Two years ago, in one of his final acts as Chattanooga mayor, Andy Berke unveiled plans to build a solar, battery and diesel generator-powered microgrid to ensure power delivery at the city's police and fire headquarters on Amnicola Highway.
At the time, Berke hoped to have the system in place in six months. The $2 million project ended up taking a year longer than originally projected to complete due to supply chain problems during the pandemic. But since last October, the new microgrid has both guaranteed power delivery for emergency services and boosted the amount of renewable energy produced in Chattanooga.
On Thursday, city and EPB officials celebrated the completion of the "Power to Protect" microgrid based at the Chattanooga Police Services Center and Fire Department administrative headquarters at 3410 Amnicola Highway. Despite the delays, officials say the new system should make power greener and more reliable for the city and could serve as a model for other microgrids the city may install over time on other government buildings.
"Facing an outage in an emergency is a place none of us want to be, especially as first responders," Chattanooga Fire Chief Phil Hyman said during the unveiling of the new facility Thursday. "From the Easter 2020 tornadoes to this spring's windstorms, we've seen how changing weather impacts our safety, and this microgrid will prepare us to be resilient in any event."
Mayor Tim Kelly said the microgrid is the latest in the list of smart city innovations Chattanooga has implemented to improve energy service, reliability and cost.
"EPB is a national leader in Smart Grid technologies, and we're fortunate to have their level of experience locally to protect our essential services in a sustainable manner that reduces cost and waste and ensures our first responders' ability to protect our city at all times,"Kelly said in a statement about the new facility.
The new microgrid includes both power generation and battery storage.
The city bought a 200-kilowatt diesel generator and 155 kilowatts of solar panels that cover the roof of the police services headquarters. Because such generation is installed "behind the meter," it reduces the amount of energy consumed at the location, lowering its monthly bill by roughly 20%, Kelly said.
For its part, EPB invested in a 500-kilowatt battery to support the microgrid and other grid services. The battery is installed "in front of the meter" so it can be used to shave peak load during extremely hot or cold weather, reducing TVA's peak demand charge to EPB and keeping energy costs lower for local residents and businesses.
The project should pay off for EPB in six or seven years, EPB President David Wade said.
EPB's Smart Grid already provides two pathways for power to reach the Chattanooga Police Services Center and Fire Department administrative headquarters, so the new microgrid adds a third line of defense should widespread outages affect Chattanooga, Wade said.
To ensure comprehensive power resiliency, EPB also relocated a power pole from the front to the back of the building to avoid damage from possible wrecks in the future on the busy Amnicola Highway corridor.
"Our technology depends on electricity, so it's essential we don't lose it," Chattanooga Police Chief Celeste Murphy said in a statement. "It's a relief to know we won't have to worry about how we'll access power should we lose connection to the Smart Grid."
Kelly said he is talking with EPB and other government officials about whether it makes sense to install other microgrids across Chattanooga, using rooftops for solar panels and installing batteries or diesel generators for storage and generation when the sun doesn't shine.
"This project is a great example of how we're using microgrid technology to enhance EPB's local energy mix while providing customized energy solutions to address the specific needs of customers in different areas," Wade said.