Dresser-Rand has patented a Variable Radius Turbine (VRT) called HydroAir to be used on OWC power plants. This technology has been developed in conjunction with Cranfield University, UK.
Incoming surface waves induce an oscillating flow of air within the chamber which, in turn, flows backwards and forwards through an air turbine installed in a duct connecting the chamber to the atmosphere. The turbine converts this air movement into electrical energy. The HydroAir impulse turbine is constructed to withstand the rigors of a marine environment using a combination of stainless steel, aluminum and reinforced composites to resist corrosion.
In addition, it offers the following benefits when compared to other turbines being used for wave energy capture:
- Above average efficiency
- One moving part – the rotor
- Lower rotational speeds than competing turbines
- Currenly designed up to 1 MW
- Wide operating range
- Reduced noise