Written on: May 27, 2025
In the conversation about reducing carbon emissions, it’s crucial to think about the full life cycle of the energy we use. For example, an electric vehicle may not emit carbon dioxide (CO2) or other greenhouse gases from a tailpipe, but what about the plants that are generating the electricity powering it? If these plants are burning coal, then the life cycle carbon impact of that grid power could be considerably worse than gasoline or diesel.
To accurately compare the CO2 effect of different energy sources, researchers and industry insiders tend to look at their carbon intensity (CI) score. Carbon intensity refers to the amount of carbon dioxide equivalent (CO2e) released per unit of energy produced. Unlike total emissions, carbon intensity highlights operational efficiency independent of scale. It also makes it possible to quantify the full life cycle impact of a given energy source.
For example, here is a comparison of the carbon intensity scores of popular home heating sources in the U.S.:
| Energy Source | Carbon Intensity (gCO2eq/MJ) |
|---|---|
| Average U.S. Grid Electricity | 130 |
| Fuel Oil | 91 |
| Conventional Propane | 79 |
| Natural Gas | 71 |
Source: The Propane Education & Research Council
It’s worth noting that the CI scores of different states’ grid electricity can vary widely. While some states that use hydroelectricity, natural gas and renewable generation sources may have lower scores, others are still highly dependent on coal. Their grid power can have a lifecycle CI score well above 200!
Renewable propane is produced using organic feedstocks like cooking grease, plant oils, woody biomass and plant oils. Like biodiesel, renewable propane has a much lower CI score than its petroleum equivalent because it uses “recycled” carbon.
How low the score is depends on the feedstock. For example, domestic, unrendered used cooking oil can produce renewable propane with a CI score of 20.5. Renewable propane produced using camelina (an oilseed crop that grows quickly on otherwise fallow land, uses little water, and serves as cattle feed after oil extraction) can achieve a CI score of only 7!
Other innovative liquid gas blends are achieving comparably low carbon intensities. For example, renewable dimethyl ether (rDME) is a biogas that can be blended with conventional propane to achieve a CI reduction of roughly 60%. With added research, there’s potential to create a blend with negative carbon intensity.
Renewable propane is becoming a carbon reduction solution in a range of industries. One surprising recent example comes from our ports. The maritime industry depends on terminal tractors and Class 7 forklifts to generators and light- and medium-duty vehicles that for years have been reliant on diesel. Converting to propane equipment provides an immediate CI reduction, and the incorporation of renewable propane drops it even further.
Jeff Stewart of Blue Star Gas in Santa Rosa, CA, told Maritime Professional that “it’s not difficult to get renewable propane physically to a port… The challenge at this point is really in the volume and production. But we are starting to see new producers coming into the marketplace, and as the volume grows, there will be more supply available for ports.”
The Renewable Propane Alliance is committed to providing energy providers with up-to-date information and resources related to this revolutionary fuel. Reach out to us today to become a member.