An Essay on the Hydrogen Economy

A monumental challenge: the transition to a hydrogen economy

Gregory Briner

At some time in the future the fossil fuel regime will have to be replaced. Many

believe that it should be superseded by an economy based on hydrogen, and

proponents believe that such a hydrogen economy would have numerous benefits over

the existing system. However, there are several large technological, social and

economic barriers impeding the emergence of hydrogen energy technology. To steer

the economy away from its dependence on fossil fuels and towards a hydrogen-based

alternative will be a monumental challenge.

Large-scale changes to the energy regime in the past have caused step-changes in the

progress of Western civilization. The transition from horses and water wheels to coal

was the driving force behind the industrial revolution of the 18th and 19th centuries.

The expansion of the petroleum industry in the 20th century has shaped modern life as

we know it, with its large commercial enterprises, highly centralized economic

infrastructure and densely populated urban areas. The harnessing of coal, oil and

natural gas has facilitated great economic growth and enabled those in the developed

world to enjoy an unprecedented standard of living (Rifkin 2002).

However, the benefits of fossil fuel use have come at a price. There are energy

security risks for countries such as the UK and the US which are becoming

increasingly reliant on the import of fossil fuels from politically unstable regions. The

by-products from the combustion of fossil fuels contribute to air pollution and affect

the health of humans and other wildlife. There is also “new and stronger evidence”

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that anthropogenic carbon dioxide emissions resulting from the burning of fossil fuels

are contributing to global climate change (IPPC 2001).

For these reasons alone it is desirable to look for an alternative energy regime.

However, we will also be forced to do so, as coal, oil and natural gas are finite

resources. For each there will come a point in the future at which half of the resource

will have been consumed, after which the rate of production will be in constant

decline. The question of when these peaks in global production will occur is a topic of

much debate. Estimates for peak oil range from anywhere between the present day to

around 2040 (Rifkin 2002). The ever-increasing price of oil following peak oil

production will force an energy regime change before fossil fuel supplies run out

altogether. As Don Huberts, CEO of Shell Hydrogen, has noted: “The Stone Age did

not end because we ran out of stones, and the oil age will not end because we run out

of oil.” (Dunn 2002).

Be it sooner or later, the end of the fossil fuel regime is therefore imminent. The

prospects facing any replacement regime will be daunting. Having raised standards of

health care, increased agricultural output and enabled many in developed countries to

lead energy-intensive lifestyles, the fossil fuel regime will leave in its wake a growing

population with a seemingly insatiable appetite for energy. 83.7 million barrels of

crude oil were consumed per day in 2006 (BP 2007), and if current trends continue

world energy demand is projected to grow by 55% between 2005 and 2030 (IEA

2007).

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One candidate which many believe could face up to this monumental challenge is an

economy based on hydrogen. Hydrogen is a colourless, odourless and non-toxic gas.

Like electricity, hydrogen is an energy carrier rather than an energy source and may

be used to store and transport energy. Hydrogen fuel cells may be used to power most

vehicles, portable electronic devices and stationary energy generation systems (Hart

2007). Hydrogen may also be combusted in internal combustion engines or heating

systems for buildings. In a hydrogen economy it is not envisioned that hydrogen

would replace electricity altogether, but rather it would “complement electricity as an

alternative energy delivery service” (Busby 2005).

The attractiveness of hydrogen as an energy carrier is that it has the potential to

provide an incredibly clean and efficient way of storing and transporting energy.

Hydrogen is also in virtually unlimited supply as it is the ninth most abundant element

on Earth, and has been dubbed the “forever fuel” (Hoffmann 1981).

When hydrogen is oxidised in a fuel cell, it releases only water vapour and heat with

near-zero emissions. Therefore the widespread use of hydrogen fuel cells would

improve air quality and dramatically decrease carbon dioxide emissions (Hart 2007).

