Gunnison County, Colorado Reduces Energy Use in County Buildings By 10% Annually

John Cattles, Sustainable Operations Director for Gunnison County, Colorado, uses a number of unique methods to help the county achieve its goal of reducing energy use in county buildings by 10 percent annually and reducing GHG emissions countywide by 20 percent compared to 2005 levels by 2030.

Last year, the county retrofitted the Family Services Building in Gunnison including the installation of a ground source heat pump (GSHP) system to take advantage of the heat of the earth from 300 feet deep underground. The county courthouse also utilizes a GSHP system and uses one-third the energy of the previous courthouse as a result, according to Cattles.

“We drilled several holes almost 300 feet into the ground and we pump water through pipes in those holes. It is a closed system; the water just goes down and back up and along the way either rejects heat or absorbs it from the earth, depending on whether we are in heating or cooling season,” writes Cattles. “The water from the ground is typically 52 degrees and our heat pumps can harvest heat out of that and deliver 90-plus degree air to a room. The water then returns to the ground cooler and absorbs heat from the earth and comes back up again to repeat the cycle. The process can be reversed in cooling mode. GSHP systems can be up to 400 percent efficient, meaning for every one unit of electricity we use pumping water or running heat pump compressors we can get four units of heat energy out. They work great in commercial buildings that have very consistent and large loads.”

He also oversees the county’s transition from gasoline and diesel to compressed natural gas to power its trucks and buses. Currently, the county has 11 CNG vehicles on the ground, including one RTA bus, and has received grant funding to purchase five more light CNG trucks in 2018.

Homeowners in the valley can retrofit aging homes to be safer and more energy-efficient through the GVHEAT program, administered by the Gunnison Valley Regional Housing Authority (GVRHA). Following an energy audit, assessors recommend renovations to improve energy efficiency and point homeowners in the direction of low-interest loans or rebates that might be available, depending on their income.