The 22MW energy storage facility is connected to the 76-turbine, 228MW Pen y Cymoedd wind farm in south Wales and provides enhanced frequency response — helping to keep the grid system at a frequency of 50Hz.
Vattenfall's battery system consists of six storage units, five of which contain 500 i3 battery packs – lithium-ion batteries with a capacity of 33kW – manufactured by car manufacturer BMW.
The sixth container contains supporting and controlling plant, meters and computers.
The battery system is capable of responding to power fluctuations on the grid within a second, whether frequency drops or rises, ensuring reliable electricity supply, Vattenfall stated.
Windpower Monthly visited the site in September 2017, while the battery was under construction.
Vattenfall’s Dutch subsidiary Nuon is planning solar arrays at its 400MW Wieringermeer and 18MW Haringvliet in the Netherlands, both of which are due to come online in 2019.