A total of 413 schools, or about 10 percent of U.S. higher education institutions — where about 30 percent of full-time U.S. college students are enrolled — have signed a climate pledge from Second Nature, an organization committed to accelerating climate action through these institutions. By signing, schools vow to achieve carbon neutrality as soon as they can, according to Tim Carter, the organization’s president.
Some large institutions have been at the forefront of efforts toward sustainability, but the push is growing as colleges of all sizes join the fight. Many are also adopting solutions specific to their local community or environment.
Ohio University turns scraps to soil
Ever wondered what happens to all the uneaten food in dining halls? Where does your food go after it’s carried away on conveyor belts?
The answer is grim. Most food waste generated in college dining halls ends up in the trash and then a landfill. Food waste overall is the single most common material dumped in landfills and incinerated in the United States, according to the Environmental Protection Agency.
But at Ohio University, the kitchen is just the beginning of your leftover food’s journey.
After students leave the dining hall, trained staff separate food left on serving trays. Nearly five tons of food waste per day is collected from dining halls around campus and brought to OU’s $2 million composting plant.
The plant, which opened in 2009, features a rooftop solar array that provides about 75 percent of the system’s energy, according to Steve Mack, the university’s director of facilities management. Its rainwater harvesting system provides all the water used at the facility.
By 2012, the university was composting nearly 100 percent of its dining hall waste.
“It’s the right thing to do; food waste going towards composting is much better than going to a landfill,” Mack said. “We’ve taken what was a waste stream and turned it into a resource.”
The campus has one of the most efficient university food services in the country, despite the unique challenges posed by the all-you-care-to-eat facilities. About 99 percent of campus food waste is post-consumer — left over from trays — while pre-consumer food waste from the preparation process makes up less than 1 percent.
The school uses an in-vessel compost system that combines organic waste — including meat, dairy and landscape waste — with bulking agents in which naturally occurring microorganisms break down material. It’s the largest known in-vessel system at any college or university in the nation. The material is then trapped in an enclosed environment where temperatures, moisture levels and airflow are monitored for two weeks. Once removed from the in-vessel system, the compost is placed in narrow piles outside for three to four months.
Food scraps are turned into nutrient-rich soil, which is used for landscaping and filling in intramural athletic fields. The soil has also been shared with the local school district.
All told, the university composts about 612 tons of waste a year. That’s equivalent to the weight of about 102 full-grown male elephants, according to the university.
Composting saves the university $14,000 each year in landfill fees and $22,000 in annual fertilizer costs, said Sam Crowl, associate director of sustainability at Ohio University.
Ball State University fires up a greener system for heating
When engineers tell you that you can’t replace a university’s 70-year-old heating system with the largest geothermal plant in the country, you’d probably heed their warning.
But Jim Lowe didn’t.
“For an engineer, it’s a once-in-a-lifetime opportunity to build a system that’s beneficial to the environment and efficient for use of energy around campus,” said Lowe, who is associate vice president for facilities planning and management at Indiana’s Ball State University.
Lowe wanted to replace the coal-fired boiler heating system, which burns coal to create steam and heat, with a geothermal power plant — which draws heat from the earth and turns it into hot water, which, in turn, is used to heat buildings.
In 2009, BSU began the daunting task — and Lowe’s team had to start from scratch.
The team building the system drilled approximately 3,600 holes that were 500 feet deep under sporting fields and parking lots, digging up streets and sidewalks to place nearly 5.3 million feet of piping.
It took eight years, but the school said the process caused very little disruption to students’ day-to-day activities. Now the largest geothermal system in the country runs hidden under the school and provides heat and cooling to “50-plus major buildings” on campus, Lowe said.
Completed in 2017, the $83 million project has cut BSU’s carbon footprint in half — helping the school get halfway to its goal of becoming carbon neutral. Lowe estimates that BSU now saves $3 million in energy costs each year.
BSU’s project has inspired nearly 65 higher education institutions to start building their own geothermal plants.
Colleges and universities “have a responsibility to protect our environment and pay it forward for future generations,” Lowe said.
University of Iowa uses resources from its backyard
Most people who stumble across the inedible outer cover of an oat grain think nothing of it, but the Quaker Oats production facility in Cedar Rapids, Iowa, looked at piles of leftover oat hulls and saw a potential energy source. The company asked the nearby University of Iowa for help. And the school jumped in.
The University of Iowa became a green-energy champion by harvesting biomass energy using resources in its backyard — the oats facility is just 25 miles away. Biomass energy is generated by burning living or once-living organisms to create heat or electricity: Think of wood, corn or soy.
Oat hulls were once a treat for farm animals, but UI began buying the crop two decades ago. Now, the university buys nearly 40,000 tons of oat hulls each year from the Quaker Oats facility, reducing its reliance on coal.
“It’s hard for anybody to find much fault in what we’re doing because it’s good on cost, it’s good for the environment, it’s good for local businesses. It’s a good thing all around,” said Ben Fish, director of utility operations at UI.
