Chapter 17: Nonrenewable Energy 17-1 Energy Resources and Fossil Fuels Fossil Fuels: remains of ancient organisms changed into Coal Oil Natural gas Source of most of the energy we use 90% of the energy used in developed countries

4 Main Purposes of Fuels Transportation Manufacturing Heating and cooling buildings Generating electricity (to run machines and appliances) Fuel’s Suitability depends on: Energy content Cost Availability Safety Byproducts of use (You wouldn’t use coal to power an airplane. You wouldn’t use jet fuel for a campfire.)

4 Main Purposes of Fuels Transportation Manufacturing Heating and cooling buildings Generating electricity (to run machines and appliances) Fuel’s Suitability depends on: Energy content Cost Availability Safety Byproducts of use (You wouldn’t use coal to power an airplane. You wouldn’t use jet fuel for a campfire.)

Energy Use in the U.S.

Electricity + easily transported = convenient - difficult to store - other energy sources have to be used to generate it Electric Generator: converts mechanical energy (motion) into electrical energy By moving an electrically conductive material within a magnetic field Turbine: a wheel that changes the force of a moving gas or a liquid into energy that can do work

How Most Power Plants Work Water is heated by Burning fuel (coal-fired and gas-fired power plants) Fission of uranium (nuclear power plants) Water is boiled to produce steam that turns a turbine Turbine spins a generator to produce electricity

How a Coal-Fired Power Plant Works

World Energy Use Patterns

How Do Fossil Fuel Deposits Form? Coal – from the remains of plants that lived in swamps hundreds of millions of years ago Oil and Natural Gas – from the decay of tiny marine organisms that accumulated on the bottom of the ocean millions of years ago Both were compressed by sediment and exposed to heat and pressure within the Earth’s crust

Coal Abundant in N. America and Asia Produces more than ½ of the electricity generated in the U.S. Relatively inexpensive Needs little refining Environmental Effects of Coal Minimal w/ underground mines Surface Operations can include mountain-top removal Waste rock must be properly contained or toxic chemicals can leach into nearby streams Research focuses on Developing less damaging mining methods Locating more productive, cleaner-burning deposits

Coal  Air Pollution & Acid Precipitation Higher Quality Coals (ex. bituminous coal) produce more heat and less pollution Lower-Grade Coals (ex. lignite) produce less heat and release large amounts of sulfur Petroleum – a.k.a. crude oil: oil pumped from the ground Petroleum products: anything made from crude oil (fuels, chemicals, plastics) Locating Oil Deposits: Geologists look for rock deposits that could contain oil Exploration wells are drilled to determine volume and availability Profitability is calculated Profitable wells get drilled Petroleum goes to a refinery to be turned into fuels or other products.

Environmental Effects of Using Oil Air pollution Smog Acid precipitation Global warming Oil spills & everyday sources (leaking cars) contaminate waterways Habitat destruction Natural Gas Often found above oil deposits (used to be burned off as a nuisance before transporting technologies improved) Generally release fewer pollutants than burning coal or oil

The Future of Fossil Fuels Oil Reserves: oil deposits that can be extracted profitably at current prices using current technology Demand is projected to double by 2050 (as population and industrialization increases) Cost will likely increase making other forms of energy more attractive Future Oil Reserves Calculations of fossil-fuel reserves predict that oil production will peak and then decline in the early 21st century. Land-Accessible production will peak in about 2010 Ocean-floor drilling is much more expensive

17-2: Nuclear Energy Nuclear Energy: energy that exists w/in the nucleus of an atom. Fission: uranium nuclei are bombarded with neutrons and release large amounts of energy Nuclear Power Stations Heat from fission reactions heats water to generate steam Steam drives turbines that generate electricity

Advantages of Nuclear Power: Fuel is compact NO air-polluting gases When properly operated, they release less radioactivity than coal-fired power plants do Disadvantages of Nuclear Power: $ - building and maintaining a safe reactor is expensive Thermal Pollution (released cooling water warms aquatic ecosystems) Storing waste – radioactive waste must be stored in a geologically stable area for tens of thousands of years (see Yucca Mountain case study) Safety Concerns Fission can go out of control (see Chernobyl and Three Mile Island case studies)  Most of the safety measures at Catawba are back-ups to other safety measures.

The Future of Nuclear Power Fusion: the nuclei of 2 forms of hydrogen join to form helium and release large amounts of energy This is how the sun works Creates less dangerous radioactive byproducts than fission Difficulty Extremely high temperatures are required (180,000,000 °F) Nuclei must be maintained at very high concentrations Nuclei must be properly confined Achieving all 3 simultaneously may be impossible.