Following the issue of National Grid's invitation to tender for supply of Enhanced Frequency Response (EFR) services back in July, the results are now in. Seven companies have been successful and will be providing energy storage facilities at eight sites across the UK resulting in an estimated 201MW of EFR capacity by March 2018.

EFR is a new service which is looking to provide capacity to the electricity network through technologies that can supply full power output within one second of activation. These supplies need to be automatically triggered in response to frequency fluctuations in the network and are required to provide the additional network stability needed due to the loss of system inertia as the number of heavy thermal plants across the country decreases.

Battery storage appears to be ideally suited to fulfil this need and in fact over ninety percent of the recent tenders fell into this category. The successful tenderers are listed below and will be supplying schemes of between 10MW and 49MW in size with contracts awarded for a duration of 4 years.

  • EDF Energy Renewables: 49MW scheme at West Burton, Nottinghamshire
  • Vattenfall: 22MW scheme at Pen Y Cymoedd near Neath
  • Low Carbon: two schemes totalling 50 MW at Cleator and Glassenbury
  • E.ON UK: 10MW scheme in Sheffield
  • Element Power: 25MW with their TESS scheme
  • RES: 35MW scheme through Battery Energy Storage Services 4 Limited
  • Belectric: 10MW Scheme at Nevendon.

Popularity and results

In response to the call for 200MW of capacity, the total capacity submitted in the tender documentation surpassed 5000MW: it appears that the energy sector sees great opportunity in this market, and that in the future such systems are likely to become more commonplace as the UK works towards a smarter grid.

Also evident from the successful tenders is that the ability to locate such schemes adjacent to existing generating plant has been an advantage. EDF's successful bid is located next to its coal and gas plants in West Burton, Vattenfall's will be next to its Windfarm at Pen y Cymoedd and E.ON are to build a facility next to its biomass plant at Blackburn Meadows near Sheffield.

This approach potentially demonstrates one of the main ways forward where such technologies are located 'in front of the meter'. Combining existing systems (including renewables) with energy storage enables the provision of artificial inertia to the grid, improving stability without the need for additional grid connections. Longer term it also enables power to be supplied as needed on a renewable basis at the point of demand without the need for daylight or wind, or the need for the large infrastructure of pump storage.

EFR should demonstrate the commercial viability of such schemes, as demonstrating such viability was a part of the tender process. Investors and financiers may be provided with the confidence that such the technologies can provide a significant revenue stream.