Supplementary memorandum submitted by
the Department of Energy and Climate Change
Annex A
CARBON FOOTPRINT
AND ENERGY
PAYBACK OF
ELECTRICITY GENERATION
All electricity systems, even renewables, have
a "carbon footprint". This means that during their construction
and operation, greenhouse gases such as carbon dioxide (CO2)
are emitted. For fossil fuel plants, a large proportion of the
footprint is CO2 from burning the fuel itself. For
a nuclear plant, there are no direct emissions of CO2,
so the carbon footprint results from the wider lifecycle emissions.
In general, the more a technology is "low-carbon", the
greater the importance of considering complete lifecycle emissions.
The size of these carbon footprints is the subject of some controversy,
so the purpose of this note is to point the reader to the more
reliable estimates.
Summary of estimates of carbon footprints
The Postnote "Carbon footprint of electricity
generation"[23]
gives further background on carbon footprints and the lifecycle
assessment (LCA) approaches used to derive them. The results of
an LCA will depend on its scope (ie where the boundaries are drawn),
which is one reason for the variation in published carbon footprints.
This Postnote summarises carbon footprints for a range of generation
technologies (Table 1).
Also included in Table 1 are values from Lenzen's
group at the Centre for Integrated Sustainability Analysis in
Sydney. This peer-reviewed work formed the Australian Government's
independent assessment of the indirect emissions associated with
the nuclear fuel cycle, as well as comparisons with other types
of generation. This work also has the advantage that consistent
assumptions were used for each generation technology, as does
the work from the Paul Scherrer Institut. The report from the
World Energy Council (cited in the IPCC's Fourth Assessment Report
in 2007) reviewed existing LCA studies, leading to a wide range
of estimates.
What is most striking about the numbers in Table
1 is that nuclear and wind technologies have lifecycle emissions
at least 10 times less than those from fossil fuels. Some of the
Lenzen values are greater than those cited in the Postnote, but
this reflects the different scope of the different approaches.
The AEA study for British Energy (cited in the Postnote) includes
fuel and electricity use for uranium mining and enrichment, but
not the energy required to construct these facilities, for example.
However, some of the reported variation in lifecycle
emissions in a given analysis itself provides useful information.
For PV, lifecycle emissions per kWh are lower when installed in
(sunnier) southern Europe than in the UK, although the higher
value for PV in the Lenzen work presumably reflects a wider scope.
Table 1
TOTAL LIFETIME GREENHOUSE GAS EMISSIONS FOR
DIFFERENT ELECTRICITY GENERATION TECHNOLOGIES
Units are g CO2eq /kWh electricity
generated. References marked * reported their own lifecycle analyses,
while the others collated data from other sources.
| Coal | Gas
| Nuclear | Wind
| PV |
| Postnote[24]
| -1,000 | 500 | 5
| 4.6 (onshore) 5.3 (offshore) | 58 (UK) 35 (Southern Europe)
|
| *Lenzen and co-workers[25], [26]
| 941 863 (supercritical) | 577
| 58 (baseline: coal economy) 33 (gas economy) 10 (nuclear & renewables economy)
| 21 (onshore) | 106 (Australia)
|
| *Paul Scherrer Institut[27]
| 1,180 | 680 | 13
| 15 | 51 (USA) |
| World Energy Council (2004)[28]
| 847 (USA) CCS, 90% capture: 247 (USA) 130 (Australia)
| 411 (UK) | 3-40 | 7-15
| 13-104 |
| CONCAWE[29]
| | 440 (North Sea Gas) 660 (imported LNG)
| | | |
For nuclear power, Lenzen's work shows that the calculated
lifecycle emissions decrease if the wider economy is decarbonised.
The 33 g CO2eq /kWh value would be broadly applicable
to nuclear new build in the UK, while new build further in the
future, if the economy were to be based on nuclear and renewable,
would give lifecycle emissions of only 10g CO2eq /kWh.
The UK is increasingly importing liquefied natural gas. This
leads to substantially greater lifecycle emissions than electricity
from North Sea gas due to increased leaks and transport emissions.
However, carbon capture and storage (CCS) has the potential to
decrease emissions from coal and gas-fired plant, although even
with 90% carbon capture, lifecycle emissions may still exceed
100g CO2eq /kWh.
Energy payback time
Related to the concept of carbon footprint is "energy
payback time", which is the length of time in normal operation
after which the electricity generated will have "paid back"
the energy need to build, maintain and decommission the power
plant. This can be a straightforward way of summarising energy
benefits, although this runs the risks of comparing "apples
and pears" as the outputs will be electricity but the inputs
may be fossil fuels. It can be seen from Table 2 that wind turbines
"pay back" the energy inputs in a few months, while
even the longer energy payback times calculated for PV and nuclear
are less than a fifth of their expected lifetimes.
