NREL is collaborating with other national laboratories, federal agencies, universities, and industry members to develop comprehensive and validated sets of computer-aided engineering modeling tools to accelerate the development of marine hydrokinetic technologies and improve the performance of hydroelectric facilities. Recent modeling efforts include:
- Wave Energy Converter Device and Array Modeling
- Current Device and Array Performance Modeling and Optimization
- Reference Model Development
Wave Energy Converter Device Modeling
NREL is developing numerical modeling tools to simulate wave energy conversion (WEC) devices. These dynamic modeling tools will be useful for analyzing the hydrodynamic loads and power generation potential of current and future WEC designs with an initial emphasis on point absorbers and surge/pitch devices. The tools will include (1) a multibody dynamic model to solve the dynamic response and to estimate power; (2) a wave generator to model both regular and irregular waves; and (3) a quasi-static mooring dynamic modeling tool to estimate mooring line loads. In collaboration with Oregon State University and Massachusetts Institute of Technology, NREL is developing these tools to assist private industry, academia, and other national laboratories to assess the practical extractible energy levels based on realistic WEC designs.
Current Device and Array Performance Modeling and Optimization
NREL has released a publicly available version of HARP_Opt, a rotor design code that utilizes blade element momentum theory and a generic optimization algorithm to determine the blade's shape and rotor operating characteristics, which maximize annual energy production and minimize blade mass.
NREL also assessed the utility of computational fluid dynamics (CFD) simulations for the study and analysis of the performance of tidal current turbine arrays by employing large-eddy simulation.
Judicious placement of turbines in an array is critical to obtaining maximum energy capture and minimizing the cost of energy. Large-eddy simulation also allows for the examination of the effects of naturally occurring tidal turbulence on array performance. This work has developed a preliminary computer aided engineering tool for evaluating array performance and demonstrates that performance characteristics of tidal current turbine arrays can be evaluated using CFD simulations.
Reference Model Development
The U.S. Department of Energy's Reference Model Project aims to provide the Water Power Program with baseline levelized cost of energy estimates for marine and hydrokinetic (MHK) devices. These estimates help evaluate the feasibility of the disparate MHK technologies presently in development. Work performed also helps accelerate the pace of tidal current turbine technology development by providing a design methodology that can be utilized by industry.
NREL has designed and analyzed the performance of both a twin-rotor horizontal-axis tidal current turbine and a floating-point absorber wave energy device for the DOE reference model project.