Memorandum by the UK Energy Research Centre
SUMMARY
To meet the EU 15% renewable energy target will
be a significant challenge for the UK. It is important to understand
that reductions in the UK's total energy demand will produce proportional
reductions in the renewable contribution required. Although self-evident,
this simple fact is often overlooked. Indeed the UK has to date
failed to achieve any reductions in energy use, in fact the reverse
is true: energy consumption in the key sectors of electricity
and energy for transport continues to rise steadily.
In addition to reducing the demand for energy,
there will need to be a massive increase in the contribution of
renewables to transport fuel (predominately biofuels), heat and
electricity. This submission concentrates on renewable electricity
because UKERC has core competency this area. In Table 1, below,
UKERC presents an illustrative scenario for the contribution of
renewable electricity technologies towards the 2020 target. In
this scenario 41% of UK electricity will need to be generated
by renewables, most likely dominated by wind power (28%) and biomass
(7%). This will be extremely challenging both in terms of renewable
energy generation plant installation rates and the world capacity
to build and deliver the technology, and also in terms of integration
issues. Immediate and wide scale mobilisation of resources (human
and otherwise) is required.
Table 1
AN ILLUSTRATIVE 2020 SCENARIO FOR THE CONTRIBUTION
OF VARIOUS RENEWABLE TECHNOLOGIES TOWARDS UK ELECTRICITY GENERATION[25]
| | 2006
| 2020 |
| | |
| | | |
| |
| Technology | MW
| GWh | LF % |
% Elec | MW | GWh
| LF % | % Elec |
| Onshore wind | 1,651 | 3,574
| 25% | 0.9% | 20,000
| 52,560 | 30% | 13.1%
|
| Offshore wind | 304 | 651
| 24% | 0.2% | 20,000
| 61,320 | 35% | 15.3%
|
| Wave | — | —
| 0% | 0.0% | 1,000
| 2,978 | 34% | 0.7%
|
| Tidal | — | —
| 0% | 0.0% | 1,000
| 3,679 | 42% | 0.9%
|
| PV | 10 | 7 |
8% | 0.0% | 571 |
1,000 | 20% | 0.2%
|
| Hydro | 1,522 | 4,605
| 35% | 1.1% | 1,522
| 4,606 | 35% | 1.1%
|
| Biomass | 1,837 | 9,946
| 62% | 2.5% | 5,350
| 28,119 | 60% | 7.0%
|
| Severn[26]
| — | — | 0%
| 0.0% | 5,000 | 10,950
| 25% | 2.7% |
| TOTAL | 5,324 |
18,783 | 40% | 4.7%
| 54,443 | 165,213
| 35% | 41.0% |
INTRODUCTION
The focus of this inquiry is on 2020, but it is important
to place the illustrative scenario presented in this submission
in the context of longer term developments in the UK energy sector.
Beyond 2020 it is possible that electricity will play a greater
role in the transport sector (for example through plug-in hybrid
electric and electric vehicles) and for heating (through heat
pumps, ventilation heat recovery and electric heating). This would
have knock-on effects on energy demand and as a consequence it
is important that the mix of electricity generation technologies
in terms of carbon emissions, cost and security remains effective
in the long-term to meet these targets.
It is clear that the brunt of contribution to the UK's 2020
target of 15% of primary energy will fall to renewable electricity
generation.
If it is assumed that 10% of the UK's transport fuels will
be of renewable origin in line with the draft directive, then
the proportion that needs to come from electricity will depend
on the renewable heat contribution. It is important here to also
recognise the potential for demand reduction measures. Heat demand,
in particular, has the potential to be significantly reduced through
a number of measures and an aggressive policy framework. In the
scenario summarised in Table 1 we have assumed, perhaps optimistically,
that heat demand in 2020 will be reduced by 20% compared to 2006.
In theory a substantial proportion of UK heat could come
from a combination of domestic solar water heating, sustainable
wood heating and other energy crops, plus the allowable contribution
from heat pumps.
To give a feel for possible renewable heat consider an extreme
case where 20 million households (the majority of the UK housing
stock) are fitted with solar water heating. Each system would
contribute around 2000kWh per year or 50% of domestic hot water,
thereby contributing about 5% of national heat requirements. In
this context and with policies to deliver such change, a 10% target
for renewable heat is feasible.
Table 1 presents an illustrative scenario demonstrating the
contribution of electricity towards the 2020 EU renewables target.
In this scenario it is optimistically assumed that in 2020 demand
for electricity and transport fuel remains flat at 2006 levels
and that demand for heat is reduced by 20% based on 2006 levels.
Assuming that 10% of the supply of transport fuels and heat is
derived from renewable resources by 2020, the proportion of electricity
required to meet the overall UK target for renewable energy of
15% can be estimated (assuming no significant changes to conventional
plant efficiency). The result is that 41.1%[27]
of electricity must come from renewable sources. For comparison
currently just over 4% of the UK electricity (and 1.3% of total
energy) is derived from renewable resources. Let us now consider
the different renewable electricity technologies and their potential
to contribute to the UK 2020 target.
