LED Light Bulb Versus Compact Fluorescent Light

The light-emitting diode (LED) has been around for many years for applications such as digital clocks, flashlights and traffic signals, but hasn't been used for common household lighting until fairly recently. Here is how the LED bulb compares to the compact fluorescent light, a lighting technology that is making serious inroads in the household lighting market.

LED Bulb

An LED bulb is an energy-efficient solid-state lamp that employs multiple light-emitting diodes to generate light. The LEDs are grouped in clusters with diffuser lenses and produce light when electrons move around within its semiconductor structure when current is applied. The light emitted by an LED bulb tends to be more directional (less diffused) than light emitted by CFL's and incandescent bulbs.

Compact Fluorescent Light (CFL)

A CFL consists of a tube which is curved to fit into the space of an incandescent bulb and a compact electronic ballast in the base of the lamp. When mercury vapor inside the tube is excited by an electric current, this produces ultraviolet light, which is re-radiated as visible light when it strikes fluorescent phosphors coated on the inside of the bulb.

Energy Efficiency

One of the big advantages of LED bulbs is their energy efficiency. LEDs use less power (watts) per unit of light generated (lumens) than CFLs or incandescent lights. To produce the same amount of light produced by a 60 watt incandescent bulb, an LED bulb only requires 6-8 watts versus 13-18 watts for a CFL. LED bulbs do not get as warm as CFLs, one of the reasons they are more energy efficient.

Life Span

LED bulbs last up to 10 times as long as compact fluorescents, and much longer than incandescents. Some LED bulbs last up to 50,000 hours. CFLs typically have a rated lifespan of 6,000 to 15,000 hours.

The life of a CFL is significantly shorter if it is turned on and off frequently. It is recommended that fluorescent lamps be left on when leaving a room for less than 15 minutes to mitigate this problem. CFL's often require a minute or so to warm up and reach their full brightness. The life of an LED bulb is not affected by on/off cycling. Furthermore, they reach their full brightness immediately.


Although the prices of LED bulbs have dropped considerably in recent years, they are still much more expensive than CFL bulbs. As LED bulb use expands and production efficiencies improve, their prices will continue to drop. However, even with their relatively high prices today, LEDs are less expensive to operate than CFLs over the long haul due to their much greater energy efficiency.


Because they are solid and do not have a filament or gas-filled enclosure, LED bulbs hold up well to jarring and bumping. CFLs are less durable because their glass tubing can break fairly easily, although they are more break-resistant than conventional incandescent light bulbs.

Environmental Impact

CFLs contain small amounts of mercury, a toxic chemical, so they should be recycled rather than just thrown into the garbage. LEDs have no mercury.

Other Considerations

The light output of a CFL is negatively impacted by low temperatures. At extremely low temperatures, say below -10 degree Fahrenheit, a CFL may not work at all. LEDs are not affected by low temperatures.