List of knowledge points for preparing 47124 (E23) exam: 1. Energy system (Peter) a. Give an overview of the global energy situation. Touch upon (the level of) the overall energy usage, the breakdown between major energy sources and the geographical breakdown. b. Explain the concept of price elasticity and discuss how it relates to the practical, technological availability of the chemical elements. C. What are the three thermodynamic quantities which are coupled together via the first law of thermodynamics, and discuss why thermodynamics is so fundamental to the energy problem. 2. Solar (Peter) a. Explain and discuss the three main figures of merit for a solar cell (photovoltaic cell). b. When you make a solar cell using a semiconductor to absorb the sunlight, you must pick a suitable band gap of the semiconductor. Explain what the band gap is and explain the considerations for a good pick of band gap. What happens if the band gap is chosen too high or too low? C. Explain why tandem solar cells have a theoretical efficiency advantage over single- junction cells. 3. Wind (Xiaoli) a. Please explain the turbine power curve below, addressing how energy is being generated as a function of wind speed. 2000 PRated power/kW 1800 1600 1400 1200 1000 800 600 400 200 0 1 P~PAV³ Cp cut-in wind speed 10 rated power 1 I i I 1 I 1 1 T T I 1 T I I T T rated wind speed 1 wind speed / m s™! Figure 8.28 Typical wind turbine wind speed-power curve 20 shut-down wind speed 30 b. Please explain the Weibull distribution, how to obtain Weibull distribution of wind speed and the relevant application based on the figure below. number of hours per year of each wind speed band 1200 6. 1000 800 600 400 200 0 T 2 3 4 5 5. Nuclear (Bent) 6 F(u): 7 8 9 10 || 12 13 14 wind speed/m s¹ Figure 8.29 A wind speed frequency distribution for a typical site c. Please provide names of turbine components, and explain how energy is calculated based on the figure below. Available power P = =mV² = ²pAV³ Shaft power 1 Ps= P. Cp = = PAV³. Cp Biomass (Lasse) >↑↑↑↑↑ kw-1 ()--)) exp kw Aw Aw A = лR² Weibull parameters Shape: kw Scale : 15 16 17 18 19 4. Water (Ming) a. Name the different technologies utilizing energy stored in water. Explain the basic operation principle of each technology. b. Explain how to calculate theoretical potential of energy output from hydro power stations. What are the influencing parameters? Aw [m/s] kw C. Provide an overview of the global development status on the technologies which utilize energy stored in water. a. Describe the fission process and energetics. b. What are the basic components of a PWR? C. Describe the plutonium cycle (closed cycle) of a fast reactor.