Iberdrola plans to build an underground power plant for the Santa Cristina hydro power project in Galacia, Spain.

The diversified international utility said that it had elected a project location on the Sil river in the region following two months of studies to determine the most environmentally neutral site. Iberdrola said the planned project had the backing of the Parado do Sil municipal authorities in north west Spain.

With construction due to start in 2009, the Euro 400M (US$550M) Santa Cristina project is scheduled to be completed in 2016. The cost of the project represents two-thirds of the total investment in wind and hydro power that Iberdrola plans to make in Galacia in the near future.

Iberdrola already operates 18 hydro plants in Galacia with a combined capacity of 1348MW, and which produced 2528GWh in 2006 – 64% of its output in the region.