The world could change at the flick of a switch -- a light switch, that is.

Penn State made a commitment Sept. 16 to join Energy Star's campaign, "Change a Light, Change the World," a program created to encourage people to make online pledges to replace at least one incandescent light bulb in their homes with a compact fluorescent light bulb (CFL).

"The idea is to get people thinking about the energy they use at home," said Wendy Reed, campaign director of Energy Star, a government-backed program that advocates for environment protection.

The "Change a Light, Change the World" campaign started seven years ago by bringing manufacturers and utilities together to save energy used on lighting, Reed said. Although the program is a call to action for people to change bulbs in their homes, the campaign isn't focused solely on light bulbs, she said.

"We start with a light bulb because it's the most frequently replaced product," Reed said. "We hope that when they replace bigger items in their homes they'll think about energy efficiency."

Penn State is one of more than 400 organizations--including ski resorts and school districts--that has signed up to encourage online pledging for the campaign, Reed said.

The university is one of about 30 universities involved, providing a new outlet through which to expose the campaign's message, she said.

This year the campaign is hoping to garner 500,000 pledges, but the trend thus far indicates the total will exceed that figure, Reed said.

"My goal is not to get a lot of numbers," she said. "My goal is to get meaningful numbers."

At Penn State, "Change a Light, Change the World," is focused on replacing incandescent bulbs in homes and student apartments rather than campus buildings, since most buildings on campus already use CFL bulbs, said Michael Prinkey, energy program engineer at the Office of Physical Plant (OPP). More efficient bulbs not only save energy but also residents' money on electric bills, Paul Ruskin, OPP spokesman, said.

"CFLs use about 25 to 30 percent the energy [of incandescent bulbs] for the same amount of light," Prinkey said.

University Park's main campus electric bill is about $1 million per month, Prinkey said. It is estimated that five to six percent of tuition goes toward paying for energy annually.

Students can reduce this percentage by replacing the bulb of a desk lamp brought from home with a CFL, Ruskin said.

The university has already implemented energy-saving equipment on campus that reduces energy consumption for lighting, toilets and heating, said Laura Miller, energy program engineer at Penn State. Miller said swapping older, inefficient equipment cuts down on energy consumption, and the money saved is used to buy more energy-efficient tools.

"We don't realize that when we take a hot shower for 30 minutes that we're contributing to greenhouse gases," Miller said. "Equipment change can do a lot, but behavior change can do so much more."

CFLs can be purchased anywhere that a regular incandescent lightbulb is sold, Reed said. The best deals can be found at The Home Depot, Lowe's and Wal-Mart, Reed said, but not all CFLs are as energy efficient as bulbs with the ENERGY STAR label.

Students interested in making a pledge to change a light can visit http://energy.opp.psu.edu.

"If you want to do something for your planet, the easiest thing to do is replace an old incandescent bulb," Ruskin said.