May 28, 2024
How Is the Carbon Intensity of Fuel Calculated for the LCFS?
The carbon intensity (CI) score of a fuel is a measure of its environmental impact. By understanding how a fuel’s CI score is calculated, fleet owners can be better equipped to maximize their earnings through the Low Carbon Fuel Standard (LCFS).
This article explains how CI scores are calculated and how fleet owners can better understand the CI scores of their fuels.
What Is the Carbon Intensity Score?
The carbon intensity score is a representation of the amount of greenhouse gas emissions associated with producing and consuming a fuel, measured in grams of CO2 equivalent per megajoule of energy (gCO2e/MJ). This scoring system allows for the comparison of different fuels' environmental impacts under the Low Carbon Fuel Standard. Learn more about the carbon intensity score: What Is a Carbon Intensity Score? Understanding EV Energy Rebate Programs With the ability to fairly compare fuels, the LCFS can promote the adoption of cleaner fuels by incentivizing fuels with low CI scores. Under this program, fleet owners with low carbon-intensive vehicles earn credits, which can be sold to producers of high carbon-intensive fuels. The benchmark for the allowable CI score of fuels decreases every year, gradually pushing the adoption of alternative sustainable fuels across the transportation industry. But how are CI scores actually calculated?Breaking Down the Calculation of CI Scores
Calculating the CI score of a fuel is a comprehensive process that takes into account the entire lifecycle of the fuel, including the extraction of raw materials, transportation, production, distribution, and use of the fuel.
To calculate a fuel’s total lifecycle emissions, the LCFS uses the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model developed by Argonne Laboratories. This model provides a comprehensive assessment of a fuel’s total environmental impacts by looking at its greenhouse gas emissions, air pollutant emissions, renewable and non-renewable sources, and water consumption directly and indirectly associated with a fuel’s lifecycle. This model produces the fuel’s carbon dioxide equivalent emissions in gCO2e.
Once a fuel’s total environmental impacts are calculated, the impacts are adjusted for the fuel’s energy efficiency. To do this, its environmental impacts are divided by its energy economy ratio (EER), measured in megajoules of energy. This then becomes the metric that measures CI scores:
CI = gCO2e / MJ
Through this metric, fuels are compared against each other in the LCFS, giving more credit-generation power to fuels with fewer environmental impacts and higher efficiency.