Chennai: The Tamil Nadu Generation and Distribution Corporation (TANGEDCO) has invited bids to appoint a consultant to prepare a detailed project report (DPR) for the first phase of the proposed 2,000 megawatt (MW) Sillahalla pumped storage hydro-electric project in the Nilgiris.
The Rs 7,000 crore Sillahalla project will be implemented in two phases by 2022, says a senior Tangedco official. The first phase of the project envisages construction of an upper reservoir across the Sillahalla river with a capacity of 2250 million cubic feet as also an interconnecting tunnel between the proposed dam and the Avalanche-Emerald reservoir.
The 2.75-km-long tunnel will have provision for two-way flow. The official said the consultant to be appointed by the utility would prepare a DPR, provide services to obtain statutory clearances and draft a tender specification for awarding engineering procurement construction contract for the first phase work.
“Once the contract is awarded, the consultant should complete DPR work in three months, after which the bids will be floated for construction of the dam and tunnel,” the official said, adding that they have set a target of completing the first phase of work by 2018-19.
In the second phase, an underground powerhouse with four units of 500 MW each, access tunnel, power transmission and drawal system will be constructed. “The DPR for the second phase will be prepared separately after obtaining all clearances,” the official said, adding that the entire Sillahalla project is expected to be commissioned by 2022.
The Sillahalla dam will act as a balancing reservoir between the Avalanche-Emerald dam and the downstream Pillur dam. It is called so because water from Pillur will be pumped up to the proposed Sillahalla reservoir, when power demand is low, normally at night.
Surplus power generated by various sources, particularly wind power, will be used to pump water to the upper reservoir from the lower one. Water stored in the upper reservoir will be used to generate energy to meet morning and evening peak power demand. It provides flexibility to the state grid for operation.
The Sillahalla project will come in handy to harness the full potential of wind power in the state which otherwise goes untapped during the peak wind season. At present, grid managers back down windmills if power demand is low, thereby leaving wind power untapped....
Location: Tamil Nadu