6.7-6.13 APES Unit 6 Energy Resources and Consumption (Renewable) with Pros & Cons - import

Renewable resources

Any natural resource that can replenish itself in a relatively short period of time, usually no longer than the length of a human life.

Nonrenewable resources

A natural resource that is not replaced in a useful time frame.

Charcoal

charred wood

biomass energy

renewable energy derived from burning organic materials such as wood and alcohol

Overharvesting

harvesting a renewable resource quicker than the source can renew itself; often leads to the destruction of the resource

Deforestation

The removal of trees faster than forests can replace themselves.

Ethanol

mix of gasoline and alcohol used in combustion engines

Biofuels

Liquid fuels created from processed or refined biomass, such as ethanol

Biodiesel

A diesel-equivalent, processed fuel derived from biological sources (such as vegetable oils), that can be used in unmodified diesel-engine vehicles.

Solar

energy from the sun

Photovoltaic cells

Cells, usually made of specially-treated silicon, that transfer solar energy from the sun to electrical energy

passive solar energy

Solar energy systems that collect energy without the use of mechanical devices

active solar heating

the use of technology to collect, store, and distribute the sun's energy

Dams

a barrier constructed to hold back water and raise its level, the resulting reservoir being used in the generation of electricity or as a water supply

Hydroelectric

Electricity generated by flowing water

Reservoirs

a large natural or artificial lake used as a source of water supply.

Tidal energy

Energy that comes from the movement of water driven by the gravitational pull of the Moon.

Three Gorges Dam

A dam being built over the Yangtze river in China. It will be the world's biggest dam.

Geothermal energy

Energy derived from the heat in the interior of the earth

Hydrogen fuel cell

a cell that generates electricity from a controlled reaction between hydrogen and oxygen

Hydrogen gas formula

H2

Wind energy

The energy captured by transforming the motion of air into electrical energy using a turbine

energy conservation

the practice of finding ways to use less energy or to use energy more efficiently

Energy efficient

energy efficient homes are composed of a network of elements working together to reduce the overall amount of energy consumption

electric vehicle

A vehicle that you plug in to charge a battery. The electrical energy runs the motor. Most of the time in the U.S. this electrical energy is coming from coal, natural gas, or nuclear power.

Hybrid cars

a car with a gasoline engine and an electric motor, each of which can propel it

Biomass Pros

• Doesn't increase atmospheric CO2 levels due to using modern carbon

Biomass Cons

• Releases CO, NOx, PM, and VOCs which are respiratory irritants

• Can cause deforestation

Biofuels Pros

• Decreases oil consumption

• Can be carbon neutral

Biofuels Cons

• Growing of crops can lead to soil erosion, habitat loss, greenhouse gas emissions, increased water usage

Solar Pros

• PV Cells can be scaled up or down as needed

• Small photovoltaic cells are portable and can power many applications

• No CO2 emissions when generating electricity

• Relatively high net energy gain

• Unlimited energy source during fine weather

• Solar cookers are transportable and simple to use

• No mining fossil fuels for electricity production

Solar Cons

• Ground shaded by large solar panels

• Back up and warm up systems required (usually gas)

• Large land area needed for commercial scale production

• High sunshine hours required

• High start up costs

• Solar panel farms can displace habitats

• Semiconductor metals (silicon) still need to be mined to produce PV cells

Hydroelectricity Pros

• No greenhouse gas emissions when generating electricity

• Reservoir & dam can be tourist attractions, recreational sites, or used for irrigation

• Jobs are created to maintain the dam

• Reliable electricity source

• No air pollutants generated during electricity generation

• Provides flood control

• Long life spans

Hydroelectricity Cons

• Reservoir floods habitats behind dam

• Prevents upstream migration of fish (salmon)

• Sedimentation builds up behind the dam decreasing nutrient flow downstream

• Fossil fuels combusted during dam construction

• Carbon emissions (methane and carbon dioxide) from decomposition of plant matter in flooded area

• Homes and businesses must be relocated due to reservoir flooding

• High construction costs

Geothermal Pros

• Potentially renewable, only if water is piped back into the ground for reuse

• Much less CO2 emission than fossil fuel electricity

• No release of (PM/SOx/NOx/CO) as is case with fossil fuels

• Low cost (in suitable areas)

Geothermal Cons

• Not everywhere on earth has access to geothermal energy reaching close enough to surface to access it

• Hydrogen sulfide can be released, which is toxic and can be lethal to humans & animals

• Cost of drilling that deep in the earth can be very high initially

• Easily depleted if not carefully managed

• Land subsidence possible

Hydrogen Pros

• Can be stored in tanks and transported to be used later and in different location

• Can be used as fuel for vehicles

• Only emission is H2O

• 80% efficient (Which is high compared to coal at 35%)

Hydrogen Cons

• Most hydrogen gas is produced from steam reformation of methane which is nonrenewable and emits carbon

• Needs infrastructure to be built to distribute

• Requires much larger tanks on vehicles than current gasoline tanks

Wind Pros

• No air pollutants emitted when generated electricity

• No carbon dioxide emissions during electricity generation

• Can be located in many different locations due to its ability to share land

Wind Cons

• Intermittent electricity generation (dependent upon environmental conditions)

• Batteries or backup systems would be helpful

• Can interfere with flight patterns and/or kill migratory birds and bats