Assessment of Hydrokinetic Energy Resources in the St Lawrence River and Estuary

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Andrew Cornett, Thierry Faure

Tuesday 30 june 2015

8:45 - 9:00h at Antarctica (level 0)

Themes: (T) Special session, (ST) Marine renewable energy

Parallel session: 4D. Special session: Marine Renewable Energy

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To date the marine renewables industry has been primarily focused on harvesting energy from waves and tidal currents; however, interest in exploiting river currents is growing in several countries. Machines for converting water currents into electrical energy, originally developed for oceans, are now being adapted for use in rivers where flows tend to be more accessible and far steadier. The St-Lawrence River, located in eastern North America, has an average discharge of 10,300 m3/s, ranking 23rd among the world’s rivers by this measure. This paper describes research undertaken to investigate, model and assess the hydrokinetic resources throughout most of the St-Lawrence River and Estuary. One of the unique aspects of this work is that the resource assessment spans 3 distinct reaches: the upper portion of the river, where river discharges alone control the flows; the lower portion, where both river discharges and tidal currents are important; and the Gulf, where tidal currents alone dominate. High-resolution 2-D numerical models have been developed to simulate the flows in the St Lawrence River and Estuary. The models have been employed to predict the variation in flow conditions over a typical year, including the combined effects of time-varying river discharge and tides. The model outputs have been analysed to obtain detailed predictions of the scale of the potential kinetic energy resources, their spatial distribution, and their temporal variability. This paper describes the development, calibration and application of the numerical models, as well as the analysis and assessment of the model outputs. The scale and character of the hydrokinetic resources in the St-Lawrence River and Estuary is presented and described. Results indicate that substantial hydrokinetic energy resources worthy of development occur at many locations along the river and estuary. Unfortunately, many of these high energy sites are located in the navigation channel where energy extraction may be limited due to conflicts with shipping. In addition to documenting these important hydrokinetic energy resources, the methods developed and applied in this study can be used to model and assess the resources in other large rivers. Moreover, this work can be used to guide and inform the development of codes, standards and procedures for hydrokinetic resource assessment in rivers.