Author: Janine Ty; Sources: NREL, Study.com, National Park Service, Unsplash
Geothermal Power Generation
INTRODUCTION
Geothermal power plants produce electricity by utilizing the steam that comes from reservoirs of hot water found below Earth’s surface.
“The steam rotates a turbine that activates a generator, which produces electricity.” —NREL
ACTIVITY
Geyser Air Pressure (By Study.com)
Materials: Empty plastic bottles with caps, liquid soap, Alka-Seltzer tablets, a piece of paper, a pencil // Duration: 15 minutes
Divide students into groups of 2-3.
Give each group one empty plastic bottle, some liquid soap, and an Alka-Seltzer tablet.
Explain to students that they are going to make their own geyser to see how air pressure builds up and what can happen when it does.
Ask each group to fill their bottle up with water, almost to the top.
Have students add a little bit of soap and then an Alka-Seltzer tablet, before immediately putting the cap back on the bottle.
Students should write down a prediction about what will happen when they open the bottle.
Once they are done with their predictions, each group will go to a sink to open their bottle.
Monitor each group to make sure the bottle is not pointed at anyone when it is opened.
The bottle should overflow with water because the air pressure has built up inside.
Have students write their observations on the same page they wrote their prediction on.
Lead a discussion on how the pressure built up and how it might relate to a geyser underground.
Remind students that to make the model more accurate, the water closest to the lid would have to be really hot, about 244°F or 117°C to be more exact, and the closer to the bottom of the bottle water was, it would have to be even hotter.
The boiling point of water is 212°F (100°C), so quite a bit of steam would also erupt along with the water. This is the steam that geothermal power plants use to generate electricity.
