National Grid is responsible for procuring balancing services in order to balance demand and supply and to ensure the security and quality of electricity supply across the GB transmission system.
National Grid has a licence obligation to control system frequency within specified limits. National Grid must therefore ensure that sufficient generation and/or demand is held in automatic readiness to manage all credible circumstances that might result in frequency variations.
The indications from National Grid and our own advisers are that there is no technical barrier to the connection of renewable generation at, for example, a 30 per cent to 40 per cent penetration level. The indications are that the challenge is an economic rather than technical one, ie ensuring that sufficient capacity of all technologies has the right incentives to remain on and join the network to support the deployment of intermittent renewable technologies and ensuring the economic and efficient operation of the balancing mechanism.