Driving down the cost of electric HGVs

20 February 2020

The electrification of commercial vehicles is gathering pace with every passing month and demand is soaring as operators get to grips with the environmental and economic benefits that can be achieved.

Operators know that profitability is driven by Total Cost of Ownership (TCO) and the biggest single factor in this is depreciation, typically accounting for 48% of the TCO. With an electric truck, the operating costs are lower than a diesel equivalent so to continue the acceleration of electric HGV adoption the key is to reduce the on-cost of electrification to a point where the operational savings can offset the difference.

But the high cost of battery packs big enough to provide a 120-mile+ range for a medium duty truck is currently a barrier to purchase, so reducing the energy consumption of the powertrain is a key factor in minimising TCO.

That’s where UK-based automotive engineering specialist, Drive System Design (DSD), comes in.

It has developed a design tool it believes will significantly reduce the cost of HGV electrified powertrains and accelerate their adoption. The tool, ePOP (Electrified Powertrain Optimisation Process), allows thousands of powertrain architectures to be evaluated quickly for a vehicle’s given drive cycle.

By inputting key vehicle criteria such as weight, load capacity, anticipated range and drive cycle the tool can evaluate the optimum powertrain requirements. For example, it can assess the cost benefits of using permanent magnet motors versus induction, how big the battery pack needs to be for a given range or whether a single or multi-speed transmission is more favourable.

By identifying the optimum architecture early in the design phase as much as 50% of the overall powertrain cost can be decreased for a given set of requirements, or an equally acceptable increase in range.

“Traditionally, when deciding what powertrain architecture to use, the manufacturer would have to make various assumptions and will inevitably stick with what they know,” says Mike Savage, Drive System Design, Chief Engineer. “ePOP minimises assumptions and completely removes biases at this critical stage of the design phase. The result is the most optimum electric powertrain for any given HGV.”

“In a recent project for a 13-tonne commercial vehicle, we simulated over 4,000 different powertrain permutations to optimise the configuration,” continued Savage. “Without ePOP this simply wouldn’t have been possible. Typically, a design team would have only realistically evaluated five or six concepts before progressing to the next stage of the design.”

“Because ePOP is so thorough, it’s able to identify improvements that may have otherwise been overlooked because they were counter-intuitive,” concludes Savage. “For example, adding complexity to the transmission by opting for two or more speeds instead of a single speed can actually reduce overall cost by making significant savings in motor and battery pack specification. Only by rigorously optimising the design in this way can the operational profitability of the vehicle be improved.”