Chattanooga recognized for Excellence in Green Leadership

Not content to rest on its laurels following the completion of the city’s first community solar installation and national recognition from the U.S. Department of Energy, the city of Chattanooga has continued to set the bar for green initiatives through ongoing energy-usage reduction projects, a new electric microgrid, and efforts to make city vehicles more energy efficient.

In recognition of the city’s ongoing efforts to find green solutions and alternatives while still providing safe and critical city infrastructure and services, the Tennessee Municipal League is pleased to present Chattanooga with an award for Excellence in Green Leadership.

Chattanooga has been building on its green infrastructure since the establishment of the city’s first community solar installation in 2011. The city received first Bronze and then Gold “Solsmart” status from the U.S. Department of Energy’s Sunshot Initiative in 2018.

The city also exceeded a goal set to reduce its energy-use intensity (EUI) by 2025. The city’s initial goal was to reduce its EUI by 20% before 2025 in approximately 2 million square feet of building space and 200 municipally-owned and operated facilities. The city managed to reach 30% reduction in EUI in 2018, earning Chattanooga recognition from the U.S. Department of Energy as a Better Buildings Challenge “Achiever.” After hitting its reduction goal seven years early, Chattanooga continued to move forward on EUI reduction, and the Department of Energy verified that the city had achieved 40% in EUI for the 2020 calendar year.

Chattanooga was able to exceed its EUI reduction goals through the implementation of building automation systems (BAS) in more than 30 primary, high-occupancy buildings, establishing regular building operation schedules and temperature setpoints and setbacks, as well as numerous energy efficiency projects at the city’s regional wastewater treatment facility.

While many buildings experienced reduced occupancy due to COVID-19 precautionary measures, these reductions were accounted for in the EPA Energy Star Portfolio Manager platform used to benchmark energy use. Additionally, the city recently completed a major LED lighting retrofitting project to more than 60 buildings, which contributed to significant savings.

The reduction in EUI has also equated to an increase in savings for the city. Chattanooga has saved close to $9.3 million total in annual electric utility expenditures. Likewise, the city is consuming approximately 20 gigawatt hours of electricity less than in 2012, the equivalent of which could power more than 1,300 average Tennessee homes.

In April 2021, the city executed a contract to begin construction on a new electric microgrid at the city’s public safety complex on Amnicola Highway, which houses the administrative offices for both the Chattanooga Police and Fire Departments and the Hamilton County-operated 911 Communications Services. Working in partnership with EPB, the microgrid will provide increased resilience to key critical infrastructure and operations at the safety department in the wake of increasingly intense weather events.

The rooftop mounted solar microgrid will include 1,100 kilowatts of battery storage, a microgrid controller, an existing 100-kilowatt natural gas generator, and a new 175-kilowatt diesel generator for additional backup in the most extreme outage scenarios. The $1.8 million project will also include the construction of covered employee parking with mounted solar panels and the ability to accommodate electric vehicle charging stations.

The city has also made efforts to green its vehicle fleet. The Chattanooga Police Department has recently put 20 non-plug-in hybrid police cruisers into service, and expects to expand on these efforts. The city was awarded a $950,000 grant from the Tennessee Department of Environment and Conservation (TDEC) from the Volkswagen (VW) Diesel Mitigation Fund, which the city has matched with an additional $300,000.

The funds will held replace seven medium and heavy-duty diesel vehicles with four propane, two CNG, and one all-electric vehicles allowing the city to begin exploring alternate fuel and all-electric in this class size. The project will also begin the process of reducing critical greenhouse gas emissions, and provide the necessary knowledge to expand these efforts to the remainder of the city’s fleet.