Post on 11-May-2020
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SCHOOLS DEBATES 2012 NATIONAL TOPIC
Hydrogen, an energy carrier, is considered one of the most viable fuel alternatives to fossil fuels, but an
input of energy is required for its production. Solar energy is available in abundance on the African
continent. New research is developing nanotechnology to improve the harnessing of solar energy for the
production of hydrogen fuel. Do you think these developments in Hydrogen and Fuel Cell Technology will
offer Africa a viable solution for future sustainable energy?
Scientists and politicians have agreed that human activity and current methods of energy production have
placed tremendous strain on the environment. International conferences such as COP17 highlight the
importance of achieving ‘green’ methods of energy production The link between human activities,
increased greenhouse gas (GHG) emissions (such as carbon dioxide) and climate change was scientifically
confirmed and agreed internationally in 2007, and since then there has been intense focus on developing
renewable sources of energy that are clean (emit none or less greenhouse gas) than traditional coal and oil
based energy sources. One of the major developments was the use of hydrogen and fuel cells in the
alternative energy industry.
Hydrogen is the simplest element (remember its position on the periodic table?). Each atom of hydrogen
has only one proton. It's also the lightest element. At normal temperature and pressure it is a gas. At -
253°C (in other words very cold!) hydrogen condenses to a liquid. Apart from being the simplest element,
hydrogen is also the most plentiful gas in the universe. However, because hydrogen is so much lighter than
air, it rises very easily through the atmosphere. So it is rarely found as a gas floating around by itself on
Earth. However it does bind to other elements such as oxygen to make water (H2O). For our purposes
hydrogen’s most important property is that it can be used as an energy carrier. It stores energy derived
from a source and is able to transport and deliver it.
Fuel cells were invented about 150 years ago, and they convert chemical energy into electrical energy in a
clean, environmentally friendly way, with no harmful carbon dioxide (CO2) emissions. Electricity, heat and
water can be made by the reaction of hydrogen and oxygen with a fuel cell. Hydrogen can be produced
from any hydrocarbon compounds, including fossil fuels.
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The South African government made a commitment in March 2011 to generate 42% of electricity from
renewable energy sources within the next 20 years. Given this commitment the emphasis in South Africa is
on producing energy from renewable energy sources in the long term. Fuel cell technology is more
efficient, reliable, quieter and more compact than most current electricity production methods (nuclear
energy is even more efficient). If the hydrogen used comes from a renewable source, such as solar energy,
this technology is also cleaner and better for the environment.
Nanotechnology is often called an ‘enabling’ or ‘refining’ technology as it allows existing technologies to be
improved. Since nanotechnology allows scientists to build nanometre-scale structures with molecular
precision (known as nanofabrication) from the ground up, molecules can be tailor-made for a specific
function. Nanotechnology offers a viable alternative to non-renewable fossil-fuel consumption and gives us
the means to achieve a “hydrogen economy”. Nano-applications in this area include: solar cells; fuel cells
and new energy production, conversion and storage processes. In all cases, the results are energy that is
cheaper, cleaner, more efficient and renewable.
Solar water-splitting is the process by which energy in solar photons are used to break down liquid water
into molecules of hydrogen and oxygen gas. Hydrogen produced through solar water-splitting is
sustainable and does not emit carbon into the atmosphere. This process is known as photoelectrochemical
splitting (‘photo’ meaning light).
Earlier this year a team of Californian scientists were able to make hydrogen gas by splitting it from water,
using sunlight trapped in nanowires. The scientists designed a nanowire forest of hundreds of nanowires
arranged in a 3D structure (see the image below). The nanowires trapped and reflected sunlight, and the
energy that they stored was used to split the hydrogen atom from the water molecule.
Figure 1. A nanowire forest used to trap solar energy. The image is magnified, but try to determine how
small the nano-structures are using the scale at the bottom of the picture.
Hydrogen is considered to be clean fuel compared to fossil fuel because there is no carbon emission, but
the hydrogen currently used is not generated cleanly. The benefit of the method described above is that no
greenhouse gases are released as a by-product. Solar energy then, is a very green way to make hydrogen
gas.
