Hydro power is a commercial technology, long established in Scotland, which accounts for a significant proportion of our existing renewable output. It contributes around 10% to Scotland's total current energy generation. Most output is produced by large scale hydro schemes. There are, however, an increasing number of proposals for small run of river hydro projects and these projects, together with the continuing refurbishment of the large hydro schemes will ensure that hydro will continue to play its part in Scotland's renewable energy mix.