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APES Energy Review Questions

APES Energy Review Questions. What are the two types of mechanical energy Potential and kinetic energy. What is chemical energy? Energy stored in bonds between atoms in a molecule. What is electrical energy? Energy that results from the motion of electrons.

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APES Energy Review Questions

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  1. APES Energy Review Questions

  2. What are the two types of mechanical energy • Potential and kinetic energy

  3. What is chemical energy? • Energy stored in bonds between atoms in a molecule

  4. What is electrical energy? • Energy that results from the motion of electrons

  5. Nuclear energy is stored in the nuclei of atoms. It is released by • Splitting or joining atoms

  6. How does electromagnetic energy travel? • In waves

  7. What is power and its most common unit? • Amount of work done per time and the unit is the kilowatt-hour (kWh)

  8. The unit of energy used in the U.S. is the • Btu (British Thermal Unit)

  9. What is the Btu? • Amount of heat required to raise the temperature of 1 pound of water by 1oF.

  10. What is a watt? • Approximately 3.4 Btu/hr.

  11. What is one horsepower? • 2,540 Btu/hr or 746 watts of power

  12. How much is a “ton” in many air-conditioning applications used in home? • 12,000 Btu/hr

  13. The amount of energy expended by a 1 kilowatt (1000 watts) device over the course of one hour and often measured in the context of power plants and home energy bills • Kilowatt hour (kWh) (electrical)

  14. Nuclear power plant measurement of energy • Thermal watt

  15. Thorpevill is a rural community with a population of 8,000 homes. It gets its electricity from a small, municipal coal-burning power plant just outside of town. The power plant’s capacity is rated at 20 megawatts with the average home consuming 10,000 kilowatt hours (kWh) of electricity per year. Residents of Thorpeville pay the utility $0.12 per kWh. A group of entrepreneurs is suggesting that the residents support a measure to install 10 wind turbines on existing farmland. Each wind turbine is capable of producing 1.5 MW of electricity. The cost per wind turbine is $2.5 million dollars to purchase and operate for 20 years. • (a) The existing power plant runs 8,000 hours per year. How many kWh of electricity is the current plan capable of producing?

  16. You need to show your work as follows or no points will be given for guesswork. • 20 MW x 1 X 106 watts x 1kW = 2 x 104 kW • 1 1 MW 103 watts • (2 X 104 kW) x 8,000 hours = 16,000 x 104 kWh/yr • 1 1 yr • = 1.6 x 108 kWh/yr

  17. (b) How many kWh of electricity do the residents of Thorpeville consume in one year? • 8 x 103 homes x 1 x 104 kWh/home = 8 x 107 kWh/yr • 1 1 yr

  18. (c) Compare answers (a) and (b). What conclusions can you make? • Power plants produces 1.6 x 108 kWh per year. The residents, however, only use 8 x 107 kWh per year. This leaves a surplus of 1.6 x 108 – 8 x 107 = 8 x 107 kWh in one year which can be sold to other towns. At a rate of $0.12 per kWh, this provides a surplus of 8 x 107 kWh x $0.12/kWh = $0.96 x 107 = $9,600,000

  19. Differences between Thorpeville’s consumption and the power plant’s output could be attributed to: • Compensation for line loss • More energy during peak hours • Planning for possible future growth of town

  20. (d) Assuming that the population of Thorpeville remains the same for the next 20 years, and the electricity consumption remains stable per household, what would be the cost (expressed in $/kWh) of electricity to the residents over the next 20 years if they decided to go with wind turbines?

