New tidal turbine arrives at marine energy test bed
What's yellow, 30 meters long, weighs 80 tons and is soon to be plying the waters off the Orkney Islands? The Scotrenewables SR 250 tidal turbine, of course!
Scotrenewables Tidal Power Ltd. delivered its SR 250 floating tidal turbine to the Fall of Warness test site at the European Marine Energy Centre (EMEC) in Orkney, Scotland this week. The 80 ton floating marine power plant is 30 meters long and sports twin counter-rotating rotors, each with a diameter of 8 m. The turbine has a nameplate capacity of 250 kW. The SR 250, which was manufactured at the Harland and Woolff Shipyard in Belfast, is unique in that it floats on the surface of the water, unlike other tidal power devices mounted on static pilings or weighted foundations. The turbine will be anchored to the seabed with a four-riser catenary-spread mooring system equipped with a quick-release turret. Three kilometers of undersea cable hold the power generation system in place. In extreme weather conditions, the two subsurface rotors can be retracted to protect them against excessive stresses.
Scotrenewables has a five-year lease at the EMEC testing facility, and the SR 250 will initially be tested for performance over a two-year period. The data will be also used to refine operational procedures. The turbine will not spend the whole two years at sea, however. Chief technical officer Mark Hamilton said that the SR 250 would be brought into port frequently for inspection and maintenance, "A major advantage of our floating technology is that can be easily towed to and from site for inspection and maintenance at harbour side," Hamilton said.
Company spokesperson Freya Thompson said that the SR 250 was set to begin exporting power to the grid as soon as next month. Ultimately, Scotrenewables aims to produce the machine in a full-scale 2 MW version. The EMEC test bed deployment is a key step toward scaling up the device, according to managing director Barry Johnston. "We still have a lot to learn and having the ability to test the SR 250 in open-sea conditions will provide the team with the crucial experience needed before progressing on to the full-scale prototype, 2MW commercial device," Johnston said.