Yue Cao, assistant professor of electrical and computer engineering in the Energy Systems research group, has received a Faculty Early Career Development (CAREER) Award from the National Science Foundation. The award includes a grant of nearly $500,000 over five years.

Traditional energy storage systems encompass what Cao calls “real” storage, such as batteries, supercapacitors, and fuel cells. Cao’s research aims to also incorporate currently overlooked “virtual” resources, such as HVAC systems or water heaters.

“I call those systems ‘virtual,’ because storing energy is not their primary purpose, but they consume electricity and are tied to the grid or other energy resources,” Cao said.

The purpose of Cao’s research will be to create a universal equivalent circuit for multiple energy storage systems that are controlled by connected power electronics. Cao will then develop a design approach to optimally size the hybrid energy storage systems and increase their life and reliability. By dynamically regulating virtual energy mass, this new approach aims to modulate energy usage from the grid.

“For example, if I have rooftop solar panels on my house, and it’s a sunny day and the air conditioner is on, and in the next minute a cloud blocks the sun, solar power will be reduced,” Cao said. “Current systems would use power from the grid to keep the air conditioner running. With an integrated energy system, however, the power used by the air conditioner, or the virtual resource, could be adjusted temporarily to match the reduced power of the solar panels, without my noticing a difference in temperature.”

Cao is already working on research projects that involve energy storage problems including fast charging stations for heavy-duty trucks on rural highways, electrification of locomotives, and wave energy.