Tuesday 3rd April 2018

PH Origins: Fuel cell-powered vehicles

Fuel cells seem a sound solution to zero local-emissions motoring - but they've been a long time coming...

---

Battery-powered vehicles, despite their many qualities, aren't ideal for all drivers. Range limitations, issues in colder climates and charging-related tribulations are often problematic for many potential buyers.

These issues have existed since the first EVs began quietly humming their way around roads in the 1800s. As the internal combustion engine came on song, however, the market's focus shifted to this far more flexible source of motive power. Consequently, development of electrical vehicles slowed to a crawl.

In the 1960s electric power and alternative fuels suddenly popped back onto manufacturers' radars. The rapidly expanding number of cars on the road was causing terrific increases in urban pollution, resulting in pressure from both government bodies and environmental groups.

For example, in the United States, the Clean Air Act of 1963 was expanded upon with the Motor Vehicle Air Pollution Control Act of 1965. Harmful emissions were in the spotlight and, as the years rolled by, the number of tests and requirements increased exponentially.

Consequently, manufacturers began investigating alternative forms of power to pave the way for cars that could meet the presumably far tighter regulations of the future. Battery power, hybrid technology - and cutting-edge fuel cells - became key topics of discussion and development.

It was the clean fuel cell option which proved of considerable interest to some, for a reason that's still cited today - a fuel cell would produce power for as long as you supplied it with the required fuel. Unlike a battery-powered vehicle, which would require time-consuming charging, a fuel cell-equipped car's tanks could simply be refilled and it could then continue on its merry way.

The basic concept of a fuel cell had been around for a considerable amount of time by this point. In essence, a fuel cell converts chemical energy into electricity that can then be used to run a motor. An electrochemical reaction between the fuel, usually hydrogen, takes place with oxygen in the cell, producing electricity, heat and - if it is a hydrogen fuel cell - water. This means there are no harmful local emissions and that the fuel cell can provide power as long as it's supplied with oxygen, usually sourced from ambient air, and fuel.

Welsh scientist Sir William Grove, and German-Swiss physicist Christian Friedrich Schönbein, separately developed what would later be recognised as fuel cells in 1839. As material and chemical understanding improved in the first half of the 1900s, fuel cell technology advanced rapidly - with the first effective set-up being demonstrated by English engineer Francis Bacon in 1932, followed by a far more powerful arrangement in 1959.

It was the space race, which kicked off in 1955, that first embraced this new technology in earnest. NASA had been seeking a power source for spacecraft that could meet numerous requirements, ranging from size and output through to reliability and weight, and the fuel cell proved the most competitive option. A hydrogen fuel cell also had the unique beneficial characteristic of producing water, which could be consumed by crews or used to control cabin humidity.

Fuel cells promptly became the hot new thing - and companies, including General Electric and Pratt & Whitney, scientific institutes and other government bodies ploughed seemingly endless resources into rapid development.

In the end, it wasn't a car that first demonstrated a practical wheeled application of fuel cells - but a tractor. The US-based manufacture Allis-Chalmers had also been studying fuel cells, in an effort to develop them for commercial applications. Its propane-fuelled cells and an electric motor were installed in a reworked prototype tractor, developed by engineer Harry Ihrig, in October 1959.

 

General Motors wasn't far behind, though. It, too, had been experimenting with fuel cells as it explored ways of reducing emissions and cutting fossil fuel usage. Drawing on the technology developed for space-going fuel cells, it built a hydrogen fuel cell concept called the Electrovan in 1966.

It was based on a GMC Handi-Van but, instead of a four- or six-cylinder engine, it featured a 120hp electric motor and a fuel cell developed and built in conjunction with experts Union Carbide. The fuel cell was bulky and complicated, however; it almost entirely occupied the Electrovan's load space and used cryogenically stored liquid hydrogen and oxygen.

This was, unsurprisingly, a prohibitively heavy set-up. A standard four-cylinder Handi-Van would tip the scales at around 1,400kg. The Electrovan, however, clocked in at over 3,200kg. Although it could hit 70mph, it would take a glacial 30 seconds to accelerate from 0-60mph. On the plus side, it had a claimed range of 150 miles.

GM was a little concerned about driving the oxygen and hydrogen-laden Electrovan on public roads, understandably, so trials were restricted to its property. While the project delivered much useful information, it was simply too complicated and expensive to pursue further - with GM stating that the platinum elements used in the fuel cells alone cost enough to 'buy a whole fleet of vans'.

Dr Karl Kordesch, an Austrian chemist from Union Carbide, led the team responsible for the basic design of the fuel cell - and he went on to further demonstrate the system's potential regardless, building a fuel cell-equipped motorcycle in 1967 that could travel 200 miles on a US gallon of hydrazine.

Costs remained prohibitive but many manufacturers continued developing hydrogen fuel cells, alongside other alternative sources of power, through the '70s and '80s. The technology found applications in the industrial and commercial transport sectors, too. By the '90s, several manufacturers were engaged in fuel cell development - including Toyota, which unveiled its first prototype FCEV in 1996, Mercedes-Benz, Nissan and Honda.

Low-volume, lease-only prototype series slowly evolved into the likes of today's Toyota Mirai, Honda Clarity and Hyundai Tucson FCEV, production cars which offer quiet and zero local-emissions motoring.

The development of hydrogen fuel cells continues apace, too - with GM alone having sunk more than $2.5 billion into fuel cells since it originally decided to invest in the technology. It's not all dependent on big brands, though; you also have the likes of the endearing fuel cell-equipped Rasa prototype from start-up Riversimple.

This technology still faces many issues, however, including the logistical problem of too few filling stations and the required energy-intensive generation of hydrogen itself. Excess renewable energy may solve that, though, as it could be used electrolyse water and produce hydrogen that could be stored for later use elsewhere.

Similarly, more hydrogen refuelling points are slowly starting to materialise - and ongoing developments continue to drive the cost of the hardware down. For those that find batteries too restrictive it could, given time and further investment, prove a viable alternative.

 

[modeller]

Hydrogen as a fuel for vehicles is DOA. Either it's dirty (getting the H from oil/gas) or too inefficient via electrolysis. The future is electric .. just it'll be batteries for storage and not hydrogen.