Many choices exist for efficient lighting that provide light that is similar to traditional incandescent lighting in terms of color rendering while using less energy, producing less heat, and potentially providing a longer life than incandescent bulbs.  The most common types of high-efficiency lighting are compact fluorescent lamps (CFLs), pin-based fluorescent tubes, and light emitting diodes (LEDs).

Most energy efficient lighting products come in "warm" colors to match the yellowish light of incandescent bulbs but can also come in "cooler" colors that provide whiter or bluer light. The wide variety of shades of white light, ranging from yellowish to white to bluish white light allows one to customize the mood of any space. Light color is measured on a temperature scale referred to as Kelvin (K). Lower Kelvin numbers mean the light appears more yellow while higher Kelvin numbers mean the light is whiter or bluer. For example:

• For a warmer light, look for bulbs marked 2700-3000K
• For a whiter light, look for bulbs marked 3500-4100K
• For bluer white light, look for bulbs marked 5000-6500K

Figure 1. The ability to choose a light color range allows one to customize the lighting of any space.

Lighting represents about 20% of a home’s electricity bill. Installing or switching from less efficient bulbs such as traditional incandescent bulbs to high efficiency lighting such as CFLs and LEDs is one of the easiest steps to take to save on one’s energy. CFLs and LEDs use approximately three quarters less energy as traditional incandescents to produce the same amount of light.

Compact Fluorescents (CFLs)

CFLs produce light much more efficiently than incandescent bulbs using about 3/4 less energy than incandescents. The efficiency gap is due to the fact that approximately 90% of the total energy used by an incandescent bulb is not utilized to generate light but given up in the form of heat compared to a CFL where only about 30% of the total energy used is given up as heat.

Figure 2. CFLs come in a wide array of shapes and sizes.

Due to the fact that CFLs use a ballast to help "kick start" and then regulate the current once the electricity starts flowing, they can take longer than other types of lighting to reach full brightness. However, CFLs have come a long way since their first inception and many of today’s CFLs use advanced technology, come in smaller shapes, are faster to light up, are more efficient, produce nice light color, cost less, and are available in a variety of sizes, shapes and colors. However, even with these advancements in CFL technology some limitations still exist.

Finding equivalent CFL bulbs that match some traditional incandescents in terms of bulb size, light output, light package, and aesthetics can sometimes be challenging. For example, an existing light fixture may not allow for a swap out of an incandescent for an equivalent CFL due to space limitations or an equivalent CFL bulb simply may not exist to replace a specific bulb type (e.g.  decorative).  And, while there are a wide variety of CFL bulbs that are available in the standard medium base, there is currently much less choice and variety with CFL bulbs that come in intermediate or candelabra bases. 

Most photocells, motion sensors and electric timers are not designed to work with CFLs. Always check with the manufacturer of the control for compatibility.¹

When installing dimmable CFL lighting, make sure to install a dimmer switch that is compatible.

Solid State Light Emitting Diodes (LEDs)

LEDs, or light–emitting diodes, are a type of Solid State Lighting (SSL) that produce visible light very efficiently. Common LED colors include red, green, amber, and blue which are widely used as signal lights and indicator lights, like the power button on a computer. However, since there is no such thing as a “white” LED, different color LEDs are mixed or covered with a phosphor (yellow) material that converts the color of the light to various familiar hues for general lighting applications in our homes and offices. 

Figure 3. Heat sinks are integrated into LED bulb assemblies.

Due to the fact LEDs don’t radiate heat the way traditional bulbs do, the heat produced from the power going into it must be drawn away– normally using a heat sink device (which absorbs heat produced by the LED and dissipates it into the surrounding environment) to prevent the LED from overheating and burning out. Proper removal of heat from the LED is one of the single most important factors in the longevity and successful performance of the device over its lifetime. 

The useful life of LED lighting is defined differently than incandescents or CFLs due to the fact that LEDs themselves typically do not “burn out.” Instead, LEDs do experience lumen depreciation, meaning that over the life of the bulb, the amount of light produced decreases and the light color appearance can shift. Therefore, a LED product’s “lifetime” is based upon when its light output is predicted to decrease by 30%.

In many applications LED lighting is able to use light and energy more efficiently due to the fact that LEDs are “directional” light sources - meaning they emit light in a specific direction (unlike incandescent and CFL bulbs which emit light-and heat-in all directions). Therefore, lighting design should reflect a layout compatible with current LED technology and if replacing non-LED lighting with LEDs, select lighting that will maintain or enhance overall lighting quality.

When installing dimmable LED lighting, make sure to install a dimmer switch that is compatible.

Installing High-Efficacy Lighting

1.   In existing homes, select high efficiency lighting that is rated for its installed location (i.e. interior or exterior application) and that provides proper light level, color rendering, and functionality for its location and purpose.

2.   In new construction specify high efficiency lighting in a lighting plan that is part of the overall design package, then inspect to verify correct lighting products were installed.

3.   Select the right dimmer for the specific lighting being installed; some dimmers are specifically rated for CFLs or LEDs.