Rethink Sustainability: Andrew Liu

Optimizing the Power Grid

For the average person, power systems are a means to turn on a lamp or heat a home. For Andrew Liu, they are a fascinating challenge. Liu, associate professor of industrial engineering, is using his background in math, economics and optimization to transform the way in which power is sustainably supplied and used.

Liu earned a doctorate in applied mathematics and statistics at Johns Hopkins University, then spent four years with the consulting company ICF, where he focused on the energy industry and environmental consulting. While there, he was the major developer for the Integrated Planning Model (IPM), extensively used by the Environmental Protection Agency to analyze the impacts of air pollutant regulations on the power sector. Since arriving at Purdue in 2009, he has worked on developing algorithms and optimization models to improve the systems reliability of next-generation power grids, or "smart grids." The aim is to make the power system of the future more robust and resilient, accommodate all options for energy generation and storage and enable the active participation of consumers.

Liu is working on advanced computational algorithms that could be used for decision making by system operators based on real-time data collected from sensors. He is considering the sustainability of the systems, balancing system reliability and economics.

"Future U.S. economic growth and societal needs require a secure, reliable and sustainable electric grid that can incorporate new technologies in renewable energy generation, energy storage, demand-side management and electric vehicles," Liu says. "Yet the nation’s current grid infrastructure, mainly built between the 1930s and 1980s, is overstressed to accommodate these innovations."

Making smart grids work is a challenge, according to Liu. “Without a detailed, integrated market and system design that coordinates and secures where electricity is generated, delivered and priced, the promised benefits of the next-generation grid cannot be realized,” he says.

Pilot projects in the U.S. and Europe using an advanced metering infrastructure and dynamic retail electricity rates to induce behavior change and lower consumers' electric consumption have resulted in only modest savings, according to Liu. They also revealed a vulnerability to attacks on both the physical and cyber systems of electricity grids.

To bridge these gaps, Liu and fellow researchers are working toward a solution that links the cyber and physical aspects of such systems and synchronizes the information processing and physical electricity flow with real-time prices of electricity. It's an ambitious, interdisciplinary solution at the intersection of power-system engineering, operations research, computer science, economics, consumer science and electrical engineering technologies.

"The goal is to use our research as the backbone of a secure and robust power grid and a fair, real-time pricing market design that support consumer participation, energy management and new technologies," Liu says. "This system should fully integrate bulk electricity generation and transmission macro-grids with automated, distributed generation and energy storage micro-grids."