Renewable and Nonrenewable Energy Resources

• Renewable energy resources can be replenished naturally at or near the rate of consumption and reused, while nonrenewable energy resources exist in a fixed amount and involve energy transformations that cannot be easily replaced.
• The use of energy resources is unevenly distributed between developed and developing countries.
• Fossil fuels are the most widely used sources of energy globally.
• As developing countries become more developed, their reliance on fossil fuels for energy increases.
• As the world becomes more industrialized, the demand for energy increases.
• Availability, price, and governmental regulations all influence which energy sources people use and how they use them.

Fuel Types and Uses

• Wood, commonly used as fuel in the form of firewood or charcoal, is easily accessible in Less Developed Countries (LDCs).
• Peat is partially decomposed organic material that can be burned for fuel.
• Lignite, bituminous, and anthracite are three types of coal used for fuel; their qualities are influenced by heat, pressure, and burial depth.
• Natural gas, mostly methane, is the cleanest of the fossil fuels.
• Crude oil can be recovered from tar sands, which are a combination of clay, sand, water, and bitumen.
• Fossil fuels undergo refinement into specialized fuel types for specific uses like motor vehicles
• Cogeneration involves using a fuel source to generate both useful heat and electricity.

Distribution of Natural Energy Resources

• The global distribution of natural energy resources such as ores, coal, crude oil, and gas is not uniform and depends on a region’s geological history.

Fossil Fuels

• The combustion of fossil fuels, a chemical reaction between fuel and oxygen, yields carbon dioxide and water, and releases energy.
• Energy from fossil fuels is produced by burning them to generate heat, which turns water into steam; the steam turns a turbine, which generates electricity.
• Humans extract fossil fuels using a variety of methods:
  • Coal: Mining techniques, surface and subsurface.
  • Oil: Drilling and fracking.
  • Natural gas: Drilling and fracking.
• Fracking, or hydrologic fracturing, can cause groundwater contamination and the release of volatile organic compounds (VOCs).

Nuclear Power

• Nuclear power is generated through fission, where atoms of Uranium-235 stored in fuel rods are split into smaller parts after being struck by a neutron.
• Nuclear fission releases a large amount of heat, which generates steam to power a turbine that generates electricity.
• Radioactivity occurs when the nucleus of a radioactive isotope loses energy by emitting radiation.
• Uranium-235 remains radioactive for a long time, which leads to problems associated with the disposal of nuclear waste.
• Nuclear power generation is a nonrenewable energy source.
• Nuclear power is considered cleaner because it doesn't produce air pollutants, but it does produce thermal pollution and hazardous solid waste.
• Nuclear accidents at Three Mile Island, Chernobyl, and Fukushima have led to the release of radiation, with short- and long-term environmental impacts.
• A radioactive elements half-life can be used to calculate decay and the radioactivity level at specific points in time.

Energy from Biomass

• Burning biomass produces heat at a relatively low cost.
• Biomass burning also produces carbon dioxide, carbon monoxide, nitrogen oxides, particulates, and VOCs.
• Overharvesting of trees for fuel causes deforestation.
• Ethanol can be used as a gasoline substitute.
• Burning ethanol does not introduce additional carbon into the atmosphere via combustion.
• Energy return on energy investment is low for ethanol.

Solar Energy

• Photovoltaic solar cells capture light energy from the sun and transform it directly into electrical energy, but their use is limited by the availability of sunlight.
• Active solar energy systems use solar energy to heat liquid through mechanical and electric equipment to collect and store energy captured from the sun.
• Passive solar energy systems absorb heat directly from the sun without the use of mechanical and electrical equipment, making it so energy cannot be collected or stored
• Solar energy systems can have a low environmental impact and produce clean energy, but they can be expensive.
• Large solar electric energy farms may negatively impact desert ecosystems.

Hydroelectric Power

• Methods of generation include:
  • Dams built across rivers, where water moves through the dam and turns a turbine.
  • Turbines placed directly in the flow of smaller rivers.
• Hydropower does not generate air pollution or waste.
• However, construction of plants and dams can be expensive, alter river ecosystems, affect species migration, and change sediment flow.
• Tidal power uses energy produced by tidal flow to turn a turbine.

Geothermal Energy

• Geothermal energy is obtained by using the heat stored in the interior of the earth to heat up water that is brought back to the surface as steam.
• Steam is used to drive a turbine to spin an electric generator.
• Geothermal energy can be prohibitively expensive and is not accessible in many areas of the world.
• It can cause the release of toxic hydrogen sulfide.

Hydrogen Fuel Cell

• Use hydrogen as fuel.
• Combine hydrogen with oxygen in the air to form water and release energy (electricity) in the process.
• Water is the byproduct (emission) of a fuel cell.
• Hydrogen fuel cells have a low environmental impact and produce no CO2 when the hydrogen is produced from water.
• The technology is expensive, and energy is still needed to create the hydrogen gas used in the fuel cell.

Wind Energy

• Wind turbines use the kinetic energy of moving air to spin a turbine.
• Mechanical energy of the turbine converted into electricity.
• Wind energy is clean and renewable.
• Birds and bats may be killed flying into turbines, they may spoil the aesthetics of an area and there is a need for building power lines.

Energy Conservation

• In-home conservation methods include adjusting the thermostat to reduce the use of heat and AC, conserving water, using energy-efficient appliances, and conservation landscaping.
• Large-scale conservation methods include improving fuel economy of vehicles, using BEVs (battery electric vehicles) and hybrid vehicles, using public transportation, and implementing green building designs.

Explore renewable energy sources like solar and wind, which replenish naturally, versus nonrenewable sources like fossil fuels, which are finite. Discover how energy use varies globally and the factors influencing energy choices. Learn about fuel types like wood, peat, and coal.