An Archimedean screw turbine – 2.9m in diameter and weighing 11 tonnes operating with upto 4 cumec with a rated capacity of 51.6KW – has now arrived at JN Bentley’s construction site on the banks of the River Esk in Whitby, and will generate electricity for client, Esk Energy (Yorkshire) Limited, an industrial provident society set up and managed by local residents.
National Engineering and Construction Company JN Bentley has been working with Esk Energy since 2008 during which time Esk Energy have secured funding towards the cost of the project through a community share issue along with the necessary planning and license permissions.
JN Bentley, as principal contractor, has been on site since May 2012 after completing the design for the scheme as well. Work to date has also included the refurbishment of the existing Environment Agency fish pass and its conversion to a Larinier-type fish pass to help increase salmon and sea trout stocks in the River Esk.
The arrival and installation of the screw turbine signifies a key milestone for the project, which is now on target to generate power by the end of October 2012. The Archimedean screw is so-called because it relies on a device invented in Ancient Greece by mathematician, physicist and engineer Archimedes of Syracuse. Archimedes is credited with inventing the screw originally to move water upwards from the hold of a ship. This technology has been adapted at Ruswarp to reverse the principle and move water down the weir.
The River Esk can send up to 4 tonnes of water down the Archimedean screw every second – forcing it to rotate. A generator extracts the energy made by the turning of the screw, turning it into electricity. The size and shape of the screws mean that smaller objects – like leaves or fish – can pass downstream through the screws easily and safely.
JN Bentley has many years’ experience working on hydropower schemes – including hydro-scheme development, run of river schemes, clean water and wastewater screw generators as well as turbine refurbishment and turbine decommissioning. JN Bentley’s own hydropower scheme at Linton Falls near Grassington in the Yorkshire Dales was recently awarded Contract of the Year by CECA (Yorks and Humber) and has been shortlisted for an English Heritage Angel Award.