Lighting is one of the biggest energy gobblers in your house, eating up between 10% and 20% of your total electric bill. But it’s also one area of the home where a minimal effort can yield major returns. Simply replacing standard incandescent light bulbs with compact fluorescents can lower operating costs by as much as 75% per bulb. And in places where you can’t-or don’t want to-switch to CFLs, you can use higher-efficiency incandescents and even make your existing conventional lighting cheaper to operate. When new federal legislation takes effect in 2012, all light bulbs will have to meet tougher energy-efficiency standards. But with a few small changes, you can start saving money right now.