Freight has a sustainability problem

In New York City and other major cities around the globe, last mile delivery of goods has steadily increased 15% per year for the past 15 years. This growth has been overwhelmingly good for businesses and consumers, but it has also negatively impacted public health and climate change. The trucks making these deliveries are far more polluting than passenger vehicles (Moultak et al., 2017), creating large increases in CO2 and other harmful emissions that negatively impact public health, often most severely in poorer communities. To combat these issues, governments at many levels have set CO2 reduction goals (Weiss et al., 2015; NYC, 2016) which make decarbonizing last-mile delivery trucks essential. However, the medium- and heavy-duty trucks used in urban freight still are not on track to hit the International Energy Agency’s Net Zero Scenario of 100% zero-emission vehicles by 2050 (BloombergNEF, 2023). Because lifecycle greenhouse gases (GHG) of commercial vehicles are estimated to at least double from 2015 to 2050 under the business-as-usual scenario (Moultak et al., 2017), urban freight must rapidly electrify to meet climate goals and improve public health.

Roadblocks to electrification

Battery electric trucks (BETs) present a promising alternative to traditional delivery trucks, but unfortunately, adoption of BETs for urban freight delivery has been slow, with one source of delay stemming from BETs’ inability to complete longer delivery tours in a single charge. In fact, estimates are that at least 35% of delivery tours in New York City cannot be completed with a single charge of a standard electric truck battery.

This is a novel problem for BETs. The internal combustion engines found in traditional delivery trucks are largely exempt from this challenge because the energy density of their fuel means that they can carry enough to complete their tours, and in scenarios where a single tank of fuel is insufficient, refueling takes just minutes with the existing robust refueling infrastructure. In comparison, recharging the larger batteries used by BETs can take hours.

Figure 1 shows an example operating cycle for two different BETs, one with “heavy usage”, meaning the truck more consistently hauls more goods, makes more stops, and travels long distances, requiring more energy from its battery, and one with “light usage”, meaning the truck usually hauls smaller loads for shorter trips, putting less strain on the battery. Figure 1a shows a truck with heavy usage with a state of charge (SOC) that reduces to almost 0% by the end of its tour and requires most of the truck’s off-hour period to fully recharge. In comparison, Figure 1b has a much lighter usage, so the SOC never dips as low and there is more flexibility to schedule recharging. Both scenarios have weaknesses: the ability to selectively schedule recharging of the truck’s battery in Scenario B (Figure 1b) means that the operator can choose to only recharge when the price of electricity is lowest. This freedom is important as the price of electricity can fluctuate meaningfully over the course of day, especially in high demand seasons. But while Scenario B has lower costs, it has also lower revenue because the truck is making fewer deliveries. Companies who own commercial vehicles usually try to maximize their daily use to generate as much revenue as possible, making Scenario A (Figure 1a) more likely.