Science·What on Earth?

Whatever happened to the promise of hydrogen-powered cars?

In this week's issue of our environment newsletter, we look under the hood of hydrogen-powered vehicles and the challenges of de-carbonizing the airline industry.

Also: What is district energy?

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(Sködt McNalty/CBC)

Hello, people! This is our weekly newsletter on all things environmental, where we highlight trends and solutions that are moving us to a more sustainable world. (Sign up here to get it in your inbox every Thursday.)

This week:

  • Hydrogen-powered vehicles: An idea whose time has come?
  • District energy is a different way to deliver heating and cooling
  • The steps being taken to reduce the emissions of air travel

Hydrogen-powered vehicles: An idea whose time has come?

(Tobias Schwarz/Getty Images)

Electric and hybrid vehicles are gaining traction in the car market. But what about hydrogen-powered cars? They produce zero emissions and don't need charging — you just drive up to a station and refill your tank like you would with a gasoline-powered vehicle. They've been promised for years — so where are they?

Nicole Mortillaro did an email interview with Brant Peppley, a professor in the department of chemical engineering at Queen's University in Kingston, Ont., as well as a former Canada Research Chair in Fuel Cells and former director of the Queen's-RMC Fuel Cell Research Centre. Peppley shed some light on — and busted some myths about — these potential cars of the future.

How does a hydrogen fuel cell work in cars?

A fuel cell [FC] car is an electric vehicle where the electricity is generated by the conversion of hydrogen and oxygen (from air) directly to electricity with a byproduct of pure water. The difference is that instead of having to change lithium ions from one state to another in order to recharge the battery pack in a battery electrical vehicle, you simply refill the hydrogen tank with pressurized hydrogen — a process that takes about three minutes for a passenger car with a range in excess of 480 kilometres on a full tank.

Is this clean energy?

Depends on the source of the hydrogen. Most hydrogen used in the chemical industry today is produced by reacting natural gas with steam. This hydrogen results in CO2 emissions. The other way of making hydrogen is by splitting water into hydrogen and oxygen using an electricity-powered electrolyzer. When that electricity is produced from excess renewable energy such as wind, solar or hydroelectric or from excess nuclear energy (that is often available in Ontario), FC cars are zero-carbon. By the way, when battery-powered vehicles are charged using coal power, they are not zero-carbon. 

If this is so clean, why hasn't it caught on yet?

There are approximately 10,000 FC passenger vehicles being driven by regular consumers in the world today. 

The reason they are not more commonly seen in Canada (other than Vancouver) is the lack of hydrogen refuelling stations. (Editor's note: There are also some in Quebec.) The only place you can buy or lease a fuel cell vehicle is where the refuelling infrastructure is available. California has a network of refuelling stations, as do Japan, Norway, Germany and the other countries in specific regions. The Hydrogen Council, a global consortium of 60 member companies including many of the major car manufacturers, has made a substantial financial commitment to have hydrogen refuelling infrastructure available worldwide by 2030.

Are hydrogen-powered cars any more dangerous than gasoline-fuelled cars?

No! In fact, there are many reasons to consider hydrogen-powered cars less dangerous than gasoline-fuelled vehicles, and battery-powered vehicles for that matter. Hydrogen dissipates extremely quickly.... If an FC vehicle is in a collision, the hydrogen is quickly vented and dissipates into thin air, so to speak, leaving a completely inert vehicle. On the other hand, when a gasoline-fuelled vehicle is in a collision, the gas tank filled with liquid fuel is extremely dangerous, and if it ignites can be extremely lethal. 

Likewise, when a battery-powered vehicle is in a collision, the lithium batteries that are on board still contain the equivalent of several sticks of dynamite worth of energy that can result in electrocution or explosions. It can be extremely dangerous for first responders to use the "jaws of life" on electrical vehicles due to the hazard of accidentally cutting a 300-volt cable.

This interview has been edited and condensed.

Reader feedback

The role of plastics in the world economy is a complicated one, and several readers pointed out that merely reusing plastic for bottled water, as we discussed last week, does not address a larger problem.

Gerry Walsh, for example, took exception to "a recycling story that promotes, as an essential part of your coverage, the use of water as a commodity. This article does not deal with the essential fact that water should and must be held in common, not taken by an individual or company and then sold for profit."