  21. From part (b) your answer is 8 x 107 kWh/yr. • kWh for 20 yrs =8 x107 kWh x 20 yrs = 1.6 x109 kWh • year • Direct cost for 20 years = 10 turbines x $2.5 x 106 • turbine • = $2.5 x 107 • Cost/kWh = $2.5 x 107 = $1.6 x 10-2/kWh • 1.6 x 109 kWh • = $0.016kWh

  22. (e) What are the pros and cons of the existing coal-burning plant compared with the proposed wind farm? • The electricity produced from the wind turbines costs $0.016 per kWh, but each homeowner would also have to pay $25,000,000/8,000 homes = $3,125.00 over 20 years ($156.25/yr) to pay for the wind turbines. 10,000 kWh at $0.016 per kWh for electricity produced from wind turbines = $160 plus $156.25 per year to pay for the wind turbines = $316.25 per year • Electricity from the coal-burning plant costs $0.12 per kWh. 10,000 kWh of electricity per year from the coal-burning plant costs $1,200 per year. Clearly, electricity produced from wind turbines is much cheaper. • Wind : zero emissions, wind is free, no heavy metals, no thermal pollution and multiple use of land • Coal : produces air pollution, specially SO2 and NOx • As labor prices increase, the price of coal would also increase in the next 20 years • Coal-burning plants produce heavy metals such as mercury, lead, and cadmium pollution along with radioactive contaminants • Coal produces thermal pollution to local streams • Cannot utilize the concept of multiple use of land

  23. Laws of thermodynamics • First law – energy cannot be created nor destroyed • Second law – when energy is coverted from one form to another, a less useful form results.

  24. Can energy be recycled? • NO

  25. What percent of gasoline is converted into mechanical energy to make the car move? • 20%

  26. What was the original source of energy up until the Industrial Revolution? • wood

  27. What was the predominant source of energy during the Industrial Revolution? • coal

  28. What is the predominant source of energy in this day and age? • petroleum

  29. Why did the U.S. resort to importing petroleum and natural gas after the 1950s? • Energy consumption began to outpace domestic production

  30. Who uses the most energy in the U.S.? • Industry followed by transportation, then residential and finally commercial use

  31. Who are the leading petroleum consumers? • U.S., followed by former U.S.S.R., then Japan, and China

  32. In the U.S. most of the energy comes from • Nonrenewable energy sources such as coal, petroleum, natural gas, propane, and uranium.

  33. Renewable energy sources include • Biomass, geothermal energy, hydropower, solar energy, and wind energy

  34. Renewable energy is called that because they • Are replenished in a short time

  35. Clean coal technology refers to processes that • Reduce the negative environmental effects of burning coal

  36. What does washing coal remove? • Minerals and impurities and capturing the sulfur dioxide and carbon dioxide from the flue gases

  37. What is the Future-Gen project? • A project designed to build a prototype zero-emission, coal-fired 275 MW power plant that produces hydrogen and electricity using carbon capture and storage technology.

  38. What is methane hydrate? • Methane locked in ice

  39. Where do methane hydrates form? • On land in permafrost regions and beneath the ocean floor at water depths greater than 1,640 feet (500 m) where high pressures dominate

  40. How much methane is bound in hydrates? • 3,000 times the volume of methane in the atmosphere which some believe there is enough to supply energy for hundreds or thousands of years.

  41. What is the primary waste product of burning natural gas? • Carbon dioxide

  42. Why is natural gas becoming more in demand? • Its expanded use in transportation fuel and potentially as a source of alternative liquid fuels and a source of hydrgen for fuel cells

  43. What is oil shale? • A sedimentary rock that is not really a shale that contains an organic material called kerogen which when heated in the absence of air turns into oil

  44. How much oil can be retrieved from oil shale? • 3 trillion barrels with 750 billion found in the U.S.

  45. Where is the oil shale found in the U.S.? • Wyoming, Utah, and Colorado

  46. Where are the largest reserves of oil shale found in the world? • Estonia, Australia, Germany, Israel and Jordan

  47. What are the impacts of mining for oil shale? • It involves surface mining which degrades the land and causes pollution

  48. What is the net energy yield of producing oil through oil shale? • Moderate since energy is required for blasting, drilling, crushing, heating the material and disposing of waste material, and then environmental restoration

  49. What is in-situ methods of extracting oil shale and how does it impact the environment? • Processing in place without having to transport it a power plant. It may reduce some environmental impacts but can cause groundwater pollution

  50. What are tar sands? • Tar sands containing bitumen which is a semisolid form of oil that does not flow

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