Today’s Agenda… Bellringer: What happens to some of the energy in a car engine as chemical energy is being transformed to mechanical? Notes on Sources of Energy

Sources of Energy Study Pack #6

Today’s goals… I can explain where energy comes from. I can explain what renewable, nonrenewable, and alternative resources are. I can describe the advantages and disadvantages of using various energy sources.

Using Energy According to the law of conservation of energy, energy cannot be created or destroyed, so where does energy come from?

Energy Resources Energy must come from the natural world Figure 16; page 729 Most of the Earth’s energy comes from the sun Some of the Earth’s energy comes from radioactive atoms in Earth’s core

Energy Resources Fossil Fuels Nuclear Energy Hydroelectricity Solar Energy Geothermal Energy Tidal Energy Wind Energy Biomass

Fossil Fuels Coal, oil, and natural gas Made from the remains of organisms that lived millions of years ago Ancient organisms converted the sun’s light energy into chemical energy now stored in fossil fuels until they burn

Fossil Fuels Fossil fuels are nonrenewable resource – being used up faster than they can be replaced Produce pollution Can cause illness, acid rain, global warming

Biomass Made from plants Contained stored chemical energy Corn and sugar cane Contained stored chemical energy Can be burned for energy Example: ethanol in gasoline

Nuclear Energy Energy released with uranium atoms split Energy transformations No pollution Uranium is also nonrenewable Produces nuclear waste Methods for storing waste – page 731

Hydroelectricity Transforming the potential energy of water behind dams to kinetic energy and then electricity Water is a renewable resource – constantly replenished No pollution Can harm wildlife Salmon Use of fish ladders

Alternative Energy Sources Other ways energy can be generated Solar, wind, and geothermal

Solar Energy Capturing the sun’s energy to transform into electricity Inexhaustible resource – can’t be used up by humans No pollution Expensive equipment Page 734

Geothermal Energy Using the heat generated inside the Earth to transform into electricity Magma heats water and produces steam Can only be built in areas where magma is close to the surface No pollution Heat pumps – page 735

Tidal Energy Uses the rise of fall of sea level – tides – to produce mechanical energy No pollution Inexhaustible resource Can only be built in certain areas

Wind Energy Wind turns a propeller connected to a generator to produce electricity No pollution Produce a lot of noise Can be harmful to birds

Conserving Energy To make the supply of fossil fuels last longer and to produce less pollution we can reduce our use of energy How can we do this?

More information! Energy Sources