Chapter 5

Energy Storage Innovation

For energy storage to play an important role in the UK’s future energy system, then the technology innovation needs must be addressed. This section reviews the UK’s existing capabilities, including where the sector is well-placed to meet these storage needs, and where further work is required.

5.1 Research outputs

An indication of international academic capability is given in Figure 17, which shows the ten countries that have published the greatest number of journal articles related to energy storage in the period 2000 – 2020, and the technologies they have covered . China has published significantly more papers than any other country, followed by the USA and South Korea, with the UK eighth. Figure 18 shows how publications increased since the early 2000s, led by China and the USA, with the UK lagging the strong uptick by 4 – 5 years.

The UK’s relative research strength varies between technologies; LiBs have been the subject of the most publications, followed by supercapacitors and TES (Figure 19). The UK is a leader in LAES research globally, with a third of all publications, though these are a small proportion of all publications on energy storage.

Figure 19. Energy storage articles 2000-2020 by technology, from UK (source: Web of Science).

Figure 17. Energy storage articles 2000-2020; top 10 countries (source: Web of Science).

Figure 18. Energy storage publications 2000-2020 (source: Web of Science).

5.2 UK Innovation funding

In general, public funding for energy storage has been rising in the UK since the mid-2000s, before when the amount was negligible (Figure 20) . Electrochemical batteries have been well-funded, most recently in 2018 from the Faraday Challenge. Whilst their potential to benefit the auto sector makes this a reasonable approach, there is a risk that this excludes technologies which provide energy system benefits.

(a) Funding by public bodies

(b) Technologies supported

Figure 20. UK energy storage funding: 2006 – 2019.

5.3 Patents

The development of technologies through to commercialisation can be considered from patent registrations. Figure 21 shows the number of patents filed between 2000 and 2020 based on the inventors’ countries, by technology for the UK and leading countries.

Figure 21. Energy storage patents filed 2000 – 2020 in selected countries (source: Espacenet, European Patent Office)

5.4 UK Policies and market mechanisms

Significant recent policy documents that are relevant to energy storage in particular include The Clean Growth Strategy (BEIS, 2017a), and Upgrading Our Energy System - Smart Systems and Flexibility Plan (BEIS & Ofgem, 2017; BEIS & Ofgem, 2018), along with The Road to Zero strategy which bans all sales of new petrol and diesel cars by 2040 (OLEV, 2018). The Government’s ‘Ten Point Plan for a Green Industrial Revolution’ highlights the role for energy storage as ‘essential’ to integrate clean technologies and storage energy over hours, days and months, with £100 million for Energy Storage and Flexibility innovation challenges (HMG, 2020). A new Energy White Paper is expected by the end of 2020, with a Heat and Building Strategy due to be published in 2021.

These UK national policy documents are complemented by a number of devolved and regional strategies that consider energy storage, such as the ‘The future of energy in Scotland’ (Scottish Government, 2017), ‘Energy Generation in Wales’ (Welsh Government, 2018), ‘A Regional Energy Strategy for the West Midlands’ (WMCA, 2018) and ‘Northern Powerhouse: Energy and Clean Growth’ (NP11, 2019). Reports from the Committee on Climate Change, which advises the Government on all areas of emissions reduction, have been influential in informing policy decisions and included studies on the role of storage and flexibility measures (e.g. CCC, 2019; Vivid Economics & Imperial College, 2019).

The UK has implemented a number of policies, which although not aimed specifically at energy storage, have implications for the sector. These come predominantly from the nationally legislated target to reduce greenhouse-gas emissions by 80% by 2050 compared to 1990 levels (House of Commons Library 2019):

  • The Capacity Market is part of the Governments Electricity Market Reform (EMR) and is designed to maintain security of supply and offers electricity capacity providers (including new and existing power plants, and electricity storage systems) a monthly revenue for providing electricity at times when required (usually when the system is under stress) (DECC, 2014). In 2016, 500 MW of non-PHS (battery) storage was successful in the T-4 auction. Since then the CM auction price has come down, and storage has been subject to ‘de-rating’ based on the duration over which capacity could be provided, which effectively reduced its ability to compete (NGET, 2017).
  • Contracts for Difference (CfD), also part of the EMR is an incentive for low-carbon generators (most recent CfD’s exclude onshore wind and solar PV) where a strike price is agreed per unit of electricity generated, if the market price for electricity is less than this strike price then the difference is made up by the UK Government. Energy storage can be used in conjunction with low-carbon generators benefiting from CfD’s and the rules for doing so were clarified in a Government response to a CfD consultation in 2017 (BEIS, 2017b).
  • Feed-in Tariffs (FiTs) provide a generation and an export tariff to eligible small-scale (<5MW) low-carbon generators, as with the CfD’s energy storage can be used in conjunction with FiTs. FiTs closed to new applicants from April 2019, however it has been replaced by a ‘Smart Export Guarantee’ which provides an export tariff to small scale low-carbon generators (BEIS 2019b). A number of firms are marketing home PV + storage systems.
  • For electric vehicles, the UK government compensate up to 35% of the cost of an electric car, up to a maximum of £3,000 depending on the model. There are also grants available towards the cost of electric vehicle charge-points both at home and at the workplace as well as for local authorities.

Additionally, there are several regulations aimed specifically at energy storage, though predominantly on the electricity system:

  • A revision to the charges placed on storage facilities, for which consumers and generators are charged for using both the transmission and distribution networks through Use of System and Balancing Services Use of System charges. However because energy storage consumes and generates it has been effectively double-charged. This does not take into account the benefits of storage to the network in providing a balancing service rather than contributing to the congestion of the network; therefore through OFGEM’s Targeted Charging Review these charges have been revised so that energy storage facilities only pay the generation charges (Ofgem, 2017).
  • A regulatory definition of energy storage: the government intends to amend the Electricity Act to include a specific definition of energy storage as a subset of the generation asset class. Providing a regulatory definition of energy storage will not only confirm that it should be treated as a generating asset, but will also help to cement energy storage as an integral part of the electricity system (Ofgem, 2020).
  • A clarification of the rules around co-locating energy storage with renewable energy. It can be beneficial to co-locate energy storage with renewable energy, however many renewable energy schemes receive subsidies either from FiTs or CfDs (or their predecessor Renewables Obligations). The Government and OFGEM have subsequently published guidelines around co-location to clarify the process and ensure that only renewable generation is rewarded by the subsidy schemes (Ofgem, 2020b).

An additional option, although not tested anywhere in the world, would be some form of firm power auction as suggested in the ‘Cost of Energy Independent Review’ that would promote storage to allow variable renewable generation to provide firm power (Helm 2017).