Download Balance of System - Energy Power Systems - Exam and more Exams Energy Efficiency in PDF only on Docsity! Page 1 of 5 CORK INSTITUTE OF TECHNOLOGY INSTITIÚID TEICNEOLAÍOCHTA CHORCAÍ Semester 2 Examinations 2011/2012 Module Title: Energy Power Systems Module Code: MECH8022 School: Mechanical & Process Engineering Programme Title: Bachelor of Engineering (Honours) in Sustainable Energy Programme Code: ESENT_ 8_Y4 External Examiner(s): Mr Paul Kenny, M. Conor Buckley Internal Examiner(s): Mr Kevin Davis Instructions: Answer any 4 questions. Duration: 2 Hours Sitting: Summer 2012 Requirements for this examination: Note to Candidates: Please check the Programme Title and the Module Title to ensure that you have received the correct examination paper. If in doubt please contact an Invigilator. Page 2 of 5 1. (a) Describe, using neat diagrams, the “balance of system” components for solar PV systems where (i) the feed-in tariff is the same as the cost of purchasing electricity from the grid. (ii) there is no centralised electricity supply available (operation at a remote site). Explain the function of each component in your answer. (13 marks) (b) Your client wishes to install a 2kWp solar PV system on his roof to meet his annual electricity requirement of 20,000 kWh. Using the data provided and the data sheet on Page 5, calculate the (i) interconnection arrangement of the PV modules (ii) minimum number of modules required (iii) roof area (m2) required for this PV system (iii) estimated energy that will be provided by this system System Details. Module Type used. Kyocera KC125TM Ambient temperature at site (0oC to 35oC) Performance ratio for this site/system 0.75 (kWh/kWp) Site Solar insolation: 1050 kWh/m2/Y Inverter Spec: Single phase, 230V, 50Hz, 3000W with input DC voltage : 48Vdc nominal, 38 - 66Vdc range. (12 marks) 2. (a) Discuss the advantages and disadvantages of the following energy power systems as generation sources for a national electricity grid. (i) Run of River Hydro Systems (3 marks) (ii) Pumped Storage Hydro Systems (3 marks) (iii) Tidal Current Systems (3 marks) (iv) Wave Power Systems (3 marks) (b) A pump storage Hydro station consists of two 55MW Francis turbines (generating efficiency =90.5%, pumping efficiency = 88.5%) with a flow rate of 45m3/s in each turbine, at a nominal Head of 105m between the upper and lower lakes. Each turbine can pump 36m3/s. If the upper lake is 600m long and 250m wide (i) Calculate the energy stored (MWh) and the rise in the upper lake level after 6 hours of a pumping cycle. (7 marks) (ii) Calculate the output power for a model turbine and flow rate per turbine if a 1/50 scaled homologous model is built with an available model head of 5m (6 marks)
