City Power Lines

By Jeffrey Schlegelmilch, Jackie Ratner, Daniel Kushner, and Susanna Aguilar

As climate change brings extremes in temperatures and weather, outdated electrical infrastructure across the United States has been strained. In recent instances, places such as California, Texas, Michigan, and the Pacific Northwest have served as stark warnings of the growing stressors our existing grid is facing.

Residents in these areas have endured rolling blackouts, and lengthy loss of service. These impacts are inconvenient at best, but for many people who are already vulnerable, or inaccessible electric service is life threatening.

While the situation is dire, there are solutions on the horizon. One option that has shown potential is microgrids—small power grids that can either be connected to the main grid or, during emergencies, be disconnected from it to keep locally generated power flowing.

Microgrids can contribute to social and infrastructure resilience, but they require investments that can be a hard sell without information to support the benefits and value of funding such projects. To begin to provide such information, the National Center for Disaster Preparedness (NCDP) worked with Commonwealth Edison (ComEd) to run a tabletop exercise testing the Bronzeville Community Microgrid, which ComEd built on the South Side of Chicago with the help of U.S. Department of Energy grants.

The Bronzeville Tabletop Exercise

As we wrote in a March 2020 Research Counts article, ComEd and the National Center for Disaster Preparedness at Columbia University’s Earth Institute created a partnership to incorporate insights in social vulnerability with advances in electrical grid design and implementation. With that in mind, the exercise looked at continuity of operations, societal impacts, social vulnerability factors, advantages to nearby communities, and ways to quantify the benefits of the microgrid across these areas.

The simulation was designed as a tabletop exercise using the U.S. Department of Homeland Security Homeland Security Exercise and Evaluation Program doctrine. It brought together 12 organizations from in and around the footprint of the Bronzeville microgrid to test the scenario, which was based loosely on the August 2020 derecho that caused widespread damage in the Midwest. In our scenario, conditions were amplified to depict widespread power outages across Chicago, followed by a major heat and humidity event.

Exercise participants—which included representatives from the Chicago Fire, Police, and Public Health departments; Chicago Public Schools; the Chicago Office of Emergency Management; the Illinois Institute of Technology, a local business association, and local faith-based communities—worked through three modules based on the premise that the microgrid would perform as expected in such a scenario. This allowed us to test the value of the design at multiple stages, including in the first hour after an event, in the next 24 hours after an event, and within 72 hours and beyond.

We were especially interested in learning how grid continuity affected healthcare, the elderly, economically disadvantaged populations, housing stability, transportation access, and the ability of community-based organizations to support their clients.

Exercise Findings

The general conclusions of the exercise indicated that the Bronzeville Microgrid provided enhanced benefits to the communities in its footprint and areas surrounding it. This was particularly true for populations with underlying vulnerabilities, businesses, and community organizations.

The scenario results pointed to the ability of emergency responders within the grid to respond to an event without downtime caused by electrical failures. This could not only free up responder capacity to quickly assist residents in their own and surrounding neighborhoods, but would also reduce the need to respond to subsequent issues, such as vulnerable individuals who would be at greater risk of injury or death during a prolonged power outage.

Similarly, faith-based and other community organizations indicated that the microgrid would allow them to continue their regular operations and potentially offer resources, such as cooling centers or emergency shelters, for surrounding communities. Businesses, too, saw a great benefit to continued electrical service, including a reduction in negative economic impacts for themselves and employees and the ability to provide critical resources such as fresh food and water.

We learned that more community outreach will be necessary to maximize these benefits, however. Several community participants indicated that they needed more familiarity with the microgrid footprint and its capabilities if they were to include it in their internal contingency planning. Government-level participants noted that they would likely require advance planning or formalization through memorandum of understanding or similar mechanisms.

More work will also be needed before the value of the resilience provided by the microgrid can be quantified. What, for instance, is the economic benefit of the number of response calls averted or business losses avoided? While still in early development, the exercise helped identify factors that can offer a roadmap for potential quantification strategies.

Future Directions

Simulating extreme weather events is increasingly important for understanding disruptions to the power grid as climate change, cyberthreats, and other factors introduce new vulnerabilities—and past experience is not necessarily a dependable predictor of future threats. Furthermore, understanding precisely how grid resilience correlates to social resilience is crucial to ensure that the right technologies are put in the right places.

Microgrids can offer valuable insights because they allow us to assess how a community that maintains a continuous supply of electricity during adverse events might fare differently from surrounding areas and even extend their benefits to those communities.

While the findings in this analysis are only preliminary, they do highlight the linkages between investments in grid resilience and societal resilience. While most people agree that resilience is a goal to strive for, ultimately, decisions related to investing in these projects must rely on sound economic criteria to support it.

Without the hard data to bolster infrastructure decision-making, we might unknowingly undervalue resilience and inadvertently move in the direction of risk. There is work ahead, but exercises such as this simulation indicate that investments in grid resilience can be a lifeline for communities during the extreme weather events to come.