practical test 20210827 fin

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SOLAR AND BIOMASS POWER GENERATION AY 2020-21 27th August 2021 Prof. Giampaolo Manzolini Time: 90 minutes Instructions for the examination: 1) Clearly indicate your surname and name on all the sheets you will deliver. 2) The score refers to exercises done in a comprehensive manner with exact numerical results. Numerical results correct but not accompanied by expla- nations will not be taken into account. The final score can be normalized according to the average results. 3) Answer briefly and clearly only to the asked questions. Calculations and explanations which do not respond to the questions will not be considered for evaluation even if correct. 4) Talking with colleagues and / or cheating will cause the cancellation of the exam. 5) All the needed data for the resolution of exercises lies on this paper. It is NOT ALLOWED to use material other than this (e.g. books, clipboard etc.). 6) Not all the provided inputs are necessary for the problem solving PV exercise (16 points) It is required to determine the mirror surface area and the concentration ratio of a CPV system based on two axis tracking system with the following assumptions (Question A: 3 points). Assumptions AC Power output [kW] 13 Interception factor 0.95 DNI [W/m2] 925 PV cell dimension [m2] 0.60 Diffuse radiation [W/m2] 100 DC/AC conversion efficiency 0.95 Reflectivity 0.94 PV efficiency @ actual condi- tions 0.15 Determine the energy conversion losses and the first law energy balance for the solar conversion into electricity (Question B: 3 points). Considering the heat transfer properties and temperatures reported below, determine the PV cell temperature and the nominal PV cell efficiency at STC temperature (Question C: 5 points). Assumptions heat transfer coefficient (air-module surface) [W/m2K] 10…