A methodological review to estimate techno-economical wind energy production

Abstract

Wind energy represents an important energy source and, even more, it is called to play a crucial role in the future energy supply. In this context, it is crucial to estimate the technical and economical wind energy potential in different regions and areas. This paper includes an extensive review of methodologies proposed by several authors. Based on this review, a set of equations for the evaluation of wind energy production in a given area is proposed, being the input data: mean wind speed and shape factor at any height or even just the mean wind speed. To calculate the wind energy production, wind farm configuration (array efficiency/wake losses) and extrapolation/interpolation of wind speed and shape factor of Weibull distribution to the hub height, have been the main issues discussed. The distances among wind turbines are determined according to economic criteria, where two different approaches have been considered: maximizing income or minimizing cost per kWh. Available wind data usually include mean wind speed and shape factor at certain heights but, very often, not at the hub height. Several methods for extra/interpolation of wind speed and shape factor have been reviewed and a set of equations has been proposed to calculate them at the hub height. A methodology to calculate the annualized wind generation cost (c€/kWh) is also proposed. One of the premises of this methodology has been that calculations should be able to be done simply using calculator and common office software programs. Another premise has been that the methodology proposed is not meant for a detailed evaluation of energy production of one particular windfarm, but to establish a general methodology to study relatively big areas, like islands or whole regions. A practical application of the methodology proposed has been carried out using wind data from the Canary Islands.