The Bhira Pumped Storage Hydropower Project is located in Raigad district of Maharashtra and forms part of an established hydropower system supporting the Mumbai Pune region. The original Bhira power station was commissioned in 1927 and comprises 6 generating units of 25 MW each, equipped with double overhang Pelton turbines. Along with other hydro and thermal stations in the region, the facility plays a key role in sustaining industrial and urban power demand.

To address the growing requirement for peaking power and grid stability, a pumped storage unit was developed as an extension to the existing hydropower station. The project was conceived to operate in both generation and pumping modes, enabling energy storage and rapid response to peak load conditions. At the time of its commissioning, the Bhira pumped storage unit was the single largest such unit in India and was perhaps the only pumped storage unit in the country capable of operating in both pumping and generation modes.

The scheme utilises the existing Mulshi lake as the upper reservoir, with a live storage capacity of 523.02 million m³, and an existing downstream pickup pond as the lower reservoir, with a live storage capacity of 1.536 million m³. The project involved rehabilitation of an existing low pressure headrace tunnel and construction of a new water conductor system, including large diameter penstocks, underground pressure shafts and a shaft type powerhouse.

Comprehensive hydraulic scale model studies of the entire water conductor system were carried out, along with detailed testing of rock properties in the tunnels. On site performance monitoring of the new penstock system was undertaken using vibrometers and strain gauges at critical locations. Following statutory clearances, site works commenced in February 1992, and the pumped storage unit was successfully commissioned in May 1997.

TCE’s scope