BRUNSWICK – It was midafternoon, but the February sun was still glinting off the 48 solar panels on the roof of Thorne Hall here. Downstairs, the online display that monitors the system’s performance showed the panels were producing energy, helping to warm the 4,800 gallons of water that Bowdoin College uses each day at this dining hall.

Work remains to be done, but by summer the array is expected to supply more than half the hall’s hot water. Just as important, it will keep 91,520 pounds of carbon dioxide out of the atmosphere each year, by not burning natural gas.

Bowdoin cares deeply about carbon. The school is working to honor the American College and University President’s Climate Commitment, a five-year-old initiative aimed at achieving “carbon neutrality” on the nation’s campuses. A total of 677 schools have signed on so far.

In Maine, the commitment has so far been signed by the presidents of 15 schools. These institutions account for 75 percent of all college students in Maine, and give the state one of the highest participation rates in the country.

Only one U.S. school has achieved climate neutrality — College of the Atlantic in Bar Harbor.

Bowdoin has pledged to become carbon neutral by 2020, even as the school expands in size. Becoming carbon neutral means removing from the atmosphere as much of the gases associated with climate change as each school puts in. The prime targets are so-called greenhouse gases, particularly carbon dioxide, which is a byproduct of burning fuel.

DEFINING COLLEGE’S CARBON FOOTPRINT

The program is based on a conviction that the planet is threatened by man-made climate change and that college campuses can take a leadership role in helping to stabilize the atmosphere.

That premise isn’t universally accepted. Some people, including politicians, business interests and scientists, dispute the notion that humans are contributing to climate change.

In a statement, the college presidents’ group said the science is well established, with much of the research done at member schools. Rather than engaging in the debate, however, it chooses to focus on the benefits of moving toward carbon neutrality. These include creating jobs, saving money, strengthening national security and encouraging innovation.

The first step in becoming carbon neutral is defining a starting point, a carbon footprint. Schools tally their heating, gasoline and power bills. They conduct inventories and use verifiable assumptions and calculations to estimate their greenhouse gas emissions for a given date.

Bowdoin determined that the school released 24,000 tons of carbon dioxide in 2008. The biggest sources came from electricity use, 44 percent, followed by heating and vehicles, 42 percent. The rest came largely from employee commuting, transmission line losses and travel.

The commitment program defines climate neutrality as no net releases of these gases. Schools can become carbon neutral by eliminating net emissions on campus. They also can compensate for any remaining emissions by cutting or avoiding releases off-campus, such as buying electricity from hydroelectric dams.

Bowdoin participates in a market that trades “renewable energy credits” from sources that include dams in Lisbon Falls and Rumford and a wind farm in Mars Hill. It will spend $35,000 this year to buy credits.

Schools that counterbalance emissions with credits and so-called carbon offsets must enter into deals that can be verified. They are required to trigger a reduction in gas emissions that wouldn’t otherwise have happened.

Offsets aren’t always perfect solutions. For instance: Power from the Mars Hill wind farm goes to Canada, not New England. Still, Bowdoin favors local offsets that are easier to verify, said Catherine Longley, the school’s senior vice president for finance and administration.

“It’s an investment in Maine,” she said.

‘YOU JUST KEEP CHIPPING AWAY’

Expanded natural gas lines in Brunswick have allowed Bowdoin to tap a cleaner-burning, less-costly fuel. In November, the school replaced a 46-year-old oil-fired boiler at its central steam plant with one that also can burn natural gas. The plant heats 54 buildings totaling 1.3 million square feet.

The conversion will eliminate 797,000 gallons of fuel oil a year, making a big dent in carbon output.

The school will soon add a steam turbine generator to the plant. Electricity made with waste steam will supply 9 percent of the school’s needs, and trim greenhouse emissions by 18 percent. This project costs more than $3 million, but is expected to save $230,000 a year.

The steam plant conversion will remove 1,200 tons a year of carbon. But other reductions will come from hundreds of small fixes.

“It’s just incremental,” Longley said. “You just keep chipping away, project by project.”

Small projects include: Changing 3,875 incandescent light bulbs to compact fluorescent. Setting 600 personal computers to sleep mode. Replacing the school’s 61 vehicles with hybrids.

Beyond changing technology, Bowdoin also wants to use its educational mandate to change behavior. To meet the 2020 goal, it says, everyone on campus must share an awareness of carbon neutrality. That means developing energy-saving habits, such as shutting down computers and turning off lights.

MAKING THE STUDENT BODY AWARE

One tool to raise awareness is an online dashboard. It displays real-time power consumption at school buildings and compares it to past periods and other buildings and residences.

Energy awareness already is high at College of the Atlantic, an environmental liberal arts school with 350 students. The school was one of the first in the country to sign the carbon neutral commitment, in 2006. It reached the goal a year later. While some schools are installing occupancy sensors that turn off lights in empty rooms, the college relies on student behavior.

“Our students are kind of on automatic when it comes to energy,” said Donna Gold, a school spokeswoman.

The college’s newest buildings — 20 percent of the campus — are super-insulated and use a wood pellet boiler for heat and hot water. A small wind turbine helps provide electricity for a school-run farm.

Carbon emissions are calculated for events including lectures and concerts, and student travel. The college counterbalances these emissions with offsets, including a program that provides electricity at truck stops to keep big rigs from idling their engines.

Getting to net zero is more complicated at a large public school, such as the University of Southern Maine. The school has set 2040 as an outside date to reach climate neutrality.

Heating is the largest contributor to carbon dioxide emissions at USM. This winter, the school greatly reduced the impact by converting central heating plants in Portland and Gorham from oil to natural gas. Gas is less expensive now than oil, and the switch is expected to save $315,000 next year and pay for itself right away. It also will cut carbon emissions by 1,048 tons.

Such numbers may sound abstract to students, who don’t directly pay energy bills. But Bowdoin College has found a way to make them more relevant.

On a clear but frigid day last week, the school’s online dashboard was tracking the energy output of the solar array on Thorne Hall. Based on heat equivalent shortly before 1 p.m., the panels were generating enough energy to cook 258 hamburgers.

 

Staff Writer Tux Turkel can be contacted at 791-6462 or at:

tturkel@pressherald.com