National Grid's System Control Centre manages the flow of the gas from the beach to the end consumer. It uses telemetered data from all the operational sites to monitor the system. The use of gas is not constant. The National Control Centre operates and balances the high pressure National Transmission System (NTS) while the Area Control Centre is responsible for the next level down in the gas supply network - they ensure sufficient supply is available at the right place and the right time to meet consumer demand.