It ain’t easy going green.
The energy infrastructure that powers our world was largely built to transmit electricity from traditional sources like coal-fired or nuclear power plants. As more and more electricity comes from renewable sources like solar and wind, however, big changes are necessary to ensure that the grid remains reliable and secure.
Line Roald, an assistant professor of electrical and computer engineering, is finding solutions to keep electricity flowing without interruptions so that our power can be green.
“I do what I do because I want to contribute to a more sustainable world with an energy system that still delivers power reliably,” says Roald, who joined the Department of Electrical and Computer Engineering in fall 2018.
Power from renewable sources presents a challenge for energy system operators because the amount of electricity generated from a solar installation or a wind farm can vary wildly depending on the time of day or weather conditions. That uncertainty makes it necessary to totally rethink how electricity flows through the grid and into people’s homes.
Roald has firsthand experience helping countries make the switch to renewable energy. During her PhD research at ETH Zurich in Switzerland, which she completed in 2016, Roald worked with system operators in Germany to help ease the transition away from nuclear power plants—almost one quarter of the country’s energy-generation capacity—in favor of solar and wind.
To devise strategies for switching from traditional power to sustainable sources, Roald draws from the field of optimization. Her approach hinges on representing all aspects of a power grid with mathematical equations, and then solving them to reveal strategies for delivering reliable and cost-effective electricity.
That’s no easy feat, given the extreme complexity of an electric grid and the importance of keeping the lights on in homes, businesses, hospitals and many others.
“We all use electricity all the time every day,” says Roald. “But the only time most people think about power is when it is not there.”
Roald’s work aims to avoid leaving consumers “powerless,” while empowering system operators to generate electricity from more sustainable sources. It’s an endeavor that is taking on even more urgency as extreme weather events become more common; the grid not only needs to deliver electricity, but it also must withstand an unpredictable climate.
“Reliability is a big societal question,” says Roald. “Power and energy security are really important.”
Although Roald’s research now encompasses the energy grid as a whole, she got her start working on individual power generation components. After graduating with a bachelor’s degree in mechanical engineering from ETH Zurich in 2010, she designed systems for wave power and floating offshore wind turbines during her master’s degree studies at the same institution, which she completed in 2012.
That work on renewable energy sources sparked Roald to start thinking about the bigger picture—as in how electricity makes its way from a windmill to the outlet on a wall. Those questions motivated her to pursue a PhD at ETH Zurich and subsequent postdoctoral research at Los Alamos National Laboratory, in New Mexico.
Now at UW-Madison, Roald is excited to join the long lineage of power engineering excellence in the electrical and computer engineering department as well as the vibrant community of optimization researchers on campus. She still maintains contact with system operators in Europe, and is looking forward to establishing similar relationships with people in the U.S. power industry.
Roald arrived in Madison immediately before a record-breaking rainstorm in August 2018 that left much of the city flooded for several weeks. For Roald, that severe weather event further underscored the importance of pursuing renewable power.
And although an unexpected deluge wasn’t quite the welcome she expected, Roald made the best of a soggy situation.
“I sandbagged my house, and I got to know all my neighbors,” says Roald. “People here in Madison are super friendly.”