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APES. Get out notebook paper – NO SPIRAL FRINGE Everything else away except a writing utensil. . Nonrenewable Energy. Ch. 15 . What types of energy do we use? . Direct SOLAR ENERGY Indirect SOLAR ENERGY COMMERCIAL ENERGY. 1. DIRECT SOLAR ENERGY. Photovoltaic Cells Solar Thermal.
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APES • Get out notebook paper – NO SPIRAL FRINGE • Everything else away except a writing utensil.
Nonrenewable Energy Ch. 15
What types of energy do we use? • Direct SOLAR ENERGY • Indirect SOLAR ENERGY • COMMERCIAL ENERGY
1. DIRECT SOLAR ENERGY Photovoltaic Cells Solar Thermal
2. INDIRECT SOLAR ENERGY Biofuels Wind turbines Hydroelectric dams
3. COMMERCIAL ENERGY • From nonrenewable resources • Extracting/burning nonrenewable resources (FOSSIL FUELS)
Energy Use WORLD US 93% Nonrenewable World’s largest energy user 5% of world’s population uses 25% of world’s energy • 85% Nonrenewable • Use of coal • Use of oil • Nuclear leveled off • Developing countries depend on biomass (fulewood, charcoal) for heating/cooking – can’t afford fossil fuels
FOSSIL FUELS * • Composed of partially decayed organism remains • Nonrenewable • Form too slowly to replenish • NOT sustainable EX: Coal, Oil, Natural Gas
Fossil Fuels • OIL, NATURAL GAS, & COAL • Oil and gas are less dense than coal • Move upward through porous rock and become trapped
Formation of Fossil Fuels Formation of Coal - Over time, plants die, covered by water and sediment - Heat and pressure convert material into carbon rich ore (COAL) and sedimentary rock. Formation of Oil Death and buildup of microscopic aquatic organisms. Heat and Pressure convert material to hydrocarbons (OIL) without oxygen in sediments that prevent decay. Formation of Natural Gas Same as oil, just produced at higher temperatures than oil.
FOSSIL FUELS Developed countries consume 8x MORE energy than developing countries
What is Net Energy and why is it important? Net energy is the amount of high-quality energy available from an energy resource minus the amount of energy needed to make it available. Total amount of useful energy available Energy needed to make it available Net Energy = -
Basic Science: Net Energy is the only energy that really counts • First law of thermodynamics: • It takes high-quality energy to get high-quality energy • Pumping oil from ground, refining it, transporting it • Second law of thermodynamics • Some high-quality energy is wasted at every step
Net Energy Ratio Energy Produced : Energy Used to Produce it Net Energy Ratio , Net Energy Conventional Oil = HIGH net energy ratio, But decreasing
Space Heating Passive solar 5.8 Natural gas 4.9 Oil 4.5 Active solar 1.9 Coal gasification 1.5 Electric heating (coal-fired plant) 0.4 Electric heating (natural-gas-fired plant) 0.4 Electric heating (nuclear plant) 0.3 Fig. 15-3a, p. 373
High-Temperature Industrial Heat 28.2 Surface-mined coal Underground- mined coal 25.8 Natural gas 4.9 4.7 Oil Coal gasification 1.5 Direct solar (concentrated) 0.9 Fig. 15-3b, p. 373
Transportation Natural gas 4.9 Gasoline (refined crude oil) 4.1 Biofuel (ethanol) 1.9 Coal liquefaction 1.4 Oil shale 1.2 Fig. 15-3c, p. 373
Net Energy Energy sources with low/negative net energy cannot compete in open markets with alternatives that have higher net energy yields EX. Nuclear power Need subsidies from taxpayers
Reducing Energy Waste Improves Net Energy Yields and Can Save Money • 84% of all commercial energy used in the U.S. is wasted • 43% after accounting for second law of thermodynamics • Drive efficient cars, not gas guzzlers • Make buildings energy efficient
In 2008: Energy Use in US Comprised of Oil 40% Natural Gas 23% Coal 20% Nuclear Power 8% Hydropower 3% Biomass 3% Geothermal, 1% Solar & wind
We depend heavily on oil • Petroleum or crude oil • Composed of various hydrocarbons • Produced by decomposition of dead organic matter from plants/animals
We depend heavily on oil Peak production: time after which production from a well declines • Global peak production for all world oil
