It's not just homeowners who need to turn off a few lights to save energy.

During an Energy Efficiency summit Monday, 3M, Energy Star and several other area companies schooled businesses on how they could cut their usage, too.

The all-day workshop, at the 3M Innovation Center in Maplewood, shared the secrets of success when it comes to saving energy. Along with 3M, companies ranging from Cargill and General Mills to Xcel Energy and Davisco presented at the conference.

Energy conservation is "really a journey. There really is no endgame in the world of energy," said Jon Russett, General Mills supply chain energy manager.

3M, which co-hosted the event with Energy Star, advised companies to start with the basics, such as swapping out high-energy bulbs for florescent ones. The Maplewood conglomerate touted its initiative to exchange lights across 35 million square feet of factory space and its comprehensive energy-saving plans for 240 plants in 39 countries.

3M energy manager Steve Schultz said its success came from having an energy plan, measurement and assessment tools, as well as upper-management and energy teams who adopt Energy Star tips. Schultz added that follow-through was critical so plans aren't forgotten and gains lost.

Jack Johnson, an environmental engineer for Brown Printing Co., agreed. The large magazine printer thought it had done its job for the environment years ago when it swapped out incandescent factory lights for florescent lights. But two years ago, the newly hired Johnson realized that florescent lights had improved, so he traded 36-watt bulbs for 25-watt bulbs, which saved even more money. He also started shutting off lights and press motors during down times.

Brown Printing hooked up with Energy Star and eventually spent $6.5 million on more efficient plant equipment that cut energy costs. Brown's energy plan saved enough to help it weather one of the worst economic downturns in publishing, Johnson said.

General Mills employees learned to turn off the lights, power down conveyers and motors, and installed equipment-monitoring software that turned yellow when a machine was off and using extra energy.

"It was a flag that we were using more energy than you should be," Russett said.

Combined, the efforts cut General Mills' energy use by 10 percent in the last few years. The goal is to get to a 20 percent reduction by 2015.

Greg Jason, Cargill's corporate environmental manager, said Cargill ramped up global energy conservation programs starting in 2000. One tool the company used was to turn its food and wood waste into fuel. Rice husks, sawdust, and shells from cocoa beans and sunflower seeds were burned for fuel.

"Today 13 percent of our energy comes from renewable energy sources," Jason said.

Dee DePass • 612-673-7725