If you're like most people, you've probably never added up a year's worth of utility bills. And yet you've undoubtedly heard lots of efficiency tips that can save you so-and-so percent on energy use. So what does this mean? According to the U.S. Department of Energy, the average American household spends about $2,200 per year on utility bills. That's no small change. But can 15 simple improvements really add up to $1,000 in energy savings? According to government estimates, yes, they can.