APES Unit 6: Energy Resources and Consumption

APES Unit 6: Energy Resources and Consumption

Renewable and Nonrenewable Resources

• Nonrenewable energy sources exist in a fixed amount and involve transformations that are hard to replace, including:
• Coal
• Oil
• Natural Gas
• Uranium
• Renewable energy sources can be replenished naturally at or near the rate of consumption, including:
• Biomass
• Solar
• Wind
• Geothermal
• Hydroelectric
• Hydrogen fuel cell
• In the U.S., only 7% of energy use is from renewable sources, with biomass energy comprising the largest portion of that 7%

Energy Conservation

• Finding ways to use less energy is "energy conservation."
• Lowering your thermostat during the winter or driving fewer miles can help encourage energy conservation
• Energy efficiency means getting the same result from using a smaller amount of energy.
• Governments can encourage energy conservation through smart grid technology investments, offering tax credits for replacing old appliances, and raising taxes on fossil fuel use.

Global Energy Consumption

• Energy resources are not evenly distributed between developed and developing countries
• The most widely used sources of energy globally are fossil fuels.
• As developing countries become more developed, their reliance on fossil fuels increases.
• As the world industrializes, the demand for energy increases
• Availability, price, and governmental regulations influence which energy sources people use and how they use them.
• In the U.S., 81% of energy comes from fossil fuels: 34% from oil, 21% from natural gas, and 26% from coal/peat.
• Renewable energy accounts for 13% and nuclear fuels 6%
• Total energy use in the U.S. is 495 exajoules or 469 quadrillion Btu per year.
• Commercial energy sources include coal, oil, and natural gas.
• Subsistence energy sources are gathered by individuals for their use, such as wood, charcoal, and animal waste.
• The industry sector utilizes the most energy in the U.S.

Fuel Types and Uses

• Wood is often used as fuel in firewood and charcoal forms and is common in developing countries due to its accessibility.
• From the 1800s to the 1950s, wood was the main energy resource, progressing to coal, oil, natural gas, and then hydroelectric.
• Coal's efficiency is reduced by energy needed to build the plant, waste product removal, extraction from the ground, and waste heat
• Resources that are easy to exploit, that require little refining, that are easy to transport, and that are abundant means Coal is widely used around the world.
• The primary pollutant from burning coal is carbon monoxide.
• Using "scrubbers" in stacks made of limestone can neutralize acidity of carbon emissions.
• A gas water heater is more energy efficient than an electric water heater because coal-fired power plant energy efficiency is low.
• Coal usage leads to land degradation during mining and transportation and releases toxic metals like mercury and lead.
• To reduce CO2 emissions, the US could switch from cars and trucks to railroads and mass transit.
• The countries with the greatest supplies of coal are China, United States, Russia and India.
• Natural gas is mostly methane, existing both as a petroleum component and in separate gaseous deposits within the ground.
• Natural gas contains 80-95% methane and 5-20% ethane, propane and butane.
• Natural Gas burns cleaner because it burns completely.
• Natural gas use can lead to pipelines to be built through environmentally sensitive areas, methane release, groundwater contamination and land degradation from drilling
• Advantages of Natural Gas contain fewer impurities, emits almost no sulfur dioxide or particulates, and emits only 60% as much carbon dioxide as coal.
• Disadvantages of Natural Gas leads to unburned, methane escapes into the atmosphere and exploration of gas has the potential of contaminating groundwater
• Petroleum is a mix of hydrocarbons, water, and sulfur found in underground deposits, ideal for mobile combustion in vehicles.
• The remains of ocean-dwelling phytoplankton that died 50-150 million years ago formed petroleum.
• Largest petroleum countries are Saudi Arabia, Russia, The US Iran, China, Canada, and Mexico.
• Crude oil can be recovered from tar sands that are clay, sand, water, and bitumen

Petroleum

• Petroleum is the chosen fuel for transportation in the U.S. because it has high energy value, starts quickly, and is liquid form.
• Petroleum refineries separate crude oil components using boiling points,.
• Oil reserves that we currently depend on will be depleted within 50 years from now.
• Environmental costs of oil include leaks and transporting oil around the world and creates waste, releases trace metals

Hubbert Curve/Peak

• Peak oil the point when half of the oil reserves available have been used
• Hubbert curve shows when world oil extraction would peak and when reserves will run out

Other Fossil Fuels

• Oil sands are slow-flowing, viscous deposits of bitumen mixed with sand, water, and clay.
• Bitumen (tar or pitch) is a degraded type of petroleum that develops when petroleum moves close to the surface and bacteria metabolizes light hydrocarbons.
• Cogeneration occurs when a fuel source is used to generate useful heat and electricity, improving efficiency, and reaching as high as 90% use.
• Coal distribution, natural energy global distribution varies so does coal, oil and gases.
• China has the largest coal reserves, while the U.S. and Russia are second.
• Saudi Arabia has been the largest petroleum exporter for the last 40 years.

Fossil Fuels and Fracking

• The combustion of fossil fuels involves a chemical reaction between the fuel and oxygen that produces carbon dioxide, water, and energy. Generating heat by buring fossil fuels is made into steam drives a turbine, which generates electricity.
• If current global use continues, conventional oil may run out in less than 40 years.
• Coal supplies will last for at least 200 years.
• Fracking is hydrologic fracture that contaminate groundwater, release volatile organic compounds, and contaminate groundwater through its fracking fluids.
• Humans use a variety of methods to extract fossil fuels from the earth for energy generation
• Hydraulic fracking is the pumping of highly pressurized water with a mixture of sand and chemicals into bore holes to create cracks within the rock in order to provide pathways for the release of gas and oil.

Nuclear Power

• Through fission of Uranium-235 atoms stored in fuel rods makes Nuclear Power which releases heat This heat is use to generate high heat and powers electricity through turbines.
• Uranium-235 remains radioactive, problems arise from nuclear waste disposal.
• U235 is a metal with a half life of 710 million years - when radioactivity drops to 10% it is considered “safe” (must be stored for 7,100,000,000 years to be safe)
• Nuclear power generation is a nonrenewable energy source.
• Nuclear power is considered a cleaner energy source because it does not produce air pollutants, but it does release thermal pollution and hazardous solid wastes.
• Nuclear power does NOT produce any CO2 emissions!
• Water vapor released to protect power plant in Nuclear Reactors.
• The control rods can release toxic elements as radiation to the environment.
• -Nuclear power plants use uranium pellets to fuel rods to generate heat while using control rods to prevent meltdown.
• K. Long term solution to waste: EPA standards for geologic burial meets Yucca Mountain and humans is being proposed in Mausoleums.
• Spend fuel rods from nuclear reactors last 10 half lives.

Nuclear Disasters

• Three Mile Island, Chernobyl, and Fukushima are three cases disasters.
• 1970- most serious reactor accidents is through 50% meltdown of reactor core- Containment kept buildings and no subsantial harm
• 1986, worst accident destroyed the nuclear reactor. Large of radiaiation was spewed after explosions.
• Fukushima on March 11 2011, following earthquake and meter long accident crippled the power supply. All three were meltdowns on the core.