Date:11/01/2009 URL: http://www.thehindu.com/2009/01/11/stories/2009011153290400.htm

Karnataka

An underground powerhouse

Special Correspondent

HOSANGADI: The Varahi Hydro Electric project, which has two stages with four generating units, is an engineering marvel as it is an underground powerhouse built by excavating a huge rock.

A huge cave with a width of 20 metres and height of 30 metres is built for a length of 155 metres to house generation units and related components nearly 78 metres below the ground level.

In addition to this, nearly a km-long access tunnel has been excavated.

The Underground Power House was built in 1989-90 as part of the Stage-1 of the project. It then created a record as it was the first underground powerhouse of the State and second in a Southern State after the one in Idukki of Kerala. The construction of the dam powerhouse was started in 1978-79.

The concept of the underground powerhouse has not only resulted in savings with respect to the length of penstocks, but it is environment-friendly as the degradation of forest cover is less compared with the surface power stations.