e7/ppa Workshop on Renewable Energy - TEST ANSWER -

Transcription

1 e7/ppa Workshop on Renewable Energy - TEST ANSWER - NAME UTILITY 1

2 Question 1: Give two kinds of gases that cause the global warming. Most serious Green house gas. CO 2 (Carbon dioxide), CH 4 (Methane), N 2 O (Nitrous oxide) Other green house gas. HFC (Hydro fluorocarbons, such as CHF 3 ), PFC (Perfluorocarbons, such as CF 4 ), SF 6 (Sulfur hexafluoride), CFC (Chlorofluorocarbon, including HCFC) Question 2: Give two possible impacts on the environment that are caused by global warming. The sea level rises and land is eroded. Abnormal phenomena such as droughts and floods occur frequently. Growth of agricultural crops is negatively affected (causes famines) Causes disease epidemics and produces large increase of harmful insects Temperature of the sea raises annihilating coral and so on, thereby eliminating the effect of reducing CO 2 in the atmosphere by turning it into calcium carbonate. Question 3: The following sentences are describing a reason why waste power generation (use city waste as fuel) helps prevent global warming. Please mark the two right sentences. a) It can prevent methane gas from being produced when waste decomposes. b) It can absorb CO 2 by electricity produced by waste power generation. c) It can stop the amount of electric power produced by fossil fuel power generation that is equivalent to the amount of electric power produced by waste power generation. Question 4: The following sentences are describing a reason why biomass power generation helps prevent global warming. Please mark the two right sentences. a) CO 2 is produced when biomass fuel is burned. But the same amount of CO 2 will be absorbed by photosynthesis when plants grow again. Therefore the total amount of CO 2 does not change. b) Because of its nature, CO 2 produced by biomass fuel has little effect on global warming c) When trees are cut in an organized manner in order to collect biomass fuel, growth of the forest as a whole is stimulated, so more CO 2 can be absorbed. Question 5: Which of the following sentences is(are) true concerning renewable energy? Please mark the right sentence(s). a) Producing energy by renewable sources such as photovoltaic power or wind power does not involve fuel cost for operation, so even if you include installation cost, electricity can be produced cheaply. 2

3 b) Renewable energy involves construction of facilities and maintenance, so it cannot be said to be a cheap way to produce electricity. c) The amount of electricity that can be generated by photovoltaic or wind power is unstable. Therefore it must be combined with storage battery or diesel generators for small independent grid system. d) It is important to take into account the fact that electrical power generation by renewable energy may produce new other environmental destruction. Question 6: What is the relation between the power (P) of a turbine and the wind (v)? Please mark the right answer(s). a) P ~ v b) P ~ v 2 c) P ~ v 3 Question 7: Which sentence properly describes a stall effect? Please mark the right sentence(s). a) control of a wind turbine by changing the rotor blade angle? b) control of a wind turbine by tear off of the flow around a rotor blade profile? c) shut down of a wind turbine by breaking the rotor by a mechanical brake? Question 8: What information of wind speed is best to estimate the average annual energy yield of a turbine? Please mark the right answer(s). a) time series of hourly wind speed values for one year? b) weakly average of wind speed values for one year? c) monthly average of wind speed values for one year? d) a histogram for the distribution of wind speed values for one year? Question 9: Is the rotational speed of a turbine linked to the frequency of the grid? Please mark yes or no. - for direct coupled turbines with induction generator Yes No - for indirect coupled turbines with inverter systems Yes No Question 10: How long should a wind speed measurement be minimum and at what height? Please mark the right answer(s). a) 4 Weeks? b) 6 Months? c) 1 Year? 3

4 a) at 10m height? b) at 20m height? c) at 70m height? d) at hub height of a wind turbine? Question 11: Witch is the correct order of PV s efficiency in current technology? Please mark the right answer. a) Poly crystalline > Single crystal (Mono crystalline) > Amorphous b) Amorphous > Ploy crystalline > Single crystal (Mono crystalline) c) Single crystal (Mono crystalline) > poly crystalline > Amorphous d) Amorphous > Single crystal (Mono crystalline) > poly crystalline Question 12: What is the best orientation for a photovoltaic system in Fiji? Please mark the right answer. a) facing south. b) facing north.. c) don t care, any orientation is good. d) only a facing south-east is good. Question 13: What is the approximate area needed for a 1 kw single crystal (mono crystalline) PV array? Please mark the right answer. a) about 1 m 2 b) about 10 m 2 c) about 50 m 2 d) about 70 m 2 Question 14: If the usage parameter is 12%, how much power can you get in a year from 10kW PV? Please mark the answer which is nearest. a) about 8,000kWh b) about 10,000kWh c) about 13,000kWh Question 15: What is the relationship between temperature and efficiency? Please mark the right answer. a) Increase of temperature causes increase of efficiency for single crystal (mono crystalline) PV. b) Increase of temperature causes decrease of efficiency for poly crystalline PV. 4

5 c) Temperature sensitivity of amorphous PV is stronger than that of single crystal (mono crystalline) PV. Question 16: The following sentences are describing the characteristics of micro-hydropower. Please mark the right sentence(s). a) The environmental impact of micro-hydropower development is minimal. b) Initial construction cost is relatively high, but no fossil fuel is required for its operation. c) Micro-hydropower can provide electricity only in daytime. Question 17: The followings are components of micro-hydropower plants. Which one is essential component for a micro-hydropower plant? Please mark the right answer(s). a) High dam b) Reservoir c) Penstock Question 18: During preliminary site survey to estimate potential of the site, what are the important items to be surveyed at the site? Please mark the right answer(s). a) River flow at intake site b) Elevation difference between intake site and powerhouse site (Head) c) Electrical & mechanical equipment (turbine & generator) cost Question 19: How much is the theoretical hydropower (kw), in the case of the following conditions? Net head : 40m Design discharge : 1m 3 /s gravitational acceleration : 9.8m 2 /s a) 4.1kW b) 40kW c) 392kW Question 20: The following sentences are describing the characteristics of hydraulic turbine. Please mark the right sentence(s). a) Francis turbine is categorized as an impulse turbine b) Cross flow turbine is prevalent technology in the field of micro-hydropower c) Pelton turbine is suitable for low head 5