Fuel cells also produce very low levels of noise and could be more reliable than grid-

supplied electricity in developing countries (Bauen et al. 2003). Fuel cells do not

suffer the Carnot thermodynamic limitations of the petroleum-based internal

combustion engine and so greater fuel efficiencies are possible (Hart 2000) – fuel cell

automobiles have been built which are 60% efficient, while conventional petroleum

engines have an efficiency of around 20% (UKHA 2006). When hydrogen is

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combusted directly in an internal combustion engine the production of nitrogen oxides

is reduced by more than 90% in comparison to petroleum (Cho 2004).

Hydrogen could also offer the solution to the intermittency problem that is restricting

the progress of renewable energy sources such as wind, wave and tidal energy (DTI

2003, Carrasco et al. 2006). The variable output of such renewable energy sources

currently causes problems for grid integration. However, by using these energy

sources to generate hydrogen during times of excess production and then converting it

to electricity during times of lean production, the electrical supply to the grid may be

“smoothed out”.

A hydrogen economy could have further benefits. Hydrogen may be extracted from

water using any source of renewable electricity (Adamson 2004) or produced directly

by the biological activity of algae and bacteria (Das and Veziroğlu 2001), and this

large range of potential sources would greatly improve energy diversity (Busby 2005,

Tseng et al. 2005). The increased flexibility of supply could lead to a decentralization

of the energy grid, and such a decentralized energy infrastructure would be less

vulnerable to terrorist attacks (Rifkin 2002).

Consequently hydrogen energy research and development is an area of great

international activity. The greatest focus so far has been on transportation. The

transport sector is heavily reliant on petroleum, which accounts for over 99% of all

transport fuel in the UK (DfT 2007), and this means that there is a greater demand for

competitive hydrogen technology in this sector than other less homogenous energy

sectors (Solomon and Banerjee 2006). Over $3 billion is being invested into

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hydrogen vehicle research annually by the automotive industry and governments. The

Japanese Millennium Project aims to have 50,000 hydrogen fuel cell vehicles on the

road by 2010, while in the US the Bush administration launched a $1.2 billion

program in 2003 with the aim of bringing hydrogen fuel-cell cars into the marketplace

by 2020 (Hart 2003).

In 1998 Chris Fay, then Chief Executive of Shell UK, made the statement: “We

believe that hydrogen fuel cell powered cars are likely to make a major entrance into

the vehicle market throughout Europe and the US by 2005” (Hoffmann 2001).

However, this has still not been achieved and according to energy experts such as

Ernest Monitz at MIT, hydrogen technology is still “very, very far away from

substantial deployed impact” (Service 2004a). The development of hydrogen

technology is taking longer than predicted primarily due to the enormous

technological challenges involved in finding economic methods for the production,

storage, and distribution of hydrogen.

Elemental hydrogen does not occur naturally on Earth and so must be extracted from

hydrogen-containing compounds such as natural gas or water. Hydrogen is tightly

bound within these molecules, and so extraction processes require large amounts of

energy and are expensive compared to the techniques used to harvest fossil fuels

(Kreith and West 2004). Currently the most cost-effective method of hydrogen

production is steam reformation of natural gas, but this releases carbon dioxide and

continues to rely on depleting fossil fuel supplies (Turner 2004). Although hydrogen

is often described as a “clean” fuel, it is only as clean as its source and it is important

to assess the impacts of the full lifecycle of a product before using such a description

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(Refocus 2004). Until production methods using low-carbon renewable energy

sources become economically competitive, natural gas will remain the principal

source of hydrogen fuel. Carbon sequestration could be used to reduce carbon

dioxide emissions during this interim period, but this would add 25-30% to the cost of

production (Hart et al. 1999, Service 2004b).

The extremely low density of hydrogen makes it a difficult substance to store in a fuel

tank. Although it contains about three times more energy per unit weight than

petroleum, due to its low density hydrogen gas contains around four times less energy

per unit volume (UKHA 2006). To store enough hydrogen in the fuel tank to give a

vehicle an acceptable driving range, the hydrogen must be pressurized, liquefied,

bound within metal hydrides or stored in absorbent materials. Fuel tanks have been

designed which can store hydrogen at pressures of up to 700 atmospheres (Cho 2004),

but such reinforced tanks are heavy. To liquidise hydrogen it must be cooled to

–253°C, and this consumes a large amount of energy (Kreith and West 2004). Metal

hydrides with high hydrogen contents have been synthesised (eg. Wang et al. 2007),

but to release the hydrogen within them metal hydrides must be heated to around

300°C which again consumes energy. Research into novel materials such as carbon

nanotubes and heavy metal complexes which can store and release hydrogen at near-

ambient temperatures is being conducted at the University of Bath (Yin et al. 2000,

Brayshaw et al. 2007).

