Hydrogen to charge your phone?

Here's how hydrogen can power a car or charge a phone while only emitting water. #DWScience. The problem is it takes 3 to 4 times the energy to produce the hydrogen to go a given distance than to just charge an EV to go the same distance.

From food to clothes to electronics, most things consumers purchase are likely delivered on trucks. One could even call them the backbone of commerce.

But they are massive polluters. In Europe, heavy duty vehicles are responsible for 28% of transport emissions though they only make up 2% of vehicles on the road, according to the European Federation of Transport and Emission.

And as more and more freight is moved around, these emissions will keep increasing — unless truck manufacturers and governments take drastic action.

Truck producers' best bet is to make their new vehicles zero emissions by using electric motors. These can be powered with two options already familiar from the car industry: batteries or hydrogen fuel cells.

Batteries won the race to power passenger vehicles because they are cheaper. But trucks face a completely different set of challenges: They usually drive further and carry much heavier loads. That means truck companies are weighing their options.

Just a few years ago, talk of a battery-powered truck might have gotten you "laughed out of a room," said Felipe Rodriguez, director for the Heavy-Duty Vehicles Program at the International Council on Clean Transportation (ICCT).

"There were many preconceived notions about what batteries could do. They were too expensive, too heavy, too big," he said.

The idea was that big trucks would need massive batteries, which would compromise how much cargo the vehicle could carry. And transporting heavy loads would make them run out mid-journey, making drivers stop for hours of charging. Not a great choice for operators running on tight profit margins.

"But what has happened in the last few years is mind-boggling," said Rodriguez.

The price for lithium-ion batteries has plummeted in the last decade because raw materials and component prices have become cheaper. At the same time production capacity increased across the battery value chain. Part of the reason is government's high-scale investment in electric vehicles, or EVs, as they try to reduce emissions produced by passenger cars.

"It's a whole automotive industry really bringing down the cost of batteries, but only a small industry working on engineering fuel cells and hydrogen delivery," said David Cebon, professor of mechanical engineering at Cambridge University in the UK.

Over the years, the energy density of batteries has also improved, meaning a truck can get much more range from the same size unit.

And researchers are working on megawatt charging systems that could reduce battery-powered trucks' charging time from several hours to as little as 15 minutes. That would allow them to charge the vehicle during their mandated driving break. In the US and Europe, this break ranges from 30 to 45 minutes.