Testing has proved that a lead-acid and flywheel hybrid energy storage system can handle renewable energy as a pilot comes to a close in Ireland.
The trial in County Offaly uses a 160kW lead-acid battery from Hitachi Chemical and a 60kW/30kWh flywheel by US company Beacon Power.
The hybrid system by energy consortium Schwungrad Energie, along with transmission system operator EirGrid (Irish Transmission System Operator), has shown the system can handle real-time response and power output requirements.
The hybrid exploits the best of each technology – the cycling ability of flywheel with the energy capacity of a lead-acid battery.
The system can provide fast response within two seconds and sustain output for up to 20 minutes for grid frequency control application.
The pilot, developed in collaboration with the Department of Physics & Energy at University of Limerick, has been running a year.
Dr. Robert Lynch from the University of Limerick evaluated the available battery technologies that could deliver system services in response to grid frequency falls.
The consortium chose lead-acid for the pilot due to its specific needs for system services, Peter Duffy from Schwungrad Energie told BBB.
He said: “Lead-acid was deemed to be the most suitable technology for a number of reasons, technology maturity, established recycling ecosystem etc.”
The plant has been exposed to a variety of real system events, with performance continually monitored by EirGrid and periodically reviewed, jointly with Schwungrad, to assess its performance.
Duffy said: “The performance results to date have been positive and the plant has realised the target performance metrics for response time and power output sustainability.”
A flooded lead-acid battery and flywheel system is also being used in a 320kW hybrid energy storage project in Alaska.
Picture: Peter Duffy