Can today’s sustainability drive turn on a solution from the past?

As global trading and economic power dominate the news, it's essential to consider the significance of the world’s electric vehicle markets in these developments. Western and Japanese car manufacturers are realizing that China has a huge lead in electric vehicle technology and a large, receptive domestic market that fuels the success of its local brands.

Brands that historically relied on strong exports to China may never recover the ground lost against these emerging domestic players, which offer cutting-edge products at lower prices. Chinese industry data calculate that battery EVs already represent about 25% of the country’s new car market and that China has been the world’s top producer in the new energy vehicles category for the past 10 years consecutively.

EV technology has rapidly advanced, with key targets focused on increasing driving range and reducing charging time. Range anxiety remains a significant barrier to widespread EV adoption and has resulted in vehicles equipped with large and heavy batteries. Their weight and bulk can compromise drivability and cause technical and environmental problems. Moving the vehicle demands a large quantity of energy, even though the powertrain may achieve extremely high energy-conversion efficiency.

Additionally, tire stress and wear increase, and producing the batteries demands large quantities of strategically important minerals like lithium. As the first wave of large-scale EV adoption reaches the end of life for many batteries, we will face urgent challenges with battery disposal and reclamation of valuable materials.

An abundance of hydrogen. If larger batteries are not a good long-term solution, hydrogen may offer an alternative power source. It’s much lighter in weight and has acceptable energy density. As the most common element in the universe, there is none of the scarcity challenges associated with lithium or fossil fuels. On the other hand, how clean hydrogen is depends on how it’s made. One method, electrolysis, splits water using electricity from renewable or nuclear sources – this is considered cleaner. Another method, called methane reforming, is more common today but produces a lot of CO₂, which harms the environment. These production methods are the reason hydrogen is labeled by color: green and pink hydrogen come from cleaner sources, while gray hydrogen comes from reforming and is less environmentally friendly.

Perhaps electric road systems (ERS) could offer a solution. Leveraging inductive charging, ERS lets electric vehicles go further with smaller batteries. Researchers in Sweden have built short stretches of experimental roadways and run simulations that suggest a combination of home and dynamic charging could shrink car battery sizes up to 70%. Clearly, ERS will be expensive to install and maybe viable only in urban areas, although the Swedish team reckons the system could be viable if only 25% of the road network is converted.

There’s a cool piece of lateral thinking at the heart of this idea. Since the beginning of the automobile age, the vehicles we drive have carried their energy source. Semantically, it’s a defining principle, but ERS flips the concept on its head by taking the energy source off the vehicle. This enables lighter and more affordable EVs with extra range, something that traditional methods have struggled to achieve so far.

Historical precedents. Like many of the technologies currently being explored and developed to support a sustainable future, there are historical precedents. The San Francisco cable car system provides an example that dates from the 1870s. Cables running in trenches are driven continuously at 9.5 miles per hour, each powered by a DC electric motor, while the cars are simple and unpowered. An operator on board manually clamps the vehicle to the cable when it is time to move. Through the 20^th century, people began to phase out the system until they acknowledged its cultural significance and preserved the remaining routes. The three surviving lines are still operating today, carrying passengers and sightseers to their destinations.

You may have noticed I’ve moved the goalposts, as the cable car system is an example of mass transit and not personal transport. Its simplicity is admirable, however, and this enabled the engineers to deliver a service of great value to the community using the limited capabilities of the time.

Similarly simple, functional and extremely environmentally friendly, are water-powered railways. Several are operating in different locations worldwide, including Braga in Portugal, Fribourg in Switzerland and the Lynton and Lynmouth Cliff Railways in the UK. Designed to carry passengers to the top of the steep coastal cliff, the Lynton and Lynmouth system comprises two carriages linked by a cable and consumes no power at all. Each carriage has a large tank filled at the top station using water from the nearby West Lyn River as ballast. The intricately engineered brakes are used to control the system as the heavy top car descends, which raises the lower car. At the end of the descent, the water is released and the other car is filled, permitting the process to repeat continuously.

Although the cliff railway has an extremely low carbon footprint, there would have been no such environmental imperative at the time it was built. A lack of funding is quite likely to have driven the unpowered design. Although ingenious, it was not widely copied. Today, under pressure to decarbonize, we should let ourselves be inspired by engineering like this as we seek to create solutions that are functional, affordable and fossil-fuel-free.

Alun Morgan is technology ambassador at Ventec International Group (venteclaminates.com); alun.morgan@ventec-europe.com. His column runs monthly.

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