Some (possibly optimistic) observers have noted that we have approached the beginning of the end of the carbon era. Professor Keith Guy looks at one of the alternatives to fossil fuels and discusses whether the hydrogen economy can ever become a reality.

By: Professor Keith Guy, Institution of Chemical Engineers, UK

A growing global population, rising standards of living, and more industrial production mean the amount of energy the world consumes could rise by 50 to 60 per cent in the next 25 years.

Today, the biggest forms of energy are fossil fuels – oil, gas, coal. But, that will change for at least two reasons: ‘easy’ oil and gas sources are declining; and emissions of greenhouse gases related to fossil fuels are rising to unacceptable levels given their potential impact on climate change.

The world clearly needs more energy from alternative sources. Nuclear power is in the ascendance again. China and India have announced ambitious construction plans and the UK government has also made positive signals about nuclear energy.

Renewable energy use is also growing rapidly but still have a relatively small share of total energy use. Countries vary considerably in their adoption of renewables. China has announced a target of increasing renewables to 20 per cent of its total energy use by 2020 whereas New Zealand already generates about 70 per cent of its electricity from renewable sources. However, storing electricity generated from renewable energy sources in large quantities is very difficult so an alternative is needed.

On the biodiesel front, production has increased from negligible quantities in 1990 to over 2.5 billion litres in 2005. In markets like Brazil, biofuels already have a large market share and geopolitical developments have encouraged others, such as the US, to ramp up crop production for biofuels. This helps to reduce our dependence on oil but has a knock-on effect of increasing the price of corn (maize). So, these are some of the alternatives to traditional fossil fuels but what other options are open to us?

Hydrogen is already providing a growing alternative energy carrier for transportation with many countries viewing it as key to tackling the growing crisis of carbon emissions and the elimination of fossil fuels as a major energy source.

Impeccable ecological credentials

The hydrogen economy has strong green credentials. Many believe it will be key to overcoming some of the problems created by the ever-increasing use of fossil fuels in today’s economy. But how?

For a start, the use of hydrogen has none of the pollution problems associated with fossil fuels. When used in a fuel cell to create power, the only by-product is water, making hydrogen a clean technology with no environmental dangers.

Secondly, hydrogen does not contribute to the problem of greenhouse gas emissions. The production of hydrogen occurs within a perfect cycle. Electrolysis, using renewable electricity, produces hydrogen from water, and the hydrogen then recombines with oxygen to create water and power in a fuel cell, having absolutely no negative impact on the environment.

Thirdly, at a strategic level, the increased use of hydrogen would reduce our dependence on fossil fuels from markets such as the Middle East, spreading the risk and shielding economies from oil price hikes.

And finally, hydrogen can be produced at virtually any location as long as electricity and water are present. In fact, it could even be produced in individual homes with relatively simple technology.

There is increasing noise coming from the hydrogen sector as the world starts to get behind this alternative fuel source. The environmental challenges of fossil fuels combined with technology breakthroughs in fuel cell technology are enabling us to take the first steps towards this new approach to energy.

Economic and political world leaders such as the USA and Japan are increasingly adopting hydrogen technologies, typically within the transport sector where the benefits are more transparent. And, in a bold move, Iceland has set itself the challenge of becoming the world’s first hydrogen economy, with hydrogen supporting all of its energy needs, including transport vehicles and shipping, by 2050. This means the total elimination of fossil fuels and should result in a cut in the country’s greenhouse emissions of up to 50 per cent.

But, one could argue that Iceland’s natural energy resources, its waterfalls and hot springs give it an unnatural advantage over less well-endowed countries. And, at a more general level, hydrogen opens up major commercial, political, technical and sociaßl concerns that could have a real impact on its more widespread adoption.

So let us look at what progress the world is currently making towards the hydrogen economy.

Fuel cell efficiency

The most obvious step that we are beginning to see is the introduction and take-up of fuel cell-powered vehicles. Although there may be an intermediate stage with onboard gasoline reformers, these hydrogen-powered cars offer immediate benefits – they are about twice as efficient as current fossil fuel-based cars and can significantly reduce air pollution in cities.

Public and private sectors must work together if the hydrogen economy is to replace a fossil fuel-based infrastructure
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This is a truly international effort. For example, in the USA, General Motors’ designers and engineers have developed the vehicle chassis, as well as the engineering and electrical system integration for Hy-wire (hydrogen drive-by-wire) vehicles. German engineers worked on the integrated fuel cell propulsion system, which was first shown at the 2001 Frankfurt Motor Show. Italian and American designers worked together closely to build the body of the car while in Sweden, SKF Group developed the by-wire technology itself.