Distribution problems are caused by the small molecular size of hydrogen, which

allows it to diffuse easily through small fissures. Natural gas pipelines would have to

be modified in order to carry hydrogen, as existing pipelines would leak and hydrogen

6

would cause embrittlement of the metal (Rahman and Andrews 2006). This would be

expensive, and improved methods for leak detection would have to be developed.

The transport of pressurised hydrogen by lorry is also uneconomic, as it is estimated

that 20% of the energy content of the fuel would be consumed during a journey of 300

km (Bossel 2006). A distributed energy generation grid which allows hydrogen to be

generated locally would be more practical. Such local generation could consist of

stationary fuel-cell power plants in homes and offices into which hydrogen-powered

cars may be “plugged in” (Lovins and Williams 2001), but again it will be many years

before this technology is available.

There are also social and economic factors obstructing the emergence of a hydrogen

economy. Public acceptance will be essential if hydrogen is to succeed in the

marketplace (O’Garra et al. 2007). A review by Schulte et al. (2004) showed that

although attitudes towards hydrogen are generally positive, fears remain about its

safety. It was found that those who have not had personal experience of the

technology are more likely to see a greater risk, while associations with the hydrogen

bomb and the 1937 Hindenburg airship disaster persist particularly amongst older

generations. Scientific assessments have suggested that hydrogen poses a comparable

or even lower risk than conventional fuels (Adamson and Pearson 2000, Carpenter

and Hinze 2004, Winter 2006), particularly as its low density and tendency to

dissipate quickly means that it does not form pools of flammable material

(Verfondern and Dienhart 2007). Hydrogen has been used safely on large scales for

many years in bulk chemicals manufacture and for the hydrogenation of oils.

Although public fears about the safety of hydrogen may be unfounded, they are likely

to persist until people become more familiar with the technology (Schulte et al. 2004).

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The public acceptance of hydrogen technology could be damaged by premature

demonstrations of the technology. Demonstrations are an important part of promoting

an emerging technology (O’Garra et al. 2007), and around 400 hydrogen energy

demonstration projects are currently in progress worldwide (IEA 2005). However,

because it is still many years before many hydrogen applications will become

commercially available, some fear that demonstrating such technology too early on

could cause a negative “backlash” (Romm 2004, Service 2004a), especially as there is

now perhaps a greater public expectation for new technology to be developed quickly

following the rapid proliferation of technologies such as the internet and mobile

phones (Leiner et al. 2003, Banks and Burge 2004).

In the transport market, hydrogen faces tough competition from more established

technologies such as biofuels and electric cars (IEA 2005), while the longer

timescales involved in the development of hydrogen energy are less likely to attract

investors seeking quick returns (Agnolucci 2007). Studies suggest that marketing

hydrogen-powered cars on their environmental credentials alone would not be a

successful method, as price, convenience and performance are also important to

consumers (Schulte et al. 2004). As Andreas Klugescheid, a spokesman for BMW

has put it: “Our customers don’t buy a car just to get from A to B, but to have fun in

between” (Cho 2004). In addition, the proliferation of hydrogen-powered cars is

being delayed by a “chicken-and-egg” relationship between car manufacturers and

energy providers (Schwoon 2006). The car manufacturers are hesitant to spend large

amounts of money on producing hydrogen-powered cars for which there are few

8

refuelling stations, while energy companies are reluctant to invest heavily in a

refuelling infrastructure for which there would be very few customers.

