Geothermal Power Station. Image credit MediaWiki

ZIMSEC O Level Geography Notes: Natural Resources: Energy:Geothermal power

  • Geothermal power is generated using steam rhythmically shooting out from underground at high pressure in the form of geysers.
  • To control the movement of steam, an intricate network of pipes is installed collecting and directing the steam to turbines on the ground surface.
  • The power of the ejected steam turns the turbines which turn the generators to produce our electricity.
  • Some of the pipes act as safety valves to release excess pressure and steam while others are for driving steam to cooling chambers to convert it back to water.
  • This water is then pumped back to the geyser source underground for reboiling naturally by hot rocks in an area of active volcanicity.
  • Volcanicity is the process where molten magma or lava forces its way out from the earth’s crust unto the earth’s surface.


  • It is clean and environmentally friendly
  • It is renewable
  • Does not require clearing or damming nor does it result in displacement of people
  • It is inexpensive to run as there is no fuel required to turn turbines
  • Reduces dependency on fossil fuels


  • Pollution for example through the release of gases such as hydrogen sulfide
  • Potential water pollution
  • They are location specific and cannot be moved to suit other factors e.g distance to market
  • Plants have high maintenance costs
  • The construction of geothermal stations can affect land stability as there is risk of land subsidence
  • There is also the possibility of depletion

To access more topics go to the O Level Geography Notes page