Utilitarian
There can be no doubt that with an ever increasing urbanised population, South Africa needs to invest
heavily in alternative energy. The recent power supply problems experienced by Eskom highlight this
problem. There is also no doubt that if we are going to invest in alternative energy, we should opt for
cleaner, greener, more sustainable sources. Nanotechnology is already playing a role in other areas of
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product development. It is just as useful in the development of sustainable energy. Some of the major
advantages of using alternative energy are that it can be non-polluting and renewable. The use of
nanotechnology can improve the efficiency of alternative energy technologies. Nanoparticles are used to
improve the catalysts and membrane assemblies that are used in fuel cells. For example, platinum is used
as a catalyst for fuel cells. Nanoparticles are used in this process to reduce the amount of platinum needed.
Nanotechnology miniaturises the pores through which the ions pass in the fuel cell. A nanotechnologically
enhanced membrane can allow hydrogen ions to pass through the cell while blocking the flow of other
atoms or ions, such as oxygen. This allows more efficient membranes to be manufactured, making them
lighter and longer lasting. This, in turn, makes the resulting fuel cell smaller, lighter, more durable and less
expensive to produce.
Nanotechnology has also proven useful as a refining technology in solar energy. It is estimated that the
amount of energy that hits the earth every minute is enough to supply global energy needs for a week. So
theoretically, the world’s energy requirements for a whole year can be met by harnessing all the solar
energy that hits the earth in 52 minutes (which is only 10 minutes longer than an episode of Gossip Girl!).
Even though we can’t harness all the solar energy that hits the earth, we should try to harness as much
solar energy as possible in an economically efficient way. At present the efficiency of harnessing solar
energy has been recorded at a one time high of 43%, although the typical efficiency is usually between 11-
20%. At an efficiency of 20%, for every 100 watts of solar energy that hits a solar panel, it can produce 20
watts of power. Nanotechnology will be able to help in improving this efficiency and reducing the
economic cost. In 2009, a study conducted by Dr Rajesh Sharma and his colleagues at the University of
Arkansas in Little Rock in the USA developed a process involving nanostructures that showed great promise
in boosting the efficiency of titania photoanodes to use solar energy to generate hydrogen in fuel cells.
Socio-cultural
A major problem with energy sources today is that many of the oil rich nations are also the nations most
prone to war and civil unrest. There is thus a very real link between the price we pay for petrol in South
Africa and the civil unrest in Libya for example. Using alternative energy solutions and nanotechnology
offers the potential to reduce the impact of fluctuating world’s oil prices caused by political unrest. Also, by
allowing for local areas to cater for their own energy needs based on what is available (for example in
South Africa, people nearer a water source would benefit from hydropower, whilst solar power might be
better for areas like Oudtshoorn), energy sources can be decentralised. This means that more jobs can be
created in local economies and disruptions to large groups of people can be prevented. This is as true
about oil as it is about coal power.
Furthermore, both oil and coal reserves will someday soon be depleted leaving us with a much bigger
problem and perhaps no options other than turning to alternatives. By using this model, South Africa could
break its over-reliance on a single energy supplier (Eskom), which has not been able to meet all current
demands for electricity, and begin to rely on locally generated power. Every major town and city could thus
be responsible for its own energy needs. Alternatively, the energy generated locally can be fed into the
national electricity grid (Eskom) to supplement supply nationally. How does nanotechnology fit into this
picture? The more efficient you can make the alternative energy sources (as nanotechnology seeks to do),
the better these decentralised power stations can be. This means a greater energy supply to a larger
number of people, hopefully at a reduced cost. With nanotechnology being used in a hydrogen fuel cell
that uses solar radiation as a source of energy, the amount of energy produced can be increased quite
dramatically. People would be able to create a whole new industry from this type of technology and so
increase their livelihood while improving their quality of life and saving the environment. By using solar
energy as a means of making hydrogen we are able to decrease the amount of greenhouse gas that is
released into our atmosphere, which can only be a good thing.
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Economic
One of the biggest reasons why the implementation of alternative energy is hindered is the expense of
many of the forms of alternative energy. For example, a new wind farm that is to be erected just outside
Grahamstown in the Eastern Cape is reportedly going to cost R200 million. Other forms of alternative
energy also come with pretty high price tags. The question that needs to be asked is whether, in the long
run, the benefits we stand to reap by lessening the burden on the environment will be worth it? Solar
energy for example typically requires four to five years of expensive energy before production costs are
recovered and systems begin paying for themselves. With nanotechnology however, tiny solar cells can be
printed onto very thin, flexible light-retaining materials, known as thin-film photovoltaic (TFPV) systems.
