The Potential of Strong Tidal Currents May Assist Our World’s Depleting Energy

In the advent of our increasing need to find an alternative to the ever depleting, dangerous carbon based energy fuels and our interest in finding renewable sources of energy, an effort to understand the potential of strong tidal currents has been gaining attention. Channels with strong tidal currents are selected to exploit the kinetic energy in the current, by aligning tidal turbines uniformly similar to wind farms, for generating power. Tidal turbines interact with the channel’s flow by increasing the drag coefficient of the channel as the turbine farms grows in scale. There is an upper bound to the power available for generation as too many turbines will merely block the flow. In this study we turn our attention towards maximizing the power output from the turbines. A 1D model in combination with a theory is used for the turbines to discuss the interaction of tuning the flow through turbines and density of turbines across the cross section with larger scale flow, via drag coefficient, to determine power available for production. Tuning the turbines in densely packed farms to a particular channel and turbine density is necessary to maximize the power output. It is necessary that the turbines occupy maximum possible fraction of the cross-section permissible by navigation and marine life in order to maximize the farm efficiency. Optimal tunings depend on the number of turbines per row, number of rows, channel geometry, background friction and tidal forcing, i.e. dynamical balance. Large number of optimally tuned turbine farms can realize most of the channel’s potential.

Tuning any one row of turbines reacts with the flow in the channel and hence the flow through other rows of turbines by affecting the channel’s drag coefficient. …

…counted to be virtually inexhaustible is present in the form of kinetic energy through flow of water in ocean/river. This energy extractable from ocean/sea can be seen as cost-effective, environment friendly, easily available and endless source to meet the demand of the present day. The source of this energy is the currents of water which are continuous, directional movements driven by external forces caused by the effect of earth’s gravity, wind, salinity/ temperature/ pressure differences, Coriolis forces and the tidal currents due to Moon’s gravitational pull. Tidal currents are found to be the most effective of all the sources as it is highly predictable in hydrology regardless of climate changes and also have flow speeds sufficient for extracting power. Tidal energy extraction is similar to wind energy but is predictable in amplitude, direction and time period.