Urbanization has been growing faster than at any point in human history, where 68% of the world’s population expected to live in urban areas by 2050. With this shift come adjustments in lifestyle, including an increasing demand for more affordable and fuel-efficient vehicles.
Across the world, automakers are responding with bold commitments to increase efficiency, expand their electric fleets and reduce consumers’ dependence on fossil fuels for transportation. From GM committing to 30 new global electric vehicles by 2025 to Volvo planning to become a fully electric car company by 2030, battery-powered driving is poised to take a rapidly increasing share of the mainstream market. This increase in vehicle electrification is happening at the same time electricity generation is decarbonizing, with a shift toward low-carbon and renewable production.
The transportation sector is the largest contributor to U.S. greenhouse gas emissions, responsible for over a quarter of our country’s climate-damaging emissions. Government leaders tackling the climate crisis realize the value of electric vehicles as part of the solution. Most recently, the Biden Administration’s $2 trillion infrastructure plan proposes up to $174 billion investment in electric vehicles using tax incentives and creating a national charging system.
To meet automaker, government and societal demands, the plastics industry will be an important partner in the transition to low-carbon transportation. At the center of solutions that make vehicles more lightweight, plastics represent a net positive for the environment in the auto sector, enabling greater fuel efficiency and longer BEV range, improved safety, enhanced performance and increased lifespan.
Plastics and plastic composites have been used for vehicle improvements for decades. Because plastics are so lightweight, they can help reduce the weight of vehicles by replacing heavy materials like metal and glass to save energy. As a physics 101 reminder, a lighter object requires less energy to accelerate and keep in motion than a heavier one. So, when the weight of a car is reduced, the vehicle’s fuel efficiency increases.
As government regulators mandate even more stringent emissions standards in the years to come, weight reduction will be an ever-important lever for automakers to minimize fuel consumption and reduce greenhouse gas emissions of conventional vehicles. To meet needs for better fuel efficiency, the industry is expected to increase lightweight share from 30 to 70% by 2030.
For fuel efficiency, weight has a considerable impact: According to the Office of Energy Efficiency & Renewable Energy, a 10% reduction in vehicle weight can result in a 6%-8% fuel economy improvement for conventional vehicles. And the performance benefits provided to gasoline and diesel-powered vehicles are equally important for electric vehicles.
Without lightweight components, electric vehicles wouldn’t have the range necessary to be functional for consumers. Compared to similar components made from other materials, plastic components can often weigh 50% less. This means lightweight plastics today can make up 50% of a vehicle's volume, but only about 10% of its weight. While any car can use lightweight materials, they are especially important for electric and hybrid vehicles, to help offset the weight of electric motors and batteries, and to enable performance that makes electric vehicles attractive to consumers.
A widely felt industry challenge for electric vehicles continues to center on battery life. Again, the lighter the vehicle, the longer it can run. Today’s electric vehicle, however, rely on heavy lithium-ion batteries that can increase the weight of a car by as much as 35%. One of the largest, the battery for the fully-electric Mercedes-Benz EQC comes in at 1,400 pounds.
Replacing heavy electric cells with lightweight plastic components, however, automakers can extend electric vehicles capacity to stay charged and extend their driving range. But realizing that potential will depend on battery makers’ ability to design for the large volume production of lithium battery packs that are smaller, lighter and less expensive.
To take first-mover advantage, many manufacturers are turning to advanced polymer solutions for lightweight, energy dense battery packs that resist overheating and are compatible with large-volume automated assembly systems. Under our MobilityScienceTM platform at Dow, we’re working with automakers to integrate the value of silicone, polyurethane, polyolefin, acrylic and hybrid materials into electric vehicles, helping them reduce operating temperatures and extend the life and performance of batteries: From engineered elastomers designed for heat-resistant sealing and gasketing, to silicone gels and encapsulants for potting electronic circuitry in the battery pack’s power management system.
For decades, silicone, polyurethane, polyolefin, acrylic and hybrid materials have proven performance under the harshest automotive conditions through their resistance to shock, oxidation and moisture, maintaining their mechanical and chemical properties. As the move toward carbon neutrality becomes a top priority across the public and private sectors, these materials will be critical to making electric vehicles – and all cars – more lightweight and energy-efficient.
Plastics are also being used in innovative ways to make cars safer. From side doors and seat belts to airbags and child safety seats, plastics and polymer composites play a critical role in the safety of vehicles today, helping to save thousands of lives each year.
For front and rear bumpers, for instance, plastics are considered safer to use because of their durable properties and high impact-resistance. This includes polymers which are significantly lighter in weight than traditional manufacturing materials like metal and can absorb four to five times more energy on impact.
Additionally, the use of plastics in auto glass not only helps to reduce vehicle weight but mitigates potential passenger injuries caused by shattering glass. Today, most windshields are made from laminated glass with a thin plastic layer between two sheets of glass. Because of this layer of plastic, the sheets of glass stay bonded during impact and are less likely to shatter into flying pieces and harm passengers.
A sustainable future is our only future, and lightweight plastics offer automakers a path forward to realizing a low-carbon economy; one where transportation is not exacerbating the climate crisis. From the U.S. pledge for carbon neutrality by 2050 to long-term global warming reduction targets in the Paris Agreement, lightweight materials are the clear solution to progressing toward these bold climate commitments.