The Geothermal Engineering plant will pump water down to rocks that are at high temperatures – around 200 degrees centigrade, approximately 5 kilometres below the ground – where most of the water turns to steam. This is then pumped back up and converted into geothermal electricity using a steam turbine, and, when cooled, the water can be reused to produce more geothermal energy.
Geothermal energy
Geothermal energy (from the Greek roots geo, meaning earth, and thermos, meaning heat) is power extracted from heat that is stored in the earth. Literally, it is heat and power from the earth.
Our planet is a huge source of energy. In fact 99.9% of the planet is at a temperature greater than 100 degrees Centigrade, so geothermal energy is a significant renewable resource.
Geothermal energy plants have been around for a long time (electricity has been generated for over 100 years) and are normally located in regions where there is volcanic activity, such as in New Zealand and Iceland.
However, new techniques are allowing geothermal energy plants to source heat at greater depths (often at 5kms) thus allowing geothermal energy plants to be sited in more locations. These deeper systems by pumping cool fluid through the hot rock, allowing it to turn to steam and pumping the steam up to drive a turbine.
Harnessing geothermal energy