Wind energy is the most developed of the technologies.
Given the excellent UK wind resource, installation rates have
been disappointing with only 2 GW currently installed (including
0.3 GW offshore)—accounting for around 2% of UK electricity.
On a positive note there is currently around 8 GW of wind capacity
in the planning system. Although unlikely, if all of this was
consented, and built, it would be able to generate an additional
7% of UK electricity bringing the total to 9%, and in principle
this could be achieved within a few years. This leaves around
a decade to install an additional 30 GW, assuming that there is
sufficient space and wind resource to do so, which is enough to
generate, in total, 28.4% of UK electricity. We understand that
UK policy anticipates that the majority of this capacity will
be sited off-shore (up to 20 GW in 2020), with presumably the
remainder on-shore. At around 3 GW per annum this represents an
order of magnitude increase on current UK installation rates (0.24
GW per year averaged over the last five years). Germany has achieved
an installation rate of 2.5 GW per year averaged over five years
between 2000 and 2005[28]
(IEA data). Globally, over the same period around 7 GW of wind
power was installed per year on average, possibly indicating global
wind turbine production capacity. Since the UK is not the only
country with ambitious plans for wind energy deployment meeting
its ambitions are contingent upon the capability of world companies
to expand their wind turbine manufacturing capacity to meet this
demand.
Wave energy The UK has the best wave energy resource
in the EU, with 50TWh/year offshore (equivalent to 15% of UK electricity
demand), 7.8TWh/year in nearshore waters and 0.2TWh/year on the
shoreline. However, currently LIMPET, a shoreline device on Islay
(operating since 2000), is the only UK device supplying electricity
to the grid.
The European Marine Energy Centre (EMEC) opened in 2004,
provides test facilities for offshore testing. The Pelamis device
was the first to be tested at EMEC, and Pelamis Wave Power (PWP)
are currently installing three devices (2.25MW) off the coast
of Portugal—the first offshore wave farm. PWP also have
consents and funding for a farm off the coast of Orkney (3MW),
and are planning a 5MW farm at in the South West of England in
the WAVEHUB project. Wavegen, the developers of LIMPET, are currently
installing a harbour wall device at Mutriku in Spain. In addition
there are a number of other developers with funding for sea trials
in the next 12-18 months: Aquamarine, AWS Ocean, Ocean Power Technologies,
and Wavedragon. Wave energy is very much an emerging technology,
with deployment at the MW level. Its development pathway is approximately
15 years behind that of wind power.
It is estimated that 1GW of both wave and tidal current energy
could be installed by 2020 in UK waters (see UKERC's Marine Technology
Roadmap). This would require a rapid increase in deployment from
2012 onwards. A deployment of 1GW of wave energy by 2020 in the
UK would translate to 0.8% of the UK's total electricity. The
Carbon Trust predicts that there could be between 1-2.5GW of wave
energy in European waters by 2020. There is a lot of activity
and planned deployments in the UK, but it will be challenging
to meet the Carbon Trust/UKERC 2020 predictions.
Tidal current The Carbon Trust estimate that the UK
tidal current resource is 18TWh/year, equivalent to 5% of UK's
electricity demand and about 10-15% of the total world tidal current
resource. The technologies for tidal current generation show less
variation than for wave energy generation, in which every device
operates on very different principles. Hence, it could be argued
that the technology is nearer to market. Marine Current Turbines
(MCT) is the only UK developer to have successfully demonstrated
tidal current turbine technology and have been operating a 300kW
device off the north coast of Devon since 2003. They have also
recently installed the first commercial device (the Seagen project)
in Northern Ireland which is rated at 1.2MW. MCT also plan a 10.5MW
tidal current farm at the Skerries between the Welsh mainland
and Anglesey, which could be installed as early as 2011. A full
scale tidal current test site has been established at EMEC, with
Open Hydro, an Irish developer, testing a 300kW grid connected
device.
Like wave energy, tidal current energy is an emerging technology,
with deployments at the MW level, but has the potential to make
a significant contribution to the UK's renewable energy targets.
It is estimated that 1GW of tidal current energy could be installed
by 2020 in UK waters (see UKERC's Marine Technology Roadmap).
A deployment of 1GW of wave energy by 2020 in the UK would translate
to 0.9% of the UK's total electricity. The Carbon Trust has predicted
that between 1-2.5GW of tidal current could be deployed in European
waters by 2020.
Photovoltaics remain expensive but policies in both
Japan and Germany have demonstrated that with appropriate market
support significant capacity can be installed relatively quickly.
