Enduring Understanding:

• Humans use energy from a variety of sources, resulting in positive and negative consequences.

Learning Objective:

• Describe the use of geothermal energy in power generation.

• Describe the effects of the use of geothermal energy in power generation on the environment.

Essential Knowledge:

• Geothermal energy is obtained by using the heat stored in the Earth’s interior to heat up water, which is brought back to the surface as steam.  The steam is used to drive an electric generator.

• The cost of accessing geothermal energy can be prohibitively expensive, as it is not easily accessible in many parts of the world.  In addition, it can cause the release of hydrogen sulfide.

Process

• Water is pumped down an injection well

• Stored heat from the Earth’s interior turns the water into steam

• Steam rises from the production well

• The steam turns a turbine, turning a generator, creating electricity

Consequences

Positive

• No combustion

  • No CO2 emitted

• Not dependent on variables such as weather, sunlight, wind

• Homes can be heated

Negative

• Accessibility at a reasonable cost is limited

  • Unless you’re at a location where geothermal heat rises high enough to be harnessed, it’s too expensive to consider viable

• Release of gases during drilling and processing

  • Hydrogen sulfide

• Short-term depletion of heat is possible

• Impact on groundwater