Also known as CF bulbs, Simran says these last 10 times longer than a regular bulb—and you can save as much as $5.40 per bulb per year. Their original squiggly shape is now shifting to a more traditional bulb to fit in more fixtures, Simran says. They can also be dimmed, come in colors and throw a softer glow. "You're looking for a yellow spectrum light, not the white one," she says. "That's not the light that you're looking for [at home]."

They do contain mercury, so Simran says it's important to dispose of them correctly. Contact your local municipality to find a program in your area. Simran says many big-box stores also have takeback programs. Find out how much money you can save using a programmable thermostat.