John Eichberger |
December 2024
There continues to be an endless fascination with the new and exciting. However, as we continue down the path to lower transportation emissions, it is useful to reflect on how far we have come so far and how we got here. Since 2004, the United States light duty fleet has increased its fuel efficiency 45% and reduced its greenhouse gas emissions by 34%. This was achieved by a combination of improved vehicle engineering and performance and the introduction of lower carbon fuel. It is important to recognize the role energy plays in the environmental performance of the sector because it is only through fuel (including liquid, electric and gaseous forms) innovation that we can further reduce the emissions of the vehicles that are currently on the road.
A Life Cycle Approach
According to our life cycle analysis study published in 2022, nearly three-quarters of life cycle GHG emissions from both internal combustion engine vehicles and battery electric vehicles come from the energy used to power those vehicles. For both technologies, improvements can be made in new-to-market vehicles, but for the nearly 300 million vehicles registered in the U.S. and 1.5 billion in the world, addressing the carbon emissions potential of the energy is the only way to reduce emissions.
As we look at the current fleet, it is most helpful to focus on the legacy ICE vehicles, considering EVs currently represent less than 2% of the fleet. So how do we do reduce the emissions potential of the existing liquid fuel supply? There are innovative projects and products that can be brought to the market over time, such as e-fuels, renewable gasoline and advanced production practices, and we should continue to work on these and bring them to market because they hold great potential. (The links provided take you to research TEI has already published on these topics.) One dangerous assumption we should remain mindful of is the idea that we need a “single” source solution, one breakthrough that will solve all of our emissions issues. The reality is this may not exist; instead, we should be looking at a combination of incremental improvements that are compatible with each other.
For example, when we apply a life cycle approach to solving the problem, we open up a host of possibilities. A life cycle approach means that we value the reduction of carbon emissions wherever they exist, including at the oil and corn fields and lithium mines, within the refineries and electricity generation facilities, as well as at the tailpipe and in final disposal or recycling of depleted resources. By doing so, we might be able to compound environmental benefits. Imagine a crude oil that is extracted using renewable energy and methane sequestration rather than flaring and then processed into gasoline at a refinery that also uses renewable energy and sequestration. Then, blend this lower carbon product with 15% volume ethanol that was produced from corn grown using sustainable agricultural practices in a biorefinery that also uses renewable energy and sequestration. Then, perhaps we could also add up to 5% renewable gasoline and some e-fuel, both of which are not yet scalable to mass volumetric production and may only be available in small volumes. If these options can effectively be combined to yield the finished gasoline product, how much carbon might we be able to remove from the transportation sector?
The Impact of Biofuels
If we take a look at our use of biofuels, which has been enabling lower emissions and enhancing domestic energy security over the past three decades, we can better understand what we might be able to achieve with existing and potentially new processes and products.
Since 2011, we have increased our monthly consumption of biofuels in the U.S. by 65%. This was of course supported by the Renewable Fuel Standard (RFS) and the California Low Carbon Fuel Standard (LCFS), as well as the Blenders’ Tax Credit, programs which resulted in a significant increase in renewable fuel use and reduction in carbon emissions. Today, ethanol comprises about 10.5% of the gasoline pool and biodiesel and renewable diesel comprise around 10% of the diesel pool. The expansion of this market has been incredible and it has had a positive impact on emissions.
When we look back at just the past three years and use the TEI Carbon Avoidance Tracker tool, which applies the carbon reduction variables published by Argonne National Laboratory in their GREET model, we can see how effective biofuels have been in reducing GHG emissions from transportation. On a monthly basis, the use of ethanol, biodiesel and renewable diesel takes an average about 5% of carbon out of the system and over the past three years these products have mitigated more than 455 million metric tons of CO2 emissions. According to a calculator provided by the U.S. Environmental Protection Agency (EPA), reducing 115 million metric tons of CO2 per year is equal to taking nearly 35 million vehicles off the road or operating 44,800 wind turbines for a year (the U.S. currently operates approximately 75,000 turbines).
Despite the progress made with leveraging biofuels to expand the fuel supply and reduce emissions, there is more we can do. Our 2024 report, Balancing the Benefits of Biofuels, demonstrated that we can use more biofuels and develop new sources of feedstock while not disrupting the supply or affordability of food as some have contested. It is possible to pursue environmental progress while protecting our economic interests – these need not be mutually exclusive objectives.
As we begin the new year, let’s work together to identify solutions to our environmental challenges that preserve access to affordable and reliable transportation energy for all consumers, that support the specific use cases for which certain vehicles are deployed, and provide economic opportunities for businesses that will encourage investments in such solutions. TEI will continue to evaluate all viable options to provide the market with some insight into what might be possible and feasible. It is our hope that, but supporting the conversation, we can help decision makers reach for solutions that improve the transportation market for all stakeholders.
