Contribution of tidal energy to an integrated island energy system

Abstract

Tidal stream energy is an emerging sector of the energy generation industry. Compared to many other renewable energy resources it has high potential to provide base-load power due to the predictability of the speed and direction of tidal currents. However, the practical use of tidal stream energy requires extraction that is both efficient and appropriate; in engineering design, social impact; and economic viability. This study designs a tidal array for Orkney waters, testing it against a wide range of constraints from engineering efficiency to market suitability. It explores various approaches to achieving efficient energy extraction. Different energy generation patterns are examined to find the strategy that best fits the pattern of energy demand of the islands, without conflicting with the existing supply. The study demonstrates the potential of integrating tidal energy into an island energy system without the need for expensive grid upgrades. It shows that arranging the turbines in a staggered sub-array (SSA) layout, and regulating the power output of the tidal device, increases the capacity factor of the installed system. This strategy improves the economic viability and commercial competitiveness of tidal energy.