If you’re still lighting your home with traditional incandescent light bulbs, you’re wasting money and energy. Let’s look at your options to become more energy efficient and put a few dollars back in your pocket every month.
Incandescent bulbs have been in use for well over 100 years, and we’re so accustomed to them that we accept their shortcomings as a given. Inside the glass bulb of an incandescent lamp is a metal filament through which electricity flows. Electrical resistance in the filament causes it to get hot, and it gives off light as a side-effect. In fact, only 5% of the electricity an incandescent lamp consumes becomes light. The rest turns into heat, which is mostly wasted. Incandescent bulbs have a short lifecycle, typically 750 hours, so they need frequent replacement. On the positive side, they’re inexpensive. The cost of a typical 100-watt bulb is about $0.50.
Halogen incandescents are a relatively recent development. They work much like a traditional incandescent bulb, except that the filament is inside a small quartz capsule inside the bulb that contains halogen gas. Through a fairly complicated chemical process, the halogen gas allows the filament to get hotter than in a traditional bulb while consuming less energy, thus generating more light. Halogen bulbs use about 30% less energy than standard incandescents, but cost about $1.50 each for the same amount of light as a 100-watt traditional bulb. Typical lifecycle is about 2,000 hours.
Most of us are now familiar with compact fluorescent light (CFL) bulbs. They work just like the straight, 4- or 8-foot long fluorescent tubes that are ubiquitous in commercial buildings. There is no filament inside them: instead, it is the gas in the tube that lights up in response to an electric current that flows between electrodes at both ends. In CFLs, the tube is relatively small and it’s curled up in a spiral, but otherwise it works the same. In some CFLs, the tube is hidden inside a glass or plastic bulb to make it look and act more like a conventional incandescent bulb.
CFLs use only a quarter the energy of an incandescent bulb for the same amount of light, and they last more than ten times longer – typically 10,000 hours. At a cost of about $2.00 each, they’re more expensive to install, but produce savings on energy and replacement costs. One serious downside of CFLs is that they contain hazardous mercury and must be disposed of carefully.
LEDs, or light-emitting diodes, are the most recent lighting option. The convert electricity directly into light without filaments or gas, so they are far more efficient than incandescents, and they produce almost no heat. An LED with the same light output as a 100-watt incandescent bulb consumes about 20 watts. That’s a little better than a CFL (about 23 watts), but the kicker is in lifecycle. The LED will last about 20,000 hours, twice as long as a CFL. At this time, they cost about $10.00 each, which is a lot more expensive to install than any of the alternatives, but the savings add up due to energy efficiency and lower replacement costs.
According to the US Department of Energy, using a typical 60-watt incandescent bulb for two hours per day will cost $4.80 in annual energy bills, given average energy costs. In comparison, a halogen bulb producing the same amount of light will cost $3.50; a CLF will cost $1.20; and an LED will cost $1.00. By replacing just the five most frequently used lights in your home with more efficient bulbs, you can save $75 per year.
In practice, bulbs of all types vary greatly in cost, and their efficiency is affected by the fixture they’re used in. But the bottom line is clear: you’ll save money and energy with the newer types of bulbs, and LEDs will reduce the chore of changing dead bulbs to a rare occurrence.