4 ENERGY
STORAGE AND
TRANSMISSION
93. The move towards low carbon energy generation
will be challenging because of the intermittent nature of renewable
energy sources, as supply may not coincide with demand. For this
reason energy storage and transmission will become increasingly
important in a green economy.
STORAGE
TECHNOLOGIES
94. The main types of energy storage technologies
currently in use and being developed are:
- Batteries: A combination of
one or more electrochemical cells, used to convert stored chemical
energy into electrical energy. Conventional batteries include
nickel-cadmium, nickel-metal hydride, and lead-acid. Lithium-ion
batteries are currently the dominant technology in laptops and
mobile phones. Considerable research is ongoing to develop more
efficient and longer-life batteries for hybrid electric vehicles.
- Supercapacitors: Capacitors with very high energy
density. A capacitor consists of two conducting metal plates,
separated by an insulator. Energy is stored in a capacitor by
applying a voltage, which separates positive and negative charge.
This charge separation creates a potential between the metal plates
that can later be harnessed in an external electronic device.
- Fuel cells: An electrochemical cell that generates
electricity when a fuel (e.g. hydrogen) combines with oxygen,
producing water as a by-product. These differ from batteries because
the fuel can be stored outside the electrochemical cell.
- Pumped-storage hydroelectricity: Stores energy
in the form of water by pumping it from a low elevation reservoir
to a higher elevation reservoir. The stored water can be released
through turbines when needed, generating electricity.
- Thermal energy storage: Traditionally, these
are water-based technologies that store energy in the form of
heat for later use in space heating, hot water or to generate
electricity. Molten salt technologies can also be used.
95. Energy storage technologies are vital to
the green economy. For example, advances in batteries will help
to increase the efficiency of electronic devices such as televisions
and household appliances, whilst domestic fuel cell micro-CHP
(combined heat and power) is being developed to burn gas, producing
space and water heating as well as generating 3,000 kWh of electricity
annually. E.ON told us "Given that fuel cell micro-CHP can
deliver electrical efficiencies in excess of 60%, and the technology
makes use of the existing gas infrastructure, micro-CHP is well
suited for the UK."[137]
96. Energy storage encompasses
many of the enabling technologies that will play an extremely
important role in underpinning the move towards a green economy.
The Government should consider a long-term programme of support
for energy storage research, development, demonstration and deployment.
THE
GRID
97. Solarcentury told us they advocate the use
of "the grid as a battery, so that you are feeding in during
the day and taking out at night."[138]
However, constraints on access to the electricity grid represent
a major challenge for both existing and future renewable energy
generation projects. About 17 GW of renewable electricity developments
- of which nearly 6 GW have received planning consent - are currently
awaiting connection to the grid, and developers in some parts
of the country have been offered an earliest connection date of
2020.[139] We recently
published a comprehensive report on the future of Britain's
electricity network that deals with the subject of grid access
in greater detail. In this report we take an overview of the main
issues and focus on the potential for the grid to contribute to
a low carbon future.
98. We heard from a number of organisations about
the need to invest in Britain's electricity network if the Government's
targets for renewable generation are to be met. The Crown Estate
told us "In order that the most efficient and economic solution
for network investment is delivered, it is essential that a strategic
plan is developed and implemented."[140]
The Energy Technologies Institute (ETI) agreed with this, they
told us:
"The UK has a significant industrial and technological
capability in software development, control systems and information
management. Integration of these various capabilities with new
generation and demand technologies (including low carbon vehicles)
offers the potential for rapid introduction of smart-grid systems
with the potential for significant benefits to both plant operators
and users including the public consumers. Creating industrial
and economic benefit in this highly competitive global sector
is likely to require the rapid introduction and implementation
of a coherent strategy across a range of government bodies with
the focus on regulatory structures and business offerings just
as much as smart meter roll-outs and support.
This coherent integrated approach is starting to
emerge in the specific case of low carbon transport and plug-in
electric vehicles (all electric and hybrids). Linked with this,
a range of government initiatives at regional and national level
are underway with the next phases becoming better coordinated
as ETI strengthens its leadership role with industry and government.
Applying a similar approach to the 'smart grid' aspects of low
carbon energy should yield similar benefits."[141]
99. The Sustainable Development Commission told
us that in order to redesign the grid, the Government needed to
"commit up to £5 billion a year on grid improvements
of one kind or another, over and above the £7.6 billion expected
to be delivered through CSR 07 [Comprehensive Spending Review
2007]".[142]
100. Alongside a smarter grid system, smart meters
will provide consumers with the information necessary to manage
their energy use and carbon emissions in real time. The Government
is committed to installing smart meters in all homes by the end
of 2020. We will discuss the use of smart meters in greater detail
later in this report (paras 192-195). In December 2009, the Government
published Towards a Smarter Future: Government response to
the consultation on electricity and gas smart metering, which
outlines the decisions that will be the basis of the smart meter
implementation programme. At the same time, they published a discussion
paper, Smarter Grids: the opportunity, setting out a high
level vision of what a UK smart grid might look like. The Government
intends to develop a more detailed smart grid route map as part
of its 2050 roadmap in Spring 2010.
101. We are pleased that the Government
is producing a detailed smart grid route map in collaboration
with Ofgem and industry representatives and look forward to receiving
further information. The Government has rightly stated in its
recent discussion paper, Smart Grids: the opportunity,
that smart meter policy decisions and investment must take into
account the goals of a smarter grid system, in particular regarding
decisions on smart meter functionality and communications infrastructure.