Analysis by the PV EU Platform estimates that 3% of EU electricity
can be met in this way by 2030, which is considerably less than
Germany has already achieved (see UKERC's Solar Energy Road map).
In the UKERC scenario a 0.2% contribution (representing a 57 fold
increase on current installed capacity) to UK electricity by 2020
has been estimated.
Hydro electricity currently accounts for 1.1% of UK
electricity through large (1%) and small scale (0.1%) schemes.
The scope for new hydro schemes in the UK is limited because the
majority of the resource has already been successfully exploited.
For example, the potential for new hydro electricity in Scotland
has been estimated to be a maximum of 200MW.[29]
In the UKERC scenario it has been assumed that there is no increase
in the contribution of hydro electricity from current levels.
Biomass electricity currently accounts for approximately
2% of total UK electricity through a mixture of biomass co-firing
at large coal power plants, combined heat and power plants and
anaerobic digestion plants. Professor Gail Taylor (UKERC) has
estimated that that biomass electricity could account for between
7% of UK electricity demand by 2020.[30]
The Severn estuary barrage is currently undergoing
a two year feasibility study to assess the cost and environmental
impact of the proposed scheme. It is uncertain whether the barrage
will be completed by 2020 and what contribution it will make to
UK electricity generation. In this response we have optimistically
assumed that an 8 GW barrage will be partly completed by 2020
and at time able to generate up to 5GW, and thereby providing
2.8% of the UK's total electricity. Of course if the Severn barrage
is not contributing, for whatever reason, then the onus will be
on an alternative renewable technology to take up the slack.
Integration issues will become significant as renewable
energy electricity penetration levels in the UK move beyond 20%
of electrical energy. There are a number of key issues associated
with integration of 40% renewable electricity, including:
— connection charges and transmission charges;
— new distribution lines and reinforcing existing
lines;
— integrating renewable resources that produce heat
and electricity—for example biomass CHP—so that both
outputs are used effectively and efficiently; and
— system management and stability.
Research into these issues is underway but has not yet progressed
to a sufficient level to give confidence as to the technical and
commercial consequences of very high levels of penetration. It
is likely that 30-40% of electrical energy from renewables will
require major investment in transmission and, possibly, distribution
infrastructure, and changes to operational practice.
Energy demand reduction is a mechanism through which
the overall size of the EU 15% renewable energy target can be
reduced in absolute terms (ie you would simply need to install
less renewable energy capacity to meet the target). The University
of Oxford Environmental Change Institute[31]
(ECI) in their report to the Royal Commission on Environmental
Pollution (The Urban Environment report) examined the potential
for demand reduction from the UK housing sector in 2020 comparing
the difference between a business as usual and aggressive policy
scenarios with a focus on major carbon emissions reductions.
The findings of this report indicated that an aggressive
policy scenario of demand reduction from the UK housing sector
could reduce overall UK energy demand by approximately 5%.[32]
In the context of the 15% renewable energy target this would reduce
the absolute number by the equivalent of about 1%. The potential
for demand reduction in the business and transport sectors is
approximately the same. Therefore, if aggressive demand reduction
policies were applied in the UK housing, business and transport
sectors then approximately one fifth of the 15% target might be
delivered through energy efficiency.
CONCLUDING REMARKS
Even with optimistic targets for the installation of renewable
energy generation technologies, meeting the UK 2020 15% renewable
energy target will be extremely challenging. Demand reduction
could potentially reduce the size of the overall effort required,
but even with aggressive policies there is a large renewables
gap that must be filled. This will be extremely challenging both
in terms of renewable energy generation plant installation rates
and the world capacity to build and deliver the technology, and
also in terms of integration issues. Immediate and wide scale
mobilisation of resources (human and otherwise) is required.
25
Following assumptions used to calculate contributions. Energy
consumption based on BERR 2006 figures. 2020 energy consumption
scenario assumes that electricity and transport consumption remain
flat and that heat is reduced by 20% because of demand reduction
measures. This scenario is for example only and should not be
construed as UKERC policy. Back
26
2020 figure based on estimate-not to be taken as UKERC policy. Back
27
If the contribution of renewable heat towards total heat is increased
by 5% (eg to 15%) then the contribution of renewable electricity
towards total electricity is decreased by approximately 10% and
vice versa for a decrease in the contribution of renewable heat. Back
28
IEA data from Economic and Social data service. Back
29
Forum for Renewable Energy Development in Scotland: Scotland's
Renewable Energy Potential: Realising the 2020 Target-Future Generation
Group Report. Back
30
Professor Gail Taylor, Bioenergy for heat and electricity in the
UK-a paper for the Office of Science and Innovation (in preparation). Back
31
UKERC Demand Reduction theme is based at ECI. Back
32
The difference in 2020 is 93 TWh (about 17%), with 20 TWh of electricity
saved in appliances and 73 TWh saved in heat (mainly gas). Back
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