Iberdrola is to build the UK’s largest battery linked to a wind farm, said the Spanish group’s ScottishPower unit. The 50MW lithium-ion battery will store power from the 539MW Whitelee project in Scotland that is currently Britain’s biggest operating onshore wind facility. The battery is set to be operating by the end of 2020. Adding large-scale storage capability is seen as a key strategy to allowing variable renewable sources such as wind power to respond effectively to demand. The Whitelee battery will be able to offer services such as reactive power and frequency response to the National Grid.