ENERGY

Energy: the ability to do work Work - the movement of matter Life depends upon the constant flow of energy. Humans in many parts of the world have become dependent upon energy to maintain a “comfortable” lifestyle.

Laws of Energy 1. Law of Conservation of Energy - energy cannot be created nor destroyed 2. 2nd Law of Energy - when energy is changed from one form to another, some of the usable energy is lost. some of the energy cannot do work usually lost in the form of heat that cannot be recovered

Energy Efficiency - a measure of the amount of energy that it can convert to useful work

Two Sources of Energy 1. Nonrenewable 2. Renewable

Nonrenewable Resources - a natural resource which is not replaced by ecological cycles at the same rate as it is being used up Fossil Fuels - remains of ancient organisms that formed coal, natural gas, and petroleum over many years with heat and pressure. Fossil fuels are limited and cause many environmental and health problems.

Four Main Uses of Fuel 1. transportation 2. manufacturing 3. heating/cooling buildings 4. generating electricity

Coal is our most abundant fossil fuel. - U.S. is the largest exporter - generates 60% of the U.S.’s electricity - by-products used to make such things as dyes, drugs, synthetic fibers, films, adhesives, insecticides, fertilizers, varnish, and plastics

supplies about 25% of the nation’s energy with an increasing demand. Natural Gas supplies about 25% of the nation’s energy with an increasing demand. - natural gas is a clean-fuel alternative to gasoline

Petroleum (Crude Oil) supplies 40% of the U. S Petroleum (Crude Oil) supplies 40% of the U.S.’s energy needs and 97% of our transportation fuels.

Environment and Health - Many deaths associated with coal mining - major source of air pollution - source of water pollution - Oil Spills - not frequent, but very devastating - shipping, drilling, pipeline breaks - kills massive numbers of animals and vegetation - affects water supplies - Subsidence - natural gas leaks are very dangerous

Production of Energy - Fuel energy is often converted into electrical energy because it is more convenient to use. Electricity is generated in a power plant.

Energy depends on a spinning turbine. The turbine is connected to a generator. The generator creates a magnetic field that causes the electrons to flow through a wire. The flow of electrons transmitted along wires is electricity. (Figure 3, page 436)

Renewable Resources- one that is produced at least at the same rate it is used

In the 1850’s almost all energy was derived from renewable sources: - wood - wind - water

Today, the demand is too high, and almost all energy we use is derived from nonrenewable fossil fuels. So…