1. Geothermal energy

2. heat coming from the Earth
GEO (geology, geography) is
a Greek word meaning Earth
THERMAL (thermometer, thermal underwear) means HEAT
GEOTHERMAL
heat coming from the Earth

3. Sources of the Earth’s heat:
1) leftover heat from the formation of our planet
2) radiogenic heat (the heat resulting from radioactive decay within Earth)

4. Capturing Earth’s heat
1) For a long time until recently – people could only use geothermal energy that’s made its way to the Earth surface – Geothermal hot springs used for recreational and medicinal bathing. The oldest knowing pool created for this purpose was built in China in the 3rd century BC.

5. Today people go to hot springs to relax and for health reasons.
The water in these hot springs is warmed as it comes into contact with rocks heated by magma below the Earth’s surface. So the springs are most common in the volcanic areas.

6. Capturing Earth’s heat
2) In the 20th century people started using geothermal energy for electricity generation.

7. Capturing Earth’s heat
3) Geothermal heat pumps use the constant temperatures near the surface of the earth to heat and cool buildings.