Submission from the Institute of Physics
The Institute supports the implementation of
present renewable electricity generating plant and also of continued
R&D into new and improved renewable electricity-generation
technologies. As well as being low carbon energy sources, renewables
have a number of advantages. They enhance diversity in energy
supply markets, secure long-term sustainable energy supplies,
reduce dependency on imported energy supplies, and reduce emissions
of local air pollutants. Their dominant use is for grid connected
electricity, but in conjunction with storage they can contribute
to stand-alone off-grid systems. Hence, renewables are an essential
part of present and future electricity generation in the UK.
The Institute notes the government's commitment
to see renewables grow as a proportion of the UK's electricity
supplies to 10% by 2010, with an aspiration for 20% by 2020. According
to the 2007 Energy White Paper, Meeting the Energy Challenge,
around 4% of the UK's electricity was generated from renewable
sources in 2006, with the percentage contribution gradually increasing.
The Institute believes that these targets represent
significant challenges, especially the 2010 target, when considering
present market conditions and planning consents, which are significant
barriers to exploitation. However, analyses carried out to support
the 2003 Energy White Paper, Our energy future: creating a low
suggested that about a third of electricity could be supplied
by renewables by 2040, although this could be substantially more
if some of the other options for low carbon energy supply were
not adopted. For example, renewables could supply up to two thirds
of electricity demand if no new nuclear plants were built and
carbon capture and storage for fossil fuel-fired plants were not
implemented. The modelling work suggested that wind, in particular
offshore wind, and biomass would account for a significant proportion
of renewable electricity generation. In addition, technologies
with a higher cost but sizable potential resource, such as photovoltaics,
could also contribute significantly.
In October 2005, the Institute published its
report, The Role of Physics in Renewable Energy RD&D,
which was prepared by Future Energy Solutions, AEA Technology
Environment. The report set out the challenges facing renewables,
the important role of research, development and demonstration
(RD&D) in meeting this challenge, and areas where physicists
contribute to this RD&D.
Section 3 of the report (pages 6-20), highlights
in detail the progress made in a number of key technologies, including
photovoltaics, marine energy, fuel cells, hydrogen infrastructure,
electricity transmission and distribution, energy storage, as
well as mature technologies. The report provides a robust review
of these technologies, citing case studies from UK university
departments and offering commentary on the barriers to progression
According to the report, the two key areas where
the UK has an opportunity to take a lead on are:
the new generation of photovoltaic
technologies, although this would require a strong RD&D effort;
research into wave and tidal energy,
where there are a number of universities with significant research
Ensuring that these RD&D strengths are developed
could bring substantial benefits to the UK, both in terms of enabling
deployment of these technologies, with subsequent environmental
benefits in terms of reducing carbon dioxide emissions, and in
terms of export earnings as technologies are deployed globally.
This will require RD&D support and the availability of suitably
qualified individuals to work in these areas.
The Institute's report revealed that an important
area where physicists are contributing to RD&D is in photovoltaics,
where they are carrying out much of the fundamental research required
to develop novel types of cell that may result in step changes
in the cost of photovoltaic generation. Photovoltaics can readily
be adapted to suit the diffuse light conditions as evidenced by
their widespread use in Germany. There is a strong research effort
in the UK but to benefit fully from this vitally important technology,
investment in the underpinning science needs to improve considerably.
Currently, over 95% of photovoltaic modules
are made of silicon in its various forms, of which about 5% is
non-crystalline silicon (such as amorphous silicon). They convert
sunlight into electricity with an efficiency ranging between 13
to 17%.The maximum potential efficiency is only about 25% because
only the light with photons of the right energy to generate the
charge carriers (the bandgap) is absorbed.
The vast majority of solar cells on the market
today are so-called "first-generation" solar cells made
from monocrystalline silicon. However, they are expensive to produce
because of the high costs of purifying, crystallizing and sawing
electronic-grade crystalline silicon, which is rather fragile
and in short supply.
Furthermore, the POSTnote, Carbon footprint
of electricity generation,
reported that, "The silicon required for photovoltaic
modules is extracted from quartz sand at high temperatures, which
is the most energy intensive phase of module production, accounting
for 60% of the total energy requirement. However, future reductions
in the carbon footprint of photovoltaic cells are expected to
be achieved in thin film technologies which use thinner layers
of silicon, and with the development new semi-conducting materials
(organic cells and nano-rods) which are less energy intensive".
As detailed in the Institute's report, most
physicists are now working on "second-generation" solar
cells, which are near market, with the aim of reducing costs by
using thin films of crystalline silicon and other semiconductors,
such as amorphous silicon, gallium arsenide, copper indium diselenide
and cadmium telluride, which are mounted on glass substrates.
For the future, physicists are also working on "third-generation"
solar cells, such as dye-sensitised photochemical, and quantum/nanotechnology
solar cells, which could potentially yield extremely high efficiencies
and be as cheap as thin-film devices.
