The Grid Controller of India Limited (Grid-India) is a wholly owned central government enterprise under the aegis of the Ministry of Power, functioning as the national grid operator and a key institution in the Indian power sector. Its origin traces back to March 2009, when it was incorporated as the Power System Operation Corporation Limited (POSOCO), a wholly-owned subsidiary of the Power Grid Corporation of India Limited (PGCIL). The creation of POSOCO was intended to separate the grid management and load despatch functions from PGCIL, addressing the problem of potential conflict of interest between the transmission utility and the system operator.
The core mechanism of Grid-India is the round-the-clock integrated operation of the Indian Power System, which it achieves by operating the National Load Despatch Centre (NLDC) and five Regional Load Despatch Centres (RLDCs). Its mandate for load despatch functions is derived from the Electricity Act, 2003, specifically sections like Section 26 and Section 27, which provide for the establishment and operation of the NLDC and RLDCs for optimum scheduling and despatch of electricity. Grid-India is also the nodal agency for major power sector reforms, connecting it to concepts like the Renewable Energy Certificate (REC) Mechanism, the Deviation Settlement Mechanism, and the operation of the Green Energy Open Access Portal.
A significant recent change occurred on November 14, 2022, when the name of the institution was officially changed from POSOCO to Grid Controller of India Limited (Grid-India). This name change was made to better reflect the critical role of the entity in ensuring the integrity, reliability, and sustainable operation of the Indian electricity grid, especially in the context of the clean energy transition. The fundamental function of system operation and load despatch, however, remained the same.