The deployment of in-stream flow-energy converters in rivers is an opportunity to expand the renewable energy portfolio and limit carbon emissions. Device performance and lifetime, environmental conservation, and the safety of fluvial communities against flood events, however, present unresolved challenges. In particular, we need to understand how multiple submerged hydrokinetic turbines interact with the sediment bed and whether existing technologies can be deployed in morphodynamically active natural rivers. Here, we present a scaled demonstration of a hydrokinetic turbine power plant deployed in a quasi-field-scale channel with sediment transport and migrating bedforms. We measure high-frequency sediment flux, the spatiotemporally resolved bathymetry and the turbine model performance. We find that with opportune siting, kinetic energy can be extracted efficiently without compromising the geomorphic equilibrium of the river and the structural safety of the turbine foundation, even in the presence of large migrating dunes, thus paving the way for harnessing sustainable and renewable energy in rivers.
Bibliographical noteFunding Information:
We thank the SAFL engineering staff for their technical support during the experiment preparation. In particular, we thank C. Ellis and J. Mullin for their ingenuity in the design and fabrication of the Laser Scan Cart measuring system. Funding was provided by the National Science Foundation CAREER: Geophysical Flow Control (award ID 13513013) and partially by the Institute on the Environment (IonE), University of Minnesota.
M.M. performed the experiments, processed the data, prepared the figures in the manuscript and partially contributed to the writing; he is also the main contributor to the Supplementary Information file and Supplementary Videos. C.H. performed experiments with the large model turbine, set up the data acquisition system and provided key suggestions on the array deployment, the main channel configuration and monitoring, and in the Supplementary Video preparation. F.S. is the Principal Investigator of the NSF BIC grant and the IREE grant providing support for the turbine model construction and introducing MHK research at SAFL. He provided comments and suggestions to the manuscript. M.G. is the Co-principal Investigator of the above grants and Principal Investigator of the NSF CAREER (award ID 1351303) currently supporting this research. M.G. planned this experiment, wrote most of the manuscript and is M.M.’s PhD advisor.