Table 2
ENERGY PAYBACK TIMES, IN MONTHS, FOR DIFFERENT ELECTRICITY
GENERATION TECHNOLOGIES.
| Nuclear | Wind
| PV |
| Martinez et al (2008)[30]
| — | 4.8 (onshore) |
— |
| Vestas[31]
| — | 6.6 (onshore) 6.8 (offshore)
| — |
| Lenzen (2008) 26 | 75 | —
| — |
| US DoE[32]
| — | — | 44 (US, multicrystalline) 36 (US, thin film)
|
Annex B
COMMUNICATIONS TECHNOLOGIES
FOR SMART
METERING
I said I would report to the Committee on a point raised
by Sir Robert Smith regarding communications technologies for
smart metering. Sir Robert suggested that wireless mesh technology
seemed to be the preferred communications solution to support
smart meters. He expressed concern that there might be a lack
of available spectrum for use of mesh technology once Ofcom has
reached conclusions following its recent consultation on the 872-876
MHz/917-921 MHz band.
As regards whether there is a preferred smart meter communications
technology, we have held two full consultations on smart metering
roll out over the past three years and the evidence from these,
from our wider discussions with stakeholders and roll outs around
the world suggests that there are a variety of potential communications
options for smart metering, and no consensus has emerged in favour
of any one solution. Indeed many hold the view that a mix of technologies
will be needed to ensure complete coverage across Great Britain.
In addition to the variety of wired and wireless technologies
that can be used for the communications solution for smart metering,
for the wireless technologies there are a variety of spectrum
bands that can be used. Many of these bands are available today.
This holds true for mesh technology so, for example, we understand
that one company, is deploying mesh technology for smart meters
in the 2.4GHz band in Ireland. The 2.4GHz band is already available
in the UK (and around the world) on a licence-exempt (ie unlicensed)
basis.
We are in the early stages of the Implementation Programme
for the smart meter roll out. A key task in this area under the
Programme will be to define the requirements for smart meter communications
in detail. Potential technologies can then be assessed against
these requirements. Our view is that we should not be aiming to
pick or favour certain technologies at this stage.
My officials and Ofgem have had several discussions with
Ofcom about the regulatory issues relating to communications technologies
for smart metering and will continue to do so as we move forward
with work under the Smart Meter Implementation programme. Ofcom
themselves have met with a number of operators interested in providing
communications solutions for smart metering in the UK, this includes
a number of meetings with Silver Spring Networks Networks and
they expect to meet them, and others, again.
Ofcom recently held a consultation (11 August 2009 to 3 November
2009) in relation to the use of the 872-876/917-921 MHz band.
The aim of the consultation was to allow Ofcom to gather input
from stakeholders to inform their approach as to the manner in
which this band could be released. Responses confirmed that there
are a range of uses that this spectrum could be put to with the
most widespread interest from respondents being in Short Range
Devices (including Radio Frequency Identification) and GSM-R (wireless
communications on trains). Only one respondent, Silver Spring
Networks, expressed an interest in this band for Smart Meters.
Ofcom will use the consultation responses as an input to
assess the appropriate authorisation approach and necessary technical
conditions in line with its primary duty to further the interests
of citizens and consumers in communications matters. It plans
to publish an update shortly.
In general, spectrum can be accessed either by way of a licence
granted by Ofcom or by complying with requirements set by Ofcom
for licence-exempt use. Wherever possible, Ofcom authorises licence-exempt
use. Where spectrum is licensed to prevent harmful interference,
some is available direct from Ofcom, some through primary awards
(typically auctions) and some through trading with existing licence
holders in the secondary market.
Given the pace of change in communications markets, Ofcom's
general approach to both licensing and licence-exemption is to
avoid service- and technology-specific conditions wherever possible.
This makes spectrum available for the widest range of applications,
subject to the need not to cause harmful interference to other
users. The communications elements of smart metering therefore
is not limited to any preordained part of the spectrum.
As an example of this, Ofcom's predecessor, the Radiocommunications
Agency, only made 1 MHz of spectrum available for remote metering
products. Following Ofcom's reform of Business Radio now more
than 70 MHz of spectrum is available for smart metering and similar
uses. This is in addition to the tens of MHz of tradable spectrum
that it has awarded through open processes in recent years without
service and technology restrictions. It also expects to release
further spectrum in the coming years, again without service or
technology restrictions, a process mirrored by other Government
departments' plans to improve the efficiency of their spectrum
use.
I hope this helps to reassure the Committee that my Department
and Ofgem are aware of the regulatory issues regarding communications
technologies for smart metering, and that we are in close contact
with Ofcom on the matter.
Annex C
SMART METERING:
UNIVERSALITY OF
ROLL OUT
AND COSTS
The Committee also asked how universal the smart meter roll
out will be, and whether consumers in remote locations will face
higher costs for their smart meters because of factors such as
higher communications costs.
The plans we announced on 2 December 2009 are for smart energy
meters to be rolled out to all residential consumers in Great
Britain. My Department and Ofgem are working together to develop
detailed plans to deliver the Smart Meter Implementation Programme.
This will include an assessment of the different communications
technologies to enable smart meter information to be transmitted
to consumers in their homes—and sent out from the home—in
a range of locations and property types.
Decisions on the communications solutions to be deployed
will be taken on the basis of this work. Different approaches
are likely to be needed in different areas. Further analysis and
an assessment of potential solutions will be carried out.
