What About Geothermal Power?

Geothermal energy is something of a Cinderella in the world of alternative energy sources.  Most of the attention goes elsewhere, onto things such as wind power, solar energy and hydro energy.  But geothermal energy certainly fits the description of being a clean and sustainable energy source:

It consumes no polluting fuels and the source of the energy won’t be used up in a hurry.

About Geothermal Energy

What is geothermal energy?  The word “geothermal” comes from two Greek words: geos, meaning earth, and therm, meaning heat.  Therefore, it’s not hard to work out that geothermal energy uses the heat of the planet’s core and mantle.  The inside of the earth is obviously packed with heat and energy – just ask anyone who’s seen a volcano or volcanic activity – and it makes sense to tap this energy source instead of using non-renewable resources or things that carry a pollution risk.

The big question is how to use that heat.  While many volcanic areas (the volcanically active area closest to Australia is the North Island of New Zealand, particularly in the Rotorua region) already make use of the natural hot springs as tourist attractions, are there any other possible ways of using geothermal energy?

How Geothermal Energy Works

The answer to that is yes.  Geothermal energy is used to generate electricity.  The principle is the same as the one in a coal-fired electrical power station.  Water is heated to produce steam, and the pressure exerted by the steam pushes a turbine around, which generates electricity.  However, in a geothermal power plant, no fuel is burnt and no carbon or smoke is emitted into the atmosphere.

The first geothermal power station was built in Italy, but New Zealand was the second.  At the moment, about 20 countries use geothermal energy as a form of generating electricity: Italy, New Zealand, the USA, Iceland, Germany, Turkey, France, the Netherlands, Lithuania, Mexico, El Salvador, Nicaragua, Russia, Costa Rica, Indonesia, China, Japan and St Kitts & Nevis.  

Other developments are underway in Africa around the Rift Valley area.  Some work is being done on exploring geothermal energy in Central Australia, drilling down to the “hot rocks” deep in the earth’s crust and using their heat to create steam to power turbines.  These hot rocks are located 4 km below the earth’s surface.  This project should be able to provide Australia with about 6–7% of its energy needs by 2030, according to some sources.

Geothermal energy disadvantages

• Not everywhere is suitable for geothermal energy – you need to have a volcanic “hot spot” where the heat of the mantle and the magma is easily reachable.  Or else you need hot rocks!
• The water that is often associated with volcanic areas is quite corrosive, which makes for a fair bit of wear and tear on the pipes, etc. of the power plant.