NONRENEWABLE ENERGY RESOURCES Chapter 12

Nonrenewable Energy  Nonrenewable a. once used up, cannot be replenished b. supplies are finite

 2 main categories a. fossil fuels - coal, oil, and natural gas b. nuclear fuels - derived from radioactive materials that give off energy

 Worldwide Patterns a. US – greatest energy consumption b. reasons for patterns 1. developed countries * fossil fuels through electricity 2. developing * wood, charcoal, animal waste c. commercial v. subsistence energy

 Patterns of Use in US a. 1 st was wood, then coal, and then oil and natural gas b. majority of energy used in US (in order of importance) 1. oil, coal, and natural gas c. inputs and outputs 1. inputs – oil, water 2. output – work and waste d. produces 70% of energy used, 30% from other countries (petroleum)

Reminder of Energy Calculations  Energy = Power X Time  Energy – kWh Power – W or kW  BTU – usually has been replaced by J - amount of heat required to raise the temperature of 1 1b of water by 1 degree F.

Electricity  Primary sources of energy – coal, oil, and natural gas  Secondary source of energy  Energy carrier a. moves and delivers energy in a convenient and usable form

 Generation of Electricity a. example – coal burning power plant 1. fuel is delivered to boiler 2. steam is produced 3. KE within steam transferred to turbine 4. turbine turns generator creating electricity 5. electricity transported along electrical grid 6. steam is cooled or discharged to nearby water

 Efficiency of Generation of Electricity a. capacity factor 1. the fraction of the time a plant is operating  Cogeneration a. use of a fuel to generate electricity AND heat b. used by steam users to create greater efficiency

Fossil Fuels  Provide MOST of the energy in both developed and developing countries  Coal, Oil, and Natural Gas

 Coal a. solid fuel b. four types ranked from lesser to greater age, exposure to pressure, and energy content 1. lignite  subbituminous  bituminous  and anthracite 2. precursor – peat c. largest reserves 1. United States, Russia, China, and India d. greatest production 1. China, United States, India, and Australia

e. advantages of coal use 1. generates electricity 2. steel production 3. easy to obtain (surface mining) 4. low economic costs f. disadvantages of coal use 1. releases sulfur when burned 2. mercury, lead, and arsenic 3. increases CO 2 concentrations in atmosphere

 Petroleum a. fluid mixture b. occurs in underground deposits c. oil and gasoline (ideal for vehicles) d. contains natural gas e. crude oil – liquid petroleum from the ground f. top use 1. Saudi Arabia, Russia, US, Iran, China, Canada, and Mexico

f. advantages 1. easy to transport and use 2. energy dense 3. cleaner-burning than coal g. disadvantages 1. releases carbon dioxide 2. contains sulfur, mercury, lead and arsenic 3. potential for oil leak/spill or runoff

 Natural Gas a % methane b. electricity generation and industrial processes c. nitrogen fertilizers, fuel for cooking, water heaters d. advantages 1. contains fewer impurities e. disadvantages 1. methane escapes from unburned natural gas 2. groundwater contamination

 Other fossil fuels a. oil sands 1. bitumen (tar) 2. extracted through surface mining 3. extend petroleum supply

Nuclear Energy  Nuclear Reactors a. Uranium-235 – fuel source b. undergoes fission c. product – heat * used to generate steam

 Nuclear Reactor Structure

 Advantages of Nuclear a. no air pollution b. achieve independence from imported oil  Disadvantages a. potential accidents (Three Mile Island and Chernobyl) b. disposal of radioactive waste

Nuclear Accidents  Three Mile Island a. March b. closed cooling water valve c. lack of cooling water around reactor core, led to partial meltdown

 Chernobyl a. April 26, 1986 b. violation of safety precautions c. disconnected emergency cooling systems d. removed control rods e. led to explosion f. winds blew radiation across most of Europe g. increase counts of cancer afterwards (Thyroid)

Radioactive Waste Emitted radioactivity after enough heat is produced High-level, low-level, uranium mine tailings Uranium-235 half-life: 704 million years Disposal of waste a. required to store spent fuel at the plant itself b. cannot be incinerated, destroyed by chemicals, dumped in ocean

Half-Life Example  Strontium-90 is a radioactive waste product from nuclear reactors. It has a half-life of 29 years. How many years will it take for a quantity of strontium-90 to decay to 1/16 of its original mass?

Nonrenewable Energy Resource Recap OilMobile combustionPotential oil spillSecond highest emitter of CO2 CoalNo refining necessary Large contributor to acid rain in US Highest emitter of CO2 among energy sources Natural GasEfficient for cooking Fewer impurities than coal or oil Risk of leaks/explosions Methane Hydrocarbons Nuclear EnergyEmits no CO2 once plant is operational Generates protests Possible meltdowns Radioactive wastes hangs around for hundreds-thousands of years

Renewable Energy  Nonrenewable Refresher a. petroleum, natural gas, coal, and uranium  Renewable Energy a. biomass – potentially renewable b. solar, wind, geothermal, hydroelectric, and tidal - nondepletable

 Facts about Renewable Energy a. 13% of energy used worldwide b. biomass – most widely used today c. 7% of energy use in US (biomass and hydroelectricity) d. more sustainable than nonrenewable, but still has environmental impacts

Using Energy Less  Energy Conservation and Efficiency a. conservation – ways to use the source less 1. locally - turning down thermostat when out of house - turning off lights when not in the room 2. government - taxing electricity, oil, and natural gas - offer rebates or tax credits 3. can increase efficiency by conserving - get the same amount of work from using less energy

b. sustainable design 1. passive solar heating - solar radiation maintaining building temperatures - carefully placed windows (heating and lighting) - dark-colored roofs v. light-colored roofs 2. “green roofs” 3. recycled denim insulation in walls and ceilings

Biomass  Fuel Types a. wood, charcoal, animal wastes, plant remains, and municipal solid waste (MSW) b. ethanol and biodiesel (biofuels)  United States a. 2/3 – wood b. 1/3 – MSW and biofuels

 Solid Biomass a. wood 1. heating, pulp and paper industries, power plants 2. sustainable if forest growth is able to keep up b. charcoal 1. contains more energy than wood 2. produces less smoke c. manure 1. indoor heating and cooking 2. reduces risk of disease transmission, but does give off pollutants causing respiratory illnesses

 Biofuels a. ethanol 1. derived from mostly corn products 2. sugarcane, wood chips, crop waste, or switchgrass 3. US world leader in production of ethanol, Brazil second 4. Gasohol - ethanol mixed with gasoline - produces less air pollutants - reduces gas

b. biodiesel 1. derived from soybean oil or processed vegetable oil 2. typically diluted to B lower emissions of CO compared to petroleum diesel biodiesel-projects/