Fuel for Thought

The topics of clean cars and zero carbon emissions are becoming hotly debated as the path towards reducing New Zealand’s carbon footprint becomes a reality.

Globally, Toyota has set significant targets both in emission reductions and the availability of low- or zerocarbon- emission vehicles, and has committed to having electrified options across our whole range by 2025. With transport emissions accounting for nearly 20 per cent of all carbon output in New Zealand, as the market-leading automotive brand we have a large influence on and responsibility for the progression to a zero-carbon economy.

Toyota is accelerating its development of low - and zero-carbon emission vehicles across multiple technologies, including self-charging hybrid electric, plug-in hybrid electric, battery electric and fuel-cell electric vehicles. Toyota is taking a diversified approach to technology investment, and we fully expect to be selling 30,000 fuel-cell electric vehicles a year globally in the not-too-distant future. A fuel-cell electric vehicle runs on hydrogen and emits only water, making it a zero-emission vehicle solution. Fuel-cell vehicles are going to play an important part of Toyota’s global decarbonisation in the future, especially in the commercial sector.

New Zealand is perfectly placed to create green hydrogen from renewable resources such as solar, wind and hydro power and there are many large New Zealand companies working on making advances in green hydrogen production and infrastructure. The New Zealand Hydrogen Association includes many of these companies as members, alongside Toyota. The Hydrogen Association see the use of renewable hydrogen as an integral part of New Zealand’s evolving energy needs.

So what is hydrogen?

Hydrogen is the lightest and most abundant chemical element in the universe. On Earth hydrogen is found in more complex molecules, such as water, plants and manure. To be used in its purest form, it has to be extracted from these complex molecules. When it is in its purest form it is a gas that is lighter than air.

Isn’t hydrogen dangerous?

Hydrogen, in many cases, is safer than the fuels we currently use to power our cars, including petrol and natural gas. In fact, some of hydrogen’s differences actually provide safety benefits. Carbon-based fuels, such as petrol, tend to spread as liquids. When theyburn, carbon-based fuels produce hot ash, creating radiant heat. This isn’t the case with hydrogen; in its pure form it produces very little radiant heat. An explosion cannot occur in a tank or any enclosed location that contains only hydrogen, which is different from gasoline for example, where a tank contains not only the gasoline but a layer of air. All you need is an ignition source to light this flammable cocktail. Hydrogen is also lighter than air, so if it does leak, it very quickly disappears into the atmosphere.

Toyota performed a series of very demanding safety tests on the tanks used in its fuel-cell vehicle, the Mirai. It put the tanks through burst, bonfire, crush and gunshot tests. The tank passed all tests, including a crush test with a force of 150 tonnes, and even survived a point-blank gunshot.

How is hydrogen produced for use as a fuel in fuel-cell vehicles?

There are a lot of ways to produce hydrogen, but the greenest way is through electrolysis. This process uses an electrical current to separate water into its two fundamental elements, oxygen and hydrogen. In order to separate the water molecules, an electrical current is passed through the water. This electricity can be generated using clean, renewable sources such as wind, solar and hydro and generated at off-peak times.

How does a fuel-cell vehicle work?

When you fuel the vehicle the hydrogen gas travels to carbon-fibre-reinforced fuel tanks, where it is stored. The hydrogen then travels from the tanks to the fuel cell stack. There it goes through a chemical reaction involving the oxygen in the air, delivered to the fuel cell stack from front intake grilles. The chemical reaction creates electricity that then powers the vehicle. When you put your foot on the accelerator, electricity from the fuel cell stack is sent to the electric motor to propel the vehicle forward.

In the end, the only by-product of creating electricity with hydrogen and oxygen in the Mirai’s fuel cell stack is water, which exits from the tailpipe.

THE HISTORY OF THE HYDROGEN FUEL CELL GENERATORS

Francis Thomas Bacon creates the first fuel cell generator, producing 5kW of power.

THE HISTORY OF THE HYDROGEN FUEL CELL SPACECRAFTS

NASA equips their crafts with fuel cells for onboard electronics and water.

FORKLIFTS

Machinery company Allis-Chalmers builds the first fuel cell forklift.

SUBMARINES

The German Navy uses fuel cell technology to power their U31 submarine.

VEHICLES

Toyota unveiled its first hydrogen vehicle, the Mirai, in November 2014 at the Los Angeles Motor Show.