Area: Energy Efficiency and Renewable Energies ―Selected Proceedings from the 1γth International Congress on Project Engineering‖. (Badajoz, July 2009) RISK ASSESSMENT OF WIND POWER GENERATION PROJECT INVESTMENTS BASED ON REAL OPTIONS Muñoz-Hernández, J. I. Contreras, J. Caamaño, J. Correia, P.F. Escuela Técnica Superior de Ingenieros Industriales de Ciudad Real Abstract This work presents an assessment model for investment in renewable power generation projects and its associated risk. The first part presents a classic economic study whose objective is to determine the profitability of eolic energy power plants, calculating the energy productions and the price of the energy sold to the market in each case. The economic parameters used to determine the profit value of the installations have been: the Net Present Value (NPV), the payback and the Internal Rate of Return (IRR). The economic appraisal has been calculated on different settings, in which different values for significant variables have been considered in the study of the economic viability of the project. In the second part, real options valuation methods for generation investment have been applied. The work goes deeper into the deferment option to calculate the premium that a company should pay to have the option to defer the investment. The idea is to compare this premium with the result obtained in a NPV classic analysis. The main idea is to insert the values obtained by NPV analysis in different periods into the option valuation tree. Thus, a classic approach to have a more realistic trinomial option tree can be used, as well as other tools like American real options or NPV curves. This makes risk management easier and more reliable. Several practical cases will be present in order to validate the model. Keywords: investment assessment, risk management, real options, eolic electric generation, renewable energy Resumen En el presente artículo se expone el desarrollo de un modelo de valoración de inversiones en proyectos de generación eléctrica eólica y su riesgo asociado. En una primera fase se acomete la valoración por métodos clásicos calculando la producción y los precios de venta al mercado eléctrico para niveles de producción equivalentes en distintos escenarios. Los parámetros económicos empleados para determinar la rentabilidad de la instalación han sido el Valor Actual Neto (VAN), el Plazo de Recuperación y la Tasa Interna de Rentabilidad (TIR). A continuación, se realizan valoraciones en las mismas condiciones y con los mismos parámetros con un método de valoración basado en opciones reales (OR). Con este método se analizan distintas posibilidades (opciones) a acometer las distintas inversiones. Es esta forma, y basándose en el método de OR (contrastado con el clásico), se obtiene una valoración de la conveniencia y del riesgo de acometer este tipo de inversiones utilizando 290