Scotrenewables’ tidal turbine demonstrates its capacity in waters off the U.K.

A Scottish company’s tidal turbine is a few degrees away from commercial deployment. Weighing 100 tons and measuring 33 meters, a 250-kW prototype reached a peak power export of 273 kW during a recent trial. Bigger tests are on the horizon.

Hydraulically retractable rotor legs give the tidal turbine two configurations: operational mode with the rotors down to generate power and survivability mode with rotors retracted to decrease draught.

Essentially, the turbine is a floating cylindrical tube that supports dual horizontal axis rotors. The rotors extract kinetic energy from the tidal flow, which is converted to electricity and transmitted to shore.

Since its founding in 2002, Scotrenewables Tidal Power (www.scotrenewables.com) has built nine scale models of the turbine. ABB recently invested funds that will assist in building a 2-MW full-scale machine that incorporates lessons learned from smaller iterations. “This is a major step on the road to making the company a real clean-energy success story,” says Scotrenewables CEO Barry Johnston.

This “commercial scale” turbine, which will be well suited for tidal array deployment, is under development now. Known as the SR2000, it will reach its rated power at 3m/s, making it one of the most powerful tidal turbines in the world, according to the company.

The design process for the SR2000 will be similar to that of the 250-kW turbine, using existing hydrodynamic and structural modeling techniques to optimize the structure for a 20-year design life.

The SR2000 will be the first tidal turbine installed as part of a 10-MW demonstrator array in U.K. waters. WPE