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4WD MODIFICATIONS - TECH TORQUE

FUEL CELLS EXPLAINED
The fuel cell will power future 4WDs and here's how it works.

As vehicle makers enter a new era of propulsion based on electric motors it’s timely to look at the fuel cell. This cold (or warm) combustion power source is already in service in several areas, including portable electricity generation and vehicle power.

 

The concept of a fuel cell was demonstrated in the early nineteenth century by a number of scientists, including Humphry Davy and Christian Friedrich Schönbein. William Grove, a chemist, physicist and lawyer, is generally credited with inventing the fuel cell in 1839.

The fuel-cell generator is an (expensive) alternative to a petrol or diesel portable generator, but recent developments in fuel cell technology are reducing pricing to the point where major vehicle makers, headed by Toyota, Hyundai and Honda, have released fuel-cell-powered production vehicles.

In early 2017 Honda and General Motors announced a plan to produce hydrogen fuel cell power systems in the United States from 2020. The companies said they will jointly invest $85 million to add a production line at a GM battery plant in Brownstown, Michigan and create 100 jobs.

The US military already uses fuel-cell electricity generators in large numbers and is evaluating a fuel cell ute: https://outbacktravelaustralia.com.au/announcements/fuel-cell-colorado-on-test

So, where does the fuel cell fit into the electric vehicle hierarchy?

The most common partially-electrically powered vehicles are hybrids that combine a battery pack, one or two electric motors and an internal-combustion engine.

Battery electric vehicles (BEVs) are predominantly battery powered, but some have a small auxiliary powerplant to charge the battery while the vehicle is moving, known as a ‘range extender’.

Fuel-cell electric vehicles (FCEVs) are driven by electric motors, with power from a battery bank that’s charged by an on-board fuel cell. The fuel for the cell is hydrogen that reacts with air.

Because of range issues, hybrid and fuel-cell power systems are the ones most likely to be fitted to 4WDs in the near and long-term future. Hybrids are short-term solutions, because they use fossil fuels, whereas the fuel-cell emits nothing but water vapour and nitrogen that enters the fuel cell with air.

There is no hot combustion in a fuel cell, so no nitrogen oxides are formed and because there is no carbon in the fuel there are no hydrocarbon, carbon monoxide or carbon dioxide emissions either.

Rather than relying on combustion to drive pistons that power an electric generator as in a hybrid car, a fuel-cell vehicle uses electro-chemistry to generate electricity. Compressed hydrogen gas is stored in a vehicle ‘tank’ and combined with oxygen from the air in the fuel cell.

It works like this:

In addition, a fuel-cell electric vehicle is more than three times as efficient as today’s average hydrocarbon-fuel-powered automobile and its range and fuelling time are comparable to those of conventional automobiles.

The FCEV electric drivetrain and battery pack is similar to that in a BEV and both use regenerative braking, a key energy-saving feature of electric vehicles.

Although the hydrogen fuel cell generates electric power, FCEVs need a battery pack to supply acceleration energy to the drive motors and to absorb electricity created by regenerative braking. In contrast to BEV batteries, however, FCEV batteries are only of modest size, like those in hybrid cars today.

Where FCEVs and BEVs differ is in the source of electricity, the time required to recharge or refuel, the driving range and the ability to scale up the size of the vehicle. All BEVs are small vehicles and a full-sized 4WD BEV is unlikely, unless there’s a breakthrough in battery size, weight and cost.

The electric driving range of mid-priced BEVs falls between 60 and 320 kilometres. Tesla is a (higher priced) exception, with claimed range up to 480 km. FCEVs and conventional vehicles typically travel 500-800km on a tank.

FCEVs are the base of Toyota’s plan to rid 90 percent of carbon dioxide emissions from its vehicles by 2050. The company has long contended it’s more likely to convince consumers to use petrol-electric hybrids and fuel-cell vehicles rather than battery-electric autos that have less range and take longer to recharge.

A BEV takes half an hour to more than four hours to charge when a high-voltage source is available and more than six hours using off-peak household power.

Toyota’s Mirai FCEV production vehicle looks like this under the skin:

 

 

 

 

The obvious issue with a fuel-cell vehicle is: where do I fuel it? There are many initiatives overseas, but very little interest yet in Australia.

That’s hardly surprising, given Australia’s governments that are chock-full of climate-change sceptics and members who are in coal-miners’ pockets.

However, in January 2017 Australia and Japan signed a memorandum of understanding, allowing for liquid hydrogen to be shipped in bulk for the first
time as part of a sustainable energy trade project scheduled to commence as a pilot project in 2020.

The Federal Government is happy to encourage pollution here, but canny enough to make money out of exporting clean fuel to Japan!

Ironically, while coal power plants and fuel cells may seem like unlikely bedfellows, this is exactly what’s happening in a joint project being undertaken by the United States Department of Energy and FuelCell Energy Inc. Together they are developing carbon-capture technology which will sequester CO2 and nitrogen dioxide from coal burning power plants and use it to power an attached two-megawatt fuel cell. The model they are currently working on is designed to capture about 60 tonnes of CO2 per day.

Bloomberg reported that in early 2017 Toyota, BMW, Daimler, Honda, Hyundai and Kawasaki are joining oil and gas companies Royal Dutch Shell, Total, Air Liquide, Linde, US miner Anglo American PLC, electric utility Engie and rail company Alstom SA with plans to invest a combined €10 billion
($13.9 billion) in hydrogen-related products within five years.

The California Energy Commission states that there were 27 hydrogen filling stations operating at the end of 2016, with 44 in build in 2017, and 74
forecast for 2020. The need for a hydrogen-fuelling infrastructure elsewhere in the USA is being addressed byH2USA, an initiative supported
by theUS Department of Energy.

In Europe, there were around 50 hydrogen-fuelling stations at the end of 2016 and a program called Hydrogen Mobility Europeis ensuring there will be
many more.

As of mid-2016, there were 80 hydrogen stations operating in Japan and the government is keen to boost the number to 160 before the 2020 Summer Olympics in Tokyo.

 

Hydrogen stations

 

 

 

There has been much written about
the dangers of hydrogen transport and storage, and memories of the pre-WWII ‘Hindenburg’ airship disaster revived.

However, any fuel handling and refuelling operations involve hazards. It’s quite likely that if we tried to implement vehicle refuelling as it’s
now practised around the world in service stations – done by untrained, unskilled people – it wouldn’t pass current OH&S regulations!

In contrast to liquid fuels and LPG hydrogen is much lighter than air and doesn’t ‘pool’ if spilt. It rapidly dissipates upwards.

At present, most hydrogen is produced in plants, then transported and stored, but eventually hydrogen filling stations will simply electrolyse mains water in real time. The technology isn’t far away and several streams are being pursued, including the use of sunlight to split water and ‘particle spin’ to eliminate the by-production of electrode-poisoning hydrogen peroxide during electrolysis.

FCEVs are on the way!

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