There are plenty of options for saving energy at work, from energy-efficient office equipment to redesigning workspaces. But the most effective power saver is still the light switch. On the average, 40 percent of at-work power use goes toward artificial lighting. Much of that total is spent lighting empty offices and parking areas.

Take stock of what you really need. Studies suggest that bright security lighting really doesn't provide much in the way of additional protection — but it certainly impacts wildlife and your monthly power bill. Put that money into locks and alarm systems instead. And pocket the savings!