Energy Engineering - Power Production from Renewable Energy

Ex 1 - ENERGY AND ECONOMIC ASSESSMENT OF A WIND TURBINE - Text

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ENERGY AND ECONOMIC ASSESSMENT OF A WIND TURBINE Power Production from Renewable Energy– A.Y. 2020/21 Prof. Paolo Silva – Ing. Elena Crespi A company wants to evaluate the economic feasibility of the installation of a modern wind turbine Vestas V90GS. The turbine has a horizontal axis and a 3-bladed rotor; the nominal power is 1’800 kW and the operational wind speed ranges from 3 m/s (cut-in speed) to 25 m/s (cut-off speed). CASE A Consider the attached figure and table, which illustrate the wind speed distribution for the considered geographic location and the power curve values for the Vestas V90GS turbine (referring to ISO standard conditions). Consider a venture capital investment and the following plant costs: • Turbine and transportation 1’810’000 € • Plant design, engineering and work supervision 227’000 € • Civil works 403’000 € • Grid connection 277’000 € The annual average availability of the plant is 8600 hours and the O&M annual cost is 35’000€ in the first year, while in following years it has to be updated according to the inflation rate. Assume the following economic data: • plant life 20 years • inflation rate r inf = 0.5% • discount rate r disc = 4.0% • tax rate r tax = 38% • financial amortization 12 years, constant shares • feed-in tariff F feed-in = 12.96 c€/kWh (1000-5000 kW range; DM 06/07/2012) • feed-in tariff duration 20 years The construction time of the plant is 2 years and the investment cost is split in two tranches: 55% during the first year of construction and 45% during the second year. Draw the curve of the power coefficient (Cp) of the turbine and calculate the expected annual energy production, the capacity factor and the equivalent working time of the plant. Determine the performances of the investment (pay-back period, net present value, internal rate of return, etc.) and the levelized cost of energy. CASE B Repeat the same analysis of CASE A adopting the Weibull distribution to represent the measured wind speed distribution on the site. CASE C Consider the Weibull wind speed distribution defined in CASE B and repeat the evaluations for a Vestas V90- 2000 wind turbine, whose power curve is given in Table 1. The turbine and transportation cost is 7% higher than the one for the V90GS. Compare the economic performance of the investment to CASE A and B and motivate the observed differences. Figure 1 Table 1 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 f(v) v [m /s] Performance V90 GS Performance V90 2000 v [m/s]f(v)P_el [ kW]P_el [ kW] 02.600 17.200 210.100 312.0200 413.08551 511.0202223 610.0364411 78.5583619 87.0879844 95.312271100 103.515701388 113.017561723 122.317911957 131.818002000 141.218002000 150.818002000 160.518002000 170.218002000 180.018002000 190.018002000 200.018002000 210.018002000 220.018002000 230.018002000 240.018002000 250.018002000 Wind speed distribution