Electrical energy storage (EES) could play an important role in meeting UK government targets to reduce carbon emissions by 80% by 2050, by helping to optimise the capacity of the electricity network.
The likely benefits of implementing energy storage are well known: the UK Energy and Climate Change minister, Greg Barker , has referred to energy storage as a 'silver bullet'. David Willetts, the minister for Universities and Science, has also enthused about EES and describes it as one of the 'eight great technologies, which will propel the UK to future growth'.
The adoption of renewable energies is key to realising government targets but they are less manageable than traditional electricity production methods. The energy industry cannot control when weather dependent technologies such as wind turbines and solar PV panels can work at optimum levels. As we become more reliant on these types of low carbon technologies, energy storage takes on a more important role.
Assessment of smart grid technologies
Ofgem-funded smart grid project the Customer-Led Network Revolution (CLNR) is assessing a combination of novel network technologies, new commercial arrangements and customer flexibility to find ways to help meet future UK energy challenges. Ofgem is the UK's energy industry regulator. The project, which is led by Northern Powergrid, the distribution network operator for northeast England and Yorkshire, is looking for cost-effective solutions to help manage peak electricity demand, increasing grid efficiency and support the integration of renewable energy sources. EES is one such network technology that CLNR is testing to understand how the technology might benefit both customers and network operators.
The project's EES trials have seen six storage batteries of varying capacities connected to live networks across a variety of sites. The devices have been installed across a combination of rural and urban locations, which offer a representative sample of 80% of the UK's total electricity distribution network. The results can therefore be applied to a significant proportion of other networks across Great Britain; the information gained will provide understanding of how this technology can be effectively implemented, as part of a 'smart grid toolkit'.
Ian Lloyd, CLNR Network Technology project manager at Northern Powergrid, commented: "We've deliberately positioned the batteries at different points on our network to help us understand how the technology works across different types of networks, with different types of construction and with different types of customers, those in off-gas rural areas who rely on electricity for both heating and lighting for example.
Three of the devices have a capacity of 100 kWh, two are 200 kWh and the biggest has a capacity of 5 MWh, making it one of the largest currently in operation in Europe. We've installed the largest of the storage batteries in Darlington, to help us to balance the electricity demands of 14 000 different homes and businesses in and around the town. One of the smaller batteries has also been installed to help support about 300 homes in Maltby, South Yorkshire, where there is a large proportion of customers with solar PV technology."
Crucially, the trials are taking place on real-life networks, which means that authentic real-world results are being produced and shared with the distribution network operators to help bring about practical solutions.
The project's cross-section of energy industry partners, including Northern Powergrid, energy supplier British Gas, power consultancy EA Technology and academics from Durham University and Newcastle University, also means that trials are being undertaken with a holistic approach.
Ian Lloyd again: "Our EES trials are unique for two reasons; because of the size of our largest battery, rated at 5 MWh; and the fact that for the first time we are monitoring the devices and networks they are located on through a complex Active Network Management (ANM) control system, which has been developed for the project, called GUS (Grand Unified Scheme). This allows us to view in real time when and where we need to release the stored energy, as well as enabling autonomous control of the other network technologies that we are currently trialling. This is essentially what the CLNR project is all about: the learning gained for operating and co-ordinating these types of systems together."
Dave Miller, CLNR technical architect, who has overseen the implementation of the GUS, says: "With the challenges presented by low carbon technologies and micro-generation, ensuring the network is fit for the future is crucial. We are trying to build a 'smarter powergrid' to ensure that we can meet carbon reduction targets economically and provide customers with more choice in how they use and generate electricity. It is essential that the electricity network is prepared for a variety of eventualities.
EES is one solution that will allow us to cope with unexpected demands on the network and be more flexible, ultimately assisting continuity and quality of supply as the network continually evolves and the pressures on it change."
However, while industry experts agree that EES could help meet future energy demands, the technology is expensive and there are relatively few deployed in working installations, which has resulted in a knowledge and confidence gap within the industry.
The benefits of EES are clear and many government officials acknowledge the instrumental role EES is likely to play in the UK's journey to decarbonisation, yet there is currently no incentivisation scheme to encourage EES deployment.
A recent report by industry body the Energy Storage Network (ESN) called for the government to impose a target of 2 GW of new electricity storage by 2020, claiming it will provide a vital stepping stone towards the widespread adoption of renewable energies. Without setting a target, on the lines of that set by California for 1325 MW by 2020, the UK will fall behind, says ESN.
John Baker, manager of the New Energy Technologies Team at EA Technology, has worked closely with DNOs and the energy industry on energy storage for many years. He agrees that a clear government strategy is needed: "I absolutely agree that the UK should aim high - the only reason we have penetration in the wind industry and the only reason it has had any degree of success is because targets were set and the government went for it.
The Technology Innovation Needs Assessment, the project led by the Low Carbon Innovation Co-ordination Group to help inform the prioritisation of public sector investment in low carbon technology, has targets ranging from 4 to 17 GW by 2020, so a target of 2 GW is fairly modest and is definitely achievable."
Creating a commercial framework
There are, however, significant challenges that may prevent EES getting to market. While field-experiments like the ones being undertaken by the CLNR project can work on both the efficacy and applicability of energy storage technology to the grid, UK wide deployment could be another challenge.
John Baker comments: "Energy storage is a multi-faceted technology, with various functionalities which slot into different parts of the supply chain." The breadth of functionality offered by energy storage is, arguably, proving to be one of its greatest barriers to market, inhibiting its commercialisation. This holistic approach - from similarities to generation plants to T&D equipment - is at odds with the existing UK energy market.
John Baker again: "The challenge is, fundamentally, the fact that 25 years ago the industry was segmented with artificial barriers when everything was privatised.
Because the technology is holistic and can be applied throughout the energy industry at a number of different levels and vertically integrated, bringing it to market when everything is segmented will make it difficult to extract its full value."
The challenge now is to bring about a commercial framework for the deployment of EES. There are calls for the government to initiate a programme of investment, and acknowledge that, while the upfront costs of infrastructure, development, deployment and market structuring will add to consumer energy bills, the long-term benefits of EES will far outweigh the costs.
There are encouraging signs, however, says John Baker: "Having worked on EES at EA Technology with a number of British DNOs, I'm very pleased that it has been recognised by the government as one of the 'eight great technologies'. I am likewise very encouraged by the funding support provided by the government, via the Engineering and Physical Sciences Research Council.
Our work, including our partnership with the CLNR project, is generating significant learning and experiences which has led to our establishing ESOF - the Energy Storage Operator Forum, with the support of all six of the UK's DNOs. Such work is identifying the various challenges of EES, which will need to be addressed on a co-ordinated basis if the UK is to gain the full benefits of this potentially vibrant sector.
The UK could realise huge benefits in terms of supply chain and wealth, new industry, employment, export opportunities, increased resilience, energy security - the list goes on. The co-ordinated approach we are working towards will enable the UK to reap the benefits of this vital technology for years to come."
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