Welcome to the NAPA Greenhouse Gas Calculator v5
NAPA's Greenhouse Gas (GHG) Calculator allows users to evaluate greenhouse gas emissions related to asphalt pavement manufacturing in a gate-to-gate analysis. The web-based software tool is free to use.
The user-friendly interface provides a list of typical fuels that are linked to GHG emission factors. GHG emissions are expressed as carbon dioxide equivalents (CO2e), the universal measure of greenhouse gas emissions in terms of global warming potential.
The GHG Calculator provides inputs for separate fuels used by a rotary dryer plus additional fuels used inside the facility by equipment, including vehicles. A final category addresses CO2e attributed to electrical use, with location-specific factors to account for the different types of power generation used in each region of the country. Fuel used for onsite power generation can be entered in the Equipment & Vehicles section. Generally, the more fuel combusted or burned, the higher the CO2e emissions.
Version 5 uses most of the same assumptions, calculations, and emission factors as the previous version. The biggest change is that it was migrated to a new format in 2020 because the Flash-based format of the previous version will become obsolete in 2021. It should also be noted that the GHG Calculator uses a different set of system boundaries, assumptions, and emission factors than the Emerald Eco-Label environmental product declaration (EPD) tool, so the results from the two tools are not directly comparable. A detailed account of how the GHG Calculator works can be found in the GHG Calculator User Manual.