Harvard’s first ever conference on campus sustainability kicked off yesterday with a pledge from University President Lawrence H. Summers to double the Green Campus Iniatiative’s loan fund for campus conservation projects to $12 million.

Harvard Vision 2020: A Bridge to Campus Sustainability, coordinated by the Green Campus Initiative (GCI), an interfaculty organization, highlights the best practices that the University has adopted over the past five years, from purchasing renewable energy to using “green” cleaning solutions to planning and building green buildings.

The loan fund supports projects that reduce energy use and increase environmental sustainability. Recent examples include the installation of motion sensor lights in classrooms on campus.

According to GCI organizers, the loan fund has generated over $2 million in savings per year, and the projects supported by the fund have reduced campus greenhouse gas emissions by almost 70 million pounds annually.

“The best investment in the University is not the endowment but the Green Loan Fund,” said Summers, referring to the savings generated by the fund. The University’s $25.9 billion endowment has averaged more than 15 percent growth over the past 14 years.

Summers delivered the keynote address along with Boston Mayor Thomas M. Menino at the Harvard Business School yesterday afternoon.

The three-day conference, to which more than 580 people from the Harvard community and the Boston area have registered, features panel discussions, workshops, and tours of the University’s green facilities.

The conference seeks to convey to the University community “all the efforts Harvard is taking in the direction of environmental sustainability,” said Thomas E. Vautin, co-chair of the GCI.

Summers commended undergraduates for promoting environmental awareness and practices on campus over the past few years and said that their efforts have helped him understand the importance of environmental sustainability.

“If I had to plan expansion to Allston four years ago, environmental sustainability would not have been one of my top priorities,” Summers said.

Students attending conference events yesterday said that it has made them rethink their own behavior.

“I didn’t realize how much water we use and how much energy it takes to treat the wastewater,” said Robin S. Bellows ’09 after attending a workshop on water use at the University. “It makes me think again about everything. Every extra minute I spend in the shower really makes a difference.”

“I love that the school is invested in, and willing to put out the effort and money to, support sustainability,” said Spring Greeney ’09, who has registered for the conference.

“People were thrilled about the conference,” said Leith Sharp, director of the GCI. “They seem to be very happy about what’s going on at Harvard.”

The conference continues through Saturday. Environmental attroney Robert F. Kennedy Jr. will speak today and the President of the U.N. Foundation Timothy E. Wirth will address the conference tomorrow.