The Stern Review concluded that carbon dioxide emissions must be reduced to 25%

below present levels by 2050 to avoid risking the worst impacts of climate change,

and immediate action is recommended (Stern 2007). The transport sector is the

fastest-growing source of carbon dioxide emissions, increasing by over 2% per year

(IEA 2001), and already accounts for over a quarter of global carbon dioxide

emissions (IEA 2000). Given the numerous barriers restricting the proliferation of

hydrogen technology, particularly in transportation, some believe it unlikely that the

deployment of hydrogen-powered devices will significantly reduce carbon dioxide

emissions within this timescale (Romm 2004). Others warn that the pursuit of

hydrogen energy may in fact exacerbate the global warming situation, because

generating hydrogen from natural gas is less efficient and emits more carbon dioxide

than burning the natural gas directly (Kreith and West 2004). It is argued that energy

policies should instead focus on developing existing energy-efficient technologies,

such as electric hybrid cars, rather than hydrogen (Romm 2004, Van Mierlo and

Maggetto 2007, Bossel 2006, Demirdöven and Deutch 2004).

Despite these criticisms, the hydrogen movement is gaining momentum (Veziroğlu

2000). Many believe that investment in hydrogen energy is justified as the

technological challenges could be overcome with greater funding and government

support (Hart 2003, Dunn 2002), and should be viewed as opportunities rather than

barriers (Clark and Rifkin 2006, Tseng et al. 2005). It is pointed out that much of the

research into hydrogen energy is socially beneficial in other ways (LHP 2007,

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Rahman and Andrews 2006), and that innovation in hydrogen technology is to be

encouraged as it creates added value from its environmental benefits and by accessing

previously untapped sources of energy (Winter 2006). It also increases the number of

technological options available to society, which may be regarded as a form of

knowledge capital (Winnett 2007).

Institutions such as the International Partnership for the Hydrogen Economy (IPHE)

and the IEA Hydrogen Implementing Agreement have been established to coordinate

an international transition towards a global hydrogen economy. However, in their

domestic energy policies, different governments are promoting hydrogen energy to

varying degrees. Iceland announced its intention to become the world’s first complete

hydrogen economy in 1998, and Professor Bragi Arnason, formerly of the University

of Iceland, believes that this could be achieved by 2050 (CNN 2007, MIC 2003,

Vogel 2004). Japan, Brazil, Canada and some states such as California and Hawaii in

the US are also pursuing ambitious policies intended to increase uptake of hydrogen

energy (Solomon and Banerjee 2006).

Although it is a member of the IPHE and the IEA and continues to fund hydrogen

energy research projects, the UK government is yet to commit itself to a hydrogen-

powered future, stating that “whether or not hydrogen will contribute to our future

energy needs is still a matter of great uncertainty” (DTI 2003). An assessment of the

prospects of hydrogen as a fuel in the UK, commissioned for the DTI in 2003,

concluded that the resource potential for hydrogen generation from renewable energy

sources is large, and that the knowledge base is strong in bulk hydrogen handling,

hydrogen storage, fuel cells and energy economics (Hart et al. 2003). Therefore the

10

UK is well equipped to sustain a hydrogen economy should the government commit

to doing so, although its implementation would remain a huge challenge.

Even if a transition to a hydrogen economy should become possible in the future,

history should tell us to proceed with caution. The consequences of such a major

paradigm shift may not all be favourable. As Gary Staunton of the Carbon Trust has

remarked: “The issue with solving today’s problem is that you create tomorrow’s

problem” (Observer 2007). Some potential issues have already been identified, such

as increased vehicle use, hydrogen-induced ozone depletion and land use conflicts

(Cherry 2004, Tromp et al. 2003), and other adverse effects are sure to be discovered

if a transition is made.

In conclusion, a change in energy regime is imminent and an attractive successor is an

economy based on hydrogen energy. Although progress is being made in hydrogen

technology, there is still a long way to go before a hydrogen economy becomes

feasible. The technological, social and economic barriers restricting the proliferation

of hydrogen energy technology are numerous and formidable. Even if the

monumental challenge of a successful transition is achieved, it may be that more than

simply a change in technology is required in order to realise the full benefits of a

hydrogen economy. It is perhaps more our current attitudes and habits of excessive

consumption rather than the fossil fuels themselves which are responsible for the

severity and urgency of the situation we now face.

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An Essay on the Hydrogen Economy

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