Dale Corbett added this: "Among the biggest threats to the planet is consumers equating 'convenience' with 'necessity,' and an overwhelming belief that life is too busy to seek out alternatives to plastic use, which is nothing more than laziness."

Also, we are looking for New Year's resolutions for living greener in 2020. Are you making any? If so, let us know.

Email us at

Old issues of What on Earth? are right here.

The Big Picture: District energy

Earlier this week, Emily Chung wrote a couple of stories about a "renaissance" in district energy. The basic idea is that rather than each home or building having an individual heating and cooling system, multiple buildings are linked to a central system — similar to a municipal water service. District energy allows for a variety of heating and cooling methods, depending on the location. Maybe it's from solar energy. Maybe it's natural gas. Maybe it's the cool water at the bottom of Lake Ontario. Here's a look at how it works.

Hot and bothered: Provocative ideas from around the web

How are we addressing the environmental challenge of air travel?

(Martin Bureau/Getty Images)

Delegates from more than 200 countries are in Madrid this week to take part in COP25, the UN's annual climate conference. 

One of the biggest challenges in reducing global carbon emissions is air travel. According to the Intergovernmental Panel on Climate Change (IPCC), aviation accounts for about two per cent of worldwide emissions — but air travel is only growing. 

The International Air Transport Association (IATA) predicts 7.8 billion passengers will be flying by 2036, a near doubling of the four billion who flew in 2017. Here are some of the measures being taken to address the problem.

The industry

In 2009, the International Civil Aviation Organization (ICAO) set out to reduce its CO2 emissions through:

  • More fuel-efficient aircraft and sustainable low-carbon fuels.
  • More efficient aircraft operations (such as reducing on-board weight).
  • Technology and infrastructure improvements, including modernized air traffic management systems, to allow for more direct routes.

In 2016, ICAO airlines (about 290 worldwide) also agreed to the Carbon Offsetting and Reduction Scheme for International Aviation, which aims to offset 2.6 billion tonnes of emissions by 2035 through more than $50 billion Cdn for climate projects.

Many airlines encourage travellers to buy carbon offsets, fly direct (which uses less fuel) and even pack less (lighter planes use less fuel). KLM has gone a step further by encouraging potential customers to consider travelling by train instead. 

Carbon offsets

As CBC News reported earlier this year, the general consensus is that carbon offset programs have improved. But there is still debate about whether they actually work. 

Kathryn Ervine, an associate professor at Saint Mary's University in Halifax who has researched carbon offsets, said they are a way for airlines and individual travellers to appease their guilt, and aren't beneficial. Her suggestion? "Go and find a worthwhile green initiative that you know is making an impact and make a financial contribution to it."

A carbon tax

Nine European Union countries (including Germany and France) are calling for an aviation tax. In a letter to the EU chief executive of climate, the countries' finance ministers said an aviation tax where "the polluter pays a fairer price for the use of aviation transport" is necessary to combat climate change.

Banning business class

Jozsef Varadi, head of Hungarian economy flyer Wizz Air, is calling for a ban on business class for flights of less than five hours. Why? It emits more carbon. How? First and business class seats on airplanes are bigger and fewer passengers sit there, which means the aircraft's fuel is used to move fewer people. 

This online carbon calculator shows that a round-trip flight in economy from Toronto's Pearson airport to London Heathrow produces 4.9 tonnes of emissions. The same trip in business produces 9.5 tonnes. 

Electric flight

Companies are working on building all-electric aircraft. One of them is Vancouver-based Harbour Air, whose CEO will fly a DHC-2 de Havilland Beaver float plane retrofitted with a 750-horsepower electric motor for the first time on Dec. 11. It should be about a 10-minute flight, but it will add to the growing body of research about electric aviation.

NASA is also playing a big part in that research. Its first all-electric aircraft, the X-57 Maxwell, was unveiled in early October. NASA's goal is not to build the first all-electric commercial airliner, but to help the Federal Aviation Administration (FAA) establish standards for electric flight. 

Stephanie Hogan

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Editor: Andre Mayer | Logo design: Sködt McNalty


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