When we think of energy storage, batteries typically come to mind. But Allison Mahvi envisions something bigger: the buildings in which we live and work.
“Buildings can be a good way to store energy,” says Mahvi, who joined the UW-Madison Department of Mechanical Engineering as an assistant professor in fall 2022. “A lot of the energy that buildings consume is used for heating and cooling purposes. So, integrating thermal storage into buildings can give us this really big, flexible storage resource that is built into the supply side of the electric grid.”
Mahvi’s research focuses on characterizing thermal energy storage materials and integrating them into building energy systems. She has extensive experience in experimentally and computationally evaluating novel heat transfer components for these systems. Ultimately, her goal is to help increase the amount of renewable energy sources that are incorporated into the grid.
New storage solutions would allow intermittent energy sources such as solar to generate a much larger fraction of our electricity. For example, in a residential home that uses solar power, the HVAC system could freeze water when the sun is shining brightly. Then, when people return to their homes in the evening the system could discharge the energy stored in the ice to cool down their home.
“The idea is to develop ways to store a bunch of cooling or heating while you have extra renewable power generation, so your generation and use don’t need to be aligned,” Mahvi says. “And, compared to batteries, the lifetime should be a lot better with thermal storage systems. You can freeze water over and over again, and it doesn’t degrade the ice.”
In her research, Mahvi has investigated different phase change materials that transition at a higher temperature than ice. These materials could enable more efficient thermal storage systems that integrate seamlessly with HVAC equipment that many people already use. And of course, the ubiquity of buildings means there’s already an existing infrastructure that these systems could be integrated into, avoiding the need to construct expensive, standalone facilities for energy storage.
Mahvi completed her PhD in mechanical engineering at Georgia Institute of Technology in 2018 and earned her bachelor’s degree in mechanical engineering from UW-Madison in 2012.
She says her UW-Madison undergraduate education strongly influenced her career path. In particular, the thermodynamics course she took with Professor Greg Nellis ignited her passion for this area and inspired her to participate in undergraduate research. Additionally, her undergraduate work with Mechanical Engineering Professor Robert Lorenz in WEMPEC pushed her to pursue a graduate degree.
Prior to joining UW-Madison, Mahvi was a postdoctoral researcher at the National Renewable Energy Laboratory. Mahvi says the College of Engineering’s excellence in energy systems research was a big draw for her.
“The Solar Energy Lab was a big attraction, because it has a great group of researchers with a wide range of expertise who I plan to collaborate with on energy systems research,” she says. “At the same time, I have the freedom to bring in new research projects in areas that other faculty aren’t currently working in. Also, I loved my time at UW-Madison as an undergraduate and Madison is a really nice place to live, so I’m excited to come back.”