theoretical test 20210706

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SOLAR AND BIOMASS POWER PRODUCTION AY 2020-21 6th July 2021 Prof. Giampaolo Manzolini Time : 40 min Ins tructions for the examination: 1) Clearly indicate your name on all the sheets you will deliver. 2) The s core refers to exercis es done in a comprehens iv e manner with exact numerical res ults . Numerical res ults correct but not accompa- nied by explanations will not be tak en into account. The final s core can be normalized acc ording to the av erage res ults . 3) Answer briefly and clearly only to the as k ed ques tions . Calculations and explanations which do not res pond to the ques tions will not be cons idered for evaluation even if correct. 4) Talk ing with colleagues and / or cheating will caus e the cancellation of the ex am. 5) Al l the needed data for the resolution of exercis es lies on this paper. It is NOT ALLOWED to use material other than this (e.g. book s , clipboard etc.). 6) Not all the provided inputs are neces s ary for the problem s olving Each answer shall fit in one A4 page Question A) PV: What is a multijunction PV cell? please report a schematic of an multijunction PV cell with the layers and the corresponding positions Question B) CSP: Please write and discuss the optical efficiency of a linear Fresnel (LFR) and a parabolic trough (PT) collectors at design conditions. Point out the differences and support your discussion with schematic of LFR and PT systems Question C) Biomass: Draw the biogas production of a landfill. Discuss the design options of a biogas plant producing electricity using the abovementioned landfill (time of collecting the biogas, number of collecting pipes, inter- nal combustion engine numbers and size)