We would like to see a fully integrated smart meter and smart
grid implementation plan produced by the Government that takes
these issues into account.
SMART
COMMUNICATIONS
102. There is huge potential for demand-side
management of energy supplies through the combination of a smarter
grid with smart meters and smarter appliances, for example, white
goods that are capable of responding to changes in price or demand
as signalled by a smart meter. However this will only be possible
if the grid, meters and appliances can reliably communicate with
one another.
103. During our visit to California, we met with
a company that specialises in smart grid communication technologies,
Silver Spring Networks (SSN). They outlined the main requirements
for a smart grid communication platforms:
- Open—open standards to
maximise competition and consumer choice
- Secure—grid and consumer
protection
- Future-proof—flexibility
to accommodate advances in technology
- Ubiquitous—ability to
reach urban, suburban and rural homes
- Low latency—available
capacity for new services
- Scalable—able to roll
out to tens of thousands of homes daily
- Cost-effective—low build
cost and very low operating cost
104. A wide range of communication platforms
are available, including broadband, mobile, tower RF (radio frequency),
and RF mesh (also known as wireless mesh). In countries such as
Australia and the United States where the full range of technologies
are available, utility companies have overwhelmingly chosen wireless
mesh as the technology of choice for their smart grid programmes.
Wireless mesh is a communications network made up of radio nodes,
which allow appliances and meters to communicate with each other.
Utility companies representing over 40 million homes in Australia
and the U.S. are now implementing wireless mesh-based communications.
105. Unfortunately, a lack of appropriate sub-GHz
radio spectrum prevents the use of this technology in the UK.
Current frequency allocations and rules do not permit a practical,
cost effective use of ubiquitous wireless mesh as an option. However,
Silver Spring Networks told us that there is a chance to change
this. Ofcom is currently consulting on the future use of the 872-876
MHz and 917-921 MHz frequency bands. These are not used by other
technologies at present, and are ideally suited for smart grid
use. SSN argues that the proximity of these bands to those used
in Australia and the U.S. offers the potential for the UK to benefit
from substantial economies of scale, since it should be possible
to use the same radios across all markets.
106. When we questioned the Minister about smart
grid communication technologies, he told us "We are aware
of the wireless option […] but there are other options […]
third generation broadband lines and even GPS-type solutions […]
we are discussing them all with Ofcom as well as the industry
as we go forward."[143]
The Minister followed up by sending us supplementary evidence
explaining that a radio frequency band at 2.4 GHz is "already
available in the UK (and around the world) on a license-exempt
(i.e. unlicensed) basis."[144]
One company is piloting wireless mesh technology for smart meters
at this band in Ireland. However, sub-GHz frequency bands propagate
and penetrate (through trees, walls and other potential barriers)
further than would a band at 2.4 GHz, thus allowing a more robust
communications network. The Department of Energy and Climate Change
went on to explain that with regard to the recent Ofcom consultation,
"responses confirmed that there are a range of uses that
this spectrum [872-876 MHz and 917-921 MHz] could be put to […]
only one respondent, Silver Spring Networks, expressed an interest
in this band for smart meters."[145]
107. We do not advocate picking
or favouring specific communications technologies for the smart
grid and smart meters at this stage. However, we believe strongly
that there should be a level playing field, and that all technologies
should be given the opportunity to demonstrate both their strengths
and weaknesses as the Government develops a universal smart meter
implementation programme. Rural communities often suffer from
a lack of broadband and GPS coverage. One of the benefits of wireless
mesh technology is that through the use of multiple radio nodes,
communication across both urban and rural areas is possible. Given
the choice, the market will decide which communication technology
is best suited. Having heard that utilities in other leading countries
have overwhelmingly chosen sub-GHz wireless mesh technology, it
would be absurd to exclude such a technology from the UK. The
fact that only one respondent to Ofcom's recent consultation (on
the future use of the 872-876 MHz and 917-921 MHz frequency bands)
expressed an interest in this band for smart meters does not detract
from the argument that this spectrum currently provides the only
opportunity for sub-GHz wireless mesh technology to be trialled
in the UK.
108. In light of the Government's
target of rolling out smart meters to every home by the end of
2020 and the wider GHG emissions reduction targets, there is no
time to waste in assessing smart grid communications technologies.
We recommend that the 872-876 MHz and 917-921 MHz frequency bands
be reserved for smart grid and meter communications immediately.
The result for UK consumers and energy providers can only be increased
choice, greater innovation and lower prices. If, after utility
companies have completed pilot projects using sub-GHz wireless
mesh technology, they overwhelmingly choose other communications
technologies, the radio frequency bands could be reallocated.
The UK must not be at a disadvantage compared to countries that
are quickly moving forward with smart grid communication technologies.
137 Ev 189, para 15 [E.ON] Back
138
Q 326 [Mr Leggett, UK Photovoltaics Manufacturers' Association
/ Solarcentury] Back
139
HM Government, The UK Renewable Energy Strategy, July 2009, p
96 Back
140
Ev 172 [The Crown Estate] Back
141
Ev 205 [Energy Technologies Institute] Back
142
Ev 279 [Sustainable Development Commission] Back
143
Q 503 [Mr David Kidney MP, Department of Energy and Climate Change] Back
144
Ev 182, Annex B [Department of Energy and Climate Change] Back
145
Ev 182, Annex B [Department of Energy and Climate Change] Back
| 
