The company is calling for bids to drive a 530m long exploratory drift at the location of the underground power house for the Luhri project, and interested local parties have until 7 September to tender. The bid deadline was extended from 24 August. The works are expected to take 12 months to complete.

Bids have also been called for site investigation works at the dam site, intake and diversion tunnel. The same deadline is set – 7 September.

The Luhri project is being built on the river Satluj and is to be commissioned by mid-2015. Earlier studies proposed that the plant have an installed capacity of 465MW but a proposed alternative dam site would enable SJVN to benefit from 90m of additional head.

While noted as a run-of-river development, the proposed scheme would have a 78m high concrete gravity dam at the alternative locations to divert 575m3/sec through five intakes. The project would also involve construction of a 29km long, 10.5m diameter headrace tunnel, a 34m wide by 153m high surge tank.

The underground power house is sized at 131m by 24m by 47m in height and is to house six units of 116.67MW capacity, generating electricity from a flow of 477m3/sec and a net head of 162m. The discharge would be conveyed to the river by a 10.50m wide horseshoe-shaped, 250m long tailrace tunnel.

Separately, SJVN is also advancing preparations for site investigation works for another development – the 34.5MW Naitwar Mori plant in Himachal Pradesh, which is scheduled to be commissioned in 2012.

Previously known as Nathpa Jhakri Power Corp Ltd, SJVN is a joint venture between the Indian government and the state of Himachal Pradesh.