Signature Projects are intended to bring focus to a selection of the U.S. Departments of Energy's Water Power Technology Office (WPTO) projects. By designating a Signature Project, the project reports, data sets, and associated papers can be easily discoverable. By bringing together all aspects of a project, whether a completed legacy project or an ongoing investigation, the MRE community can be informed of what investigations have been undertaken, which have succeeded, what tools are available, and where gaps in information persist.
Reference Model 2: River Current Turbine
- Project Summary
- The Reference Model Project was a partnered effort to develop open-source marine hydrokinetic (MHK) point designs as reference models to benchmark MHK technology performance and costs, and an open-source methodology for design and analysis of MHK technologies, including models for estimating their capital costs, operational costs, and levelized costs of energy.
- Reference Model 2
- River Current Turbine
- Reference Model 2 (RM2) is a variable speed dual-rotor cross-flow river turbine that is deployed at the water’s surface. It was designed for deployment at a reference site modeled after a reach in the Mississippi River near Baton Rouge, Louisiana. The rotors are anchored to a two-pontoon vessel platform. Surface deployment of the turbine minimizes the handling requirements during deployment and recovery and reduces overall costs for all O&M activities, including allowing for easy access to the power conversion chain (PCC). The design (two rotors per platform) also reduces the environmental footprint and associated environmental compliance costs.
- Plan dimensions of the pontoon are 28 m by 20 m. The diameter of each rotor is 6.45 m. The dual-rotors on each unit are offset by one and a half diameters (9.675 m) from each rotor centerline. The rotor centerlines are submerged one blade length (4.84 m) below the free surface to guard against cavitation. As compared to the RM1 tideway resource site, the water depth at the RM2 river resource site can vary greatly; this fact restricts the height of each rotor to 4.8 m. Even at shallow depths, which occur with reduced discharges, the rotors remain well above the riverbed (at least 5 m of clearance above the bottom). This reduces potential boundary layer effects that can cause velocity, turbulent shear, and loading asymmetries across the rotor.
- Similar to the RM1 device, the structural design and materials specifications for all RM2 device components considered the maximum of two extreme load conditions along the horizontal direction. The rotor frame was designed with a pivot joint at the pontoon connection with a 90 degree stop to allow for the rotor frame to be lifted to the surface for maintenance and transportation. The rotor frame structure supports the rotors and the entire PCC.
- A wide channel is welded to the top of each pontoon to connect with the three cross-bridges. Each cross-bridge, which has eight cross-members, connects the two pontoons together and provides lateral rigidity to the platform. The mid cross-bridge will serve the additional purpose of providing an access walkway to the PCC units for service.The pontoons were sized to allow for approximately 50% submersion during operation. The central vertical support as well as the downstream lateral bracing is designed to reduce both vertical and downstream deflection of the frame due to loading. Thin sheet metal fairings are used on the main vertical members to reduce the drag on the rotor frame. Mooring attachment points for the device are located on the rotor frame at the vertical centerline of the rotor drag.
- The overall arrangement of the PCC consists of the following key components:
- Generator and gearbox in shovel mount
- Shafts and bearings
- Power conditioning electronics on platform
- Drivetrain assembly, including rotor driveshaft, bearings and U-joint
- The RM2 turbine pontoon is moored to the riverbed by attaching a mooring leg to each side of the turbine frame. Using two anchor legs ensures that the unit can maintain station if one leg fails. Mooring legs are stainless steel chains and are connected to a plate anchor at the riverbed.
Project Information
| Primary Project: | Reference Model |
|---|---|
| Status: | Completed |
| Start Date: | 2010/09/01 |
| End Date: | 2014/09/01 |
| Organization: | National Renewable Energy Laboratory (NREL), Oak Ridge National Laboratory (ORNL), Pacific Northwest National Laboratory (PNNL), Pennsylvania State University, Re Vision Consulting LLC, Sandia National Laboratories (SNL), US Department of Energy (DOE) |
| Contact: | Vincent Neary |
This table lists documents associated with the RM2: River Current Turbine project, including reports written by the project team and/or papers that have used the project outputs or are closely associated with them.