Lowest Boiling Point Gases Oil Extraction & Refining Gasoline Aviation fuel By boiling point temperature Heating oil Diesel oil Naphtha Grease and wax Heated crude oil Asphalt Furnace Highest Boiling Point
Petrochemicals Raw materials used in manufacturing
How long might conventional supplies of oil last? SHORT ANSWER = ??????? • Rapid increase of use since 1950 • Largest consumers in 2009 • United States, 23% • China, 8% • Japan, 6%
How long might conventional supplies of oil last? • Proven oil reserves • Identified deposits that can be extracted profitably with current technology • Unproven reserves • Probable reserves: 50% chance of recovery • Possible reserves: 10-40% chance of recovery Proven and unproven reserves will be 80% depleted sometime between 2050 and 2100
OPEC Controls Most of the World’s Oil Supplies Organization of Petroleum Exporting Countries (OPEC) • 13 countries have at least 60% of the world’s crude oil reserves • Saudi Arabia: 20% • United States: 1.5% • Global oil production leveled off in 2005
The United States Uses Much More Oil Than it Produces • Produces 9% and Uses 23% • 1.5% of World’s Proven Oil Reserves – most in Environmentally sensitive areas • Import 52% of our oil for $ 200 billion
What are our options? • Look for more oil • Use less oil • Waste less oil • Use other energy sources
Oil to be Found • Conventional oil: smaller, dispersed, and harder to find • Heavy oil from existing wells • Unconventional Oil – Tar sands & oil shales $$$$$$ & Low Net Energy
Bakken Oil Formation Under parts of Montana, S. Dakota, N. Dakota, & Canada 2008 U.S. Geological Survey Projections over next 20 years • 10% of estimated conventional & unconventional oil in unproven reserves could be removed • Low net energy • High environmental costs • New oil meet current U.S. needs for only 1 year.
Arctic National Wildlife Refuge Fragile Arctic Tundra • Extremely cold/dry conditions • Short growing season • Permafrost • Shallow/nutrient poor soils • Slow Growth/decomposition rates • Specialized species • Low biodiversity How would drilling affect this ecosystem?
Crude Oil in the Arctic National Wildlife Refuge Fig. 15-5, p. 376
ANWR • Crude oil that might be found tiny fraction of U.S. Oil Consumption • Would take 10 – 20 years to develop this oil supply • Only lower gas prices by 6 cents/gallon
ANWR • ANWR meet current world demand for only 1 – 5 months and U.S. demand for 7 – 24 months
The United States cannot even come close to meeting its huge and growing demand for crude oil and gasoline by increasing domestic supplies. U.S. Energy Consumption by Fuel
Trade-Offs Conventional Oil Advantages Disadvantages Ample supply for several decades Water pollution from oil spills and leaks Environmental costs not included in market price High net energy yield but decreasing Releases CO 2 and other air pollutants when burned Low land disruption Vulnerable to international supply interruptions Efficient distribution system Fig. 15-6, p. 377
3 caveats when evaluating future oil supplies • Potential reserves are not proven reserves • Must use net energy yield to evaluate potential of any oil deposit • Must take into account high global use of oil
Natural Gas • Mixture of gases • 50 -90% Methane (CH4) • Versatile with high net energy
Natural Gas Uses • Heat space & water • Produce electricity
What are the advantages & disadvantages to using Natural Gas? • more plentiful than oil • has a high net energy yield • fairly low cost • lowest environmental impact of all fossil fuels.
Formation of Natural Gas • Same as oil, just produced at higher temperatures • Conventional natural gas – lies above most reservoirs of crude oil
Conventional Natural Gas • Pipelines • Liquefied petroleum gas (LPG) • Liquefied natural gas (LNG) • Low net energy yield • Makes U.S. dependent upon unstable countries like Russia and Iran
Coal • Solid fossil fuel • Burned in power plants (inefficient)
What are the advantages & disadvantages of using coal? • Plentiful • high net energy yield • low cost • very high environmental impact.
What are the advantages & disadvantages of coal? Gaseous and liquid fuels produced from coal • could be plentiful • have lower net energy yields • higher environmental impacts than conventional coal has.