Going off to college used to require little more than packing a couple of suitcases. These days, it’s an excuse for a buying binge.

According to the National Retail Federation, U.S. college students and their parents expect to spend $3.6 billion this year outfitting their dorm rooms with the latest electronic equipment, small appliances and color-coordinated home furnishings. That’s up nearly 40 percent since 2004, according to the federation’s annual spending survey.

The millennial generation and their indulgent parents may only be looking to bring along to school the considerable comforts of home. But some think this kind of conspicuous consumption isn’t just unseemly, it’s bad for the planet.

All those things that need to be plugged in suck up energy. All that cheap plastic and polyester is manufactured in a process that uses tons of nasty chemicals. And what’s worse, at the end of each school year, mountains of this stuff get left behind and end up in landfills.

The alternative? Going green.

“You have to sit back and think, ‘How much is really necessary?'” said Philip Kreycik, coordinator of Harvard University’s undergraduate Resource Efficiency Program, which promotes sustainable living in the school’s dorms. “The bottom line is, as much as you can simplify, that’s the best way to go.”

While a survey of local colleges revealed no formal programs to promote a more environmentally friendly dorm living, green ideas are taking hold at a growing number of schools across the country.

Students at Colorado College, for example, run a sustainable-living theme house. At Humboldt State University in California, one student residence has a bike-powered generator and a greenhouse that helps heat a living room. At Oregon State University, students can have their dorm rooms certified “green” by meeting criteria for recycling efforts and water and energy use.