A builder in Connecticut who installs a condensing propane tankless water heater instead of an electric storage tank unit can save the equivalent of 480 pounds of carbon dioxide (CO2) per year. That’s the same as taking about 540 miles from an average gasoline-powered car off the road.

A builder in Missouri who makes the same switch, however, has an impact nearly 12 times greater, saving 5,690 pounds of CO2 or 6,408 miles on the road.

The two scenarios illustrate the impact of the local electrical grid on efforts to reduce the CO2 emissions of our homes. Although more renewables are brought online each year, most of our electricity is still generated by power plants burning natural gas or coal. And when you factor in efficiency losses at the power plant or during transmission, an on-site fuel source like propane can have a significant positive impact on a home’s carbon footprint.

In the map below, we’ve calculated the impact on CO2e (the amount of greenhouse gases that have an impact equivalent to CO2) of switching from an electric storage tank water heater to a propane condensing tankless water heater in each state. Hover on your state to see the impact.

CO2e savings with propane tankless water heating

How it’s calculated

The carbon emissions savings for each state are calculated using the Energy Planning Analysis Tool (EPAT), an online calculator developed by the Gas Technology Institute (GTI). The tool allows builders and analysts to customize a range of variables about their project to understand the cost and emissions impact of different choices for energy source, mechanical equipment, and appliances. Learn more about the tool’s background in “Calculate your gas vs. electric savings.”

For this graphic, we assumed:

  • A single-family detached home with an average size of 1,926 square feet and three people per home
  • A 0.88 EF electric storage tank water heater as the base case
  • A 0.95 EF condensing propane tankless water heater as the alternative
  • Electric source energy and emission factors calculated from the eGRID all-plants database
  • Emission calculations based on the Source Energy and Emission Analysis Tool developed by GTI Energy
  • Miles driven calculated using the EPA’s Greenhouse Gas Equivalencies Calculator

Customize your own project

EPAT allows users to try out the impact of other mechanical systems such as heating or cooling, compare new construction or replacement scenarios, and add other variables such as PV panels or combined heat and power (CHP) systems.

An additional factor that could play a role in the future? Renewable propane. Even in states with a cleaner emissions profile for the electric grid, builders in the future can provide all the performance benefits of gas tankless water heating — especially hot water on demand — without sacrificing on carbon emissions by utilizing renewable propane as part of the mix.

The next time your clients are interested in learning more about the carbon emissions impact of their product choices, take a spin through the map infographic to illustrate how their equipment and energy source affect their carbon footprint.