As regards costs, energy suppliers will be responsible for
provision of the meters and will need to recover their costs over
time. Exactly how they do so is one of the issues that will need
to be examined during the Implementation Programme.
Annex D
CARBON PRICING:
PRICE FLOORS/MARKET
INTERVENTION
The UK remains strongly committed to using the carbon market,
and ensuring there is a robust carbon price to help drive emissions
reductions and provide certainty for industry. A higher carbon
price and greater carbon price certainty should lead to better
returns and lower costs of capital for investors. We would expect
this to encourage more investment in low carbon generation, at
the risk of higher energy bills for industry and households.
The Government considers that there are risks in intervening
in the market to control the carbon price. There is the danger
that introducing a price floor sets a precedent for intervening
in the market and leads to increased calls for a price ceiling
in times of higher economic growth.
To deliver a price floor at EU level would require agreement
through co-decision with the EU Council and Parliament. Because
of the fiscal context, it is likely that the measures would require
unanimity. This would be extremely challenging, as there is no
support from other Member States or the European Commission. It
is also possible that some other Member States would push for
a low price floor combined with a price ceiling. For example,
during the negotiations on the EU Climate and Energy Package,
Poland called for a price ceiling of
30.
A unilateral UK price floor would be subject to a number
of significant legal barriers, some of which breach EU law.
Even if legal constraints are overcome, by itself it is unclear
that a price floor would be sufficient or that it is the best
option to ensure the levels of low carbon investment we need in
the UK to decarbonise our electricity market.
The carbon price and its long-term certainty is one of many,
and not the most significant factor, that affects investment decisions
in low carbon electricity generation. Gas price volatility and
its relationship to electricity price is a key driver, as well
as, uncertainty around future electricity demand, impact of renewables,
the oil price, construction and capital costs and capacity factors.
Although stakeholders are in general supportive of interventions
to encourage more low carbon investment, there is no consensus
(and some strong opposition) amongst industry that establishing
an EU ETS price floor is the right intervention.
Providing more carbon price certainty through a price floor
is therefore not a panacea and will not necessarily lead to the
required low carbon investment.
The Government believes that the best approach to give the
long-term signal sought by investors is through setting the right,
long-term regulatory framework with a reducing cap on emissions.
Under the revised EU ETS Directive the EU ETS cap will fall by
1.74% (compared to the cap in the first carbon budget period)
each year after 2013.
Longer term, the most effective way of strengthening the
carbon price is by limiting the supply of allowances by tightening
the cap.
Our efforts will now be focussed on taking forward the work
agreed at Copenhagen to secure an ambitious legal treaty this
year. We are committed to reviewing and tightening the cap further
as part of a move from 20% to 30% in the EU emissions reduction
target for 2020, in the context of a new global climate agreement.
Tightening of the EU ETS cap would deliver a higher carbon price
and provide clearer incentives for investors. In addition, the
Government is taking forward work to ensure the electricity market
framework can most effectively deliver a fair deal for the consumer
and the low-carbon investment needed in the long term, and will
report its initial findings at Budget 2010.
January 2010
23
Parliamentary Office of Science and Technology, October 2006 http://www.parliament.uk/documents/upload/postpn268.pdf Back
24
Lenzen M, Dey C, Hardy C, Bilek M (2006) Life-cycle energy
balance and greenhouse gas emissions of nuclear energy in Australia.
ISA, University of Sydney http://www.isa.org.usyd.edu.au/publications/documents/ISA_Nuclear_Report.pdf Back
25
Lenzen M (2008) Life cycle energy and greenhouse gas emissions
of nuclear energy: A review. Energy Conversion and Management
49, 2178-2199. Back
26
LCA of current coal, gas and nuclear electricity systems and electricity
mix in the USA http://gabe.web.psi.ch/pdfs/lca/Dones_etal-LCA_of_current_coal_gas_and_nuclear_electricity_systems_and_electricity_mix_in_the_USA.pdf Back
27
LCA of current coal, gas and nuclear electricity systems and electricity
mix in the USA http://gabe.web.psi.ch/pdfs/lca/Dones_etal-LCA_of_current_coal_gas_and_nuclear_electricity_systems_and_electricity_mix_in_the_USA.pdf Back
28
World Energy Council (2004) Comparison of energy systems using
life cycle assessment http://www.worldenergy.org/documents/lca2.pdf Back
29
http://www.inference.phy.cam.ac.uk/wiki/sustainable/en/index.php/Chapter_I Back
30
Marti«nez E, Sanz F, Pellegrini S, Jime«nez, Blanco
J (2008) Life cycle assessment of a multi-megawatt wind turbine.
Renewable Energy 34, 667-673. Back
31
Life cycle assessment of offshore and onshore sited wind power
plants based on Vestas V90-3.0 MW turbines http://www.vestas.com/Admin/Public/Download.aspx?file=Files%2fFiler%2fEN%2fSustainability%2fLCA%2fLCAV90_juni_2006.pdf Back
32
US DoE (2004) PV FAQs. US Department of Energy, January 2004.
http://www.nrel.gov/docs/fy04osti/35489.pdf Back
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