By now you know that switching off the lights when you’re not using them will save both energy and dollars on your electric bill. WRONG! Turns out, if you’re using CFL bulbs you may actually be better off leaving the lights on! Whaaaaa? Carter Oosterhouse recently shared this little tidbit on the Rachael Ray show, prompting us to check into just how CFLs actually work. Here’s the deal.

CFLs work by using electric current to generate (invisible) ultraviolet light which in turn creates visible light by disturbing the phosphor (a fluorescent coating) inside the bulb. This process takes a little more energy up front but then uses 75% less compared to a traditional bulb. This is also why CFLs take a little longer to reach full power.

Carter recommends that if you plan to leave a room for 15 minutes or less, leaving the CFLs on in the interim will actually be MORE energy efficient because it will keep you from expending the initial startup energy when you return and flip them back on. You could, he says, save up to $150 a year. We’re not mad at that!

Learn more about CFLs at Energy Star .

Thanks for the tip, Huffington Post.