A new report from Lux Research, Electric Vehicle Lightweighting 2030, analyzes the future of vehicle lightweighting and necessary BEV success factors over the next decade.
Lightweighting has been a key tool for improving the fuel economy of internal combustion engine (ICE) vehicles over the past years. However, the transition from ICEs to BEVs changes both the goals and the design considerations around lightweighting, Lux says. Key changes include:
Range: BEVs are overwhelmingly more efficient than ICE vehicles due to regenerative braking and more efficient motors. BEVs’ main weakness is range; most midprice BEVs have a limited range of 200 km to 400 km. Much of the drive to lightweight BEVs comes from a desire to extend range.
Platform design: BEVs are increasingly being designed around shared rolling frames or platforms that contain the batteries, drive systems, and in some cases structural elements of the cars. Decisions around lightweighting these elements—such as battery packs—will have a major impact across all BEVs produced by an OEM, heightening the importance of collaborating on these platform designs.
Mass distribution: BEVs have predominantly located their batteries in a low, flat container on the floor of their vehicle. This mass, combined with the removal of the ICE, means BEVs naturally have very low centers of gravity, and their mass is much more evenly distributed front to back. These conditions are highly favorable for tight control, enabling even midprice BEVs like the Model 3 to handle extremely well. The consequence, however, is that performance-driven lightweighting is far less necessary.
For the report, Lux collected data on 64 model year 2019 BEVs to build a data set on BEV range and performance. The vehicles were separated into two categories: sedans, which also includes hatchbacks and other small cars, and SUVs, which includes vans and utility vehicles. Lux then compared the range of the vehicles to the ratio of total mass to battery pack size.
Taken together, this data suggests that as vehicle pack sizes go up and vehicle mass comes down, range increases—an expected result. The data was used to calculate how much of an impact an increase in pack size or a decrease in vehicle weight would have on the range of a generalized BEV. This was then used as the basis of the forecasting of the future BEV.
Lux predicts that battery pack energy densities will increase by roughly 15% over the next decade. This increased energy density can be used to either extend the range of a vehicle by keeping battery size the same or reduce cost by shrinking the size of the battery pack.
In its analysis, Lux modeled both scenarios and calculated a lightweighting benchmark. Lux determined that in order for lightweighting to be a cost-effective solution against batteries by 2030, it will need to cost, on average, less than $5 per kilogram of weight saved.
This benchmark is not the only thing guiding lightweighting decisions. To find adoption, materials companies and manufacturers will need to find solutions that save on both weight and cost.
We predict vehicle structure will be an opportunity for high-strength steel and aluminum, as they provide weight reductions at minimal cost. Bumpers are expected to benefit from design advancements that utilize glass fiber, carbon fiber, and thermoplastics. Other material priorities, such as sustainability, durability, and end-of-life issues, however, will take priority over lightweighting by 2030.—Anthony Schiavo, Senior Analyst at Lux
Lux found that there’s far more risk of disruption from improving energy storage technologies—which could substantially outstrip forecast improvements by 2030—than there is from novel innovations in materials.