Skip to main content

Think outside the battery: Weird, clever, crazy tech driving green cars further

Efficiency isn’t sexy, and the sorts of technologies that improve it don’t help matters much either. Small engines, lightweight, aerodynamic designs, and slow speed just doesn’t do much to get the heart racing.

Despite that, automakers aren’t content to leave it at that. In the last year, automakers from Mercedes to Peugeot to Volvo have announced paint that collects power from the sun, batteries built into body panels, and hybrids that run on compressed air.

These oddball technologies not only show that green can be sexy, albeit sexy with nerd glasses, but may also revolutionize the cars we drive.

Power from the air and sky

No doubt the biggest green news of the week came from the Mercedes with the debut of the insane G-Code concept crossover. Though the Mercedes concept is host to a laundry list of innovations, the most compelling is its ‘multi-voltaic’ paint. This paint, in essence, turns the car into one giant solar cell.

This paint, in essence, turns the car into one giant solar cell.

The details of just how this works weren’t forthcoming, but the claims didn’t stop there. Mercedes also says that the paint is capable of generating electricity from the electrostatic potential of either the relative wind from the car’s movement, or from natural wind when the car is standing still. Again, Mercedes wasn’t parting with details, but the obvious inference is that the paint is capable of generating and then harvesting the static electricity built up by air molecules passing over the car.

Just how much electricity these systems can gather isn’t specified, but judging from the fact that Mercedes has included a speculative hydrogen fuel cell in the design, it sounds as if it won’t be nearly enough to power the entire vehicle. Still, when combined with other new technologies, the system could help make the most of range and efficiency.

Mercedes, for example, has announced that the G-Code will feature a suspension that recovers energy from the travel of the wheels. Again, the recovery may not be large but every little bit helps. Once captured, however, where does one store that energy?

An electric body

Traditional batteries come with a host of problems: expense, bulk, weight and – most of all – a low energy density. For the Tesla Model S to achieve its 265-mile range, it has to have 1,300 pounds of batteries. A 30-mpg internal combustion-powered car can make the same journey on just 75 pounds of polar-bear-melting fossil fuels. This makes batteries an inherently difficult technology to work with in a competitive market. However, there are alternatives.

Volvo has been experimenting with turning entire cars into batteries.

Volvo has been experimenting with turning entire cars into batteries. Well, to be technically accurate, super capacitors. The technology involves sandwiching a polymer resin between layers of carbon fiber to create a super capacitor thinner than a dime, proving that everything is better with carbon fiber.

When the hood, roof, and trunk of an electric Volvo S80 are replaced with these carbon capacitors vehicle weight drops 15 percent and range is extended 80 miles.

There are already examples of what super capacitors can do in the real world. Mazda’s i-Eloop system uses a capacitor and regenerative braking to run its cars’ accessories. Under ideal conditions, this system can save close to 10 percent on fuel usage.

Volvo S80 electric Nano battery project
A composite blend of carbon fibres and polymer can store and charge more energy faster than conventional batteries can. Image used with permission by copyright holder

Capacitors, like the ones being proposed by Volvo have the additional benefit of not containing rare-earth metals like lithium. These are difficult and environmentally costly to mine and refine, and making batteries with them is so energy intensive that it can completely cancel out the environmental benefit of driving an EV.

Just imagine pairing this with some of Mercedes innovations; the result would be a car that took full advantage of the environment and didn’t waste precious space and weight on big batteries. A car like that might shatter what our expectations of efficiency and environmental protection.

Cars that run on air

If all this talk of capacitors and solar cell paint sounds a little complicated, don’t worry. The French have a much simpler idea: using compressed air.

Small engines, lightweight, aerodynamic designs, and slow speed just doesn’t do much to get the heart racing.

Peugeot Citroën PSA  has been quietly working on a technology that replaces the batteries in hybrids with simple air. The system works like this: as in a normal hybrid, most of the power comes from a gas engine. In the air hybrid, however, this is supplemented with a holding tank, a hydraulic compressor, and hydraulic motor.

When the driver applies the brakes, he or she activates the compressor, which charges the holding tank with air. This compressed air can then be used to run the hydraulic motor to supplement the gas engine, just as the electric motors do in a traditional hybrid.

The advantages of this system are that the technology is brutally simple, and – compared to big batteries – light. Conceivably, this sort of system could be included in a broad array of vehicles with considerably fewer modifications than are typically required to build a true hybrid.

