Page 31 - European Energy Innovation - summer 2018 publication

Summer 2018 European Energy Innovation 31
100%
Normalized ELCC (%)
0% 50% 100%
20%
Normalized Power Rating (%)
Figure 2: The contribution of storage to security (normalized ELCC) as a function of different ES power and energy
capacity (left panel), and mean duration of an outage in hours (right panel).
(vii) Generation investment (G CAPEX)
since ES reduces the need to
invest in peaking capacity units
(other) and low-carbon units
(low-C).
In the scenario with carbon target of
50gCO2/kWh, most of the benefits
of ES are related to reducing the
investment in low-carbon generation,
while meeting the carbon reduction
objective, through enhancing the
ability of the system to integrate
variable renewable generation. In
this case, ES enables the system to
meet the carbon emission target by
building 10GW less nuclear generation
or 17GW less wind generation.
SECURITY CONTRIBUTION OF
ENERGY STORAGE
ES can also play a role in enhancing
the security of electrical systems;
they can provide peak shaving
capability and maintain supply
during network faults. Nevertheless,
current design standards do not
recognise that ES can be an attractive
alternative to conventional network
reinforcements and little work has
been done to quantify the firm
capacity that ES can provide. Note
that ES is fundamentally different
to other assets in two respects (i)
ES faces energy constraints due to
its limited capacity (ii) ES ability to
charge is tied to the reliability of the delivery procedures. ES entails lower
network. In this context, extensive
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COMMUNICATION
100%
80%
Energy
Capacity
(hours)
n 3h n 12h n 24h n 240h
analysis undertaken by Imperial
College has demonstrated that the
Equivalent Load Carrying Capability
(ELCC) of ES can be significant, but
it largely depends on a number of
factors such as ES power/energy
capability, network reliability, demand until uncertainty is resolved:
shape and others.
In Figure 2 (left panel) we show
the security contribution of ES as
a function of power (expressed as
a percentage of peak demand) and
energy capacity (expressed in terms
of hours); we show that energy
capacity plays a key role since it is
key in sustaining operation during
fault conditions. In the right panel we achievement of carbon reduction
show ELCC of six different ES plant
sizes across four network reliability
scenarios; the less reliable the
network, the less the ES contribution.
This analysis is the first step towards these benefits are not recognised by
incorporating ES in existing design
standards and enabling it to compete
with other technologies.
OPTION VALUE OF STORAGE
ES’s recognized ability to defer
investment can have additional
strategic value when facing long-term
uncertainty. Nowadays planners often
have to green-light projects ahead
of need due to anticipation of rapid
demand and/or generation growth
and lengthy permitting and asset
stranding risks because even if the
Normalized ELCC (%)50%60%
20%/2h40%
20%/5h20%
50%/2h
50%/5h0%
100%/2h
100%/5h
envisaged scenario that warranted
its deployment does not materialize,
it can still contribute to operation
by providing other support services.
Furthermore, fast-deployable
solutions such as ES can ‘buy time’
CONCLUSIONS
It is clear that ES can offer a
multitude of services which are bound
to become increasingly important
in the future decarbonization
effort. ES can assist with system
balancing, frequency regulation, defer
investment in network and generation
assets leading to cost-effective
targets, provide network security as
well as provide option value by aiding
in the management of long-term
uncertainty. Nevertheless, many of
the current regulatory regimes and
design standards worldwide. Levelling
the playing field and allowing ES to
compete with other technologies is
imperative to ensure efficient levels
of ES are deployed and that our
future energy systems are flexible and
future-proof. l
Contact information
Goran Strbac
Imperial College
Email: g.strbac@imperial.ac.uk