Geology Quiz 6: Energy Resources

Energy

The capacity to do work or to cause a change.

Energy Resource

Matter that can produce heat, power muscles, generate electricity, or move machinery.

Human energy needs…

Have greatly increased in the past 150 years. The mix of energy resources required to address those needs has changed dramatically.

Sources of Energy

1) the sun, 2) solar radiation and gravity, 3) photosynthesis, 4) fossil fuels, 5) nuclear fission reactions, 6) earth’s internal energy, 7) energy in chemical bonds.

Oil and Gas

Industrial society depends on hydrocarbons from oil and natural gas. Hydrocarbons are made of hydrogen (H) and carbon (C) and derive from the material that composed once-living creatures. There are many types of hydrocarbons, which are found in nature as complex mixtures. Pure compounds are separated by refining.

Hydrocarbon Systems

A known supply of oil or gas is a hydrocarbon reserve. If mostly oil, it is an oil reserve. Most oil reserves are located in super-giant fields in the Middle East. Reserves require a specific association of materials, conditions, and time.

Traps and Seals: Anticline Trap

Oil and gas rises to the crest of the fold.

Traps and Seals: Fault Trap

Oil and gas collect in the tilted strata adjacent to the fault.

Traps and Seals: Salt-Dome Trap

Formed when deeply buried salt flows like plastic. Less dense than overlying rock, salt will flow upward and deform overlying strata.

Traps and Seals: Stratigraphic Trap

Oil and gas collect where the reservoir layer pinches out.

Tar Sands

Deposits of residual petroleum in sand reservoirs that have lost lighter hydrocarbons by bacterial digestion.

Oil Shale

Contains abundant kerogen that has not been subjected to oil window conditions. Heating can transform some of the kerogen into liquid hydrocarbons that can then be used like oil. Large supplies occur in Estonia, Scotland, China, Russia, and the western United States.

Coal

A black, brittle, carbon-rich sedimentary rock made up of the altered remains of fossil vegetation that grew in swamps. This is an important global energy source and a dominant CO2 emitter. It is only found in rocks younger than 420 Ma.

Coal Formation

Dead vegetation falls into stagnant, oxygen-poor water. The absence of water prevents decay. Burial to depths of 4-10km compacts the heat and the peat. Chemical reactions drive off hydrogen, nitrogen, and and sulfur as gases. The remaining residue is greater than 70% carbon.

Finding Coal

Vast quantities of this lie buried in continental sedimentary basins. Cretaceous and Carboniferous coal-bearing rocks occur in great abundance in the midwestern United States and Rocky Mountain regions.

Nuclear Reactors

High tech nuclear facilitates engineered to manage nuclear chain reactions safely. A reactor heats water, producing high pressure steam inside a closed loop. Heat is transferred to an external water loop that is used to spin electrical turbines.

Nuclear Power

Derives energy from breaking apart atomic nuclei. Fission splits a large nucleus into smaller fragments, producing enormous amounts of energy.

Geothermal Energy

Energy from Earth’s internal heat. Geothermal plants utilize hot groundwater in places that have a high geothermal gradient (mostly located in volcanic regions). Geothermal energy is also useful in nonvolcanic areas. Groundwater can be used to heat and cool buildings very efficiently with no wastes, no greenhouse gases, or air pollution

Hydroelectric Energy

Flowing water turns potential energy into kinetic energy as water is directed past turbines to create electricity. Some dams generate electricity via tidal flux.

Positive Aspects of Hydroelectric Energy

Dams reduce the risk of floods, impound water for drinking, irrigation, and recreation, and provide renewable energy without creating wastes.

Negative Aspects of Hydroelectric Energy

Dams destroy valued landscapes and alter ecosystems, trap sediment that requires expensive dragging, and accelerate erosion downstream.

Wind Power

Steady winds drive a large turbine to produce electricity. Wind-derived electricity is renewable and carbon-free. High-tech wind farms are sprouting worldwide. Wind farms have negative aesthetic impacts and turbine blades are noisy and kill birds.

Solar Power

By far the most abundant source of energy to Earth’s surface. This type of energy is hard to use because it is diffuse, highly variable on a seasonal and daily basis, and difficult to convert into more usable forms of energy.

2 Ways to Use Solar Energy

1) Solar collectors concentrate sunlight for heating. 2) Photovoltaic (PV) cells convert light directly into electricity. Both are useful for small buildings, not big cities.

The Oil Age

The Oil Age for future historians will span for about 300 years.

Global Energy

Use continues to increase dramatically, reflecting rapid expansion of industrialization. Oil, the dominant energy source, is a nonrenewable resource that is declining. In the future, humans will need to have a different energy mix.

The Oil Crunch

M. King Hubert correctly predicted the peak of U.S. oil production to be 1971. We are now close to the peak of global oil production. Oil extinction is likely to occur between 2050 to 2150. Humanity faces many changes as oil runs out.