It's a bright idea to use energy-efficient lighting for your home or business. But you’ll see a couple different type of light bulbs available for purchase, how do you know which type of bulb is the right choice for you?
On this page, you'll learn about the different types of light bulbs you can buy, including energy requirements and how to dispose of them.
Light-Emitting Diode (LED) light bulbs produce light more efficiently than other bulbs, use the least amount of energy, and
produce the least amount of heat! Since they’re so energy efficient, if you replace out five incandescent bulbs for LEDs, you could save up to $75 per year!
How do they work? They use electric current passed through a semiconductor to illuminate the light emitting diodes (light source). LEDs convert 90% of the electricity you put into them to produce visible light.
How long do they last? LEDs can last 25,000+ hours.
How much energy does it take to light this bulb? LEDs take 9 watts of energy to get to a brightness of 800 lumens.
Where do I get these bulbs? LED bulbs can be found at any store that sells lighting fixtures. Due to new efficiency standards for light bulbs, LEDs are going to be taking up most of the light bulb aisles!
How do I know which LED bulb to choose? Make sure you know what fixture you’d like to use the bulb in. (indoors or outdoors? Dimmable or non-dimmable?). Once you know that, look for those features, the ENERGY STAR label (this means the bulbs are certified to deliver efficiency and performance), the color temperature for the bulb, and the bulb’s brightness (shared in lumens)!
How do I dispose of them? LEDs do not contain mercury and can be disposed of in regular trash similar to incandescent bulbs.
Compact fluorescent light bulbs (CFL) are more energy efficient but harder to dispose of due to the mercury inside of them.
How do they work? CFLs rely on an interaction between electric current and argon and mercury to produce light. They convert 85% of the energy you pump into them to make visible light, but the mercury inside makes them hard to dispose of safely.
How long do they last? CFLs last about 10,000 hours.
How much energy does it take to light this bulb? CFLs take 14 watts of energy to get to a brightness of 800 lumens.
How do I dispose of them? CFLs must be disposed of safely because they contain mercury, which is hazardous to human health and the environment. CFLs should be brought to the Household Hazardous Waste section of the I-66 Transfer Station or the I-95 Complex, where the mercury will be removed, and the remaining lamp components will be recycled. Be sure to transport CFLs carefully so they do not break in transit.
Incandescent light bulbs may be the “traditional” light bulb, but they are the least energy efficient and most expensive to use over their lifetime.
How do they work? They contain a metal filament which heats up and glows once hot. The glow then produces visible light. Only 10% of the energy pumped into an incandescent bulb produces light; the other 90% is given off as heat.
How long do they last? These types of bulbs burn out the quickest and have the shortest lifespan (~1,000 hours).
How much energy does it take to light this bulb? It takes 60 watts of energy for this bulb to produce a brightness of 800 lumens.
How do I dispose of them? Incandescent light bulbs should be disposed of in the trash. Wrap them in a bag or paper to prevent them from breaking in the trash.
Cost Savings
LED light bulbs, in addition to being the most energy-efficient bulbs available, they last the longest and are the least expensive option over the lifetime of the bulb. In fact, if you purchase an LED to replace an incandescent bulb, the initial investment will pay for itself back in less than 1 year. Below is a chart about the annual operating cost and lifespan.
| Lamp Type | Wattage for 800 Lumens | Annual Usage Per Lamp* | Annual Operating Costs** | Hours (Lifespan) | Lifetime* |
| Incandescent | 60 W | 55 kWh | $6.07 | 1,000 | 1.1 years |
| CFL | 14 W | 13 kWh | $1.41 | 10,000 | 10.9 years |
| LED | 9 W | 8 kWh | $0.91 | 25,000 | 27.2 years |
* Assumes lamps are used 2.5 hours per day.
** Assumes an electricity price of $0.11/kWh, which is approximately what most Fairfax County residents currently pay. The actual price will depend on several factors, including your electric provider - Dominion Virginia Power or the Northern Virginia Electric Cooperative.
Wattage vs. Lumens
Before LEDs, purchasing light bulbs used to be based on wattage numbers. "Watts” can often be confused with "brightness", but it is actually a measurement of the energy used by the bulb. A 60-watt bulb isn’t necessarily brighter than a 45-watt bulb, it just uses more energy.
When purchasing LED light bulbs, we recommend looking for lumens: more lumens = more light. Use the chart below to make an informed decision that will fit your lighting needs. On the left, find the watts for a standard, incandescent bulb, and what their typical brightness equates to in lumens. For example, if you are looking for an energy-efficient alternative to match the brightness of a 60-watt incandescent light bulb, you should look for an 800 lumen LED light.
| Incandescent Bulb (Watts) | LED Bulb Brightness (Lumens) |
| 40 | 450 |
| 60 | 800 |
| 75 | 1,100 |
| 100 | 1,600 |
| 150 | 2,600 |
Color Temperature (Kelvin)
Not sure what color temperature means? Light bulbs can come in a range of color temperatures, measured in degrees Kelvin (K). When referring to standard white light bulbs, low temperatures (K measurements), correspond to warm white light, which is typically used in the home. High temperatures correspond to cool white light, sometimes called "daylight", which is often used for workspaces. The chart below can help explain the different color temperatures.
