DesignEnergy Systems

Free Geothermal Power from Earth’s Heart

I have yet to get my mind around the idea that Earth’s inner core is dense iron and nickel, surrounded by boiling liquid like the stuff that comes out of volcanos. Nevertheless I find the potential power of it awesome, although it does remind me how transient life is on earth. The ancient Greeks were not far off when they believed everything – including you and me – is a composite of the classical elements of earth, water, air, and fire.

It would be absurd to speculate how hot the Earth’s core is. The temperature would read off any human scale. What is more important is the geothermal energy potential this represents. From time to time, the molten lava wells up through a crack or fissure. If it encounters water, it makes it warm or instantly vaporises it as steam.

The Oldest Known Hot Spring Pool: Y Trotttier: CC 3.0
The Oldest Known Hot Spring Pool: Y Trotttier: CC 3.0

The Oldest Known Hot Spring Pool

This water carries beneficial mineral properties with it. Hence, the earliest uses of geothermal power were therapeutic baths. The dip pool in the image dates from the third century BC and is in China. Archaeologists rediscovered it when they excavated a 3,000-year-old holiday resort of the Emperors in the 1980’s.

When water superheats, as it does in kettles and in geothermal vents, it expands into hot steam at up to 1,700 times the original volume. It shoots out of vents like Old Faithful Geyser in Yellowstone National Park, Wyoming, United States. The first working steam engine saw the light of day in 1712. Since then, engineers have built a variety of steam devices for turning pressure into motive power.

Old English Mill Engine: Chris Allen: CC 2.0
Old English Mill Engine: Chris Allen: CC 2.0

Emergence of Steam Engines

Almost all electricity comes from turning an armature inside a magnetic field, with the exception of solar power. The earliest power stations were hydro. In 1862, Thomas Edison built the first steam power station in London, England. Since then, superheated steam has been the main driving force for the electricity we use in industry, and in our homes.

The traditional energy source to heat the water continues to be fossil fuel, or a controlled nuclear reaction. Coal continues to accelerate global warming. Unfortunately it has the advantage of being relatively cheap, and able to provide consistent power around the clock, unlike solar, wind, and tidal. The current global generation mix is 31% coal, 27% oil, 23% natural gas, renewables 14%, nuclear 5%. The 81% non-renewables are steadily suffocating our planet.

Steam Turbine Rotor: Siemens: CC 3.0
Steam Turbine Rotor: Siemens: CC 3.0

Drum Roll for Geothermal, Please

There is nothing wrong in principle with the rotor in the picture. It is an inanimate object and a thing of great beauty in engineering eyes. The problem is the non-renewable nature of the energy source that drives it. I think it is time to call a drum roll for geothermal energy. It is waiting deep down in the heart of the earth, and I believe promising to be our sustainable solution.

The first thermal power station energised five light bulbs in 1904, using thermal steam emerging from the ground in the Larderello Valley. This evolved into a commercial venture others copied in California and Japan. The first large-scale enterprise appeared in 1958 in New Zealand, where it still produces 13% of the nation’s electricity. Nowadays there are geothermal power stations in most places where there is a reliable supply of naturally boiling water.

World Geothermal Power Map: GEA: Public Domain
World Geothermal Power Map: GEA: Public Domain

The Extent of Global Geothermal Power

The World Energy Council reports that geothermal power could meet up to 8.3% of global energy needs. All things being equal, this would reduce reliance of coal by 25%, which would be a good start. Leading electricity beneficiaries are the United States, Italy, the Philippines, Indonesia, and Mexico. The largest direct users for heating and cooling are China, the USA, and Sweden. The Geothermal Energy Association thinks we have tapped less than seven percent of the potential.

There are currently three ways to generate electricity using geothermal power once we have taken it in pipes to a generating station:

• In dry steam power stations, geothermal steam of 150 °C or higher is sufficient to turn turbines and make electricity

• Flash steam stations pull high pressure water at 180 °C plus into lower-pressure tanks where it super-expands

• In binary stations, water as low as 57 °C passes through a secondary fluid with a lower boiling point that drives the turbine

Dry Steam and Flash Steam Stations: Goran Tekan:  CC 3.0
Dry Steam and Flash Steam Stations: Goran Tekan: CC 3.0

The ‘Best’ is Not Good Enough for Me

I reject the World Energy Council’s estimate of limited geothermal potential. If we can frack the earth in order to release natural gas, why can we not drill a hole and release more heat for geothermal steam. Iceland is drilling a five-kilometre hole into molten magma. It thinks that this could generate supercritical steam ten times more powerful than traditional geothermal wells.

That is news I want to hear!


  1. How do we even know what the core is when we have only drilled 8 miles?

    If you look at the stories around the deepest drilling operations you will come across fascinating stories…

    None of which have anything to do with a core of this type.

    1. All the land around any volcano is constantly polluted. That’s a given, and also why in volcanic regions farms are thick on volcanoes, despite the danger. The pollutants are fertilizer waiting to be used. I’ve a cousin on Maui, and while he and his wife, a Polynesian, are very into natural and protecting the environment, I’ve never heard of man-made pollutants around the electricity plants. People on the islands are very concerned about the health of their state, and i would have heard something if the pollutants weren’t natural.

  2. The problem here is, that the molten core is in constant state of flux. Always churning and volatile. This makes it near impossible to harnass without great risk to both the plant, the people who work there and many other potential risks that can’t be foreseen when toying with forces that is still far beyond our understanding.

  3. …it is artificial to pull the energy human needs is pulled from deep ground. It is natural to get it from the surface in a way that keeps all in balanced harmony for eternal time. This is what real human race who would deserve to be named a human race would do.

  4. Real human is responsible more than any other creature on the planet. He/she is given not a chance but real responsibility to lead, protect and maintain everything that exists on the planet. What was done is complete failure due to idea that it is all here for us. The truth is it is not for us. It is for all. We have just been given the highest role.

  5. Human race is like a baker man who got a job and eats each bread he makes. Not that all others remain hungry, he also throws all the rubbish on all around him. What’s the use of such a bake man?
    Or take the bank employee who puts every dollar into his pocket and uses the money to bribe and gets more remaining money in the world for himself. The rest he uses for buying weapons and drugs.
    Something like that has become the so called human race. It deviated totally to wrong direction. Why? Not because of thinking it is all for him but because of deep ignorance. The root cause for this ignorance which has no beginning is that he doesn’t inquire. Honest Inquisitiveness leads one to the right direction to get that knowledge.

  6. My father described to me how he saw greenhouses heated by geothermal energy in Iceland in 1945, so this isn’t a new concept.

    Just hot water from geothermal energy is a fantastic resource. If you have a hot spring home heating becomes a simple matter of a pump and pipes.

    I took a fantastic hot bath on the island of Dominica in the Caribbean, just from a hot spring. Near Dallas, TX, the well water comes out too warm to pipe into houses and must be cooled before storage.

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