A port tractor goes by many names — terminal tractor, shag truck, shunt truck, yard truck and yard goat are just a few of them. No matter the name, a port tractor is the workhorse of both seaports and inland ports, moving cargo containers quickly and efficiently to keep pace with the demands of commerce. Traditionally, short, stout port tractors have been diesel-powered vehicles, meaning thick, smelly emissions cloud the air at ports with dozens, or even hundreds of tractors often operating 24/7/365. In recent years, some have contended that new electric port tractors will be a panacea for ports since they are purported to produce zero emissions. But is that really true? It’s important to look at the full equation before making that determination, and the best way is to pair up electric port tractors against an alternative fuel that can make more sense for port operations: propane.

Lower Carbon Intensity Than Electric

While it’s true there is no tailpipe on an electric port tractor, consider that the electricity that powers it has to be generated, more often than not by a coal- or natural gas-fired plant. But that’s not all: the electricity also has to be moved across the electrical grid, sometimes over great distances, transformed onsite into usable energy, and then consumed. The numbers tell the story when it comes to port decarbonization. The national average for carbon intensity of the electrical grid is 131. Conversely, the national average for carbon intensity of conventionally produced propane is just 79. With the onset of renewable propane, or propane made from sustainable sources like cooking oils and wood waste, that carbon intensity drops to about 20. Electric port tractors lose their charge over a shift and obviously have to be recharged. Electrical utilities will only permit a certain amount of power to be distributed at a given site, like a port, which by consequence limits the amount of electrical chargers. Chargers can be powered by propane generators – another way that propane proves its decarbonization value at ports.

Emissions Beat Diesel and Electric

Without question, propane port tractors dramatically reduce emissions at ports compared with diesel models. According to new data recently released from the Propane Education & Research Council (PERC) and the Port Newark Container Terminal (PNCT), a propane port tractor yielded 99% fewer nitrogen oxide (NOx) composite and idle emissions than diesel. Additionally, a propane port tractor produced 77.5% fewer THC idle emissions, 14% fewer brake-specific carbon dioxide (CO2) emissions and 75% fewer TPM emissions, again compared to diesel. And not only that — like electric models, propane port tractors produce virtually zero particulate emissions, or the black smoke that comes out of a diesel tailpipe.

Don’t forget to consider cost. A new propane port tractor can cost as little as $175,000, while the total cost of an electric model could be $400,000, when you factor in charging and related infrastructure costs. Propane fueling infrastructure can be built onsite for minimal cost with signage of a fueling contract. That’s beneficial because that “locks in” the cost of propane for a given period of time, making budgeting easier, whereas electrical rates can vary over time, sometimes wildly. More significantly, from a practical standpoint, it simply takes time to recharge an electric port tractor. It might take over an hour to charge an electric port tractor up to 70% — not optimal, considering ports are given a set amount of time to unload a ship; exceed that time and fines add up. It takes about 10 minutes to fuel a propane port tractor, meaning meeting a time schedule doesn’t mean a time crunch.

Cost and Fueling are Manageable

Decarbonizing a port, be it a seaport or an inland counterpart, doesn’t have to be complicated. Looking at the largest source of emissions — port tractors — and committing to reducing them can be done quickly and most efficiently and effectively with propane models.

Compared to electric port tractors, propane models cost substantially less, are easy to fuel, and when considering the entire emissions equation, are simply cleaner.

Learn more about propane port tractors today.