National Grid ESO procures balancing service contracts to balance demand and supply and to ensure the security and quality of electricity supply across Britain’s transmission system. For some of the balancing services contracts which fall within trading timescales, (i.e. several days ahead to a couple of hours ahead) the trading team will evaluate all the possible balancing actions including trading and balancing services, and take the most cost-effective actions. If the balancing services contract provides the best solution, the contract will be enacted. The balancing service contracts come in different shapes and forms. We are grouping some of the contract enactment here which typically has relative similar structure or price are fixed at the time of the decision. For example, it can be for constraint management in Scotland, or deliver reactive power requirement. Usually, the balancing service contract enactment doesn’t have the physical exchange of power or energy, the balancing services contracts that are not enacted by trading team are not included here.