APES Unit 6 Notes— Energy Resources and Consumption

Module 35: Renewable and Nonrenewable Resources and Global Energy Consumption

  • Nonrenewable energy resources are finite and important

    • Fossil fuels, for example

    • Units of energy: calories, British thermal units, kilowatt-hour (kWh)

  • Renewable energy resources are infinite and becoming more important

    • Nondepletable vs potentially renewable resources

    • Nondepletable: wind, solar power, hydroelectric power, geothermal

    • Nonrenewable: oil, natural gas, coal, nuclear

    • Potentially renewable: wood, biofuel

  • Trends in energy use are changing around the world and in the United States

    • Worldwide patterns of energy use

      • Oil, coal and natural gas are 3 largest sources

      • Renewable energy 15% of worlds energy

      • Energy consumption, vs per capita energy consumption

      • Developed/ industrializing countries are more likely to use fossil fuels

      • Commercial energy resources: those that are bought and sold

      • Subsistence energy resources: gathered by individuals for their own immediate needs

    • Patterns of energy use in the US

      • Oil, natural gas, and coal are main sources

      • 100 EJ use

    • Quantities of fossil fuels use in the US and Worldwide

      • Years are remaining for fossil fuels

      • The Hubbert curve: represents when world oil production will reach a maximum and when it will be depleted

    • The future of fossil fuel use

      • We may run out, however technological advances propose a promising future

  • We can use less energy through conservation and increased efficiency

    • Different forms of energy

      • Energy that requires more processing, energy per mass, etc

    • Quantifying energy efficiency

      • EROEI= energy obtained/ energy invested to obtain

Module 36: Fuel Types and Uses

  • The sun is the ultimate source of many of the fuels we use

    • Also creates things like biomass

    • Doesn’t control tidal, nuclear, or geothermal energy

    • Modern carbon vs fossil carbon

  • Each fuel has specific optimal applications

    • Wood: used for heating

    • Coal/ peat: used or electricity or industrial processes

    • Natural gas: used for electricity or for industrial processes, and manufacturing nitrogen fertilizer

    • Crude oil: used for combustion, gas, turned into asphalt, gas, diesel, and kerosene

    • Tar sands: creates tar and crude oil

  • Fossil fuels have specialized uses for motor vehicles and electricity

    • Hot water heaters

      • Use electricity or fire, burn things like natural gas

      • Important to consider heat produce and energy transport etc

    • Fossil fuel choices and transportation

      • Public transport is more efficient

  • Generation and cogeneration convert fuels to electricity

    • Process of electricity generation: electricity is clean, however, when fossil fuels are used to produce it, pollutants are released (and it isn’t very efficient)

      • Convert other energy into electricity

    • Efficiency of electricity generation

      • Combined cycles

      • Capacity

        • Max electrical output of a power plant

        • Capacity factor: fraction of time a power plant operates during a year

    • Cogeneration

      • Combining heat and power

Module 37: Distribution of Natural Energy Resources: Fossil Fuels

  • Fossil fuel and ore distribution around the globe depends on the geology of the region

    • Deposits of coal, etc.

  • Fossil fuels have many advantages and disadvantages

    • Advantages of coal

      • Energy dense and plentiful, easy ish to surface mine and needs little refining

    • Disadvantages of coal

      • Environmental consequences of mining, contamination

    • Advantages of oil

      • Relatively energy dense and cleaner burning, also easier to transport

    • Disadvantages of oil:

      • Contains toxins, potential for oil leaks (like Exxon Valzez and Deepwater Horizon)

    • Advantages of natural gas

      • Cleanest out of all fossil fuels

    • Disadvantages of natural gas

      • Methane is more efficient at absorbing heat as a greenhouse gas, and escapes into atmosphere

      • Fracking: provides jobs but also steals water and pumps the environment full of chemicals, releasing VOCs

  • Fuel is converted to electricity and releases carbon dioxide and heat energy

    • Energy efficiency— considering the transition, transport, and efficiency

    • Electrical grid: interconnected transmission lines

    • Energy quality: the ease at which energy can be used to do work

Module 38: Nuclear Power

  • Nuclear reactors use fission to generate electricity

    • Heat energy is produced which spins a turbine which generates electricity

    • Concentrating the uranium ore

      • People must remove large amounts of host uranium rocks and chemically enrich it