Silicon panels are fragile, bulky, heavy, and expensive. Thin-film modules are less expensive to manufacture
and use; they are flexible, light weight, and do not require expensive silicon, reducing the overall cost of
the technology itself. With nanotechnology, the time it will take consumers to recover production and
installation costs may be reduced since nanotechnology provides more light-collecting capabilities. Since,
as discussed earlier, the cost of production has been reduced, it is not unrealistic to say that
nanotechnology would be able to reduce the cost of alternative energy, whilst yielding a greater overall
benefit.
In terms of hydrogen fuel cells, Platinum Group Metals (PGMs) are the key catalytic materials used in most
fuel cells, and with more than 75% of the world’s known platinum reserves found in South Africa there is
great potential for economic benefits. Imagine, for example, if South Africa can start producing its own fuel
cells. South Africa’s platinum mines will be able to produce their own electricity and also sell the unused
electricity to the electricity grid, such as that of Eskom. Platinum mines could potentially become self-
sustaining in terms of their energy production, saving enormous amounts of money. The use of
nanotechnology can reduce the cost of energy production, distribution and storage, since it has the
advantage of reducing the amount of materials used without compromising the expected power outputs.
Use of solar energy would require a substantial capital outlay but, by applying nanotechnology, the amount
of sunlight absorbed by solar panels can be increased significantly, giving you more ‘bang for your buck’.
Furthermore, since the solar energy would be used to generate hydrogen for fuel cells, the economic
benefit is extended to more than just saving electricity. There are many uses for hydrogen fuel, for
example hydrogen powered cars, allowing us to save more money in the long run.
Advancement of Science
Through miniaturisation, nanotechnology also provides an opportunity to tailor-make solutions. In South
Africa, the interest in hydrogen and fuel cells forms part of the Hydrogen South Africa’s (HySA) strategic
objectives. HySA aims to position the country to drive and optimise the use of local natural resources to
produce fuel cells from supplying value-added products such PGMs to the potentially increasing global
markets. Furthermore, one of the well-reasoned and well tested aspects of capitalist competition would
lead to the exponential increase in research and development in the area of nanotechnology and
alternative energy: quite simply, if the market for these emerging technologies becomes big enough and
attractive enough for investors (who are always looking to invest in something that will pay them back one
day), the competition to produce better technology would propel the science in leaps and bounds.
Using solar energy to create hydrogen also allows for the advancement of hydrogen technology in general.
If the means of generating hydrogen become cleaner and more sustainable (as is the case when solar and
nanotechnology are used) then the only limit to the use of hydrogen energy would be our own
imaginations. The switch from a fuel to a hydrogen economy would bring with it ample opportunity for
greater technological ingenuity.
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Democratisation of Science
Quite apart from advancing the science in the international arena, there is great potential for capitalising
on the spread of nanotechnology-enhanced alternative energy solutions as a way to educate the South
African population about various technologies and the benefit that they offer. A prime example of this is
the A hi fambeni (which in Tsonga means “let’s go!”) hydrogen powered tricycle which was unveiled by
Minister of Science and Technology, Naledi Pandor, at a technology and innovation conference in early
August 2010. According to Minister Pandor, “A hi fambeni offers a practical way to promote public
awareness of hydrogen and fuel cell technology as a clean energy alternative”. The bike was developed by
students of the Tshwane University of Technology in partnership with the Department of Science and
Technology and Hydrogen SA (who developed the hydrogen storage capability), proving that innovative
solutions that can be created when key groups work together. You may be wondering how popular this e-
bike (short for electric bike) will be (remembering this is meant for demonstrations). In China there were
only 400 000 e-bikes in use in 1998. By 2007 there were over 21 million e-bikes in use! In 2007 the
Department of Science and Technology launched Shova Kalula, which means “pedal easily” in isiZulu. This
is a partnership with the private sector and civil society that plans to give 1-million bicycles to school
children by 2015 and to build dedicated bicycle paths across the country. Minister Pandor stated that she
hopes a partnership can develop between the creators of A hi fambeni and Shova Kalula. This would be
another fantastic way of educating school children about hydrogen and fuel cell technology,
nanotechnology and other emerging technologies.
Conclusion
There are many ways in which nanotechnology is already in use in our everyday lives. Could it prove useful
as a means of making alternative energy solutions more viable? Are we willing to shoulder the economic
cost? Will it really provide a positive impact on the lives of ordinary South Africans?
Consider what you have read above and research the topic further. The answers are yours for the finding.
Good luck!
Compiled by The Collective Genius