ES220908 theoretical test

Page 1

POWER PRODUCTION FROM RENEWABLE ENERGY AY 2021-22 8th September 2022 Prof. Paolo Silva Time: 1 hour Instructions for the examination: 1) Clearly indicate your name on all the sheets you will deliver. 2) Give a synthetic and clear answer to as many questions as possible. The final score will be normalized according to the average results. 3) Talk with colleagues and / or cheating will cause the cancellation of the exam. 1. Consider a wind turbine installed on a site with a high roughness factor, that brings about a significant wind speed gradient across the area swept by the blades. Explain the effects over velocity triangle at the tip for a blade respectively positioned at the top (vertical), middle (hori- zontal) and bottom (vertical) point of its path. 2. Considering a liquid-dominant geothermal source, discuss the advantage and disadvantages of direct steam cycles with pressure lamination with respect to binary cycles. 3. Consider two identical wind turbines installed on sites with an average wind speed respectively equal to 6 and 7 m/s. What is the ratio between the Levelized Cost of Electricity (LCOE) of the 2 plants? 4a: ENERGY ENGINEERING STUDENTS (8 CFU): Consider a run-of-river hydroelectric plant and explain, from an energy point of view, pro and cons of a weir integrated plant compared to a diversion channel plant. 4b. MECHANICAL ENGINEERING STUDENTS (6 CFU) : For some renewable sources, discuss the energy and environmental advantages related to cogenerative or even thermal applications compared to those involving a fully electric configuration 4c. MANAGEMENT ENGINEERING STUDENTS (5 CFU): Explain the concept and the calculating method of the Levelized Cost of Electricity (LCOE) for renewable energy sources. With the same investment cost (€/kW), what are the…