  • Nuclear power has advantages and disadvantages

    • Advantages: no air pollution, super cheap, long half lives

    • Disadvantages: Transporting, mining, processing, and making plants are costly, as well as impacts to people and environment

  • Nuclear power depends on radioactivity, but as a result, it generates radioactive waste

    • Radioactive isotopes undergo radioactive decay

      • Half lives

    • Radioactive waste: the byproduct

      • High level, low level and residue

    • Measuring half lives:

      • 200 years/ 50 years=4 half lives, 100–> 50–>25–>12.5–>6.3 curies

      • Curie: 37 bil decays per second

      • becquerel: rate at which a sample of radioactive material decays

    • Radioactive waste disposal

      • Facilities have waste sitting around until it isn’t dangerous in pools of water

      • Long term storage: site in Yucca Mountain controversy

  • Three mile island, Chernobyl, and Fukushima are the three nuclear accidents

    • Nuclear power compared with other fuels

      • Cleaner, but unpopular

Module 39: Biomass and Solar Energies and Hydroelectric Power

  • Biomass energy resources are derived from biological material and can displace fossil fuels

    • Solid biomass: wood, charcoal, manure

      • Wood and charcoal are used for heating and are renewable if we allow forests to grow

      • Combustion results in pollutants

    • Manure

      • Used for subsistence

      • Releases pollution when burned

    • Liquid biofuels: ethanol + biodiesel

      • Ethanol

        • Cleaner but less efficient

      • Biodiesel

        • Same issue

  • The energy of the sun can be captured passively and actively

    • Passive solar heating

      • Can’t be stored, needs backups

    • Active solar technologies

      • Storing things, photovoltaic solar cells, thermal systems

      • Solar water heating systems

        • Uses a heat exchanger that heats water

      • Photovoltaic systems:

        • Capture energy as light and convert into electricity

      • Concentrating solar thermal electricity generation

        • Sort of like concentrating sunlight in a magnifying glass and burning steam to generate electricity

    • Benefits and drawbacks of active solar energy systems

      • Benefits: clean energy, reduces need for fossil fuels

      • Drawbacks: expensive, requires toxic metals to build, etc

  • The kinetic energy of water can generate electricity but there are consequences

    • Methods of generating hydroelectricity

      • Tides, dams, etc

      • Water impoundment systems: storage of water behind a dam

      • Run-of-rivers systems

        • Like a smaller dam

      • Tidal systems

        • Rely on moon movement and capture kinetic energy

  • Hydroelectricity and sustainability

    • Expensive but require minimal amounts of fossil fuels

    • 3 gorges dam displaced people and did not help ecosystems

      • Fish ladder

    • Siltation doesn’t help

Module 40: Geothermal Energy and Hydrogen fuel Cells

  • Earth’s internal heat is transferred to water that we use for heating and electricity generation

    • Harvesting geothermal energy

      • Hot groundwater can heat homes, steam turns turbines

    • Ground source heat pumps

      • Transfers heat from the ground to a building

      • Hot water heat pumps

        • A variation

  • Hydrogen fuel cells use hydrogen as an energy source and are almost pollution free

    • Converts hydrogen into an electrical current

    • Requires electricity to make electricity

    • The viability of hydrogen

      • Efficient, good for transport, 80% efficient

      • Renewable hydrogen (?)

      • Can power cars

Module 41: Wind Energy and Energy Conservation

  • Wind energy is the most rapidly growing source of electricity

    • Generating electricity from wind: no steam required

    • Benefits: nondepletable, clean, can share land

    • Disadvantages: relies on expensive batteries, birds/ bat populations are killed, noise pollution

  • We can use less, and use different technologies to conserve energy

    • We can do this at home and on a large scale, reducing phantom loads etc

    • Efficiency

      • Using more efficient technology

    • Sustainable design

      • Sustainably designing technology

    • Energy summary and synthesis

      • Everything has its benefits and downsides

      • Efficiency, conservation, and the development of renewable and Nonrenewable energy resources

      • A renewable strategy: people are focusing on electrical grids and smart grids