Led by Professor Dan Gladwin from the Department of Electronic and Electrical Engineering at the University of Sheffield, the AdD HyStor Project aims to provide a demonstration of dynamic grid stabilisation with an adaptive-flywheel/battery hybrid energy storage system whose discharge duration and power can be matched exactly to the requirements.
For the first stage of the project, the flywheel facility was installed in Ireland, piloted by Schwungrad Energie Limited at their 400V hybrid flywheel-battery facility in collaboration with EirGrid. The facility hosted a 250kW flywheel system and a 160kW lead-acid battery which was used to demonstrate its capability frequency response services for EirGrid’s DS3 programme. The second phase led by the University of Sheffield incorporates two flywheels capable of a peak power of 500kW which, when combined with the battery, can provide 2.5MW of power and over 1MWh of energy, enough to power 6000 homes for 30 mins.
Professor Gladwin says “This is a technically challenging project utilising state-of-the-art flywheels that effectively spin something weighing the equivalent of a grand piano around 216 times every second balanced in free air using a magnetic field. We have demonstrated for the first time that these flywheels can be installed on a low-cost platform above ground in a safe and efficient way to successfully store and deliver power to the electrical grid. The next steps in this project will see them being put into service alongside our battery as a hybrid energy storage system enabling us to validate our control methods that we have developed in the lab”.
Flywheel and battery energy storage systems are well suited to assist with CO2-neutral dynamic grid stabilisation. Each technology has characteristics that make them preferable for different scenarios, for example, flywheels are suitable for short term energy storage and can typically respond for a time measured in minutes. Battery systems are better utilised for use during longer destabilisation periods from several minutes to several hours. Batteries suffer from degradation meaning that their capacity and efficiency decreases with usage, significantly so when the power demanded of them is high. Flywheels do not suffer the same and will maintain their original performance capability regardless of usage.
This project demonstrates that it is possible to combine the technologies and develop control methodologies that can optimise the use of each technology together in a single energy storage system. This results in optimised sizing of both the batteries and the flywheels minimising installation costs, and extending the useful life of the batteries compared to a battery only installation. Utilisation of both technologies in a combined system provides a flexible energy storage that can effectively deal with a range of stability events and offer a sustained return on investment based on changing future market requirements.
For more information on this project please contact Professor Dan Gladwin on d.gladwin@sheffield.ac.uk or visit sheffield.ac.uk/CREESA. The flywheels are developed and manufactured by Adaptive Balancing Power GmbH and the multi-source converter is built by Frecon GmbH. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 760443.