However, the article, "Bright outlook
for solar cells", published in the July 2007 issue of
the Institute's membership magazine Physics World,
whilst commenting on how future research efforts could transform
solar cells from niche products to devices that provide a significant
fraction of the world's energy, offers some caution by reporting
that building cheap and efficient cheap solar cells does not guarantee
that solar power will become a major part of the world's energy
mix. Even if these devices can be converted into high-performance
commercial products, there remains the problem of actually building
and installing the enormous number of panels that would be required.
Mankind currently consumes energy at a rate of 13 terawatts, and
many experts predict that population growth and economic expansion
will increase this figure to around 45 terawatts by 2050. Generating
20 terawatts of that with panels that are around 10% efficient
would, according to the 2005 report, Basic Research Needs for
Solar Energy Utilization,
sponsored by the US Department of Energy, mean installing such
panels over 0.16% of the Earth's land surface.
Nonetheless, commercial forces around the world
are participating in and helping to maintain an expansion in photovoltaic
installations, for example, with building-integrated photovoltaics.
In the UK approximately two thirds of electricity is consumed
in residential, public and commercial buildings. At least seven
times the solar radiant energy falls on those buildings as the
electricity consumed inside. This means that more than three times
the current nuclear power contribution could be generated by covering
all roof areas and south-facing walls with first and second generation
solar cells which are around 13% efficient. Furthermore, as third
generation solar cells are 2-3 times more efficient than first
and second generation solar cells, smart windows could use transparent
lenses as blinds to generate electricity and reduce air-conditioning
and interior illumination demand.
Perhaps the biggest challenge, however, is in
storing solar electricity, given that the Sun does not shine all
the time. Solar energy could be used to pump water up hill when
that energy is not needed and the gravitational potential is then
discharged when the energy is required (technology that is already
used at the Dinorwig Power Station to respond flexibly to rapid
changes in demand). It is also possible that developments in batteries
or flywheels might help solve this problem, while solar electricity
could be used to split water and produce hydrogen.
Given the possibility that solar power is the
only source capable of providing the amounts of electricity that
will be demanded by the world's consumers by around 2040 without
excessive carbon emissions or limited abundance of fuel, it is
imperative that the government removes any remaining barriers
to the realisation of this technology.
Realising the large potential benefits that
renewable and other advanced technologies, such as fuel cells,
could make to a low carbon economy requires a number of technical,
economic, institutional and social constraints to be overcome.
The Institute notes that there are a number of key challenges
that renewables have to overcome, which includes the limits of
support available from the Renewables Obligation.
The Institute notes that the feed-in tariff
system has allowed a number of European countries, such as Germany,
to install significantly more renewables capacity than the UK
at lower cost; these countries also manufacture photovoltaics
at a significant level. The feed-in tariff system guarantees a
price for renewable electricity fed back into the grid. In fact,
in Germany there has been a dramatic rise in photovoltaic installations
as the feed-in tariff system reduces and the market takes over.
The UK government is opposed to feed-in tariffs. The 2007 Energy
White Paper briefly mentions that other European countries have
introduced such schemes but dismisses them by stating that it
was, " . . . hard to draw firm conclusions as to the effectiveness
of these mechanisms . . .". This ignores the evidence of
Germany's lead in the installation of wind and photovoltaics.
In the UK, the Renewables Obligation Certificates (ROC) method
has clearly failed in comparison with the feed-in tariff system.
Therefore, it is vital that the effectiveness of the ROC system
is critically reviewed, the reasons for its relatively poor performance
established and a new and better system put in its place as soon
Other barriers to the deployment of renewables,
as highlighted in the Institute's report, include:
The maturity of renewable technologies varies
considerably. While several are commercially proven, others are
still at a pre-commercial stage, and some still require quite
In the UK, at current gas prices, without market
incentives even mature technologies are not yet competitive with
existing gas-fired combined cycle gas turbine plants, although
in the medium term (2020) some technologies (eg onshore and offshore
wind) could be. Technologies such as photovoltaics are unlikely
to be cost-competitive with centralised generation unless a step
change in cost-effectiveness is achieved by the new types of solar
cells currently under development. They may, however, become competitive
in remote off-grid locations in conjunction with storage, where
the cost of other stand-alone systems, such as diesel generators,
is high. It is also worth noting that as governments seek to reduce
carbon dioxide emissions, the emissions will acquire an economic
Most renewable technologies, for example, wind
power, are variable in output, since they follow the variability
of their resource in the environment. The Institute notes that
demand is also variable, so that some generating plant has to
be kept on standby at all times to meet short-term increases in
demand. The present grid-connected system could cope with a very
significant contribution of wind power (perhaps 25% of annual
demand) without lowering present standards for meeting peak demand.
However, this would still require the present fleet of conventional
power stations to be available to meet peak demands when necessary.
Much larger contributions of wind power would certainly require,
in addition, the development of new storage technologies and/or
online load management.
An individual renewable plant is generally small
in scale compared with conventional power stations (typically
a gigawatt or so). Therefore, the present network and control
systems are able to absorb their power without significant adjustment.
