Human Interaction With Rocks (geothermal) Flashcards
What is geothermal energy
It is energy that is extracted from the earths core
How is geothermal energy created
Heat from hot igneous rocks are used to heat water and create steam for electricity
Name two country’s that use geo thermal energy
New Zealand and Iceland
Where is iceland positioned which allows it to use geothermal energy
Its position on the mid-Atlantic ridge allows it to use geothermal energy to heat water and make electricity
How many geothermal power plants are in Iceland
5
What percentage does geothermal energy give hot water and electricity to
32% electricity
Provides water for 98% of homes
What percentage of homes use geothermal energy as a heat source
85%
What is Iceland’s capital
Reykjavik
What does geothermal provide for some footpaths in rejkjavik
It beats some footpaths
Explain how water is heated and how we get the water
> magma pushes through fissures and has temps of over 1200 degrees
magma near the surface heats water above boiling point (over 200)
hot water is captured by drilling 2km down into hot rock
What can you say about rock temp increasing
Temp increases naturally with depth by 25 per km
What happens after hot water is captured
It is distributed to home and industrys to supply hot water and heating
How do greenhouses benefit from geothermal energy
Water is used to heat the greenhouses
This allows Iceland to produce salad crop cheaply and reduce expensive imports
How is electricity formed by geothermal energy
Water is pumped into wells, heated and turned into steam
It then returns to the surface where it is used to turn turbines within a generator which in turn creates electricity
What happens when the steam cools
It condenses back into water
Is injected back underground and cycle is repeated
Name two environmental advantages of geothermal energy
It reduces the need for fossil fuels (low CO2 emissions compared to fossil fuels)
Helps reduce harmful greenhouse gas emissions
Could help reduce dangers of climate change
Is geothermal energy cheaper than fossil fuels
Yes it is 80% cheaper and is low home heating costs
Give 2 disadvantages of geothermal energy
Environmental concerns - geothermal energy leads to emmisons of sulphur dioxide which polluted out water system
High installation cost - equipment and technology is specialised (eg underground pipes)
What happens if too much water is extracted
May lead to the subsidence of overlying ground
What does subsidence mean
Gradual caving in or sinking of overlying ground
Talk about the blue lagoon
Power plant south of Reykjavik uses mineral rock water from power stations to fill up nearby lake (blue lagoon)
It is kept at a temp of 40 degrees
There is a spa complex beside it
What is a geyser
It is a spouting spring that erupts boiling water and steam every 5 minutes
Talk about geysers in Iceland
They are one of the most famous tourists destinations due to the geothermal activity that occurs here
Several hot bubbling mud pools and geysers attract thousands of tourists to the area each year
