How many Fairfax County residents does it take to change a lightbulb? Perhaps the more important and less ridiculous question is...how much impact does it have when one Fairfax County resident changes a lightbulb? What about when every Fairfax County household changes a lightbulb?

It’s seemingly one of the smallest and simplest climate actions you can take, changing out your less efficient lightbulbs for light-emitting diodes, or LEDs. You can feel good knowing you’re going to save money and spend less time replacing bulbs around your home. You can feel even better knowing you’re contributing to a very big impact with this small action. Let’s take a look at the numbers.

The most recent demographic report from the Fairfax County Department of Management and Budget estimated that in 2020, the county had approximately 417,500 households. We did some math and learned that if every one of those households changed out just one lightbulb, we could make a pretty big impact. In math class we learned that it’s important to always show your work, so we’re pleased to offer you an infographic followed by our back of the napkin calculations based on the assumption that the lightbulb in question in each Fairfax County household is on for 10 hours each day of the year.

If every Fairfax County household swapped out one compact fluorescent bulb (CFL) for one LED…

[(13.5 CFL watts – 9 LED watts) / 1,000] * (365 days * 10 hours) = 16 kWh saved annually per one CFL changed to an LED

If every household in Fairfax County changed one CFL bulb to a LED bulb, we would save 16 kWh * 417,500 = 6,680,000 kWh annually.

6,680,000 kWh is the equivalent of…

• 4,734 metric tons of CO2
• The greenhouse gas emissions from 1,030 passenger vehicles driven for one year
• 11,897,476 miles driven by an average passenger vehicle
• The carbon emissions from 860 homes’ electricity use for one year

CFL bulbs contain small amounts of mercury. When making the switch from CFLs to LEDs, be sure to recycle your old CFL bulbs properly. Recycling prevents the release of mercury into the environment and allows for the glass, metals, and other materials in fluorescent bulbs to be reused. CFLs should be brought to the Household Hazardous Waste section of the I-66 Transfer Station or the I-95 Landfill for recycling. Be sure to transport CFL bulbs carefully so they do not break in transit.

If every Fairfax County household swapped out one incandescent bulb for one LED…

[(60 incandescent watts – 9 LED watts) / 1,000] * (365 days * 10 hours) = 186 kWh saved annually per one changed bulb

If every household in Fairfax County changed one incandescent bulb to a LED bulb, we would save 186 kWh *417,500 = 77,655,000 kWh annually.

77,685,000 kWh is the equivalent of…

• 55,033 metric tons of CO2
• The greenhouse gas emissions from 11,969 passenger vehicles driven for one year
• 138,308,159 miles driven by an average passenger vehicle
• The carbon emissions from 9,996 homes’ electricity use for one year

Such a small action. Such a big impact. Imagine the scale if every household changed not one, but every lightbulb? Greenhouse gas reduction opportunities are all around us. Make a change that matters. Change your lightbulbs to LEDs.