Oat hulls aren’t the only thing UI is burning to make energy.
In 2015, UI began planting and harvesting acres of a billowing, bamboo-like grass that grows up to 12 feet high. The miscanthus grass is chopped, collected and combined with renewables and non-recyclables, like the waxy backing of labels and paper, to mimic coal when burned. The university partners with a Wisconsin-based energy company that uses the grass as a primary ingredient to create renewable energy pellets. The university also contracted with farmers within a 70-mile radius to plant the grass and expand their acreage.
Months into the worldwide pandemic, the empty university exceeded its goal of 40 percent renewable energy by 2020.
UI is making strides toward a new goal: going coal-free by 2025. Fish thinks it is “absolutely attainable.” He also said oat hulls will continue to be the “foundation” of UI’s future carbon reduction planning.
In January, the EPA ranked the school No. 2 on its list of top college and university green-power users — surpassed only by the University of California system. The 1,900-acre campus gets 84 percent of its energy from green power.
“All colleges and universities are trying to reduce their carbon impact, and we all just have a different way of doing it,” Fish said. “We’ve been able to make use of what’s around us.”
University of Minnesota at Morris moves with the wind
The University of Minnesota at Morris sits in a rural part of the state, surrounded by prairie and forest areas. The small liberal arts college with fewer than 1,300 students is about 2½ hours west of Minneapolis.
The school “in the middle of everywhere” uses a localized hybrid approach to renewable energy. Wind turbines, a biomass gasification facility and a solar array generate about 70 percent of the electricity used on campus daily. Annually, the school produces more electricity than it needs.
Two 230-feet-high wind turbines with 135-foot blades tower over the university. The turbines generate 10 million kilowatts of electricity per year, but the university uses only about 5 million kilowatts. The surplus power is exported to provide renewable energy to Morris, a city with a population of about 5,000.
The two turbines supply more than 60 percent of the annual electricity used on campus. The university achieved carbon neutrality in electricity for the first time in 2020 in large part thanks to those turbines, said Troy Goodnough, the school’s sustainability director. There are many instances when all the university’s electricity comes from wind turbines, which can generate electricity with wind speeds as low as 7.8 mph and as high as 29 mph.
UMN Morris was the first public university in the country to have the large-scale wind turbines constructed, according to university officials.
“What we try to do is be on the front edge of showing what a model of rural sustainability looks like,” Goodnough said.
Additional renewable energy comes from 636 individual solar panels and agrivoltaic solar farms. Agrivoltaic farming combines solar energy generation and agriculture.
Next to campus, cows graze the land and crops flourish in a field shared by an array of eight-foot-high solar panels. The 240-kilowatt agrivoltaic array is expected to generate more than 300,000 kilowatt-hours each year.
Arizona State University proves big schools can make big changes, too
Achieving carbon neutrality tends to be less daunting for smaller colleges and universities because they emit lower emissions compared with larger ones. Larger technical universities have nearly 10 times as many students and produce roughly four times the carbon emissions per student compared with smaller schools, according to an MIT study.
But those odds didn’t deter Arizona State University, with a total campus enrollment of more than 75,000 students, from pledging to reach zero greenhouse gas emissions by 2025. It’s a goal the school crushed six years early.
“We decided to move the goal six years early in recognition of the worsening climate crisis,” said Marc Campbell, executive director of sustainability at ASU.
Between 2007 and 2017, the university increased energy efficiency in new building construction by using regenerative and sustainable materials, installing efficient cooling and heating systems, and maximizing natural light sources and shielding, Campbell said. Older buildings were retrofitted with efficient light fixtures, water-conserving shower heads and updated cooling systems.
The university built 90 on-site solar installations, which provide enough green energy to power an estimated 18,000 homes at once, according to Campbell. ASU also partnered with the Arizona Public Service, the state’s largest electric utility, on a solar farm that generates about 65,000 megawatt-hours per year of green electricity.
The school’s emissions decreased, and it reduced its carbon footprint by more than 30 percent.
By 2018, ASU was on the brink of fulfilling its pledge and began purchasing carbon offsets to meet its goal early. Carbon offsets are investments in projects that reduce or work toward the removal of CO2 emissions from the atmosphere.
The university became carbon neutral in scope 1 emissions, or emissions over which it has direct control, and scope 2 emissions, or indirect emissions, including from energy purchased by the university.
“Sustainability is now really in the DNA of ASU,” Campbell said. ASU’s School of Sustainability was the first of its kind when it opened in 2006, according to the university.
ASU has become a sustainability model for larger institutions despite increasing the size of its campus by 40 percent and increasing on-campus enrollment by 35 percent since 2007.
In January, the EPA ranked ASU No. 3 on its list of top college and university green-power users, right behind the University of California system and the University of Iowa. ASU gets 77 percent of its electricity from green energy.
ASU’s next sustainability goal: to be completely carbon neutral, including transportation-related emissions, by 2035. “It is attainable, but we still need to think through what the full road map looks like to get us there,” Campbell said.