The Euro24M (US$34M) order for the 177MW plant was awarded by energy utility Iberdrola.
Voith will supply a Francis turbine, verticl generator and a 32m long steel liner.
San Esteban II is being built on the river Sil, which is a tributary of the Mino. It is to be in service by the end of 2012.
The project involves construction of an underground powerhouse, and the plant will share the upper reservoir with the original San Esteban facility commissioned in 1957. The San Esteban plant has an installed capacity of 265MW.
