Which Lightbulbs Save the Most Money? -- Savings Experiment

With high energy costs driving up electricity bills and an ever-widening array of lighting choices available at the local hardware store, it can be hard to pick the best -- and cheapest -- lighting option. In today's Savings Experiment, we'll explore the available lighting choices and pick the one that's best for you.

The first light bulbs -- and the ones that are used in most homes -- are incandescent bulbs. Basically, these bulbs follow Thomas Edison's original design: an electrical current runs through a filament in a glass bulb. The filament then heats up, emitting light, as well as a lot of heat.

In terms of base price, incandescent bulbs seem like the cheapest option: a four-pack costs somewhere between $2 and $3. But the cost goes up once you screw them into a lamp: incandescents use between 20 and 100 watts per hour, which translates into 2-12 kilowatts per month. Also, they don't last too long: most bulbs work for between 750 and 1,000 hours, or 6-8 months, which means that they need to be replaced fairly often.

They are also the most convenient lighting option. Incandescent bulbs can be used with dimmer switches and are available in a wide variety of shapes and sizes, making them a perfect fit for almost any lighting design. They are easy to dispose of and, after more than 100 years of use, most of the bugs have been worked out.

However the move to more energy-efficient lighting means certain incandescent light bulbs are being phased over the next few years. As of January 1, 2012, the 100-watt incandescent light bulb will no longer be manufactured for use in the United States. On January 1, 2013, the production of 75-watt incandescent bulbs will cease to exist; and in 2014, 60 watt and 40 watt bulbs will be phased out, according to The National Electrical Manufacturers Association, a trade group for the lighting industry. (In California, each of these dates go into effect a year earlier).

The current lightbulb leaders are compact fluorescent lamps or CFLs. First developed in the early 1980's, CFLs didn't become really popular until the last few years. Part of the reason for this is cost: although their price has dropped in recent years, CFLs still run $2 and up per bulb, about four times as much as incandescent bulbs. On the other hand, CFLs also last a lot longer: most will run for between 6,000 and 10,000 hours, or 4-7 years of normal use. In fact, given that they will run for 6-10 times longer than incandescents, their basic price is up to 50% less than incandescent bulbs. And CFLs also use a lot less electricity: a 26-watt compact fluorescent puts out as much light as a 100-watt incandescent, but only uses about a quarter of the electricity.

CFLs also have their downside: depending upon the brand, they may flicker a bit, and they cannot be used with a traditional dimmer switch. Worst of all, they contain mercury, which can make disposal difficult: if they are thrown in a standard landfill, the mercury can leach into the groundwater, presenting an environmental hazard. However, as the curlicue bulbs grow more popular, more and more stores are offering on-site recycling.

The brightest option is probably light-emitting diode (LED) bulbs. A nine-watt LED bulb puts out as much light as a 40-watt incandescent, but will last for 25,000 hours. Depending upon usage, this can be up to 23 years. They also don't present the same mercury hazard as CFLs, which makes them easier to throw away. Then again, with 23 years of life, chances are that you'll throw away your lighting fixtures more often than you'll throw out your bulbs.

Unfortunately, LEDs are prohibitively expensive. They run about $40 apiece; most LED bulb makers are small companies with limited production runs. On the bright side, General Electric and Sylvania have both released LED bulbs. While the new lights will probably be expensive in the beginning, competition should bring prices down.

In the meantime, though, the basic choice is still between incandescents and CFLs. Over the course of seven years, the lifetime of a CFL, the bulb will use about $25 worth of energy; with the $2 initial price thrown in, this translates into a total cost of about $27. By comparison, an incandescent bulb will use about $96 worth of electricity in the same period of time. It also will need to be replaced about eight times, leading to an overall cost of more than $100 dollars. Given the costs and limitations, your best -- and brightest -- choice is a CFL.