Large Scale Storage for Network Services

The UK has a growing share of sources of energy that are variable or intermittent in their supply of electricity and that
cannot provide the same level of system security as conventional power plants. This is leading to increasing constraints on
renewable generation, particularly in Northern Ireland, which come at considerable cost to the consumer.
The proposed project will connect a 10MW Lithium Ion battery array to Northern Ireland's grid - the largest and only
transmission connected battery of its kind in the whole of Europe - in order to work with the transmission system operator
and other stakeholders to evaluate and substantiate the value of storage in providing flexible services.
The project will address any perceived operation concerns and show its value in addressing the energy trilemma, driving
the market and catalysing future growth of energy storage.
In order to raise the system non-synchronous penetration limit (SNSP) and reduce wind curtailment, more advanced
system flexibility is needed. A grid scale battery array can provide immediate power within milliseconds of a trip -
effectively emulating the effects of conventional inertia, without moving parts. Nor do batteries need to be synchronised
with the grid - providing the equivalent service of back-up power stations but without having to inefficiently run power plants
at part load. They also provide the ability to store excess wind which would otherwise have to be curtailed, with a round trip
efficiency of over 90%. In other words, battery storage would enhance system security, displace inefficient part loading
plant and relax constraints capping wind power use. This will lower grid carbon emissions and will save the system money
by reducing pay-out on wind curtailment and constraints. All three legs of the energy trilemma, security, cost and
sustainability, will therefore be addressed.
QUB will undertake monitoring and simulation activities within the project. QUB is already unique among its peers by way
of access to plant data and has amassed significant expertise in power system asset monitoring based on the development
(over 10 years) of wide-area monitoring using both commercial and QUB-developed Phasor Measurement Units (PMUs).
Northern Ireland has particularly ambitious renewables targets, with an objective of 40% of electricity from renewable
resources by 2020. The majority of this is coming from an expansion in intermittent onshore wind generation. Due to the
non-synchronous nature of wind power, and the small and weakly interconnected grid infrastructure in Northern Ireland, the
amount of instantaneous electricity currently acceptable from non synchronous resources (both wind and HVDC
interconnector imports) is limited to 50% of demand. This is to ensure sufficient synchronous inertia and controllable output
is available from conventional power plants to ensure stable operation of the grid. The consumer cost of this 50% cap is
significant and growing as more wind is added to the system. Zero fuel cost, low carbon wind energy has to be curtailed, at
cost, in order to instead pay to run part loaded conventional power plants out of economic merit in the name of system
security. This is a situation that is clearly not tenable, politically or economically, in the long term and is a significant
impediment towards the 40% renewable electricity target.

The project will deliver benefits at three levels:
- Individual Project Participants
- Power System Operators and Stakeholders
- Wider Society
The project is an Innovate UK funded collaborative project. Lead partner AES Kilroot Power Ltd operates 520 MW of
capacity in two dual fuel oil/coal generating units. Through the additional gas-fired generation at Ballylumford Power
Station in Larne, AES is a major participant in the all-island Single Electricity Market. AES is a $16bn global company with
200MW of storage resources in operation and construction. AES has declared its ambition to deploy up to 100MW of
transmission grid connected storage at Kilroot.
The project will deliver a 10MW pilot-scale battery storage array and will position AES to exploit the capabilities of storage
in the Single Electricity Market, particularly in the provision of fast-response grid services. AES will be the primary and
short-term economic beneficiary from the project.
The project has received commitment from the System Operator for Northern Ireland (SONI, Northern Ireland's
Transmission System Operator (TSO)), the Utility Regulator for Northern Ireland (UREGNI) and Northern Ireland Electricity
(NIE, Northern Ireland Distribution Network Operator (DNO)) to participate in the Steering Group for the project.
Consequently, the major stakeholders in Northern Ireland's energy system will be able to contribute to the activities of the
project as well as receive early sight of project results. The project will directly inform future policy for energy storage on the
Northern Ireland grid both as a provider of network services and for energy aggregation/arbitrage.
Under the 2008 Climate Change Act the UK is committed to reducing greenhouse gas emissions by 34% by 2020 and 80%
by 2050 and under the EU 2009 Renewables Directive the UK is required to achieve 15% of gross final energy
consumption from renewable sources by 2020. Under its Strategic Energy Framework (2010) the Northern Ireland
Executive has committed Northern Ireland to a target of 40% of electricity from renewable sources by 2020.
Storage is key to reducing the curtailment of wind generation and to raising the amount of wind that can be accommodated
on the grid. This project will directly catalyse the deployment of storage across the all-island grid and support the
attainment of the above renewable energy targets. By contributing to the development of a sustainable power system the
project will deliver the wider economic benefit of supporting a sustainable economy. In terms of societal impact the project
serves the three dimensions of the energy trilemma y contribution to (1) Affordable Energy (2) Security of Supply and (3)
Sustainability.
The lessons of this project and any future expanded storage facility will have UK, European and global significance and will
inform policy makers and system operators as they transition their power systems to accommodate significant renewables
deployment.