Interest in alternatives to diesel technology are growing. There are several reasons why, most notably a desire to decarbonize as much of the transportation sector as possible to mitigate the effects of climate change caused by burning fossil fuels. Realistically, what will it take for hydrogen, battery electric, or other technology to replace diesel? Can any alternative fully displace diesel technology? There are no straightforward answers to either of these questions, and most importantly every option has tradeoffs.
A combination of factors is driving the consideration of alternatives to diesel. The cost of diesel fuel has hit all-time highs, in part due to global energy fallout from the Russia-Ukraine war. Electrification is getting a big boost because battery technology is becoming less expensive and performance is improving. There’s even a likelihood of higher capacity batteries in the future. Federal and state policies are also playing favorites with electrification.
Electrified power has emerged as the future for passenger vehicles. With light loads and limited driving range, cars and SUVs are good choices for electrification. The calculation is vastly different in every way for the potential to electrify heavy-duty trucks and buses and off-road vehicles and equipment. Some of these differences include the demands of the work (or duty) cycle of the equipment and its higher power and performance demand range of operation (miles or hours). The ability to access specialized charging infrastructure (higher power demands than passenger vehicles) at all locations, including remote work locations, far away from traditional electrical outlets is a significant challenge as well.
Electrified commercial vehicles have a good opportunity to compete with diesel for light-duty last mile deliveries or regional freight delivery, where centralized fleets run regular routes with base operations to optimize recharging. But for trucking on irregular routes, with fully loaded tractor trailers, other than natural gas, alternatives to diesel have not yet proven out in commercial applications. Here, adequacy of driving range and time and access to nationwide recharging are major issues far from resolution.
In the off-road sector, some manufacturers have introduced electrified compact construction machines and equipment including mini excavators. For the off-road sector – like construction and farm equipment – options to diesel must match the power and performance of diesel over a much more diverse range of equipment types, duty cycles and operating conditions. These machines are often used in remote locations far from grid power, making recharging a major challenge.
Key considerations for an all-electrified future are the source of the electricity and the ability to deliver it via the grid and dispense it to vehicles when and where it is needed. Is the grid and our electricity system ready? Clearly not, according to some reports. Unless the electricity is 100% sourced from renewables or nuclear energy, the electrified option to diesel is only shifting emissions from tailpipes to powerplant smokestacks. According to the Energy Information Administration, in the US 38% of electricity comes from the burning of natural gas, 22% from coal, 19% from nuclear, and 20% from renewables (wind, solar, hydro). And as electrification of passenger vehicles has taken off, the global demand for battery components and rare metals has skyrocketed. So too have concerns about the adequacy of supply and sourcing issues related to lithium, cobalt, and other core battery constituents from outside the country. Any substantial electrification of heavy-duty vehicles or off-road equipment would add considerably to this burden given the far larger batteries and higher power demands.