Mazda i-Eloop system
Mazda i-Eloop system Image used with permission by copyright holder

The downside is that compressed air isn’t a great storage medium. Unless automakers are willing to invest in insanely strong containers, it is difficult to store sufficient energy to make a dramatic difference in fuel economy. Then there is the small fact that a compressed air cylinder is essentially a bomb. But still, of all the technologies we have covered this is by far the closest to fruition. In fact, if Peugeot remains committed to the technology, it could be in cars in a matter of years.

Conclusion

Amazingly, some or all of these technologies could actually appear in show rooms. Even if they don’t, though, they show that thinking sideways has its advantages. By avoiding battering their heads into the wall in a futile attempt to improving batteries, companies like Volvo and Mercedes are placing themselves at the forefront of innovation.

Like the creation of hybrid drivetrains in the first place, these ideas have the prospect of dramatically changing the way the average driver thinks about cars and efficiency. I for one am excited to see what happens next.

Peter Braun
Former Digital Trends Contributor
Peter is a freelance contributor to Digital Trends and almost a lawyer. He has loved thinking, writing and talking about cars…
You Asked: State of smartphone design, Slate Truck breakdown, and soundbars under $600
You Asked

On today’s You Asked: What's to come with the new Slate Truck and its potential availability? Is it worth the hype? Why does it feel like smartphone design and innovation has stalled recently? And why do directors think that ultra wide 21:9 is a good ratio for movies?
Slate Truck breakdown with John McCann
Some of you have been in touch to ask about the availability of the new Slate Truck. I'll go through the preorder process in a moment, but first, let's get everyone up to speed on this newly unveiled EV. What is it? What makes it stand out? And why is it generating so much buzz?
This is being touted as a sub-$20,000 electric truck after government incentives, and you’ll be able to customize it to your heart’s content. It stands out not so much for what it offers, but for what it doesn’t offer as standard. There’s just one trim and one paint color. No touchscreen, no stereo, no Bluetooth, no electric windows.

So, what do you get? There are two seats. There's a five-meter bed, good for payloads up to 1,400 pounds. There's AC, steel wheels, and hand-cranked windows, plus all the standard driver safety assists you’d expect from a modern vehicle. There’s a rear-mounted electric motor, a roomy frunk, and a battery rated for about 150 miles, according to Slate.
That isn’t great in the world of EV range, but a larger battery will be available to push that figure up to a more reasonable 240 miles. That bigger battery is just one of over 100 add-ons Slate is making available. These will be offered not just at the point of purchase but also at any time during your ownership, allowing you to swap and upgrade as your needs evolve.
Want to add a splash of color? Check out the vast range of vinyl wraps you can apply and remove from the truck at will. There’s also an SUV upgrade kit that converts your two-seater truck into a five-seater car. Inside, infotainment is strictly “bring your own device.” There’s no touchscreen, no built-in CarPlay, not even a stereo. Instead, you get a universal phone mount and a few USB ports. You can also add holders for a tablet if you want a bigger display, and a Bluetooth speaker if you want to listen to music while out for a drive.

Read more
ID. Buzz recall appears to have made automotive history
The VW ID.Buzz electric van.

The National Highway Traffic Safety Administration (NHTSA) has recalled almost 5,700 ID. Buzz electric vans because the VW-made vehicle has too much space in the back.

OK, let us explain. The U.S. regulator has found that the third-row bench seat of the ID. Buzz is ostensibly designed for two people and therefore has two seat belts built in. But it’s wide enough for three, and as a result, the NHTSA wants the German auto giant to make some changes so that it fully complies with the required safety standards.

Read more
My next car must have this Carplay and Android Auto feature, here’s why
Google Maps in full screen on the driver's second display on the Chevy Equinox 2025

I’ve been driving a Chevrolet Equinox 2025 SUV rental car for the past week, and it’s reminded me exactly what my next car needs. It runs Android Automotive, which I’ve already decided is a requirement in my next car, but the more convenient feature is arguably how Chevrolet has approached its CarPlay and Android Auto integration.

CarPlay and Android Auto offer immense benefits and virtually no pitfalls to drivers. They’re designed to bring your phone and its apps into your car, and make it easier to access up-to-date maps and traffic data without relying on often-archaic solutions implemented by your carmaker.

Read more