WEST LEBANON — Dartmouth College officials are defending the school’s proposal to build a biomass plant, saying wood chips are best suited to heat its Hanover campus and that the proposed system would serve as a bridge to new technologies expected to be available down the road.
While biomass is “imperfect,” wood chips are cleaner to obtain than natural gas and significantly cheaper than other renewable fuels, Josh Keniston, the college’s vice president of institutional projects, said last week during a meeting with Valley News editors and reporters.
Dartmouth wants to discontinue its heavy reliance on fossil fuels as it faces repairs to the school’s more than 120-year-old power plant, though the new system would still rely on some “biofuels” for heating on the coldest days of the year.
“If what people are advocating for is that we just kick the can down the line and do nothing, stay on No. 6 (heating oil), I don’t think that makes sense,” Keniston said. “We’ve done that for a really long time and I think what we need is a plan that helps us in the near-term and sets us up really well for the long-term.”
Keniston was responding to calls from scientists and activists who have called on the college to rethink its plans to build the heating plant, which is part of its overall $200 million “green energy plan.” A major component of the plan, which is already underway, involves converting Dartmouth’s steam-heating system to a more efficient hot-water system.
About 60 people earlier this month attended a forum where many asked Dartmouth to consider heat pumps, solar and wind technology instead.
A second forum on the proposal is scheduled for 6 p.m. on Tuesday inside the college’s Filene Auditorium.
“Anytime you burn something, whether it’s biomass or No. 6 fuel oil, combustion is a problematic process as it relates to the release of carbon and the impact it has on the climate,” Keniston acknowledged.
But, he said, alternatives such as natural gas release large amounts of methane in the drilling process, and other forms of energy aren’t capable of heating Dartmouth buildings on their own, he added.
“We actually spent a fair bit of time looking at what we call ‘non-combustion options’ and from a technical perspective, we couldn’t make them work,” Keniston said.
The college estimates it would cost five times more to build a heating system utilizing solar, geothermal and heat pump technology, while operating costs would be three times greater than biomass. Such a system also would require 60 acres to implement, 15 times larger than the three 4-acre sites now under consideration, Keniston said. Two are along Route 10 just north of the central campus, and one is on Route 120 near the Lebanon line.
Even then, Dartmouth expects it would require some form of combustion fuel to keep the college warm, largely because solar isn’t abundant in the winter, when heat is most needed, he said. Along with burning wood chips, the college plans to use a 32-megawatt “biofuel” boiler as backup for winter’s coldest nights. Keniston said the boiler could burn most liquid fuels but would likely use some form of biodiesel.
Using wood chips derived from the stems, branches and other forms of the logging considered unmarketable also could allow Dartmouth to control where the fuel comes from, and ensure forests are treated using sustainable practices, Keniston said.
The college plans to source its wood from within a 90-minute drive time of Hanover and will have “very detailed specifications” on how the wood is to be harvested, he said.
And there ought to be plenty of wood available. The biomass plant is expected to only use 3% of the “low-grade residue” now being created in the region, Keniston said.
“Our plant is providing a market for pieces that are being harvested in some way and either being left behind of maybe are going to mulch or something along those lines,” he said.
While it’s not yet sure which route delivery trucks will take, Keniston said traffic is expected to have a “marginal impact,”
Dartmouth’s existing power plant requires six deliveries of No. 6 heating oil on the coldest nights. By comparison, officials estimate the new biomass plant could need about 15 shipments of wood chips to handle the load on the coldest days and nights.
Although Keniston presented the biomass plant as a sustainable heating source expected to last 30 years, some critics aren’t convinced.
Studies show that burning biomass emits more carbon than coal and forests, which hold as much carbon as the atmosphere, don’t grow back quickly after being cut, said William Schlesinger, one of three prominent scientists to express concern about the plan in a July letter to the college.
“I think the plan to do this, to replace oil with biomass, may have been generated in a time when we thought the world was running out of oil and the Middle East would hold us hostage,” said Schlesinger, a 1972 Dartmouth graduate and emeritus dean of Duke University’s Nicholas School of the Environment. “And while the world will eventually run out of oil, that’s not happening right now.”
Schlesinger, who attended a webinar on the biomass plan earlier this month, encouraged Dartmouth to stick with fuel oil as it replaces its steam system with hot water, which is expected to gain the college a 20% increase in efficiency.
Then it should retrofit buildings to be more energy efficient. By the time those are complete, Schlesinger said, cheaper, more environmentally friendly fuel technologies should be available, he said.
Keniston acknowledged those technologies are coming, and said Dartmouth’s new heating system is designed to hook up to a renewable fuel source at the end of the biomass plant’s roughly 30-year lifespan.
“Our projection is that we will need some form of combustion and biomass for the next 20 to 30 years,” he said.
Tim Camerato can be reached at tcamerato@vnews.com or 603-727-3223.
Correction
The next forum on Dartmouth’s biomass proposal is scheduled for 6 p.m. on Tuesday, Aug. 13, inside the college’s Filene Auditorium. An earlier version of this article reported an incorrect date.