Chapter 4 Earth Resources

Section 4.2Alternate Energy Sources

Alternate Energy Sources

A. Solar EnergyB. Nuclear EnergyC. Wind EnergyD. Hydroelectric EnergyE. Geothermal EnergyF. Tidal power

Solar EnergySolar Energy

Earths most abundant energy resource

Solar energy technologies use the sun’s rays to supply heat or electricity

Solar energy is free and nonpolluting

Earths most abundant energy resource

Solar energy technologies use the sun’s rays to supply heat or electricity

Solar energy is free and nonpolluting

Solar EnergySolar Energy

ProsFreeAbundantNonpolluting

ProsFreeAbundantNonpolluting

Cons Costly equipment and installation

Supplemental heating is needed during reduced sunlight ie., on cloudy days, in the winter, and at night

Cons Costly equipment and installation

Supplemental heating is needed during reduced sunlight ie., on cloudy days, in the winter, and at night

Nuclear EnergyNuclear Energy

In nuclear fission,the nuclei of heavy atoms such as Uranium-235 are bombarded with neutrons. The uranium nuclei then split into smaller nuclei and emit neutrons and heat energy.

In nuclear fission,the nuclei of heavy atoms such as Uranium-235 are bombarded with neutrons. The uranium nuclei then split into smaller nuclei and emit neutrons and heat energy.

The Birth of Nuclear Energy

“At one time, energy experts thought nuclear power would be the cheap, clean energy source that would replace fossil fuels.”(Tarbuck &

Lutgens, 104)

What obstacles slowed the development of nuclear

energy?

What obstacles slowed the development of nuclear

energy?

Set backs for nuclear energy

Set backs for nuclear energy

Cost of safe facilities has increased

Hazards associated with disposal of nuclear waste

Possibilities of serious accidents allowing radioactive material to escape

Cost of safe facilities has increased

Hazards associated with disposal of nuclear waste

Possibilities of serious accidents allowing radioactive material to escape

Nuclear AccidentsNuclear Accidents

Three Mile Island, 1979 -low water levels lead to reactor damage

Chernobyl, Ukraine, 1986 -much more serious, out of control reactor, fire and explosions, 18 deaths and thousands faced increased risk of death from cancer due to fallout

Three Mile Island, 1979 -low water levels lead to reactor damage

Chernobyl, Ukraine, 1986 -much more serious, out of control reactor, fire and explosions, 18 deaths and thousands faced increased risk of death from cancer due to fallout

Wind EnergyWind Energy

Wind is not a new energy source

Wind turbines harness the most energy in areas with strong steady winds like mountain passes and sea coasts

Wind is not a new energy source

Wind turbines harness the most energy in areas with strong steady winds like mountain passes and sea coasts

The Future of Wind Energy

5%-10% of the countries energy needs could be met in the next 50 - 60 years by

wind power

Difficulties and obstacles facing wind

energy

Difficulties and obstacles facing wind

energyNeed for technical advancesNoise pollutionCost of large areas of land in populated areas

Not practical in all locations

Need for technical advancesNoise pollutionCost of large areas of land in populated areas

Not practical in all locations

Hydroelectric EnergyHydroelectric Energy

The power that falling water generates to drive turbines and produce electricity

The power that falling water generates to drive turbines and produce electricity

Hydroelectric energyHydroelectric energy At a hydroelectric power plant water is held in a reservoir behind a dam.

Lake Mead is the largest reservoir in the USA and is held behind the Hoover Dam

Hydro electric power plants are limited by the availability of suitable sites

At a hydroelectric power plant water is held in a reservoir behind a dam.

Lake Mead is the largest reservoir in the USA and is held behind the Hoover Dam

Hydro electric power plants are limited by the availability of suitable sites

Geothermal EnergyGeothermal Energy

Is harnessed by tapping natural underground reservoirs of steam and hot water

The heated water is used to turn turbines to create electricity

Is harnessed by tapping natural underground reservoirs of steam and hot water

The heated water is used to turn turbines to create electricity

Tidal PowerTidal Power

Is harnessed by constructing a dam across the mouth of a bay or an estuary in coastal areas with a large tidal range. The strong in-and-out flow that results drives turbines and electric generators

Is harnessed by constructing a dam across the mouth of a bay or an estuary in coastal areas with a large tidal range. The strong in-and-out flow that results drives turbines and electric generators