Model for an evaluation of electricity production and economical affordability of a wind turbine in Ireland

The aim of this thesis is to build a model to evaluate the electricity production and the economical affordability of a wind turbine, suitable for every site considered in which a database of wind speed is available. In particular this thesis analyses a site located in Cork County, Ireland. Starting from an analysis of the windiness of the site, using the two-parameter Weibull distribution, which is defined by his two parameters, both derived from six different numerical methods. The best method is evaluated calculating the errors on the measurement and for the number of samples available for this study, the empirical method turns out to be the best way to obtain the parameters. Having the wind distribution, in particular the velocity that carries the maximum energy, a selection of different wind turbine models can be done. In this thesis three different models are compared because the selected wind turbines have different power coefficient curves that suits differently the wind probability distribution, they have different range of wind in which they can operate and different value of the diameter. As a result, the Fuhrländer FL MD7 is the model that gives the most electricity production. To evaluate the economical affordability of the investment economic tools are used, which are the Discounted Pay Back Period, the Net Present Value (NPV) of the wind turbine at the end of life of the turbine and the Levelized Cost of Electricity (LCOE). In this thesis six different scenarios are evaluated in order to show how the variation of the electricity price, the investment costs and the Weighted Average Cost of Capital (WACC) affect the cash flow, and therefore the return of the investment. The first two scenarios are considered the base scenarios, in which the investment costs, operating and maintenance costs and the electricity price are the average obtained from the literature. The first one, which does not consider the WACC, shows a return of the investment of 7.3 and a NPV of 3053929.25 € while the second, as it can be expected, gives a return of the investment of 10.6 years, a NPV of 912187 € and a LCOE of 5.17 €cent/kWh. The second two scenarios vary on the electricity price. In the first one it is chosen a current price equal to 125 €/MWh which is an increase of more than 50% compared to the base scenario. The pay-back period is about 7.1 years, the NPV at the end of life is 1169486.85 € and the LCOE is the same as the base the case since the electricity price does not affect this parameter. The second scenario is a forecast of the electricity price to the 2030 and therefore also the investment costs are a forecast. The scenario considers an electricity price of 60 €/MWh and at the same time a reduction of the investment cost to 847 € per each kW of power of turbine installed. The pay-back period is about 12.4 years, the NPV at the end of life is 198246.20 €. A further study considers an electricity price of 60 €/MWh but without a decrease on the investment costs and sees a non-return of the investment in the lifetime of the wind turbine. The last two scenarios consider a variation of ± 10% on the WACC. In the scenario in which it decreases and equal to 5.4% the pay-back period is about 10.1 years, the NPV at the end of life is 1059697.03 and the LCOE is 5 €cent/kWh. In the scenario in which it decreases and equal to 6.6% the pay-back period is about 11.2 years, the NPV at the end of life is 774947.47 and the LCOE is 5.35 €cent/kWh.