ES 05 02 2025 theoretical test

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POWER PRODUCTION FROM RENEWABLE ENERGY AY 2023-24 5th February 2025 Prof. Andrea Giostri Time: 1 hour NAME and SURNAME:.................................................................................................................................. COURSE and CFU:............................................TYPE (Complete or Theory only):.................................. Optional Teamwork grade:.....................Previous Practical text grade( if Theory only) :...................... 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. OPEN QUESTIONS (points 18) 1. For All Students Consider a CSP plant based on solar tower technology. List and discuss the losses in the conversion process from solar energy to electricity. Discuss the reason why in real plants the solar- to-electric efficiency in design conditions is higher than the yearly average value. 2b. For Mechanical Engineer and Management Engineer students (5 CFU) Consider a modern wind turbine (large scale) and draw the ideal characteristic curves (Power-wind speed and Cp-wind speed). Define and provide qualitative values for the cut-in, nominal and cut-out wind speed and discuss how rotational speed changes when wind speed changes from cut -in and nominal value. 2.c For Energy Engineer and Management Engineer students (8 CFU) Consider a liquid dominated geothermal source and compare two solutions based on direct steam flash or ORC binary cycle from both an energetic and an environmental point of view. MULTIPLE-CHOICE QUESTIONS (points 12)…