A monumental challenge: the transition to a hydrogen economy
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believe that it should be superseded by an economy based on hydrogen, and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”
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
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
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
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
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
(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
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).
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
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,
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
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
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