The greening of energy storage: U-M research team develops sustainability principles

Friday, February 05, 2016
Amy Mast

An interdisciplinary team of U-M sustainability experts and engineers has developed a “ green guide” to aid developers and operators of energy storage systems. Titled “12 Principles for Green Energy Storage in Grid Applications,” the 12 Principles offer researchers, designers and industry professionals a clear, concise picture of the most important criteria to consider when designing and operating sustainable energy storage devices and systems. The principles are detailed in the January 19 issue of Environmental Science and Technology.  

Because of the intermittency of electricity production from renewables, energy storage is an important complement to renewable power. It’s a way to keep using solar energy in the dark and wind energy on a calm day. The renewable industry is growing dramatically; the US boasts twice as many solar workers as it did five years ago. The deployment of storage technologies is expected to grow in tandem as the use of wind, solar, and other renewable technologies continue to grow.

To complement this growth, both government and industry have invested heavily in next-generation battery and other energy storage research, but no common set of guidelines exists to define what makes a given energy storage technology “green”. Guided by an interdisciplinary team of faculty, Maryam Arbabzadeh, a School of Natural Resources and Environment (SNRE) graduate student, developed the 12 Principles during two years of intense research, discussion and vetting with industrial ecologists, sustainability practitioners, electrochemists, and engineers. The criteria (see image) address guidelines related to efficiency, service life, materials used, and other key factors.

The 12 Principles are designed to be flexible, adapting to the kind of person who’s deploying them- perhaps a chemical engineer, a utility operator, or a manufacturer. No one principle, says Arbabzadeh, is assumed to be more important than another.

“Energy storage, and its integration into the grid, is a hot topic,” explained Arbabzadeh, “and its development has environmental impacts that are not always apparent. Storage systems result in their own environmental impact or emissions because of their production and the way they’re integrated into the system.”

Supervising Arbabzadeh’s work were Gregory Keoleian, an SNRE professor and the Director of the department’s Center for Sustainable Systems, Jeremiah Johnson, an SNRE Assistant Professor specializing in energy systems, and Levi Thompson, a Professor of Chemical and Mechanical Engineering specializing in energy storage.

Says Keoleian, “The timing of this project is very good. Coming out of the Paris climate talks, we’re entering into a time of hopefully even more attention to reducing greenhouse gas emissions. One of the key strategies to achieve that is more deployment of renewable energy, and that comes with more challenges in terms of managing the grid. Energy storage will continue to play a more important role. With new technology- ideally you can influence and steer it toward its most productive direction from the outset. You can think of the 12 Principles as a navigation tool to aid in the many decisions designers, engineers and utility professionals will have coming up in the next few years.”

I think the principles provide a first pass at the key considerations that will point you in the direction of better environmental outcomes,” said Johnson. “It doesn’t replace assessing environmental impacts and it doesn’t provide the definitive final answer on a system- but it points designers, operators and those integrating energy storage into the grid toward some of the fundamental things with the biggest impact on total environmental outcome.” 

The development of the 12 Principles was funded by The Sustainable Energy Pathways Program, a NSF-funded grant by authored by Thompson, the Principal Investigator, Keoleian, U-M Chemistry Professor Melanie Sanford, and Robert Savinell of Case Western Reserve University. According to Thompson, the project was designed to identify promising battery chemistries, design and fabricate small flow battery cells, and to “consider the scientific, technical, environmental, economic, and societal issues associated with energy storage.” The formal title of the grant is: “SEP: Non-Aqueous Redox Flow Battery Chemistries for Sustainable Energy Storage.” Funding was also provided by the DOE’s Joint Center for Energy Storage Research (JCESR) Energy Innovation Hub.