6.10: Geothermal Energy

Question 1

What is Geothermal Energy?

Answer 1

Radioactive decay of elements in Earth’s core emit heat which drives magma convection currents to carry heat to the upper portion of the mantle close to Earth’s surface

Question 2

Electricity Geothermal

Answer 2

1. Magma heats up water that was piped down
2. This water is turned to steam
3. Steam powers generator
4. Generator produces electricity
5. Water is sent to cooling tower before being reused

Can also use water from naturally heated water reservoirs underground

Question 3

Ground Source Heat Pump

Answer 3

Heat comes from the ground storing heat from the sun. The ground ten feet down stays a consistent 50-60 degrees due to holding heat from the sun

Question 4

More on Ground Source

Answer 4

Heat absorbing fluid is pumped through a pipe into the ground where it can either take on heat from the ground or give off heat to the ground. In the summer, heat from home transfers to liquid which transfers heat to the ground (cooling effect). It is opposite for the winter.

Question 5

Geothermal Pros

Answer 5

• Potentially renewable since the heat from Earth’s core won’t run out only if groundwater is returned after use
• Less carbon emissions than FF electricity
• No release of PM or other air pollutants as is the case with FFs

Question 6

Geothermal Cons

Answer 6

• Not everywhere on earth has access to geothermal energy reaching close enough to surface to access it
• Hydrogen sulfide can be released which is toxic to humans and animals
• Cost of drilling that deep in the earth can be very high initially making it not worth it sometimes