LEAPES UNIT 6

Describe the pattern of energy use in a developed country compared to developing countries

1. Developing countries use more biomass because its plentiful and cheap; developed countries use more fossil fuels (and hopefully alternatives) 

Describe how governments can incentivize the use of renewable energy resources

1. Incentives like tax breaks for homes or businesses who incorporate more sustainable energy systems (solar panels, geothermal systems, passive solar/green design)

Discuss the advantages and disadvantages of using the following alternative energy sources for electricity production

1. Nuclear

   1. Advantages - no carbon emissions, no air pollution, energy dense

   2. Disadvantages - where is the waste stored?, pollution from mining uranium, expensive to build power plants, thermal pollution

2. Hydroelectric

   1. Advantages - no carbon emissions, free energy once dams are built, reservoirs can be used for recreation and tourism, prevents flooding downstream

   2. Disadvantages - flooding upstream when using water impoundment dam, habitat destruction when constructing dam, decrease of sediments moving downstream (decrease nutrients), disrupts fish migration

3. Solar

   1. Advantages - No carbon emissions, no air or water pollution, free energy once they are installed, you can sell back your energy surplus, can be used on a small scale for individuals living off the grid

   2. Disadvantages - pollution from mining material needed to construct PV cells, less efficient when its cloudy, needs an external battery to store energy to use when the Sun is not out

4. Wind

   1. Advantages- no carbon emissions, no air or water pollution, free energy after turbines are installed, can be scaled up (wind farms) for large communities

   2. Disadvantages - bird deaths, aesthetic pollution, noise pollution, can take up a large amount of land, works best where it’s very windy (offshore, great plains)

5. Geothermal

   1. Advantages - no carbon emissions, no air or water pollution, heat can be used to boil water to heat homes or to make electricity

   2. Disadvantages - works best in locations on hotspots or near plate boundaries

6. Fuel cell

   1. Advantages - no carbon emissions (unless methane is burned to collect H₂), water vapor is the only byproduct

   2. Disadvantages - H₂ is rare and requires initial energy to collect.  It only becomes sustainable if this initial energy used to collect H₂ comes from renewable resources

7. Biomass

   1. Advantages - potentially renewable (must replant vegetation after harvest), cheap, plentiful, less carbon emissions than fossil fuels, can be used on a small scale for energy in rural communities

   2. Disadvantages - air pollution, carbon emissions, human health hazards (particulate matter inhaled when burned indoors in a poorly ventilated area)

Describe how electricity generation sources have changed over time

1. We have transitioned from coal and nuclear to natural gas due to recent discoveries of natural gas deposits

Describe how energy is produced in a nuclear power plant

Nuclear fission is used to boil water → create steam → turn a turbine → power a generator → create electricity → transfer the electricity along electrical transmission lines

Describe the types of fuels used in the following sectors

1. Electricity generation - natural gas, coal, nuclear, wind, solar, hydroelectric, geothermal

2. Transportation - oil (petroleum)

3. Commercial/residential- natural gas

4. Agriculture - oil (petroleum)

Describe cogeneration

Process that increases the efficiency of a power plant by capturing wasted heat energy and using it to either heat buildings or boil water → create steam → turn a turbine which powers a generator → which makes electricity

Describe fracking and explain the environmental concerns

Process where fluid is pumped underground in order to fracture a gas rich layer of rock for the purposes of extracting the gas

Water pollution - methane and fracking fluid contamination of groundwater and surface water

Air pollution - CH₄ (methane) emissions

Describe the formation of coal, oil, and natural gas

1. Burial and compaction of organic matter (plants, algae, etc.) over millions of years

Describe the environments/geographic areas where the following renewable energy resources can be used most effectively

1. Wind - near a coastline or on the open plains 

2. Solar - really anywhere but active solar technologies will produce more electricity in more desert areas (less clouds) at a lower latitude (higher angle of insolation)

3. Geothermal - along plate boundaries and hot spots 

4. Hydroelectric - near rivers, often found in more mountainous areas 

Describe how a hydrogen fuel cell generates energy

1. In a fuel cell (basically a battery) hydrogen gas is split by an electrolyte membrane into protons and electrons.  The electrons produce an electrical current (electrical power) and the hydrogen ions (protons) move through the membrane where they combine with oxygen to produce water vapor as a byproduct.

Describe the pros and cons of hydroelectric dams

1. Pros - carbon emission and pollution free electricity produced, electricity is always available as long as the river is flowing, reservoir can be used for recreation and help develop a profitable tourism industry, decreases flooding downstream

2. Cons - disrupts fish migration, habitat destruction from dam construction and flooding upstream, carbon emissions and pollution during dam construction, buildup of sediment in reservoir leading to eutrophication or turbine damage 

Generally describe where we find fossil fuel deposits in the United States

1. Coal - Appalachian Mountains (Kentucky and West Virginia) and Wyoming

2. Oil/gas - Texas to North Dakota, some in southern California, Gulf of Mexico 

Describe the benefits of using natural gas as opposed to coal or oil as a fuel source

1. Natural gas has less carbon emissions and less pollution when burned compared to coal or oil because there are fewer impurities found associated with methane

Explain passive solar heating and give some examples of how it is used in residential or commercial settings

1. A way of designing a building that maximizes sunlight to heat a building and uses that energy efficiently

2. Green roof - insulation, water absorption

3. Large double paned windows - large windows allow sunlight in during the winter (can draw shades in summer to keep sunlight out) and better insulated windows don’t lose as much heat

4. Extended roof overhang - provides shade from hot summer sun (higher angle of insolation) but allows sunlight to enter windows in the winter (low angle of insolation)

5. Deciduous shade trees - shade windows in the summertime but allow light  to enter in the winter when all the leaves fall off

6. Building materials with a high heat capacity - using materials like stone absorb heat during the day and reradiate it at night, leading to less fossil fuels needed to be burned to produce heat

Describe how photovoltaic cells produce energy

1. PV cells are made out of silicon (a semiconductor) which absorbs light from the sun.  That sunlight kicks out an electron in the PV cell which induces an electrical current

Describe radioactive decay

1. The predictable breakdown of a radioactive element into a stable element

Describe the pattern of fuels used in developed vs developing countries

1. Water pollution - methane and fracking fluid contamination of groundwater and surface water

2. Air pollution - CH₄ emissions

Identify the ultimate source of all energy on Earth

1. The sun