As the UK's renewable energy industry grows, the transmission network run by National Grid must cope with greater fluctuations in power generation, often at very short notice. This is driven by the higher intermittency of renewable energy sources such as wind and solar power generation.
When these fluctuations occur, National Grid must respond immediately to keep the transmission grid balanced and within the required frequency range.
These projects store electricity at times of low network demand and re-distribute the stored electricity to the grid at times of high demand when the network is in system stress. By addressing grid imbalances, power cuts are prevented.