Energy Resources:Renewable and Nonrenewable

Energy Resources:Renewable and Nonrenewable

Renewable vs. Non-renewableRenewable vs. Non-renewable

• Non-renewable resource– Exists in finite supply– Is used faster than it can replenish– Ex: oil, coal, nuclear fuels

• Renewable or perpetual – Replenishes very rapidly– Inexhaustible supply– Ex: solar, wind, hydropower

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Non-Renewable Energy SourcesNon-Renewable Energy Sources

• Conventional– Petroleum– Natural Gas– Coal– Nuclear

• Unconventional (examples)– Oil Shale– Natural gas hydrates in marine sediment

44

Renewable Energy SourcesRenewable Energy Sources• Solar photovoltaic

• Passive solar air and water heating

• Wind

• Hydropower

• Biomass

• Ocean energy

• Geothermal

• Waste to Energy

Evaluating Energy ResourcesEvaluating Energy Resources

US Energy Resources:Renewable energy: 8%

US Energy Resources:Renewable energy: 8%

Non-renewable energy: 92%Non-renewable energy: 92%

Considerations for ResourcesFuture availability

Considerations for ResourcesFuture availability

Net energy yield Net energy yield Cost Cost

Environmental effects Environmental effects

Petroleum (Oil): 39% of US EnergyPetroleum (Oil): 39% of US Energy

Fig. 17-8 p. 356Fig. 17-8 p. 356

• US uses 26% of oil extracted worldwide;we have 2.9% of world’s oil reserves

• Depletion of our reserves means more oil imported• World oil reserves 80% depleted in 42-93 years• Oil is a finite resource!

Oil: 39% of US EnergyOil: 39% of US Energy

Fig. 17-8 p. 356Fig. 17-8 p. 356

•Pros of Oil:•High net energy•Easily transported•Strong infrastructure

•Cons of Oil:•Requires subsidies•Air pollution•Global warming•Limited supplies

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Peak Production of Petroleum in USPeak Production of Petroleum in US

Arctic National Wildlife Refuge: Is this the answer?

•Would meet US needs for 7-24 months•1 mpg increase for new cars = ANWR

Natural Gas: 23% of US EnergyNatural Gas: 23% of US Energy

•Mostly methane + other gases

•LNG-versatile and high net energy

•Cleaner burning than oil or coal

•But, US has only 3% of world supply

Fig. 17-20 p. 364Fig. 17-20 p. 364

Coal: 23% of US EnergyCoal: 23% of US Energy

Coal: 23% of US EnergyCoal: 23% of US Energy

• Produces 62% of world’s electricity and 52% of US electricity

• Most abundant fossil fuel and could easily last at least 200 years

• US has 25% of world’s reserves, Russia = 16%, China = 12%

• High net energy yield, but…

Coal: 23% of US EnergyCoal: 23% of US Energy

• Accounts for 36% CO2 released

• Severely degrades land causing land, air and water pollution

• Severe human health threat

• Air pollution and acid rain

Mining Waste Impacts on Surface and GroundwaterMining Waste Impacts on Surface and Groundwater

Miller, 13th edition, Fig. 15-7 p. 344

Nuclear: 8% of US EnergyNuclear: 8% of US Energy

• Significant fuel supply

• Low CO2 output

• Moderate land disruption and pollution but…

•Expensive--subsidies needed•Catastrophic accidents possible•No solution to nuclear waste disposal•Subject to terrorist attack

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Nuclear: 8% of US EnergyNuclear: 8% of US Energy

Miller, 13th edition

Fig. 15-36p. 367

Nuclear FusionNuclear Fusion

Fusion-DisadvantagesFusion-Disadvantages

• Need around 100 millon degrees for duterium and tritium to fuse

• With our current technology, we use more energy than we can produce.

Oil ShaleOil Shale

• Fine grained rock containing a solid , waxy mixture of hydrocarbons called kerogen

• Extracted from rock by crushing and heating.

• Global supplies are potentially 200 times larger than conventional oil.

