Famously, Swedish climate activist Greta Thunberg came to New York on a sailboat last fall instead of on a polluting plane.
But, Time’s Person of the Year aside, the rest of us are taking more planes than ever.
“If aviation was a country, it would be among the top ten worst emitters in the world,” says Walter Merida, director of the Clean Energy Research Centre at the University of British Columbia.
Planes aren’t the only problem. Transportation, overall, accounts for about a quarter of global carbon dioxide emissions, and demand is growing. About 75 per cent of that comes from road transportation.
How do we cut emissions without staying home – and staying off Amazon? One possible solution that’s still, well, up in the air is hydrogen. If we can make it cleanly and cheaply, could hydrogen let us get people and goods around by air, sea and road without worsening climate change? Here’s where we stand.
Right now, air travel only counts for about 2.5 per cent of CO2 emissions, but that’s projected to soar.
While the United Nations aviation agency predicts that airplane trips, and emissions from them, could triple by 2050, a study by the International Council on Clean Transportation found that airplane emissions could be increasing even faster.
Electric planes could be part of the solution.
Vancouver’s Harbour Air tested a zero-emissions, battery-electric plane last month. That six-passenger plane could eventually fly a 30-minute flight on a single charge.
But, since batteries are heavy and take time to recharge, hydrogen would make more sense for longer flights, Merida says.
But for globetrotting distances, electricity isn’t feasible, whether it comes from batteries or fuel cells. Instead, planes would likely have to burn hydrogen the way they burn jet fuel now, Merida says.
Unlike jet fuel, hydrogen doesn’t produce CO2 when burnt.
“You need a lot of volume to store it, but its weight is very light, so airplanes could be much larger and faster,” Merida says.
In 2018, the International Maritime Organization, the UN marine agency, set a goal to reduce greenhouse gas emissions from international shipping to at least 50 per cent of 2008 levels by 2050, and zero by 2100.
In the short term, that could mean a switch from heavy fuel oil to less-polluting fuels, such as liquid natural gas, biodiesel and methanol.
Or, there are zero-emissions possibilities. The Energy Observer, a boat powered by solar panels, wind turbines and hydrogen that it produces out of seawater, is halfway on a six-year journey around the world.
For now, it’s more of a promotional vehicle for Toyota’s hydrogen fuel-cell tech than a blueprint on how to convert existing container ships to hydrogen.
At the port of Los Angeles, the ships coming in to dock are still powered by oil, but two of the semis taking away their cargo are now powered by hydrogen fuel cells.
“You swap out the gas tank with a hydrogen tank and you swap out the engine with a fuel cell,” says Ash Corson, alternative fuels vehicle manager with Toyota.
The trucks – a collaboration between Toyota and truck maker Kenworth and part of a pilot – each use two of the fuel cells that power the Toyota Mirai, the company’s hydrogen-powered sedan.
There are ten more trucks coming, with an expected range of 482 km. That’s a lot less range than you’d get from some long-haul diesel trucks, which can deliver at least 1609 km of range between fill-ups.
But these trucks are for shorter-haul trips from the port. Often they’ll see less than 241 km in a day, Toyota says. Right now, they’re being used every day.
While companies including Tesla and Volvo have announced battery-powered trucks, they’re not on the road yet.
Batteries are heavy and they take time to recharge, although Tesla says its batteries should fast-charge to their 640 km maximum range in 30 minutes.
Hydrogen fuel-cells are lighter and should be able to be refilled in about 15-20 minutes, the same time as a diesel truck. And, unlike batteries, they don’t lose range over time.
So what’s holding hydrogen back? They’ll need a network of stations. For widespread adoption, hydrogen will have to get cheaper and cleaner (right now, most is produced from natural gas, although it can be made by hydrolysis using water and electricity).
“We see a path to [cost of ownership] parity with diesel trucks,” Corson says. “The cost of hydrogen, depending on how it’s produced, is a big part of that.”
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