Yale’s residential college energy consumption fell by 10 percent this academic year, exceeding activists’ original goal by 5 percent and doubling the amount of renewable energy that the administration will purchase as a reward for conservation.

The year’s 10 percent improvement just satisfies the criteria for the University to purchase renewable energy certificates that will offset two-thirds of the residential colleges’ power consumption. Under the Greenhouse Gas Reduction Strategy, announced in October, the administration rewards every 5 percent improvement in energy conservation with monetary support for the renewable energy market equivalent to one-third of residential consumption.

Since activists’ original goal was a 5 percent improvement for this year, the latest numbers represent a significant victory, Sustainability Director Julie Newman said.

“I’m really pleased that we went beyond our goal, and I’m looking forward to working with students in the year ahead to achieve another 5 to 10 percent reduction,” she said.

During the summer, officials will conduct a review of the year’s data before deciding whether to revise their stated three-year goal of a 15 percent decrease, Newman said.

But Dominique Gomez ’07, a former coordinator for Yale’s Student Taskforce for Environmental Partnership, said she thinks much of the improvement this year resulted from the installation of energy-saving equipment. STEP’s work will become more challenging as opportunities to make changes in infrastructure decrease, she said.

“The first 5 percent are the easiest,” Gomez said. “Towards the end it will be a lot more difficult to keep cutting down, so we have to make sure that we don’t become stagnant in our quest for sustainability.”

Year-to-date improvement stood at only 1 percent in November, prompting concern that the University would have trouble making significant changes in its consumption levels. But the slow start resulted mostly from unusually hot temperatures, former STEP coordinator Evan Suzuki ’07 said, and the weather turned in activists’ favor in the spring. Conservation efforts also gained momentum after winter break, he said.

“I was confident that things would be a lot better second semester because we were really able to get to work on our first day,” Suzuki said. “It took us a lot longer to get mobilized at the beginning of the academic year.”

The student component of the University’s energy campaign involved efforts from three activist groups, including the distribution of an “energy pledge” in which students promised to reduce their power consumption. The activists also worked to educate students on ways to save energy. Suzuki said the “Yale Unplugged” campaign, which urged students to disconnect their appliances over vacations, contributed significantly to the improvement.

The University has solicited bids from three companies to sell the renewable energy certificates. The exact nature of the certificates will depend on the type of energy and market location that Yale chooses to support, Newman said.

“We’re exploring costs and opportunities from the Northeast through the Midwest, and a portfolio that includes a range of renewable energy sources,” she said.

Potential recipients of Yale’s support include companies that provide wind, solar, biomass and hydroelectric power, Newman said. A decision is expected by the end of the 2006-’07 fiscal year, she said.

The cost of the certificates — which cover 10,000 megawatt hours of Yale’s energy consumption — will depend on the type of energy produced. Yale Provost Andrew Hamilton said the purchase will not strain the University’s budget, even though it is double the original goal.

“The beauty of this challenge is that it does not negatively affect the budget,” he said. “Funds saved through energy conservation can be reinvested in more renewable forms of electricity production.”

Yale also made strides this month in its conservation efforts related to transportation, Associate Vice President for Administration Janet Lindner said. The administration struck a deal with local biodiesel distributors to supply the University’s shuttles with cleaner fuel, she said.

“It burns a lot clearer, and it’s certainly much more of a sustainable fuel,” she said. “We’re going to be conducting lots of initiatives to make sure that our transportation system is as environmentally friendly as possible.”

The new fuel will be 20 percent biodiesel and 80 percent ultra-low sulfur diesel.