Green Mountain – By the Numbers

Our customers make a difference for the environment every single second they use cleaner energy from Green Mountain.

All of our impact statistics are, by nature, estimates. The carbon dioxide (CO2) avoided estimates are based on the average CO2 emissions avoided when producing electricity from renewable resources like wind and solar instead of the usual mix of fossil fuels, nuclear and a much smaller amount of renewable energy. Here’s a brief explanation of how we arrive at these estimates:

  • In 2016, Green Mountain customers avoided an estimated 8.6 billion pounds (lbs) of CO2.1 Dividing this number by the number of seconds in a year gives us an estimate of the CO2 avoided per second. This amount of CO2 avoided is added to the counter each second. Here’s the math:
8,695,672,748 lbs CO2 avoided per year ÷ 31,536,000 seconds per year = 275 lbs CO2 avoided per second

To help put that number in context, we also report the avoided CO2 pollution in terms of equivalent number of cars taken off the road, households turning off their lights for a year or trees planted. Here’s how we do it:

  • A typical tree takes in 8,397 lbs CO2 over its 60-year lifetime.3 Dividing 275 lbs of CO2 by this number gives us an estimate of the avoided CO2 equivalent number of trees planted that is added to the counter each second. Here’s the math:
275 lbs CO2 avoided per second ÷ 8,397 lbs CO2 per tree = 0.033 equivalent trees planted
  • Through 2016, Green Mountain customers avoided 54.4 billion lbs of CO2.1 That’s like planting 6.4 million trees (or taking 5.9 million cars off the road for a year or 49.8 million households turning off their lights for a year). Each second, the counter adds 275 pounds of CO2, and 0.033 trees to these baseline numbers. Here’s the math:
54,419,303,719 lbs CO2 avoided + 275lbs CO2 avoided per second = estimated cumulative CO2 avoided
6,480,803 trees + 0.033 trees = estimated cumulative trees planted


1 Estimate based on our customers’ electricity usage, how much of their electricity comes from new renewable resources, and applicable CO2 emission rate from the U.S. Environmental Protection Agency’s (EPA’s) Emissions and Generation Resource Integrated Database (eGRID).

2 Estimate based on U.S. Department of Energy annual average household electricity end-use data and eGRID national average CO2 emission rate.

3 U.S. Department of Energy. Method for Calculating Carbon Sequestration by Trees in urban and Suburban Settings.