A theatre in Oxfordshire is to use water from the River Thames to produce its own electricity.
The Mill at Sonning will celebrate the completion of its own hydro electricity supply with a party on Monday.
The scheme will generate enough electric energy for the theatre lighting, restaurant, bars and offices.
The theatre expects to produce more "green electricity" than it needs and plans to sell the excess to the National Grid.
Flour mill
Funding for the project has come from the owners of The Mill at Sonning, Oxfordshire County Council, South Oxfordshire District Council and an anonymous donor.
About 162,000 units of electricity will be generated each year.
This flour mill dates from the 18th Century and when it closed in 1969 it was one of the last flour mills on the Thames.
It opened as a theatre in 1982.