Alternative Energy Sources

Methane Hydrates

• Methane-trapped ice

  • Decomposition of organic matter

• Hydrocarbon source

Hydrogen Fuel Cells

• Convert hydrogen into electricity, heat, and H2O

• Alternative energy source

• Emits only water vapor as a byproduct

• Used in vehicles

• Technological issues

  • Storing compressed hydrogen

  • Producing hydrogen efficiently

  • Distributing hydrogen to customers

Photovoltaic Cells (PV Cells)

• Solar panel adjacent that converts sunlight (photons) into electricity

• Direct way to store energy from the sun.

What causes acid rain?

• Sulfur and nitrogen oxides react with water vapor - form sulfuric and nitric acids

Buffering

• Neutralization of acids

• Carbonate/calcite (soils+limestone)

• Reacts with acid to form bicarbonate

Dry Deposition

• Dry particles

• Reacts with ground with waterfall

• Acidification and nutrient imbalances

• Beneficial for air quality

Wet Deposition

• Wet particle

• Rain or precipitation containing acids

• Contributes to soil and water acidification

• Reacts in atmosphere

Hydrothermal Energy

Internal heart from Earth generates steam - powers turbines to produce electricity

Wind Energy

• Differential heating causes air varying in mass, heat content, & density to power turbines to generate electricity

  • Vary in time, place + density

• Vertical and Horizontal Convergence

  👍 Widespread, abundant, inexhaustible, low pollutant, inexpensive

  👎Affects birds, requires roads, not aesthetic

Low-level Wastes

• Small amounts of radioactive substances

• Isolated 500 years

• Success based on time to reach groundwater

Nuclear Fission

• Splitting an atom by nuclear bombardment

• Heavy atoms emits _ during fission:

  1. 3 neutrons

  2. Lighter atom

  3. Energy

Transuranic waste

• Human-made radioactive waste

• Low radioactive levels

• Isolated 250,000 years

  • New Mexico salt burial site

High-level Waste

• LARGE amounts of radioactive substances

• used fuel assemblages from reactors

• Isolated 250,000+ years

• Yucca mtn burial site

Geothermal Energy

• High heat @ surface

• Divergent/convergent boundaries

• Less adverse to environment

• Energy production exceeds nuclear rates

  • Hydrothermal convection (Steam)

  • Groundwater systems

Groundwater Systems

• Temp. difference btwn groundwater and surface temp

• Heat and cool buildings

• Costly, but growing

  • Sewers

Centralized Power

Power collected and distributed through large organizations

👍 concentrated profits, well-established distribution systems, unlimited resources

👎outages, high transmission losses

Decentralized Power

Power from many sources, distributed through small orgs + individuals

👍 Dispersed profits, more secure

👎Complicated distribution systems

Alternatives to fossil fuels

1. Nuclear energy

2. Geothermal energy

3. Renewable energy

   1. Solar

   2. Hydrogen

   3. Water

   4. Wind

   5. Biomass

Nuclear Reactor

Generates electricity by using nuclear fission to heat water into steam - drives a turbine connected to a generator - converts nuclear energy into electrical energy.

Reaction Chamber

Where nuclear fission occurs and uranium atoms split

Control Rods

absorb excess neutrons to regulate explosion

Graphite Moderator Rods

slow down neutrons to create a sustained reaction

Breeder Reactor

• solution to sustainable nuclear energy

• take 90% discarded U from typical reactors

  • convert to plutonium 239

Burner Reactors

Designed to use and destroy radioactive waste, primarily actinides, rather than breeding new fuel

Nuclear reactor that produces more fissile material than it consumes

How is nuclear waste stored?

Deep underground repositories, dry casks, and cooling pools. 

Risks: contamination/radiation

How does geothermal energy work with groundwater and hydrothermal convection?

Internal heat heats groundwater → hydrothermal convection circulates heated water through rocks → steam powers turbines (aka geothermal energy)

How can solar energy generate electricity with photovoltaic cells?

Photons from sunlight strike the semiconductors on the solar panels → loosens electrons → creates an electric current (photovoltaic effect)

Biodiesel Pros/Cons

Vegetable oil, fats, etc

👍 Less energy-intensive production, burned as motor fuel

👎 Pollution? Economics?

Ethanol Pros/Cons

Alcohol derived from corn/sugar

👍 Produced in large quantities, cleaner energy burning

👎 Pollution? Farmland loss? Economics?

Energy Vampires

• Transmission loss

• TV, computer, laptop, printer, microwave, etc