Since 2000 when the first hydrogen filling station was set up in Dearborn, MI, USA, we are also beginning to see growing numbers of filling stations opening up to meet the increased demand, most notably in the US, Japan, Germany and Iceland.

Today, some fuel stations in Germany offer hydrogen as part of the Clean Energy Partnership, bus refuelling depots in a number of small European cities are providing hydrogen for public service vehicles as part of the Clear Urban Transport for Europe programme. In British Columbia, Canada, a seven node hydrogen refuelling station network from Victoria to Whistler is being developed to coincide with the 2010 Winter Olympic Games and fuel stations in California have been opened by the California Fuel Cell Partnership as part of Governor Arnold Schwarzenegger’s hydrogen highway programme.

In Iceland, which has very ambitious plans, considerable progress is also being made. Many of the country’s fleet of public buses are already converted to use hydrogen and are refuelled by a filling station on the outskirts of town. In addition, there are plans afoot to convert the country’s entire fishing fleet over to hydrogen use.

But, it is not all plain sailing. Plans for a hydrogen filling station in London, UK, serving three buses in the local area were shelved for 18 months. After various appeals the project eventually went ahead, but the problems highlighted the lack of understanding that has yet to be overcome.

Clearing the hurdles

Unfortunately, while moves towards an increased use of hydrogen are starting to gather speed, as things stand the growth of the hydrogen economy is restricted by a number of constraints at a political, commercial, technical and social level.

Safety concerns are still widespread with the spectre of the Hindenburg accident in the minds of those that can remember. The public perception of the dangers around the transportation and distribution of hydrogen need to be addressed if they are to see widespread use in the future.

At a practical level, and safety concerns aside, there are real issues in terms of how we store and transport hydrogen at present. Hydrogen is a very light gas making it far more difficult to work with than the gasoline we are used to. For example, compressing the gas for easy transportation and storage requires significant amounts of energy and the resulting compressed hydrogen contains far less energy than the same volume of gasoline. However, all is not lost, as the world is working hard to solve some of these storage problems and solutions are starting to appear.

For example, companies such as Chrysler have made the news since they started looking at how to store hydrogen in a solid form. This involves storing the hydrogen in a chemical called sodium borohydride. This chemical is created from borax and, with the simple addition of water, it releases its hydrogen and turns back into recyclable borax.

Once the storage difficulties are overcome and global standards agreed, there should be no practical reason why a network of hydrogen stations can not be rolled out with a transportation infrastructure developed around it.

This brings me on to the next constraint – economics. While the technology is being developed to support the hydrogen economy of the future, the costs associated with adapting will be high. In the US for example, the cost of converting existing gasoline stations to provide hydrogen to vehicle drivers will run into billions of dollars. Also, while fuel cells are getting cheaper they are still more expensive than conventional engines.

And, the cost of actually producing the hydrogen is still relatively high. As things stand, small system costs currently stand at around $0.08 per kWh of hydrogen while larger systems, which favour liquid hydrogen, come in at $0.04 per kWh versus $0.06 per kWh for compressed gaseous hydrogen. Even so, this gives lower running costs than gasoline or diesel offset by currently higher vehicle costs.

The good news is that although the costs of producing hydrogen are high, economies of scale do exist. As the supply increases so the costs will start to come down. It is expected that the same will apply to the associated costs of storage, transport and vehicle design.

But, what we’ll also need to see is a move from natural gas-based hydrogen, which is being used during the market development phase, to industrial-level hydrogen production using renewable resources on an economic basis. This will require further development, both in the public and private sector, if we’re to see any significant progress.

At a political level, there is a real need for a common worldwide approach to the adoption of hydrogen if we are to succeed along the path towards the hydrogen economy. National and international government organizations must get behind the technology and provide the support for research and ultimately the commercialization of hydrogen if we are to succeed in developing a viable and green alternative to fossil fuels.

There will also be a requirement for significant investment in the infrastructure to support the more widespread adoption of hydrogen. As the figures involved are significant and require a large initial capital cost, it is unlikely that the private sector will be able to fully support such a move. Therefore, governments will have a critical role to play in the provision of funds.

MORE work to be done

So, the hydrogen economy is developing and progress is being made but more must be done if we are to see real progress in the medium to longer term. The public and private sectors must work together with government agencies providing the environment for research and development while industry focuses on the commercialization of technology. Only then will the hydrogen economy cease to be theory and become a reality.

Professor Keith Guy, IChE
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