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Energy Resources and Consumption

Sources, Concepts and Conservation. Energy Resources and Consumption. Energy Concepts. Forms of Energy Mechanical: 2 types; mechanical potential (energy of position) and kinetic (energy of motion)

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Energy Resources and Consumption

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  1. Sources, Concepts and Conservation Energy Resources and Consumption

  2. Energy Concepts • Forms of Energy • Mechanical: 2 types; mechanical potential (energy of position) and kinetic (energy of motion) • Thermal: Heat is the internal energy in substances- the vibration and movement of atoms and molecules within a substances • Chemical: energy stored in bonds between atoms in a molecule • Electrical: results from the movement of electrons • Nuclear: energy stored in the nuclei of atoms. It is released by either fission (splitting) or Fusion (combining) of atoms • Electromagnetic: Electromagnetic energy travels by waves

  3. Power and Units • Power: the amount of work done per time. • Work done/ time • The most common unit is kilowatt-hour (kWh)

  4. Units of Energy/Power

  5. Energy Conversion Problems • These conversion problems are often on the AP exam! • Use scientific notation • Use the factor-label method: • The factor-label method: the sequential application of conversion factors expressed as fractions and arranged so that any dimensional unit appearing in both the numerator and denominator of any of the fractions can be cancelled out until only the desired set of dimensional units is obtained • Scoring these problems by steps: 1 point correct set-up, 1 point correct calculations, No points if work is not shown!

  6. Conversion of MW to kW • Example Problem (Handout p283 Barrons) 20 MWX (1 x 106 watts) X 1kW = 2 X 104 kW 1 1MW 103 watts 2 X 104 kW X 8,000 hours = 16,000 X 104 kWh/yr 1 1 yr = 1.6 X 108kWh/yr • Remember : NO CALCULATORS in the exam

  7. Laws of Thermodynamics • 1st law • Energy cannot be created or destroyed • 2nd law • When energy is transformed, a less useful form is the result (lower quality energy) • Energy cannot be recycled to a higher quality • Only 20% of energy in gasoline is converted to mechanical energy • 80% is lost as heat (a low quality energy)

  8. Energy Consumption • Wood (a renewable source) was the predominant form of energy up until the Industrial Revolution. • Coal (non-renewable) then surpassed wood’s usage • Coal was overtaken by petroleum in the middle of the 20th century and remains the primary source worldwide today • Natural gas and coal experienced rapid development in the 2nd half of the 20th century

  9. US Energy Consumption by Source

  10. US Energy Consumption • US was energy independent, self sufficient until the late 1950’s • Then energy consumption began to outpace domestic production • This led to oil imports • The largest energy consumers have always been industry, followed by transportation, then residential, and commercial uses • Rapid increases in petroleum consumption continued through the 1970’s

  11. Energy Consumption vs. Production

  12. Domestic Supply and Imports • Beginning 1998, net imports of oil surpassed the domestic oil supply in the US • The US consumes 25% of the worlds petroleum production

  13. Energy Consumption in US by End Use

  14. Leading Petroleum Consumers

  15. Present Global Energy Use • In the US most of the energy comes from nonrenewable energy sources (limited supplies) such as: • coal, • petroleum, • natural gas, • Propane • and uranium

  16. Global Renewable Energy Sources • Renewable sources: relatively short replenishment time • Biomass • Geothermal • Hydropower • Solar energy • Wind energy

  17. US Energy Production vs. Consumption

  18. Fossil Fuel Consumption by the US

  19. Future Energy Needs • Outlook for next 3 decades • Continued growth and reliance on 3 fossil fuels: petroleum, natural gas and coal • Most realistic and Viable resources for immediate future • Clean coal, methane hydrates, oil shale, and tar sands

  20. Clean Coal • Global supply of coal is huge and can meet the global energy needs for many years to come • Clean coal technology refers to processes that reduce the negative environmental effects of burning coal. • Washing coal to remove minerals, and impurities • Capturing Sulfur dioxide and Carbon dioxide from the flue gasses

  21. Clean Coal Combustion Step 1;Oxygen introduced and Step 2 Coal is pulverized both for complete burning, then washed to remove contaminants. Step 3: ash removal via electrostatic precipitators. Step 4: condensed steam is returned to the boiler. Step 5: CO2 is recovered using lime and sequestered.

