It's a big day for a North yorkshire community group who have funded their very own hydro-electric turbine.
The Archimedean screw turbine - so-called because they rely on a device invented in Ancient Greece by Archimedes, will move water down the weir in the River Esk in Ruswarp.
The screw will be 2.9m in diameter and will weigh 11 tonnes. The size and shape of the screws mean that smaller objects - like leaves or fish - can pass through the screws easily and safely.
It's been five years in the planning, but Esk Energy (Yorkshire) Limited community group took the generation of green energy into their own hands, and fundraised for the scheme.
The turbine will generate an estimated 160,000 kWh of green electricity each year and an income - from feed in tariffs - approaching £1m during its first 20 years.
Colin Mather, a retired civil engineer and chairman of the group, said: "This is such an exciting day for everyone involved. Think global and act local has always been one of our mottos and, after five years of planning, obtaining permissions and fundraising, we are nearing the point of realising our vision of harnessing the power of the River Esk to create clean energy."