power, the U.S. is building long-distance transmission lines and installing stationary banks of batteries.
“While both of these resources are necessary, we wanted to explore additional, complementary technologies,” said Natalie Popovich, a Berkeley Lab research scientist and co-author of the study. “We have trains that can carry a gigawatt-hour of battery storage, but no one has thought in a cohesive way about how we can couple this resource with the electric grid.”
The U.S. rail network is the largest in the world, covering nearly 140,000 miles (220,000 kilometers). The study looked at historical freight rail flows, costs, and scheduling constraints to see whether railroads could be summoned to transport batteries for high-impact events, given that grid operators typically have at least a few days’ notice, and sometimes up to a week, when extreme weather is coming. The analysis found that mobile energy storage could travel between major power markets along existing rail lines within a week without disrupting freight schedules.
The U.S. electric grid faces simultaneous, evolving pressures. Demand for power from the grid is increasing as people adopt electric cars and building energy is transitioned from gas to electricity. At the same time, climate change is driving more extreme weather. Events like the 2020 heat wave that led to rolling blackouts in California are relatively infrequent, but they are happening more often – and utilities need to be ready for them.
New research points to a flexible, cost-effective option for backup power when trouble strikes: batteries aboard trains. A study from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) finds that rail-based mobile energy storage is a feasible way to ensure reliability during exceptional events.
Previous research has shown that, in theory, rail-based energy storage could play a role in meeting the country’s daily electricity needs. Berkeley Lab researchers wanted to take this idea further to see whether rail-borne batteries could cost-effectively provide backup power for extreme events – and whether the scenario was feasible on the existing U.S. rail network.
“There’s a lot of uncertainty around when extreme supply shortfalls are going to happen, where they will happen, and how extreme they may be,” said Jill Moraski, a graduate student at the University of California Berkeley, a researcher at Berkeley Lab, and the paper’s lead author. “We found that the U.S. rail network has the capacity to bring energy where it’s needed when these events happen, and that it can cost less than building new infrastructure.”
The paper, “Leveraging rail-based mobile energy storage to increase grid reliability in the face of climate uncertainty,” was published recently in the journal Nature Energy.
A Ready Resource in Freight Rail
The idea for the study came to Amol Phadke, a Berkeley Lab staff scientist and co-author of the study, while he was watching a long freight train trundle past at a railway crossing. He began counting the cars and tallied over 100 on that single train.
“A thought then struck me – how many batteries could such a massive train carry? If those were used for emergency backup power, how significant would their contribution be?” Phadke writes in a briefing on the study.” A quick, back-of-the-envelope calculation revealed an astounding capacity, potentially sufficient to provide power to every household in Berkeley for a few days.”
To meet electricity demand and build capacity for backup power, the U.S. is building long-distance transmission lines and installing stationary banks of batteries.
“While both of these resources are necessary, we wanted to explore additional, complementary technologies,” said Natalie Popovich, a Berkeley Lab research scientist and co-author of the study. “We have trains that can carry a gigawatt-hour of battery storage, but no one has thought in a cohesive way about how we can couple this resource with the electric grid.”
The U.S. rail network is the largest in the world, covering nearly 140,000 miles (220,000 kilometers). The study looked at historical freight rail flows, costs, and scheduling constraints to see whether railroads could be summoned to transport batteries for high-impact events, given that grid operators typically have at least a few days’ notice, and sometimes up to a week, when extreme weather is coming. The analysis found that mobile energy storage could travel between major power markets along existing rail lines within a week without disrupting freight schedules.
Christina Nunez writes about science and innovation. The article was first published on the website of the Berkeley Lab.
