Abdullah Gül University School of Languages EXEMPTION EXAM Sample Tasks Reading Sample Tasks (Read and answer the questions.) The Economics of Wind Energy (From the Wind Energy Foundation) 1 Wind energy costs are now lower than the costs of most new conventional sources and are close to cost-‐competitive with new natural gas generation due to continuing technological innovation. In fact, the price of American wind power has declined more than 90% since 1980, benefiting utilities and consumers. This is one reason that at the end of 2013, there were more than 12,000 megawatts of new generating capacity under construction in the United States — more than at any other time in U.S. history. The following recent examples demonstrate how wind energy costs measure up against conventional energy sources: • In Australia, wind energy is now cheaper than coal and natural gas. In fact, a study by Sinclair Knight Merz showed that during recent heatwaves in Victoria and South Australia, wind contributed to 6% of overall supply by volume in the region, resulting in reduced average prices over the 7-‐day period by more than 40%. • Wind is now cost-‐competitive with coal in India, according to a report from HSBC Global Research. 2 Price per Kilowatt-‐Hour The cost of energy from the wind is mostly a function of the wind resource – how fast it blows, how often, and when. Higher-‐speed winds are more easily and inexpensively captured. The more the wind blows, the more power will be produced by wind turbines. The term used to describe this is "average capacity," which is simply the percentage of power a turbine produces compared to what it could produce if it were always spinning. 3 A more precise measurement of output is the "specific yield." This measures the annual energy output per square meter of area swept by the turbine blades as they rotate. Overall, wind turbines capture between 20% and 40% of the energy in the wind. So at a site with average wind speeds of 7 m/s, a typical turbine will produce about 1,100 kWh per square meter of area per year. If the turbine's blades are 35 meters long, for a total swept area of 1,000 square meters, the power output will be about 1.1 million kWh for the year. 4 The power output from a wind turbine is a function of the cube of the average wind speed. In other words, if wind speed doubles, the power output increases eight times. Also, wind speed increases as the height from the ground increases. For example, if the average wind speed at 10 meters above ground is 6 meters/second (m/s), it will typically be about 7.5 m/s (25% greater) at a height of 50 meters. Finally, the power in the wind varies with temperature and altitude, both of which affect the air density. Chilly winter winds in Minnesota will carry more power, due to greater air density, than warm summer winds of the same speed high in the passes of southern California. 5 On the other hand, wind turbines operate over a limited range of wind speeds. If the wind is too slow, they won't be able to turn, and if too fast, they shut down to avoid being damaged. Ideally, a wind turbine should be matched to the speed and frequency of the resource to maximize power production. Abdullah Gül University School of Languages EXEMPTION EXAM Sample Tasks 6 Another factor in the cost of wind power is the turbines' distance from transmission lines. It is not unusual for remote areas (for example, northern Canada or Siberia) to have high average wind speeds, but be too far from major electricity demand centers (cities) for the wind power to be used economically. Considerable wind energy development has taken place in recent years in U.S. states like Indiana and Illinois, which are not as windy as North Dakota or Montana but have substantial transmission capacity. 7 For offshore wind projects, the economics depend on the distance from shore because turbine foundation costs increase rapidly with increasing water depth. Offshore wind turbines are generally much larger than land-‐based turbines. Larger rotors can be incorporated more easily because large rotor blades can easily be transported by ship. 8 In 2011 and 2012, the price of wind energy under long-‐term power purchase contracts in the United States averaged just 4 cents per kilowatt hour, which is 50% lower than in 2009. 9 Wind and Natural Gas The U.S. is currently experiencing very low natural gas prices due to a massive increase in production of gas from shale deposits. Industry experts believe that the prices are too low to be sustained because they do not provide an adequate income stream to producers. Nevertheless, gas supplies are likely to be abundant for some time. 10 Although abundant natural gas presents competitive challenges for wind power, there is still an important place for wind as part of a diversified electric utility portfolio and a hedge against volatility in fuel prices. Wind energy's fuel cost is zero, so the price of electricity from a wind farm is predictable over the long term—which is not true for any fueled power plant. 11 In addition, wind and natural gas complement each other well in a utility system— gas turbines can easily be turned up and down as needed to match variations in the output of wind farms. The combination of these two energy sources can provide abundant electricity with lower price volatility and greenhouse gas emissions than natural gas alone. 1 )What is the source of evidence that, in at least one country, wind energy costs about the same as coal energy? 2 )What does the example of Victoria and South Australia prove? 3 )What is one advantage and one disadvantage of higher-speed winds? Abdullah Gül University School of Languages EXEMPTION EXAM Sample Tasks 4 ) What are the three factors that affect the power output from a wind turbine? 5 ) Use one word to describe the cost of wind turbine foundation far from the shore? 6.) Why are there not many wind turbines in Montana? Writing Sample Tasks Choose ONE of the following three questions (To have any chance of being Exempted from the Prep Program, you must answer Question 1. If you choose Question 3, you cannot be placed higher than Writing Level 2.) Question 1 Write an essay, of 400-‐500 words, about the strengths and/or weaknesses of the education system that you know best. Write an introduction, body paragraphs and a conclusion. Express your ideas as clearly as you can. Write main ideas and supporting ideas/details. Question 2 In 100-‐300 words, answer this question: What do you think is one of the most serious problems facing the world. Question 3 Write a paragraph about a city in Turkey. Abdullah Gül University School of Languages EXEMPTION EXAM Sample Tasks Listening Sample Tasks Section A. Listen to the lecture and take notes. (Your notes are NOT marked). After you have listened, and taken notes, you will be given 4 questions to answer. Now use your notes and answer the questions. Give as much detail as possible 1. What is the aim of the speaker? ………………………………………………………………………………………… …………………………………………………………. 2. What are the four ways we are affected by sounds? Give at least 2 examples for each way. ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… 3. What does the speaker recommend doing when working in a noisy office? Why? ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… 4. What does 28% refer to? ………………………………………………………………………………………… ………………………………………………………………………………………… Section B. – Listen and write the sentences you hear. You will hear them twice. 1. ……………………………………………………………………………………………………………………… 2. ……………………………………………………………………………………………………………………… 3. ……………………………………………………………………………………………………………………… 4. ………………………………………………………………………………………………………………………