Fusion Marine, working in partnership with a number of local west coast of Scotland companies, has helped deliver the successful completion of a small hydro scheme on the Isle of Jura by developing a seaborne delivery solution for the pipes.

The Forest Estate hydro scheme is a 75kW project located at Forest Estate on the Isle of Jura. Forest Estate commissioned the construction of the hydro scheme due to the economic and environmental advantages offered, enabling a regular income whilst providing little disruption to the surrounding land. The energy produced by the scheme allows 50kW to be sold directly to the grid and 25kW to be used for heat and electricity within the estate lodge.

The scheme comprises an intake weir on the Allt Libhir at an elevation of 128m above sea level, a buried pipeline 1,280m long, and a small power house near the mouth of the burn (stream). The turbine is a Tinck single jet Pelton operating under a head of 120m.

Working under contract with consulting engineers, Adrian Laycock, Fusion Marine fabricated the 1.28km of large diameter polyethylene piping required for the scheme from its coastal production base at the Marine Resource Centre near Barcaldine on Loch Creran. Fabrication work included the specialised Fusion welding process and the fitting of specially designed brackets and caps.

Six 200m lengths of the completed plastic pipes were then towed over 60 miles to Jura from the slipway at Barcaldine by the MV Felstad operated by Knox Marine. The vessel also carried a full deck cargo of materials and other equipment needed for the installation. The pipes were then moved ashore onto a beach close to the hydro site and up the hillside into position where Fusion Marine engineers carried out the final welding of the various sections using remote electrofusion jointing equipment. There was no access track to the intake, so a helicopter was used for the placement of concrete in the intake weir to minimise damage to the site.

Stephen Divers, managing director of Fusion Marine, said, “The remote location of the site presented a real challenge for this project. However, for several years we have successfully taken advantage of our coastal location in Argyll for the seaborne delivery of salmon pens to their final farm sites, and this seemed the ideal solution for transporting the pipes to Jura.”

Large diameter polyethylene piping is ideal for small scale hydro schemes as it is flexible and light, which means the course of the pipe can closely follow the lie of the land.

“The versatility and durability of large diameter polyethylene is ideal for use in hydro schemes and other applications such as sewer outfalls,” said Divers.