The National Energy System Operator (NESO) is a new public corporation being established in the UK in 2024, taking over the critical roles of electricity and gas system operation from National Grid ESO and National Grid Gas. Its core focus is to ensure the security, reliability, and decarbonization of Great Britain's energy system, facilitate the energy transition, and operate energy markets independently. The provided website is for National Grid ESO, the predecessor entity whose functions are transitioning to NESO.