To mitigate climate change, the move is on to decarbonize the transport sector; the biggest source of greenhouse gas (GHG) emissions in the U.S. The sheer diversity in the number and types of conveyances – vehicles, vessels, locomotives, machines, equipment – and the duty cycles and types of fuel they use today is itself an indication of the challenge, and also that it is unlikely there would be a singular solution or replacement. Let’s break it down.
While the passenger car sector seems headed rapidly toward a shift to full electrification, away from gasoline power, pickup trucks and larger SUVs will likely sport a range of different powertrain choices for a longer period of time, owing to the diversity in types of use of these vehicles. That’s why today pickup trucks, vans and SUVs have gasoline, hybrid, diesel and electric options, from leading brands like Cadillac, Chevrolet, GMC, Jeep and Ram Trucks.
Beyond passenger vehicles, the goods movement sector is far more complicated.
Emerging technologies like battery electric trucks in some segments are on the market today, albeit at a limited scale. Volvo Group has delivered a number of fully electric heavy-duty tractor trailer size and vocational trucks. Hydrogen is envisioned as another possible option for decarbonizing heavy-duty trucks. Cummins has some fuel cell powered demonstration trucks in operation, but otherwise hydrogen and fully electric heavy-duty trucks are still limited in number, with the considerable limitation of adequate refueling or recharging infrastructure to overcome before more mainstream consideration of these options.
Another way to get carbon reductions is to use lower carbon fuels. This is perhaps the fastest way to reduce carbon emissions across a broad sector since it is not dependent on new vehicles to achieve the reductions. Simply switch out all or a portion of the current petroleum-based diesel fuel with a new fuel made from renewable sources that is lower in carbon content.
For diesel engines of all kinds, use of renewable biobased diesel fuels has been in place for decades and is happening today at a growing rate, to the tune of 3 billion gallons of biodiesel in 2020 and has the potential to grow dramatically in the years ahead.
According to Stratas Advisors, in 2019 one out of every three gallons of biobased diesel fuel is renewable diesel fuel, sometimes called HVO, a drop-in replacement for petroleum diesel. Investments in the production of renewable diesel fuel are growing. With established suppliers like Neste and Renewable Energy Group, along with new supply coming from energy industry leader Phillips 66, near-term production capacity could displace all petroleum diesel fuel consumed in California in 2019.
For a full consideration of the impacts and future GHG reduction benefits of the shift to electric or hydrogen in either light or heavy-duty configurations, comes the need to consider how the power or fuel is generated. Forecasted for 2022, the U.S. Energy Information Administration says that electric power generation in the U.S. will be from natural gas (37 percent), renewables – solar, wind and hydropower (23 percent), coal (21 percent), and nuclear (19 percent).
Hydrogen today can be produced from several sources and processes. Blue hydrogen is the hydrogen gas that is generated from non-renewable energy sources such as nuclear energy. This type of hydrogen gas meets the low carbon threshold. Green hydrogen is made by using zero-emissions electricity (wind or solar or hydropower) to run an electrolyzer, which splits water into hydrogen and oxygen while producing no GHG emissions. Hydrogen can also be produced from natural gas, the most available method today, but also one with the most negative climate impacts, in that it requires a lot of energy and the potential for the potent global warming natural gas (methane) leakage in the process.
It is clear that the energy and fuel landscape is changing, and that there is no “perfect” fuel or technology. The questions are how fast does it change, how far and in what sectors, and what is required to get there? , because of its unmatched attributes and continuous improvement toward zero emissions and the ability to use renewable fuels.
At the end of the day, our goal should be carbon reduction and valuing carbon reductions in whatever form they come.
The next part in this series will explore decarbonization in the off-road sector.