Editor's Note: This is the third in a series of five articles about Dartmouth and the environment.
Anyone who has seen the plume of smoke coming from behind the Hopkins Center may have guessed that Dartmouth has some sort of power plant, but they probably wouldn't guess that it generates around 315 million pounds of steam a year and supplies 40 percent of the College's electricity.
Dartmouth's power plant is the source of most of the energy and heating consumed on campus, which is no slight amount, according to Associate Vice President of Facilities, Operations and Management John Gratiot.
It operates by burning approximately 110,000 barrels of oil a year to generate steam, Gratiot said, which is used to heat and cool buildings. The steam is then run through turbines to generate electricity, making it what is known as a co-generation power plant.
"We only make as much electricity as the steam we are using," Gratiot said. "In this sense we are a pure co-generational plant."
Structuring the plant's system in this way is advantageous because it makes it more efficient.
"The plant is 80 percent efficient because the steam is used twice," Gratiot said. "If we used the steam only once through it would only be about 60 percent efficient."
With all the oil that the plant uses, however, it still emits harmful pollutants like carbon dioxide and sulfur dioxide. The plant could be more environmentally friendly, Environmental Studies professor Richard Haworth said, if it switched to burning wood chips rather than oil, which it has the ability to do.
The use of oil, Haworth said, might not be problematic in the short run, but it could cause long term problems.
"In the long run, we have to move away from an unsustainable energy source," Haworth said.
In the next twenty years, he predicted, oil will become scarcer, and once supplies are depleted, it will be a benefit that the plant has the capacity to burn other types of fuel. Also, he noted, if wood chips are burned, the carbon they produce could be absorbed by trees, while the waste produced by oil cannot.
Haworth believes that the College has not switched to the wood chips because as it is now, "the system is economical and it works effectively."
According to Gratiot, the use of wood chip fuel was discussed in the '80s and again more recently, but was set aside because of certain obstacles involved in the conversion.
"We have a boiler, installed in 1983, designed to be able to be converted to solid fuel, but there would be huge investments to be made," Gratiot said. "It would be a very significant expense."
One problem would be finding space for the sheer volume of wood needed. It would have to be brought in by truck in the form of logs and then chipped at an installation added for that purpose, Gratiot said.
"You would need a lot of wood chips, 20 truckloads a day," Gratiot said. "That would bring a lot of traffic into town."
A more viable alternative, he said, would be to burn wood on an offsite location in an airtight container, then condense the exhaust into an oil that could be burned at the plant.
Although using wood as a fuel could make the College more self-sufficient, since Dartmouth owns land that could provide timber, Haworth admitted that the present plant is "consistent with good practices" and is fairly up to date.
The original plant was built in 1898, Gratiot said, making only steam for heating, and by 1910 had its first generator.
"Over the years we have continuously added newer technology," Gratiot said. "We have the newest kinds of boiler controls and monitoring equipment."
Efficiency could be helped, he noted, if people were more conscious about turning off lights and appliances. More care could reduce the 51 million kilowatt hours of electricity a year that the College consumes.
"We want people to think about wasting energy," Gratiot said.
