Semi-analytical estimate of energy production from a tidal turbine farm with the account of ambient turbulence

Abstract

This paper presents the influence that ambient turbulence has on a tidal turbine farm. Firstly, the analytical model developed by Bahaj and Myers (2004) is used and modified in order to incorporate the ambient turbulence effects. Ambient turbulence is taken into account via the experiments of Mycek et al. (2014), where two levels of turbulences were tested, namely 3% and 15%. Modifications in wake velocity deficit are treated. However, the influence that ambient turbulence has on the power coefficient of downstream turbine(s), which is usually neglected, is taken into account. For the lower level of turbulence, three scenarios for the downstream turbine(s) behaviour are considered.

This enhanced model is then tested on a given site in the Alderney Race (Raz Blanchard). Yearly energy productions depending on ambient turbulence, turbine layouts and proposed scenarios are evaluated and compared. A technico-economical analysis is also carried out. Finally, the tidal turbine farm profitability highly depends on ambient turbulence and turbines layout.