Nevertheless, in certain regions, the aggregate renewable power
output may be comparable with that from conventional power stations.
Here, there will need to be some reconfiguring of the grid or
distribution systems. Where major renewable sources are remote
from areas of major consumption (eg in remote parts of Scotland),
new or increased grid infrastructure will be necessary to transport
the power to the load centres.
Social and institutional constraints
Issues which may hamper development include
public acceptability, planning constraints and institutional barriers.
For example, lack of clarity over planning consents, permitting
of plants, skills issues, and investment regimes. While most renewables
are environmentally benign, in that emissions of carbon dioxide
and other air pollutants are typically very small (even allowing
for their manufacture), they do have a number of other local environmental
The Severn barrage plan is a good example of
the real social, environmental and political problems encountered
in adopting many renewable technologies. The plan to build a tidal
barrage across the Severn estuary to produce electricity is, according
to the National Assembly for Wales, potentially the largest single
renewable source in the UK, which could generate at least 5% of
the UK's electricity. However, the plan has received much opposition
from environmental pressure groups that claim the barrage could
cause irreversible damage to local wildlife.
A significant problem facing renewable and other
low carbon generating technologies is that following the liberalisation
of the UK energy market, the current price of electricity is so
low that it is not economically viable to develop and introduce
new generating technologies to the market, unless they can be
developed at a low cost and can provide electricity predictably
at competitive wholesale prices.
The solution to date has been to have UK government
incentives for RD&D. Renewables have benefited from these
and support must continue to stimulate investment for pilot and
full-scale demonstrations of technologies that are sufficiently
mature for near-term deployment. Research into technologies for
mid-term deployment and "blue sky" development is best
undertaken within universities, encouraged and supported by current
funding mechanisms operating within a strategic framework that
takes due account of national priorities and policies.
Investment is also required in the development
of whole-lifecycle financial models, including full acquisition,
operating, distribution, disposal/recycling and environmental
costs, for all of the technologies under consideration. Models
are also required to predict how significant power levels generated
from renewables might change the characteristics of the transmission
network planning and operation.
The Institute's report revealed that renewables
RD&D is funded in the UK through a number of routes, the main
ones supported by the government and the public sector, together
with EU funding. In addition, there is industry funded RD&D,
and the commercial deployment of renewables supported by the Renewables
Obligation. The House of Lords Science and Technology Committee
suggested in its report, The practicalities of developing renewable
that the level of funding for RD&D is not sufficient if the
UK is to meet its renewables targets. While UK expenditure has
increased in recent years (from $37 million in 2004 to $68 million
in 2005), it is still lower than in some other leading European
countries, such as Germany ($115 million in 2005), according to
data from the International Energy Agency;
US expenditure on renewables RD&D was $255 million in 2005.
A DTI/Carbon Trust review
found that there appears to be a funding gap in moving renewables
to the pre-commercial stage, and from the pre-commercial to the
supported commercial stage. The review also considered that the
current landscape for renewables funding is complex, which suggests
that a clearer overall strategy for UK RD&D in both renewable
and other new technologies, together with a clearer map of RD&D
funding and clearer demarcation of the roles of different funding
bodies could be useful. This could be a key activity for the UK
Energy Research Centre to undertake.
Renewables seem to have developed a "low
cost" view of their implementation, which will not drive
the actual costs of developing electricity sources on the scale
needed. There is no clear route to provide a large proportion
of the UK's electricity needs by this method. Photovoltaics, for
instance, are certainly more appropriate for local power supplies
and the concept of using them for large central `power stations'
is difficult to support.
The Institute's report noted that studies which
examined the renewables supply chain have reported that several
technology and project developers have found a lack of necessary
skills in the UKboth general technical skills and also
more specialist skills,
Developers have remedied this either through in-house training
or by recruiting internationally.
Hence, encouraging physicists, and indeed other
scientists and engineers, to consider a career in renewables,
could help to plug the skills gap. One option would be to raise
awareness of and interest in the physics element in the development
of these technologies. This could be achieved by promoting the
inclusion of relevant examples on undergraduate physics courses,
or even on A-level courses. Another option would be to raise awareness
of opportunities for physicists in these areas in careers advice
material for physicists, at both graduate and postgraduate level,
and in advice provided for mid-career changes.
There is also concern regarding the shortage
of opportunities at postgraduate level for physicists wishing
to specialise in these areas. There are a few MSc courses in renewable
technologies and fuel cells, but these are, by their very nature,
multidisciplinary, and obtaining funding or training bursaries
for such courses can be difficult. There are also few PhD research
opportunities, again partly due to the difficulty of obtaining
funding for interdisciplinary or multidisciplinary research topics.
A more flexible approach from funding bodies may be required.
231 www.dti.gov.uk/energy/whitepaper/page39534.html Back
Renewables Innovation Review, DTI/Carbon Trust, 2004. Back
Mott MacDonald 2004 "Renewable energy supply chain analysis",
ICCEPT & E4Tech Consulting 2004 "The UK innovation
systems for new and renewable energy technologies". A report
for the DTI. Back