Microgrids in Music City: Nashville Project Shows Benefits of Community Input on Resilience Needs
In 2020, a tornado hit Nashville Electric Service’s (NES) territory, downing 972 poles and sparking an outage that lasted nine days in certain areas, said Tony Richman, engineering manager of grid transformation at the utility.
A research project involving NES, the Electric Power Research Institute (EPRI), Tennessee State University (TSU), Tennessee Valley Authority (TVA) and the city of Nashville asked the question: What would have happened if NES deployed a solar-plus-storage microgrid that served critical services identified by community members? And what would have occurred if community members on the ground were able to provide real-time input to the utility during the tornado?
Community leaders gather to identify resilience needs
To test these ideas, project participants recruited community leaders in Nashville–representing businesses, houses of worship and local organizations–to join a study group, called the Community Resiliency Advisory Board–that met monthly for 3 years to identify the critical services they thought should continue operating during an outage. The project was funded with a $1 million planning grant from the federal Department of Energy (DOE).
“One of the most interesting things about this project was being able to learn from the community members themselves what those priorities would be and then what they look like,” said Brenda Brickhouse, technical executive at EPRI.
Looking beyond utility restoration numbers
After an outage, utilities usually provide data about how many people were without power and how long it took the utility to restore power. But this project showed that it’s also important to look at critical services that needed to be energized.
“This digs down another layer deeper so it's not just about the numbers, but it's about the who and the what,” Brickhouse said.
The project findings could aid other utilities with resilience planning. It helped participants think more strategically about how to approach grid planning in a way that puts the community’s needs first, she said.
In this case, community members identified a grocery store that includes a pharmacy, along with restaurants that provide take-out food, she said. Also identified as needing resilience were houses of worship that offered adult and child daycare.
“These are very specific needs that would be known to community members but not necessarily to the utility,” Brickhouse said. A project like this can help inform utility investment decisions, she added.
Because it’s unlikely that a solar-plus-storage microgrid could serve the critical services all day during an outage, the utility could potentially prioritize serving these facilities during certain times of day.
Real-time feedback from community members during energy emergencies
Not only can community members provide input that helps utilities plan resilience projects. Community members can also provide real-time feedback during an outage, communicating which facilities are most in need of resilience, Richman said.
On May 30, the partners in the project, including the community leaders, simulated the 2020 tornado, Richman said. The project simulated the effects of deploying microgrids in about six different sizes.
Nashville Electric Service (NES) has funding in its budget set aside for resilience projects to help pay for a microgrid that the DOE estimates will cost $70 million to $100 million, Richman said.
Microgrid scenarios aim for resilience
The simulated scenarios included adding a front-of-meter microgrid consisting of 500 kW of solar and 4 MWh of storage. The study also looked at adding solar and storage incrementally and conducting a cost-benefit analysis for each option. That cost-benefit analysis, which is being conducted by EPRI, is not yet available.
The team utilized software developed from TSU that can gather input from community members who install the software on their phones, said Saleh-Zein Sobatto, professor and chair of the College of Engineering at TSU.
Using the software, the utility could reshuffle its priorities based on community members’ input. Community leaders would rate the different options’ urgency on a scale of one to 10 in real time. The information gleaned through the software program would allow the utility to compare its priorities to the priorities of community members, he said.
“This project shows the ability of us to come together as a community and to look at how we could improve the resilience not only of the NES power grid but the entire TVA power grid. It provides a view into a more resilient community and customers,” Richman said.
