NTPC Limited (NTPC) said its subsidiary THDC India Limited (THDC) has declared commercial operation of Unit four of the Tehri Pumped Storage Project (Tehri PSP), a 250 megawatt (MW) unit, effective from midnight on 12 April 2026. This addition has increased NTPC Group's total installed capacity to 89,378 MW and its commercial capacity to 88,298 MW, reflecting cumulative capacity additions across the group. The disclosure followed completion of commissioning and receipt of necessary regulatory approvals. The development represents a milestone in the company's planned expansion of generation assets. THDC's own installed and commercial capacity has risen to 3,907 MW after the unit became operational, underscoring incremental gains from the Tehri PSP. The Tehri project is planned as four units of 250 MW each and is being developed to enhance grid stability and to support peak demand management. Pumped storage facilities enable energy storage by moving water between reservoirs to supply power at peak and to absorb excess in low demand. The commissioning of successive units signals steady progress in executing complex hydro infrastructure works. The addition aligns with NTPC's strategy to diversify its energy mix and to strengthen flexible generation capabilities that complement growing renewable capacity. Bringing the new unit into commercial operation improves the group's readiness to generate revenue from the asset and to offer ancillary services such as frequency regulation and reserve support to the grid. The enlarged generation footprint reinforces NTPC's position among India’s largest power producers and supports its growth pipeline across conventional and renewable projects. Continued commissioning aids long term energy security and supply reliability. Stakeholders anticipate that the operational unit will assist peak power management and will help integrate higher shares of wind and solar by providing dispatchable capacity during intermittent shortfalls. Pumped storage is likely to remain central to grid modernisation and resilience as renewable deployment accelerates. NTPC and THDC will advance remaining project milestones at Tehri PSP to complete remaining units. The group will sustain efforts to execute its long term expansion plan and strengthen readiness.