Energy

1. Energy Chapters 14, 15, 16

2. What is Energy? • Net energy: usable amount of high quality energy available from a given energy source, minus the cost from extraction and processing • The more energy used in the extracting and refining process, the less energy will be available (decreased net energy) • Improved by decreasing waste • Fuel efficiency • Building insulation • Efficient coal/nuclear plants • Takes high quality energy to get high quality energy • As energy is used it is wasted or degraded • Laws of thermodynamics (Chapter 2)

3. Energy Sources • Nonrenewable Sources • Exist in fixed quantities • Most commercial energy comes from the burning of fossil fuels • Oil, Natural Gas, Coal (fossilized organisms) • Nuclear • Renewable Sources • Replenished through natural processes • Solar, Hydropower, Wind, Biomass, Geothermal, Hydrogen

4. Energy Usage • Low net energy sources subsidized by governments • Nonrenewable vs. Renewable

7. Energy Usage in the US • 5 times greater than the rest of the world • Developed countries used 70% of the worlds energy, and have 20% of the worlds population

10. Mining and Minerals • Mineral • naturally occurring, inorganic, solid element or compound with a definite chemical composition and a regular internal crystal structure • We can extract and process at a reasonable cost • Gold, sulfur, diamond, silver; salt, mica, quartz • Rock • solid, cohesive, aggregate of one or more minerals • Each rock type has a characteristic mixture of minerals • Limestone, quartzite

11. Nonrenewable Mineral Resources • Metallic • Iron (steel) , copper (wiring), gold (jewelry), and aluminum (packaging and cans) • Nonmetallic • Phosphate Salts (fertilizer), limestone (concrete), and sand (glass, bricks, concrete) • Ore • Rock containing one or more metallic mineral • High and low-grade ore • Copper and gold mined together

12. Mining • Types of Mining • Surface Mining • Shallow deposits; remove all soil, vegetation and rock to expose mineral • Used in 90% of US mineral extraction and 60% of coal mining • Ex. Open pit mining, strip mining, contour strip mining, mountaintop removal • Subsurface Mining • Underground deposits removed through tunnels and shafts • Deep coal and metal ore deposits

13. Surface Mining--Open Pit Mining • Machine digs holes to remove ore, sand, gravel and stone • Iron, copper, gold, limestone and marble

14. Open-Pit Copper Mine, UT

15. Diamond Mine, Russia

16. Diamond Mine, Canada

17. Surface Mining--Area Strip Mining • Use on flat terrain • Strip away overburden, dig out mineral deposit • Trench filled back with overburden and new trench dug parallel to previous • Leaves behind wavy highly erodible hills

19. Surface Mining--Contour Strip Mining • Used on hilly, mountainous terrain • Cut terraces into sides of hill • Overburden dumped onto terrace below • Wall of dirt in front of highly erodible rock and soil

20. Surface Mining--Mountaintop Removal • Use explosives, massive shovels to remove top of mountain to expose coal seams • Waste dirt pushed down into streams and valleys • Causes considerable environment damage • More than 500 mountaintops have been removed in West Virginia and other Appalachian States

21. Mountaintop Removal, WV

22. Mountaintop Removal

23. Mountaintop Removal

24. Mountaintop Removal, West Virginia

25. Subsurface Mining • Room-and-Pillar • Machinery gouges out coal and load onto cart • Pillars of coal left to support mine roof • Longwall • Steel props support mining roof • Coal sheared off onto mining belt • As supports moved, roof behind allowed to fall • Result in collapse of land above

26. Environmental Effects of Mineral Extraction • Land surface disrupted and scarred • Left to susceptible to weathering and erosion • Vegetation re-grow slowly (no topsoil) • Primary succession • Acidic mine drainage in streams and groundwater (sulfuric acid and mercury) • From processing of metals

27. Toxic chemicals emitted into atmosphere • By blasting rock..more toxic emissions than any other industry • Lower grade ores take more money • Human Health hazards • Black lung • Harmful effects often exceed value of minerals extracted • Costly cleanup efforts for years after mining stops

28. Mining Concerns • Overburden—soil and rock removed from mineral deposit • Spoils—piles of waste material • Tailings—piles of waste from extracting metal from ore (smelting) • Gangue-waste material mixed with mineral in ore • Subsidence- collapse of land above subsurface mines

29. How long will supplies last? • Most mineral resources are supplied by the US, Canada, Russia, South Africa and Australia • 90% of minerals needed by US are imported • Economic depletion: not cost effective to mine, process, and transport mineral

30. Mining Impacts

31. Reclamation • 1977 Surface Mining and Reclamation Act (SMRCA) • Requires mining companies to restore surface-mined land so that it can be used for the same purpose as before • Taxes on mining companies to restore sites pre-1977 • Funding weakened due to lobbying, limits enforcement

32. Reclamation includes • maintaining water and air quality, minimizing flooding, erosion and damage to wildlife and aquatic habitats caused by surface mining.  • Why do you think reclamation is such a huge issue for mining companies?

33. Legislation • Clean Air and Water Acts 1970 • Limits pollutants emitted into air and water and requires companies to comply with requirements • Superfund Act (Comprehensive Environmental Response, Compensation, and Liability Act—CERCLA) • Site contaminated with hazardous pollutants must be cleaned up following regulations • Implemented by the EPA • Used for abandoned mines prior to 1970s

34. Sustainable Solutions • Finding substitutes for metals with silicon, plastics, ceramics or nanotechnology • Fiber optic cables (replace copper/aluminum wires) • Carbon and glass fiber composites (cars/airplanes) • Decrease Use and Waste • Instead of increasing supplies • Recycle/Reuse • Less polluting, less energy use than mining for new metals

35. Proposed Pebble Mine • Bristol Bay, Alaska • Site is located in a remote and uninhabited area • Environmental Concerns • Harm to fisheries (pristine salmon run) • Harm to ecosystem • Groundwater contamination • Earthquake hazard? • Economic Benefits • Jobs for 25+ years in area with low economic opportunities • Reduce reliance on foreign sources of minerals • Recent Developments • January 2014 EPA publishes assessment on impacts of proposed mine • Allows Clean Water Act to be envoked

37. 2014 EPA Assessment • Large scale mining would pose risks to salmon and native Alaskan people who depend on them • 24-94 miles of stream potentially affected • 1300-1500 acres of wetlands, ponds and lakes destroyed • Pollution and chemical leachate from tailings ponds will affect streams • Failures in wastewater treatment, transportation, pipelines or tailings dams would have catastrophic effects on surrounding ecosystems and fisheries • (Peer reviewed and approved by 12 industry expert scientists)

38. Coal

39. Coal is extracted by mining. Either subsurface or surface mines (strip mining or mountaintop removal) • Once mined the coal is washed to remove excess materials • The energy comes from burning of the mined coal

40. Coal is burned to produce heat Steam spins turbine to produce electricity Coal is ground to powder Heat from coal warms water to produce steam

41. The burning of coal releases pollutants into the atmosphere. • Carbon dioxide (global warming) • Sulfur dioxide (acid rain) • Nitrogen oxides (smog) • Particulates (respiratory diseases and hazy skies) • Heavy metals (mecury, lead, arsenic)

42. Coal is a reliable source of energy! • One coal plant can power up to 800,000 homes! • US Coal Reserves are expected to last for 250 years! • Coal is also safe to transport. Coal isn’t radioactive and it won’t explode. • Coal supplies half the energy in the US! • Coal is cheap! • Most power plants use coal because its cost-effective and produces cheap electricity for families • It is the least expensive way to produce electricity • The average cost is $.07 per kWh, this would be about $750 per year for the average family (CHEAP!) • Coal plants have taken steps to reduce environmental impact…so the low cost is justified • “clean coal”

43. Environmental Cost of Coal • Air pollution minimized by “scrubbers” • Technology that is working on removing excess greenhouse gases from emissions from burning coal. • Yes it is the dirtiest of the fossil fuels…but we’re working on it. • Mining impacts… • Reclamation of abandoned mines • Subsurface mine less impact on land surface • Subject to Clean Air and Water Act regulations…as well as CERCLA and SMRCA

44. Coal in action…

45. Advantages disadvantages • Cheap to produce • Abundant source • Easy to transport • Non-radioactive • Non-explosive • One plant produces a lot of energy • Large environmental impact • Mining coal destructive to environment • Environmental impacts from mining as well as burning • Human health hazards from emissions and mining • Non-renewable resource

46. Natural Gas

47. Oil/Petroleum

48. Oil Spills • Major Spills in history include… • Gulf War (1991)—240-300 million gallons • Deepwater Horizon Oil Spill (2010)—210 million gallons • Ixtoc 1 Spill (1979)—140 million gallons • Exxon-Valdez (1989)—11 million gallons

49. Deepwater Horizon, April 2010