Mesa State reaps financial benefits from its new energy system
It was good for the environment and good for sustainability. The millions of dollars in savings weren’t a bad selling point, either.
Mesa State College’s idea to install a geothermal heating and cooling system has saved it 62 cents per square foot since it began operating in 2008. With four buildings hooked into the grid, the college is set to save $350,000 this year and even more next year when a residence hall near Bunting Avenue and the newly-renovated Houston Hall hook into the system.
The system was installed as part of a $2.1 million contract between the college and Chevron. Chevron performed an energy audit on the college a couple years ago and suggested ways the company could make all Mesa State buildings more efficient, including the installation of a geothermal system.
Within 15 years, the college expects to recoup $3 million from the improvements, and it will pay for the Chevron contract gradually with the savings.
The biggest savings so far have come from retrofitting lights and installing motion-sensors that turn lights off when no one is in a room, according to College Vice President of Finance Pat Doyle. But the geothermal system is no slouch in the savings department, which is part of the reason the college jumped on the idea, according to Doyle.
“We wanted to be good stewards and try to reduce our carbon footprint, and at the same time we were trying to reduce costs,” Doyle said. “We had little control over utility costs (rising), so we had to work on the consumption side.”
The geothermal system cuts down on energy costs by heating and cooling buildings by bypassing traditional sources such as natural gas or electricity and regulating air temperature through an underground system of 300 to 500 wells connected to a heat pump.
The naturally tepid temperature below ground combined with a system of wells and coils that heat or cool the well water help the geothermal system run, Mesa State Facilities Service Director Kent Marsh said.
“In the winter, we’re taking heat from the earth and pumping it into the building. In the summer, we’re pumping it from the building into the heat pump. It’s just moving one thing into another,” Marsh said.
When it’s cold outside, the water in each well is heated by a coil containing refrigerant fluid before a fan in the heat pump blows heated air out of the wells and through air vents.
When temperatures rise, hot air is pumped out of the buildings and into the well system, where the hot air is cooled in the well water. Small doses of the cooled air are pumped back into the building to regulate oxygen and carbon dioxide levels.
Senate Bill 51, which passed in 2007, required all buildings built using state dollars for at least 25 percent of the project cost had to strive for maximum energy efficiency. That led institutions across Colorado to take a look at new ways to cut energy costs.
Mesa State installed a solar array for a projected savings of $100,000 over the next 25 years, uses Green Seal-certified bathroom and facial tissue products made from 100 percent recovered fibers, encourages water conservation, and has a bike-share program. The college also removed trays from its cafeteria in 2009 to cut down on the time the dishwasher is in operation and to save 41,000 gallons of water annually, and it is recycling cardboard boxes after they’re used for moving items into the College Center, which opens later this month.
Like the college’s contract with Chevron, School District 51 has a contract with Trane to make $10.7 million in energy-efficient improvements. As with the Chevron contract, District 51 will pay Trane back incrementally with energy savings.
Cal Clark, District 51 director of maintenance and operations, said the district decided to contract with Trane after brainstorming ways to improve the learning environment in schools and lower utility bills during a December 2008 meeting with school board members and district leaders.
The three-phase project will enter its final phase Nov. 10 and wrap by June 30. The last phase will include water conservation projects, some deferred maintenance work, lighting retrofits at three schools, waste efficiency measures at 11 schools, some mechanical retrofitting projects, and the installation of “blackout” systems at Dos Rios and Pear Park Elementary Schools. The blackout systems will turn off all lights when the school is not in use to save money and deter vandalism, Clark said.
The first two phases of the district’s efficiency work included retrofitting more than 32,000 lights, electrical work, replacing inefficient boilers, insulating pipes, streamlining digital control of building functions and putting that system online, replacing 43 convection ovens with natural gas ovens, and installing solar tubes atop Pear Park and Dos Rios. The tube system tracks the sun across the sky to stream the maximum amount of sunlight into classrooms to limit the days teachers have to turn on electrical lights.
Like the college, which, according to Doyle, would like to explore attaching the Maverick Pavilion to the geothermal system and installing an off-site “solar garden,” Clark said District 51 plans to keep looking at efficiencies.
“We have an obligation to run as efficiently as we can. We’re not going to rest,” he said.