Conference article

A general discrete model was formulated for the expected Net Present Value (NPV) of the profit and for the expected yield of the investment (Internal Rate of Return - IRR) to be derived from rectangular grid shaped wind-turbine farms. The model considers the wind shade in the downwind direction and the effect of the wake behind the turbine; the joint wind-direction wind-velocity probability distribution; as well as the various relevant cost and revenue factors. It was assumed that the wind-turbines are identical and of equal heights; and are spaced equally along the axes of the rectangle; but not necessarily at the same equal distance at both axes. Using the model; the optimal layout that maximizes the expected NPV and/or IRR was derived numerically for a given data set; in stages; determining the optimal number of turbines in a row and the associated optimal distance in-between them; and also the optimal number of turbines in a column and the optimal distance in-between them. Sensitivity analysis has shown that minor changes in the parameters do not affect the selection of the optimal layout.

Wind energy; optimal layout; wind farms