Alternative Energy SourcesAlternative Energy Sources

OilOil Oil fuels the modern

world (gasoline, natural gas, diesel)

Easily transported, relatively safe, and versatile.

Finite resource: cost to recover will eventually exceed its value

Non-Renewable: will not replenish within our lifetime

Oil fuels the modern world (gasoline, natural gas, diesel)

Easily transported, relatively safe, and versatile.

Finite resource: cost to recover will eventually exceed its value

Non-Renewable: will not replenish within our lifetime

SustainabilitySustainability

Resources “needed” = resources available An increase in population impacts sustainability Growth cannot be sustained indefinitely Consider “standard of living” A sustainable society must balance resources

available with “needs” or “standard of living”

Resources “needed” = resources available An increase in population impacts sustainability Growth cannot be sustained indefinitely Consider “standard of living” A sustainable society must balance resources

available with “needs” or “standard of living”

Alternative SourcesAlternative Sources

Alternative sources are not as convenient as oil; they require additional investment and often are not as versatile as oil

They have both advantages and limitations

Some are renewable (replenish within our lifetime) and some are not.

Alternative sources are not as convenient as oil; they require additional investment and often are not as versatile as oil

They have both advantages and limitations

Some are renewable (replenish within our lifetime) and some are not.

GeothermalGeothermal

Driven by heat from within the Earth

Water heated from the Earth’s interior can turn a turbine and generate electricity

Renewable Limited accessibility

Driven by heat from within the Earth

Water heated from the Earth’s interior can turn a turbine and generate electricity

Renewable Limited accessibility

SolarSolar

Sun will exist for a long time Promising technology (solar

to electric- solar panels) Renewable Sunlight received is limited

(related to latitude) How store for the longterm

when sun not available?

Sun will exist for a long time Promising technology (solar

to electric- solar panels) Renewable Sunlight received is limited

(related to latitude) How store for the longterm

when sun not available?

WindWind

Wind (mechanical) to electricity

Clean and renewable Not reliable End product is electricity

(not a significant oil replacement)

Bird migration impacted

Wind (mechanical) to electricity

Clean and renewable Not reliable End product is electricity

(not a significant oil replacement)

Bird migration impacted

Hydro-ElectricHydro-Electric Stored water (potential)

converted to electricity (kinetic)

Non-polluting Dams increase sediment

deposition, so not truly renewable

Lowlands filled (decrease in diversity)

“Run of the river” facilities are renewable and minimize environmental degradation

Stored water (potential) converted to electricity (kinetic)

Non-polluting Dams increase sediment

deposition, so not truly renewable

Lowlands filled (decrease in diversity)

“Run of the river” facilities are renewable and minimize environmental degradation

TidalTidal

Changes in water elevation used to generate electricity

Renewable High tides and special

shaped coastlines needed Only nine sites worldwide Considerable environmental

impacts on estuaries (fisheries, migration routes, etc.)

Limited final product (electricity)

Changes in water elevation used to generate electricity

Renewable High tides and special

shaped coastlines needed Only nine sites worldwide Considerable environmental

impacts on estuaries (fisheries, migration routes, etc.)

Limited final product (electricity)

BiofuelsBiofuels

Conversion of organic material to energy

Wood = liquid fuel, but net energy low and large environmental impact

Corn = ethanol, but negative energy gain (more energy to produce), detracts from food supplies and has a significant impact on land

Renewable

Conversion of organic material to energy

Wood = liquid fuel, but net energy low and large environmental impact

Corn = ethanol, but negative energy gain (more energy to produce), detracts from food supplies and has a significant impact on land

Renewable

Nuclear FissionNuclear Fission

Splitting a nucleus yields immense energy

U-235 (.7% of all U) U-238 used to create Pl-239

(larger source), but very toxic

Nonrenewable as Uranium reserves are limited

“Clean” fuel source Electricity is end product Must deal with waste

products

Splitting a nucleus yields immense energy

U-235 (.7% of all U) U-238 used to create Pl-239

(larger source), but very toxic

Nonrenewable as Uranium reserves are limited

“Clean” fuel source Electricity is end product Must deal with waste

products

Living off our Capital and Technology Limitation

Living off our Capital and Technology Limitation

*Living in a petroleum fueled economy means living off our capital

*C.G. Darwin (1952): “The fifth revolution will come when we have spent the stores of coal and oil…it is obvious that there will be a very great difference in ways of life…a man has to alter his way of life considerable, when, after living for years on his capital, he suddenly finds he has to earn any money he wants to spend…”

*Technology cannot rescue us indefinitely, as natural resources will always be necessary (food, forests, land, etc.)

*Living in a petroleum fueled economy means living off our capital

*C.G. Darwin (1952): “The fifth revolution will come when we have spent the stores of coal and oil…it is obvious that there will be a very great difference in ways of life…a man has to alter his way of life considerable, when, after living for years on his capital, he suddenly finds he has to earn any money he wants to spend…”

*Technology cannot rescue us indefinitely, as natural resources will always be necessary (food, forests, land, etc.)

Technology vs. ResourcesTechnology vs. Resources

Technology cannot create without resources, and our resources are finite.

How many people can a renewable energy resource support?

What will be the resources we will use to do this?

Given our current standard of living, how many people can the Earth support?

Technology cannot create without resources, and our resources are finite.

How many people can a renewable energy resource support?

What will be the resources we will use to do this?

Given our current standard of living, how many people can the Earth support?