I want 5 answers
Assignment 2- MIET2131 S2 2018 Assignment 2 Electrical Energy Storage Systems (MIET2131) Semester2, 2018 1 • This assignment is worth 15% of your final mark in this course. • Please include your name and student number in the file name of your assignment. • Use Harvard reference citation system to reference all sources used. • Please submit electronically through Canvas. Due for submission on 15 September 2018 (11:59 pm) 1- A standalone household (no grid connection) with a conservative daily electrical load profile as given below this question is considering a Solar-hydrogen-battery system to supply its load. The household has been assumed to have a passive design with no heating and cooling load. Use HOMER software tool to size the system; discuss your assumptions, and demonstrate and discuss the technical and economic performance and the system. • Household typical load profile (on hourly basis over 24 hours), repeated throughout the year, is as follows (H: hour, L: Load (kW): H 1 2 3 4 5 6 7 8 9 10 11 12 L (kW) 0.3 0.3 0.3 0.3 0.3 0.5 0.8 1.1 1.3 1.2 1 0.8 • For solar radiation profile, you can use Melbourne’s data as given in the appendix (taken from the Australian solar radiation data handbook). Note that you may need to use all or some of them. Or you can use data available through HOMER. The PV panels are installed facing north and inclined at the local latitude angle of the place where the household is located (i.e. ~38°). • Make reasonable assumptions for any other data that might be required for this analysis. Describe and support your assumptions when answering this question. (5 points) 2- How much electricity (in kWh) would be needed to produce the hydrogen to power a hydrogen-fuel cell car for the same total vehicle km as one litre of petrol in a typical conventional car? Assume: a. 63.0 kWh of electricity are required to generate 1 kg of hydrogen a high pressure electrolyser and pressurised to 350 bar suitable for on-board storage in a mobile application. b. The energy content of hydrogen (HHV) is 142 MJ/kg (~40 kWh/kg) c. The average energy efficiency of the fuel cells used is 44% (based on HHV), and that of the electric motors 86% d. The energy content of unleaded petrol is 34.2 MJ/litre e. The conventional petrol car has an average energy efficiency of 20% (see the lecture materials). (2.5 points) H 13 14 15 16 17 18 19 20 21 22 23 24 L (kW) 0.8 0.9 0.9 1 1.1 1.2 1.4 1.6 1.3 1 0.8 0.3 Assignment 2 Electrical Energy Storage Systems (MIET2131) Semester2, 2018 2 3- For storage options a, b, and c, what volume of storage tank for hydrogen would be needed for a hydrogen fuel cell car to have the same delivered transport energy (that is, total vehicle-km of travel) as a conventional car with a full 50 litre petrol tank (note that the actual volume of the tank is more than 50 litre). a- If the hydrogen is stored as compressed gas at a pressure of 350 bar (1 bar = 101 kPa) b- If the hydrogen is stored cryogenically as a liquid c- If the hydrogen is stored in a metal hydride in solid form Assumptions and information required to answer this question: • Assume the same energy conversion efficiencies and energy contents as in question 2. • Note that the following gravimetric and volumetric energy storage figures are based on 50% fuel cell energy efficiency, but the energy efficiency that you need to use (based on question 2) in order to answer this question is 44%, HHV. • Assumptions for the volumetric and gravimetric electrical energy densities of different hydrogen energy storage options based on 50% electrical energy efficiency (HHV) for the fuel cell: - High-pressure hydrogen at 350 bar: 0.75 kWhe/kg and 0.35 kWhe/litre - Cryogenic hydrogen storage 1.46 kWhe/kg and 0.89 kWhe/litre - Metal hydride 0.5 kWhe/kg and 0.5 kWhe/litre (2.5 points) 4- A small electrical energy storage system is based on a 30-W PEM fuel cell (mass 285 g, efficiency based on HHV of 50%) and a number of metal hydride hydrogen storage canisters each capable of storing up to 1.2 wt% hydrogen with an uncharged mass of 134 g (NB 100% includes mass of canister plus hydrogen here). At what minimum total electrical energy delivery capacity would this system have a system gravimetric energy density advantage over a battery bank based on a number of lithium polymer batteries, each weighing 88 g and rated at 1800 mAh with a nominal voltage of 7.4 V? Assume an 80% depth of discharge for each battery and a 12% drop in voltage, linear with usage, during discharge. Consider just whole numbers of MH canisters and batteries. At the gravimetric energy density crossover point, how many MH canisters would the hydrogen fuel system employ and how many batteries (rounded to the nearest whole numbers)? (2.5 points) 5- Using what you have learnt in this course during weeks 1-6, present a critical discussion (in about 1000 words), in a quantitative and qualitative manner, about advantages and disadvantages of using hydrogen in national and global sustainable energy strategies (think about different energy sectors). Use credible references including books, journal papers, case studies, and industry examples to back your argument. Make sure all sources used for this discussion are properly referenced using the Harvard system. (2.5 points) Assignment 2 Electrical Energy Storage Systems (MIET2131) Semester2, 2018 3 Appendix: Melbourne Solar Radiation Data Assignment 2 Electrical Energy Storage Systems (MIET2131) Semester2, 2018 4