Will heavy electric trucks bear the load?
With great fanfare in late 2017, Tesla announced its heavy electric truck was ready to start production. For a decade or more, international interest has grown for the kind of leap in vehicle architecture and power that would enable heavy loads to be carried without big diesel engines.
Electric passenger car technology is in roughly its third phase now, and much of the research going into it involves lighter, stronger batteries and autonomous features. Yard trucks (those with the ability to pull heavy trailers only at low speed around terminal yards) have been in service for a while and they can operate up to 24 hours on a charge (1). These electric vehicle models should mature in the next several years and companies will be building “the next generation” of passenger EVs.
Electric vehicles help address a major concern around the globe about fossil fuel pollution. Every EV on the road theoretically replaces a diesel/gas engine, while raising the load on electric grids for charging. This load and the generation of power to meet charging demand is part of a complex equation that also includes the energy and materials necessary to manufacture batteries of this large capacity. Another large part of this equation is cost.
All-electric heavy vehicles present a huge opportunity to save more pollution per vehicle than any vehicle to date. Cars and vans are lightweight contenders to reduce pollution, but trucks and busses provide the “heavyweight” battlers in this fight. We will look at the overall progress of heavy duty electric powertrains and some specific battery products being made for class 8 trucks.
Big batteries or something new?
Battery size and weight are the top drawbacks to electric vehicles in general. The problem of reducing size and weight but boosting power is the focus of more research in EVs than any other. This includes heavy vehicles.
The Tesla Semi is no different. Many people are speculating about the exact specifications of the Semi. The most important items in question seem to be range and freight weight vs. tare weight. The weight of the four electric motors in the Semi and the weight of a large diesel engine are roughly comparable, according to reports. So, the battery weight is very important since any vehicle weight must be subtracted from cargo weight.
A report about possible battery configurations discusses the truck’s parameters in light of a freight carrier’s main concerns. Overall weight is not as important as the freight weight, so the heavier the batteries, the lower the allowable freight weight.
“For example, a typical “day cab” configuration 18-wheeler with a diesel engine weighs roughly 32,000 pounds with a relatively lightweight box trailer attached and full fuel tanks. That leaves about 48,000 pounds of freight capacity for the truck. That’s important because … it will be expected to be capable of carrying up to about that weight. Most big rigs on the road are capable of hauling 44,000 or more pounds worth of freight, depending on configuration and trailer type.”
The report notes that logistics companies like a predictable, steady flow of operations and frown on “new, unproven systems” like complete electrical operation and battery life. The electrification of the entire powertrain must be achieved with more goals in mind than simply removing fossil fuels from the equation. Power and longevity all matter above the others, but weight and lifecycles are very important to the return-on-investment strategies of fleet buyers. Fleet trucks run millions of miles and only a small number of them are yard trucks.
This sets up an interesting dilemma for transportation buyers for the next decade: regulatory branches in nearly all governments are racing toward reducing or banning some engines, but many markets will not see viable heavy electric trucks for 10 or 12 years. (3) When companies look for the most efficient overall pieces of heavy equipment, they must combine current needs – which could be five years or more due to lifespans – with long-term fleet plans using new equipment now in the experimental stage.
New battery technology will be all-important in making these decisions. “Our analyses indicate that the majority of commercial vehicles can reach cost parity with diesel-powered trucks within the next 10 years, assuming we see continued improvements in battery cost and power density,” the report said. Battery packs are the key ingredient in pushing all-electric fleet purchases from theoretical to real. In order to see how powertrains for heavy trucks are being supercharged, let’s look at some battery developments now leading the industry.
The better battery
Early this year, a battery manufacturer in Europe began a seven-year venture with other manufacturers to research lithium-ion (Li-ion) and other battery materials and packages. Saft S.A. of France has joined with Solvay (Belgium), Manz (Germany), Siemens (Germany) and others to form a European battery alliance, pooling expertise in materials, methods and engineering for better systems. (4) The focus is not only land transportation but storage, large machinery, marine and aviation functions as well.
The report noted that the group will explore “high-density and solid state” Li-ion development for batteries that will extend current technology toward solid state, safer products. “New generation batteries will provide performance, cost and safety advantages, compared to current lithium-ion products, Saft said. The batteries, which will be integrated into their system environments, with digitalized functions and interfaces, are planned to be designed together with leading material suppliers.”
While this consortium was being formed, a Massachusetts company announced the development of a completely dry Li-ion material that is much safer, faster than conventional batteries in conducting ions and will revolutionize the weight-to-power ratio. The material does not burn. It could result in a true solid-state battery package. A plastic material is the key ingredient, according to founder of Ionic Materials, Dr. Mike Zimmerman of the Woburn, Ma. Company. (5)
Every battery maker is looking for a reduction in weight, even if the result is the same power rating; ideally, new materials boost both power and weight reduction. In a demonstration of a small solid battery using this material, Zimmerman uses standard steel scissors to cut up his battery, packaged in a reflective plastic bag. Connected to an iPad device, which continues to run, the battery is sliced up. A thicker battery is punched full of holes with a screwdriver and nothing leaks, ignites or even creates heat that can be felt with the hand.
This device is in the very early stages, the report said. Packaging, power and pricing are all in the future, but the designer has received $65 million in research and development funding this year and expects much larger companies to develop his process in the future.
Which brings us back to battery makers and the agreements like Saft’s, which are growing in popularity with the explosion of all-electric vehicles and autonomous capabilities using all kinds of powered wireless devices. The new material developed at Ionic Materials is one of the exact goals set up initially at the battery consortium. Perhaps there are more companies, large and small, that will join in the battery development explosion in the next few years.
Costs and consequences
The race for battery development also brings us full circle to truck builders like Tesla. Are these ideas due to become reality with Elon Musk’s latest roadway gem?
The Semi could include new solid-state battery technology. As noted earlier, the Semi is still in design in some components, with batteries being the most important. Other companies are in the same phase of development but have launched heavy truck lines with existing battery technology. When combined with the problem of charging on the road, the power problem will continue for long range travel with class 8 trucks.
When charging is solved, cost parity between diesel trucks and all-electric trucks should quickly follow. The sales of trucks worldwide could reach 15 percent by 2030 (3), with more sales concentrated in the big industrial countries in Europe, then China and the United States of up to 25 percent.
This is not to say there are no profound advantages in the trucks being sold now; they are quickly being shown safe and reliable in short distances and in yards, where they can be charged overnight. In Canada, BYD is in full production of a class 8 heavy truck that is selling very well in China. (6) However, in an example of the potential that all-electric vehicles have in niche categories, Canada’s largest grocery firm will purchase a large number of trucks for short-haul of fresh food. The vehicle travels 92 miles on a charge but has a GVW of 120,000 pounds and includes refrigerated 53-foot trailers, the report said.
There is no question about the importance of heavy electric trucks to the economies of countries that make and sell them. They will have an immense effect of the air and water quality in those countries, as well. Battery development means faster deployment and the power ratios will rise. Watch for next breakthrough in weight-to-power du to new battery materials.