  22. Methane Hydrates • Methane locked in ice (Natural Gas) • Recently discovered in 2 types of geologic settings • On land in permafrost regions • Beneath the ocean floor at ocean depths>500 meters • Deposits of several hundred meters thick • Some believe enough to supply energy for 1000’s of years • Natural gas is taking on larger role • Cleaner and relatively inexpensive power plants

  23. US Natural Gas Consumption • Expected to increase 40% in the 21st century • Demand for transportation fuel increasing The Primary waste product of natural gas combustion is CO2

  24. Oil Shale • is an organic-rich fine-grainedsedimentary rock containing kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons called shale oilcan be produced. • If heated anaerobically, kerogen is converted to oil

  25. Abundance and Extraction of Oil Shale • Approximately 3 trillion barrels of currently recoverable oil from oil shale, in the world • >750 billion in the US • Mostly found in Wy, Ut, and Co • Global pockets: Estonia, Aust., Germ, Isreal and Jordan • Extraction occurs via surface mining or through heating the oil shale while still under ground, and extracting the oil and gasses through pumps

  26. Environmental Issues • Net energy yield is moderate • Requires energy use for blasting, drilling, crushing, heating, disposal of waste and environmental restoration • Underground Heating: • Potential to affect aquifers • Surface Mining disrupts ecosystems • Oil burning contributes to acid rain and GHG’s

  27. Tar Sands • Oil sands,tar sands or, more technically, bituminous sands, are a type of unconventional petroleum deposit. • The oil sands are loose sand or partially consolidated sandstone containing naturally occurring mixtures of sand, clay, and water, saturated with a dense and extremely viscous form of petroleum technically referred to as bitumen (or colloquially tar due to its similar appearance, odour and colour). • Natural bitumen deposits are reported in many countries, but in particular are found in extremely large quantities in Canada

  28. Extraction and Refinement • Specialized refineries convert bitumen to oil • Mined using strip mining techniques • Can also use steam in situ methods • Issue: Sulfur content is high (5%)

  29. Tar Sand Deposits • Most are located in Canada and Venezuela • Canada's are most concentrated therefore economical • Oil in tar sands represents 2/3 of total global reserves • Net energy yield is moderate for same reasons as oil shale • Mildred Lake mine site and plant near Fort McMurray, Alberta Canada • Largest in the world

  30. Energy Crisis • Free market: price driven by supply and demand, sudden changes occur in response to changes in either • Crisis can occur if markets do not adjust prices to adjust for shortages • Supply is largely controlled by nations with large reserves: Saudi Arabia and Venezuela who belong to OPEC (Organization of Petroleum Exporting Countries)

  31. Algeria Indonesia Iran Iraq Kuwait Libya Nigeria Qatar Saudi Arabia United Emirates Venezuela Organization of Petroleum Exporting Countries: OPEC

  32. OPEC Actions • OPEC controls output quotas of member countries • Reductions in quotas adversely effect supply which causes increased prices • If OPEC causes excessively high prices then demand decreases • THESE HIGH PRICES make ALTERNATIVE FUEL Prices COMPETETIVE and Profitable

  33. OIL Supplies • Most of global energy is supplied via OIL • At current consumption levels, global reserves are expected to last 50 years • US reserves are expected to last only 25 yrs • Industrialization of China is expected to shorten these timelines • Decreased supply leading to higher oil prices will make other sources more economical (tar and shale)

  34. FOSSIL FUELS 85% of the world’scommercial energy COAL NATURAL GAS OIL

  35. 20 richest countries consume: • 50% of coal • 80% of natural gas • 65% of oil

  36. U.S. energy consumption 9%

  37. COAL Fossilized, condensed carbon-rich fuel 10 X reserves of oil/gas, last 200 years at present rate

  38. Coal mines Surface (strip) mine, Western U.S. Underground (shaft) mine, Eastern U.S.

  39. Coal cheaper,but polluting Much Eastern U.S. coal has high-sulfur content, more expensive to mine Much Western U.S. coal has low-sulfur content, cheaper to mine But mining in semi-arid West more damaging to land.

  40. Heat value of coal types Anthracite 2% US Bituminous (50% of US reserve) Subbituminous Lignite 51% of U.S. use in coal

  41. Energy lost from coal 65% lost in power plants 10% lost on transmission lines (stray voltage)

  42. Effects on health • Black Lung Disease (miners) • Respiratory illnesses (public)

  43. Effects on land • Coal sludge releases • Hardpan at strip mines • Mountaintop removal • Huge water use • Slurry pipelines

  44. Effects on air • Greenhouse gases • 3/4 sulfur dioxide • 1/3 nitrogen oxides • 1/2 carbon dioxide • Toxics • Mercury • Uranium

  45. Acid rain

  46. Acidity of rain • pH of 6.0 • Kills insects, crabs • pH < 5.0 • Kills fish, trees

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