Oil Shale-Disadvantages:Oil Shale-Disadvantages:

• Lower net energy yield

• Requires large amounts of water

• Contaminates water supplies with toxic metals

• Too expensive

Tar SandsTar Sands

• Mixture of clay, sand, water, and bitumen (gooey black high-sulfur oil)

• Removed by surface mining using pressurized steam

• World’s largest supply in northern Alberta, Canada

Tar Sands-DisadvantagesTar Sands-Disadvantages

• Low net energy yield

• Requires large quanties of water

• Creates huge waste dispposal ponds

Natural Gas HydratesNatural Gas Hydrates

• Methane Hydrates found in a solid form under great pressure in deep ocean sediments

• Cannot be retreived efficiently with current technology

Renewable Energy sourcesRenewable Energy sources

Solar EnergySolar Energy

• Solar energy consists of harnessing radiant energy from the sun.

• Active solar heats water or air inside a home-requires electricity to circulate

• Passive solar-the structure is built to maximize solar capture

• Photovoltaic cells generate electricity

Solar EnergySolar Energy

Pros

• Limitless supply

• Little environmental impact

• Good for remote locations

Cons

• Inefficient where sunlight is limited

• Maintenance costs high

• Systems must be periodically replaced

• Current efficiency only 10%-25%

Wind EnergyWind Energy

• Wind turns giant turbine blades that produce electricity

Wind EnergyWind Energy

Pros

• Can be built quickly

• Maintenance is low

• Moderate to high energy yeild

• No air pollution

• Land underneath can be used for agriculture

Cons

• Steady wind is required

• Needs backup systems

• Visual and noise pollution

• May interfere with flight patterns of birds

Hydropower: 10 % of US EnergyHydropower: 10 % of US Energy

• Dams built to trap water, which in turn is then released and channeled through turbines to generate electricity

HydropowerHydropower

Pros

• Control flooding

• Low operating cost

• No pollution

• Long life span

• Moderate to high energy yield

• Areas for water recreation

Cons

• Displace many people

• Destroy wildlife habitats

• Sedimentation requires dredging

• Expensive to build

• Destroys wild rivers

BiomassBiomass

• Any carbon-based, biologically derived fuel source.

• Plants suitabelefor biofuel include switch grass, corn, and sugarcane

• Supplies about 15% of world’s energy

BiomassBiomass

Pros

• Renewable energy source

• Can be sustainable

• Does not distupt atmospheric CO2

Cons

• Requires adequate water and fertilizer

• Could cause massive deforestation

• Expensive to transport

• Not efficient

Geothermal < 1% US EnergyGeothermal < 1% US Energy

• Heat from underground rock or magma used to produce steam that drive turbines.

GeothermalGeothermal

Pros

• Moderate energy yield

• Limitless and reliable source if managed properly

• Little air pollution

• Competitive cost

Cons

• Reservoir sites are scarce

• Can be depleted if not managed properly

• Noise, odor, land subsidence

• Can degrade ecosystem

Solutions:Solutions:

Energy Efficiency! • 43% of energy in the US is wasted

unnecessarily• Incandescent bulb=5% efficient

Fluorescent bulb=20% efficient• Auto fleet standards = CAFE Standards

(Corporate Average Fuel Economy) – 12.9 mpg in 1974– 27.9 mpg today– 40 mpg CAFE standard would cut gas use by

50%

Efficiencies Efficiencies

Ways to Improve Energy EfficiencyWays to Improve Energy Efficiency

InsulationInsulationEliminate air leaksEliminate air leaks

Air to air heat exchangers

Air to air heat exchangersEfficient appliancesEfficient appliances

Efficient electric motorsEfficient electric motorsHigh-efficiency lightingHigh-efficiency lightingIncreasing fuel economyIncreasing fuel economy

Toward a Sustainable Energy FutureToward a Sustainable Energy Future

• Increase fuel efficiency standards for vehicle, appliances, buildings

• Tax and other financial incentives for energy efficiency

• Subsidize renewable energy use, research and development

• By 2050: – renewable energy=50%– cut coal use by 50%– phase out nuclear altogether