Energy Efficient Lighting


One of the easiest ways to reduce home energy bills is to install more efficient lighting. While lighting typically accounts for only about ten percent of the average home's energy expenses, today's energy efficient lighting products can cut that portion of your energy costs by 75% or more. They also produce less waste heat, helping you save even more on summer air conditioning expenses. While energy efficient lighting products may be more expensive initially, their long life and reduced energy consumption make them much more cost effective in the long term.


Lighting Efficiency

Energy efficiency, whether it applies to lighting or other types of energy use, is a measure of "energy in" versus "energy out". With electric lighting, the energy in represents the electric power in watts, while the energy out is light, measured in lumens. So the standard measure of lighting efficiency is expressed in lumens per watt. The higher the lumens per watt, the more light you get for your energy dollar.

When electric energy is converted to light, some of the energy is wasted in the form of heat. The total energy output (light plus waste heat) will always equal the energy input. Therefore, increasing the light output will reduce the waste heat by the same proportion. Since it is this heat that causes lamps to fail or "burn out", more efficient lamps will also last longer. The long-term savings on replacement costs, coupled with reduced energy costs, make energy efficient lighting an economic "win/win".


Energy Efficient Incandescent Lamps

The traditional incandescent lamp or "light bulb" has been the primary source of lighting in homes for many years. Although incandescent lamps are very inefficient, converting the majority of the electric energy into heat, they have a low initial cost and produce a high quality of light with excellent color rendition. They produce a warm light similar to sunlight, and many people prefer them for reading or task lighting. If you need or prefer incandescent lamps for some of your lighting needs, remember than not all incandescents are created equal. Long-life or "Energy Saver" incandescents have a higher lumens per watt than standard light bulbs, and last longer due to the reduced waste heat. Halogen bulbs are a type of incandescent that is slightly more efficient than the standard type. Halogen lamps produce a bright and tightly focused light that is well suited to spot illumination. Halogen torchiere fixtures are not recommended, as they use very high wattage bulbs that burn very hot and can start fires.

Recent developments in incandescent lighting technology include special reflective coatings and improved filament materials that produce less waste heat. These and other improvements can result in 25-30% less energy consumption for the same amount of light.


Compact Fluorescents

Compact fluorescent lamps are roughly four times as efficient as standard incandescents and last up to ten times as long. They are available in a wide variety of sizes and shapes, and can be installed in most common lighting fixtures. Over the last several years, prices have dropped dramatically, reducing one of the long-standing barriers to more widespread use.


Hard-Wired Fluorescents (Linear Tube Type)

Unlike compact fluorescents, the traditional linear tube type of fluorescent lamp requires its own type of light fixture. The fixture includes a ballast, which controls the lamp's operation. This type of lamp is very popular in commercial installations like offices, but is also well suited for certain areas of the home. They are an efficient option for lighting garages and basements, and for under-counter lighting in kitchens. Energy consumption is comparable to CFLs, and lamp life is equal or somewhat longer. When purchasing linear tube-type fluorescents, look for fixtures with energy-efficient electronic ballasts and lamps designated T-8. These lamps are from 25 to 40 percent more efficient than the traditional T-12 lamp.


LEDs (Light Emitting Diodes)

LEDs or light emitting diodes are small solid-state light sources that are illuminated by the flow of electrons through a semiconductor material. LEDs have been in use since the 1960s, mainly in instrument panels and electronics. By grouping them in clusters with diffuser lenses, manufacturers have now adapted them for use in residential lighting.

LEDs are much more efficient than even fluorescents, and can last more than twice as long. Because they are so efficient, they produce very little waste heat. They are manufactured and sold as an integrated lamp/fixture, and are currently more expensive than fluorescents. However, the technology is still expanding and many experts expect LEDs to revolutionize lighting over the next decade.

Another type of solid-state lighting, called OLED (organic light emitting diode) is currently under development. This technology uses thin sheets of carbon-based compounds that glow when current is applied through electrodes. While not yet available, OLEDs will likely take the form of a film applied to a wall or ceiling to illuminate a room.

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