The Metropolitan Nashville Airport Authority has finished installing a geothermal lake plate cooling system – the largest in North America.
Started in February, the project has reduced energy consumption at Nashville International (BNA) from 1.056 kilowatts annually to 0.525 kilowatts – a 50 percent reduction.
“This is a remarkable project for its scope, ingenuity and efficiency,” says Rob Wigington, president and CEO of MNAA. “The airport authority is committed to making sustainability an integral part of our business model. Not because sustainability is easy — rather, it is often a complex process — but because the benefits to our airports, the region and our environment are overwhelmingly positive. This historic project will significantly reduce our electricity usage and potable water consumption, which will result in substantial annual utility savings. This is the very essence of sustainability.”
The system was installed in a former rock quarry that has an average depth of 150 feet and contains about 1.5 billion gallons of water. At 50 feet, water is 50 degrees Fahrenheit year round.
The system circulates water through closed looping and geothermal heat exchangers in the quarry to the BNA terminal’s central plant. This provides cooling for the entire terminal. The use of this system is expected to result in an annual savings of 1.3 million kilowatt-hours and 30 million gallons of potable water. Plus, utility savings for MNAA are anticipated to be more than $430,000 a year.
