Greenhouse Gas Equivalencies Calculator

What does the scale of your company’s greenhouse gas emissions look like? The Environmental Protection Agency offers a nifty tool to help you visualize your impact on the environment.


Global climate change is an increasingly serious concern for all of us. National leaders are working together to find solutions and alternatives to these issues, though progress is not always easy to see. As individuals and corporations, we can take the initiative to make an impact in our own spheres of influence to realize immediate results.

First, it helps to understand and visualize your current impact on the environment. The Environmental Protection Agency (EPA) has created a neat calculator that estimates your carbon dioxide emissions and translates them from abstract measurements to concrete equivalencies the average person can understand. We’ve included a sample scenario below to help you use the calculator.

This is a good way to truly understand the scale of your individual contribution to climate change. Then, we can move on to setting significant and achievable goals based on this estimate.

Emissions Polluting

Here is a typical scenario for our customers:
Assume we have 20 traditional metal-halide street lights in a parking lot that run 10 hours per day, every day of the year.

A typical metal-halide bulb in a parking lot application will consume 458 watts (W) per hour for 10 hours, or 4,580 watt hours (Wh) per day. The common unit of measurement for electricity usage is kilowatt hours (kWh), so we take 4,580 Wh and divide it by 1,000 to get 4.58 kWh per day. This means that one metal-halide light bulb operating for 10 hours a day is consuming 4.58 kWh of electricity per day.

Since we have 20 lights, we multiply 4.58 kWh times 20, resulting in 91.6 kWh of energy consumption in one day. To calculate energy consumption for one year, we multiply 91.6 kWh times 365 days and get 33,434 kWh per year for the scenario.

Now open the EPA calculator and begin at step 1. Select “Energy data” and choose “kilowatt hours avoided” as your unit. Then we put the value 33,434 into the amount box and get our equivalency results. 

23.7 metric tons of carbon dioxide emissions per year

But what does 23.7 metric tons even look like? The EPA is a step ahead of you and has created this handy-dandy visual comparison:

EPA comparison chart

Avoid Greenhouse Gas Emissions

By replacing 20 traditional metal-halide street lights with 20 of our renewable lighting systems with LED light fixtures, our typical customer could significantly reduce their environmental impact. Since our renewable lighting systems are self-sustained by solar and wind energy, they use no energy from traditional on-grid energy sources and effectively produce zero carbon dioxide emissions.

A single decision can prevent emissions equivalent to the consumption of 2,666 gallons of gas or the burning of 26,189 pounds of coal every year by simply replacing inefficient street lights. As an added bonus, avoiding the use of on-grid energy knocks out monthly utility bills and saves you money while you save the environment.

Reduce Greenhouse Gas Emissions

If replacing your existing street lights doesn’t make sense for you, an LED retrofit is a good alternative option to reduce carbon dioxide emissions. LED lights are much more efficient, provide better light quality, and last around 50,000 hours of operation – compared to 10,000 hours of a metal halide bulb. Because of the improved technology, you can switch out a 458W metal halide fixture with a 150W LED fixture and maintain, or even improve, the existing level of light. This cuts your energy consumption by a third and offers almost 70% savings on your electricity bill.

In the same scenario from above, switching 20 old 458W metal halide lights to new 150W LED lights would reduce your annual greenhouse gas emissions from 23.7 metric tons to 7.8 metric tons per year. Therefore, instead of the equivalent of consuming 2,666 gallons of gas, the carbon emissions are reduced to the equivalent of 873 gallons of gas every year. A quick update of your lighting can have a huge impact on your individual energy costs and the greater environment with very little effort.

Making an investment in better lighting drives an immediate reduction in greenhouse gases and stands as proof of your efforts to help build a more sustainable society. Contact us today to see how you can minimize your carbon footprint and leave a better Earth for future generations.

 Updated February 11, 2021 – minor changes

Updated October 6, 2021 – Adjusted sample scenario and subsequent calculations from 250W metal halide bulb to 458W metal halide bulb to reflect a more common type of fixture.  Added information about LED retrofits.

Updated August 3, 2022 – Replaced greenhouse gas equivalency calculator results to reflect the new look of the calculator and made minor wording changes to clarify.