Introduction to battery electric trucks
Heavy-duty diesel-engine trucks (agricultural, cargo, mining, logging, construction, garbage, cement, 18-wheelers) are the main engines of civilization. Without them, no goods would be delivered, no food planted or harvested, no garbage picked up, no minerals mined, no concrete made, or oil and gas drilled to keep them all rolling. If trucks stopped running, gas stations, grocery stores, factories, pharmacies, and manufacturers would shut down within a week.
Since oil, coal, and natural gas are finite, and biomass doesn’t scale up, clearly someday trucks will need to run on wind, solar, hydro, and geothermal generated electricity. Yet even batteries for autos aren’t yet cheap, long-lasting, light-weight, or powerful enough for most Americans to replace their current gas-guzzlers with. And given the distribution of wealth, few Americans may ever be able to afford an electric car, since two-thirds of Americans would have trouble finding even $1,000 for an emergency.
Trucks that matter — that haul 30 tons of goods, pour cement, haul mining ore, and so on can weigh 40 times more than an average car. So scaling batteries up for heavy-duty trucks (NRC 2014) is impossible now given the state of battery technology. For example, a truck capable of going 621 miles hauling 59,525 pounds, the maximum allowable cargo weight, would need a battery weighing 55,116 pounds, and could only carry about 4,400 pounds of cargo (den Boer et al. 2013). And because a heavy-duty truck battery is so heavy and large, charging takes too long — typically 12 hours or more.
And car battery development is hitting the brick-walls of the laws of physics and thermodynamics, yet truck batteries need to be even more powerful, durable, and long-lasting.
Electric trucks do exist, mostly medium-duty hybrid that stop and start a lot to recharge the battery. This limits their application to delivery and garbage trucks and buses. These trucks are heavily subsidized at state and federal levels since on average they cost three times as much as a diesel truck equivalent (Table 1).
The Port of Los Angeles thought about using heavy-duty all-electric drayage trucks to improve air quality. Drayage trucks drive at least 200 miles a day back and forth between the port and inland warehouses. But it remained a thought experiment because electric drayage trucks cost too much, $307,890. The 350 kWh battery alone is $110,880 dollars. That’s three times as much as an equivalent diesel truck $104,360, and 100 times more than a used $3,000 drayage truck. And cost wasn’t the only problem (Calstart 2013a):
- The range is too short because of the battery weight and size. Drayage trucks need to go at least 200 miles a day, but at best an electric truck could go 100 miles before having to be recharged, which would take too long, and require expensive infrastructure to charge each truck several times a day.
- The batteries/battery pack cost too much.
- Overcoming the long time to recharge by using fast-charging may shorten battery life which would result in the unacceptable expense of a new battery pack before the lifetime of the truck ended
- Although electricity is available almost everywhere, the quantities required for a fleet of Battery Electric Vehicle (BEV) drayage trucks are very high and could require significant infrastructure. Multiple costly high-power and/or fast-charging stations would be required
- Roadway power infrastructure is complicated and expensive, and may be appropriate only in certain areas or applications. The impact on the grid and whether enough power could be supplied is unknown for the roughly 10,000 drayage trucks in the I-710 region
- Large battery pack life-cycle and maintenance costs are unknown
- Swapping stations are impractical and would require “industry standardization and ‘ruggedization’ of battery packs, as well as standardized software and communication protocols for batteries and system integration, plus many locations, and the storage space and operating space for multiple large trucks and hundreds of large battery packs.
Table 1. Electric trucks coust 3 times more than diesel equivalents (ICEV) on average. Source: 2016 New York State Electric Vehicle – Voucher Incentive Fund Vehicle Eligibility List. https://truck-vip.ny.gov/NYSEV-VIF-vehicle-list.php
Electric trucks are also not commercial yet because they have too many performance issues, such as poor performance in cold weather, swift acceleration, driving up steep hills, too short a range and battery life, they take too long to recharge, declining miles per day as the battery degrades, all of which make planning routes difficult and inefficient.
It is also much harder to develop batteries for trucks than cars because trucks are expected to last 15 years (versus 10 for cars) or go for 1 million miles. Trucks also have to endure more extreme conditions of temperature, vibrations, and corrosive agents than autos (NRC 2015), and it is hard to make battery packs durable enough for this rougher ride, longer miles, and longevity.
Calstart interviewed many businesses about their reluctance to buy hybrid or all electric trucks, and found their greatest concerns were the purchase cost, lack of confidence in the technology, lack of industry and truck manufacturer support, lack of infrastructure, and the heavy weight (Calstart 2012).
But if the devil is in the details, then read more [on the original article here] in my summary and excerpts of a paper about electric trucks. Catenary trucks, which use overhead wires, will be covered in another post. Both electric and catenary trucks are covered at greater length in “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer