1. ENVIRONMENTAL SCIENCE
Energy

2. Energy - 3 Main Ideas E resources should be evaluated on
potential supplies
how much net useful E they provide
Environmental impact of using them

3. Energy - 3 Main Ideas Using a mix of renewable energy: Sunlight Wind
flowing water
sustainable biofuels
geothermal energy can drastically reduce pollution, greenhouse gas emissions, and biodiversity losses.

4. Energy - 3 Main Ideas
Making transition to more sustainable E future requires
sharply reducing E waste
using a mix of environmentally friendly renewable E resources,
including harmful environmental costs of E resources in their market prices.

5. Evaluating Energy Resources
Energy from the sun
Indirect forms of renewable solar energy
Wind
Hydropower
Biomass
Commercial energy
Fossil fuels – non-renewable
Nuclear – non-renewable

6. Evaluating Energy Resources
75% world’s commercial E comes from non-renewable fossil fuels.
Rest comes from
non-renewable nuclear fuel
renewable sources

13. Coal Layers of coal Lignite Bituminous Anthracite
Lowest Carbon Content
Bituminous
Layer used to generate electricity
Anthracite
Layer with the most Carbon

14. Increasing heat and carbon content
Increasing moisture content
Peat
(not a coal)
Lignite
(brown coal)
Bituminous
(soft coal)
Anthracite
(hard coal)
Heat
Heat
Heat
Pressure
Pressure
Pressure
Partially decayed plant
matter in swamps and
bogs; low heat content
Low heat content; low
sulfur content; limited
supplies in most areas
Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content
Highly desirable fuel because of its high heat content and
low sulfur content; supplies are limited in most areas
Figure 13.9: Stages in coal formation over millions of years. Peat is a soil material made of moist, partially decomposed
organic matter and is not classified as a coal, although it too is used as a fuel. The different major types
of coal vary in the amounts of heat, carbon dioxide, and sulfur dioxide released per unit of mass when they
are burned. 14

15. Coal Is a Plentiful But Dirty Fuel
Used in electricity production
Main use of coal today
World’s most abundant fossil fuel
U.S. reserves should last ~ 250 years
Sulfur and particulate pollutants
Mercury and radioactive pollutants
Also used to make Steel

16. Waste heat Cooling tower transfers waste heat to atmosphere
Coal bunker
Turbine
Generator
Cooling loop s
Stack
Pulverizing mill
Condenser
Filter
Figure 13.10: Science: coal-burning power plant. Heat produced by burning pulverized coal in a furnace boils water to produce steam that spins a turbine to produce
electricity. The steam is cooled, condensed, and returned to the boiler for reuse. Waste heat can be transferred to the atmosphere or to a nearby source
of water. The largest coal-burning power plant in the United States, located in Indiana, burns three 100-car trainloads of coal per day. The photo shows a
coal-burning power plant in Soto de Ribera, Spain. Question: Does the electricity that you use come from a coal-burning power plant?
Boiler
Toxic ash disposal
Fig , p. 306 16

17. Coal Is a Plentiful But Dirty Fuel
Heavy carbon dioxide emissions
Pollution control and environmental costs
China major builder of coal plants

18. The Growing Problem of Coal Ash
Highly toxic
Black Lung Disease
Often stored in ponds
Ponds can rupture
Groundwater contamination
EPA: in 2009 called for classifying coal ash as hazardous waste
Opposed by coal companies

19. Oil
Oil Formation

21. https://visual.ly/community/infographic/science/surprising-products-we-get-crude-oil

22. How Long Will Crude Oil Supplies Last?
Crude oil is the single largest source of commercial energy in world and U.S.
Proven oil reserves
Can be extracted profitably at today’s prices with today’s technology
80% depleted between 2050 and 2100

23. Barrels of oil per (billions)14 13 12 11 10
Projected U.S.
oil consumption 9 8
Barrels of oil per (billions)
year7 6 5 4
Figure 13.4: The amount of crude oil that might be found in the Arctic National Wildlife Refuge, if developed and extracted over 50 years, is only a tiny fraction of projected U.S. oil consumption. In 2008, the DOE projected that developing this oil would take 10–20 years and lower gasoline prices at the pump by at most 6 cents per gallon. (Data from U.S. Department of Energy, U.S. Geological Survey, and Natural Resources Defense Council) 3 2
Arctic refuge oil
output over 50 years 1
2000
2010
2020
2030
2040
2050
Year 24

24. US Oil Production and Use
93% of energy from fossil fuels
39% from crude oil
Produces 9% of world’s crude oil
Uses 25% of world production
Has 2% of proven crude oil reserves

26. Oil Sand and Oil Shale Oil sand (tar sand) Bitumen Kerogen Shale Oil
World reserves
Major environmental problems

29. Natural Gas Is a Useful and Clean-burning Fossil Fuel
Conventional natural gas
Unconventional natural gas

30. Liquefied natural gas (LNG)
Less CO2 emitted per unit of Energy than with crude oil, tar sand, shale oil
World supply of conventional natural gas: years
Unconventional natural gas
Coal-bed methane gas
Methane hydrate

32. What Are Advantages and Disadvantages of Nuclear Energy?
nuclear power fuel cycle:
low environmental impact
very low accident risk

33. What Are Advantages and Disadvantages of Nuclear Energy?
…but limited because of:
high costs
low net energy yield
long-lived radioactive wastes
vulnerability to sabotage
potential for spreading nuclear weapons
technology.

34. How Does a Nuclear Fission Reactor Work?
Light-water reactors
Boil water to produce steam to turn turbines to generate electricity
Radioactive uranium as fuel
Control rods, coolant, and containment vessels

35. storage of radioactive
Small amounts of
radioactive gases
Uranium
fuel input
(reactor core)
Control rods
Containment shell
Waste heat
Heat exchanger
Steam
Turbine
Generator
Hot
coolant
Useful electrical
energy
About 25%
Hot
water
output
Pump
Pump
Coolant
Pump
Pump
Waste heat
Cool
water
input
Figure 13.14: Science: light-water-moderated and -cooled nuclear power plant with a pressurized water reactor. Some nuclear plants
withdraw water for cooling from a nearby source of water and return the heated water to that source, as shown here. Other
nuclear plants that do not have access to a source of cooling water transfer the waste heat to the atmosphere by using one or more
gigantic cooling towers, as shown in the inset photo of the Three Mile Island nuclear power plant near Harrisburg, Pennsylvania (USA).
A serious accident there in 1979 almost caused a meltdown of the plant’s reactor. Question: How does this plant differ from the coal-burning
plant in Figure 13-10?
Moderator
Shielding
Pressure
vessel
Coolant
passage
Water
Condenser
Periodic removal and
storage of radioactive
wastes and spent
fuel assemblies
Periodic removal
and storage of
radioactive
liquid wastes
Water source
(river, lake, ocean)
Fig , p. 310 36

36. Safety and Radioactive Wastes
On-site storage of radioactive wastes
Safety features of nuclear power plants
Nuclear fuel cycle
Reactor life cycle
Large amounts of very radioactive wastes

37. Fig , p. 311

38. Fig , p. 311

39. of spent fuel assemblies underwater or in dry casks
Decommissioning
of reactor
Fuel assemblies
Reactor
Enrichment
of UF6
Fuel fabrication
(conversion of enriched
UF6 to UO2 and fabrication
of fuel assemblies)
Temporary storage
of spent fuel assemblies
underwater or in dry casks
Uranium-235 as UF6 Plutonium-239 as PuO2
Conversion
of U3O8
to UF6
Spent fuel
reprocessing
Low-level radiation
with long half-life
Figure 13.16: Science: the nuclear fuel cycle. As long as a reactor is operating safely, the power plant itself has a
fairly low environmental impact and a very low risk of an accident. But considering the whole nuclear fuel cycle,
costs are high, radioactive wastes must be stored safely for thousands of years, several points in the cycle are vulnerable
to terrorist attack, and the technology used in the cycle can also be used to produce material for nuclear
weapons (Concept 13-3). Also, an amount of energy equal to about 92% of the energy content of the nuclear fuel
is wasted in the nuclear fuel cycle. Question: Do you think the market price of nuclear-generated electricity should
include all the costs of the fuel cycle or should governments pay much of these costs as they do now? Explain.
Geologic disposal
of moderate and high-level
radioactive wastes
Mining uranium ore (U3O8 )
Open fuel cycle today
Recycling of nuclear fuel
Fig , p. 312 40

40. What Happened to Nuclear Power?
Optimism of 1950s is gone
Comparatively expensive source of power
No new plants in U.S. since 1978
Disposing of nuclear waste is difficult
Three Mile Island (1979)

41. Three Mile Island: Chernobyl March 28, 1979 near Harrisburg, Pa.
stuck valve in
cooling system.
$500 million cleanup of site thru 1993.
Chernobyl
26 April 1986
plume of highly radioactive smoke fallout.
50 to 200 thousand deaths.

42. Fukushima Daiichi nuclear disaster 11 March 2011
Reactors 1, 2 & 3 experienced full meltdown.
Measurements taken by the Japanese science ministry and education ministry in areas of northern Japan 30–50 km from the plant showed radioactive caesium levels high enough to cause concern.[17] Food grown in the area was banned from sale. Based on worldwide measurements of iodine-131 and caesium-137, it was suggested that the initial daily release of those isotopes from Fukushima are of the same order of magnitude as those from Chernobyl in 1986[18][19], and that the total release of radioactivity is about one-tenth that from the Chernobyl disaster[20]; Tokyo officials temporarily recommended that tap water should not be used to prepare food for infants.[21][22] Plutonium contamination has been detected in the soil at two sites in the plant,[23] although further analysis revealed that the detected densities are within limits from fallout generated from previous atmospheric nuclear weapons tests.[24] Two workers hospitalized with non-life threatening radiation burns on 25 March had been exposed to between 2 and 6 Sv of radiation at their ankles when standing in water in Unit 3.[25][26][27] Follow up examination at 11 April from National Institute of Radiological Sciences was without confirmation.[28]
Japanese officials initially assessed the accident as Level 4 on the International Nuclear Event Scale (INES) despite the views of other international agencies that it should be higher. The level was successively raised to 5 and eventually to 7, the maximum scale value.[29][30] The Japanese government and TEPCO have been criticized in the foreign press for poor communication with the public[31][32] and improvised cleanup efforts.[33] Foreign experts have said that a workforce in the hundreds or even thousands would take years or decades to clean up the area

44. Nuclear Power Is Vulnerable to Terrorist Acts
Insufficient security
On-site storage facilities
U.S.: 161 million people live within miles of an above-ground nuclear storage site

45. Dealing with Radioactive Wastes
High-level radioactive wastes
Long-term storage: 10,000–240,000 years
Deep burial
Detoxify wastes?

46. Case Study: Dealing with Radioactive Wastes in the United States
Yucca Mountain, Nevada
Concerns over groundwater contamination
Possible seismic activity
Transportation accidents & terrorism
2009: Obama ends Yucca funding

48. What Do We Do with Worn-Out Nuclear Power Plants?
Decommissioning old nuclear power plants
Dismantle power plant and store materials
Install physical barriers
Entomb entire plant
Chernobyl sarcophagus

49. What Is the Future for Nuclear Power?
Reduce dependence on foreign oil
Reduce global warming
Advanced light-water reactors
Nuclear fusion
How to develop relatively safe nuclear power with a high net energy yield?