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Comparing Geothermal Energy to Nuclear Energy

geothermal energy line Iceland landscape

Both geothermal energy & nuclear energy at a fundamental level work the exact same way surprisingly. Both technologies use steam to turn a turbine which produces electricity. However, the way they get to that point is where these energies go in completely opposite directions.

How Nuclear Energy Works

Nuclear energy requires radioactive material called Uranium to create heat. Uranium has to be mined, refined & processed into ceramic pellets. Those pellets are then encased into large metal tubes which is how “fuel rods” are made. Those fuel rods give off high amounts of radioactive energy & heat. To maintain the levels of heat & stability of the fuel rods a coolant system is encased around those fuel rods that contains what is called “heavy water”. (Heavy water is water that consists of oxygen & deuterium instead of hydrogen & oxygen. Keep in mind that all the materials that come into contact with the fuel rods like the heavy water are extremely radioactive). That heat produced from those fuel rods is then used to heat up real water which is turned into steam. And that steam is used to turn a turbine which generates electricity. Fuel rods only last 3-7 years at which point they have to be replaces with new ones & the cycle continues. Those fuel rods are the dangerous nuclear waste we have no way to safely dispose of. The most common method to dispose of nuclear waste is to literally bury it in the Earth on selected sites (typically mountains) with signs on them.

On a sidebar, these warning signs are for future generations of people should the nuclear waste site ever be found or discovered. Now imagine if our ancestors did this tens of thousands of years ago before the mysterious disaster event occurred 12,000 years ago & we forgot much of our ancient history. We are essentially creating a very dangerous problem to be solved, burying it in our backyard & expecting future generations to figure it out. Assuming nothing happens to the nuclear waste in that time period. That aside, lets move onto how geothermal energy is created.

How Geothermal Energy Works

Geothermal energy works by drilling bore holes to a desired depth where the Earths temperature is at a minimum 149° C (300°F). Depending on where you are on Earth this could be just beneath the surface or a few kilometers down. Once we have access to the geothermal heat those boreholes are capped to handle the high amount of pressure that occurs once water is sent down the borehole. Enormous amounts of pressure & steam are created & are directed through tubes to send that steam past a turbine which produces electricity for the grid.

The steam is then sent through a cooling towers which lets of excess steam and the condensed water is sent back into the ground via an injection well. That water is heated up again by the Earth and comes back up the borehole again as steam creating a looped system where only some water is let off as steam. The fundamentals of the geothermal energy system are actually very simple. Its when we get into the engineering & depth of the boreholes accounting for the types of rock, hardness levels encountered & accounting for Earth crust stability that things can get complicated. This has been the biggest hurdle in geothermal energy. But there is new technology which could solve both of those problems & actually make the crust stronger in that area called “pulse plasma drilling”.

So when we compare how geothermal energy is made to nuclear energy there is a stark contrast in the levels of safety, the costs & the processes involved. One is simple (comparatively), the other is an overly complicated way to re-engineer a dangerous process that already happens deep within the Earth and bring to the surface where we are. Lets look further into comparing these two types of energy.

Geothermal & Nuclear Energy List of Comparisons

Availability of Resources

Nuclear Energy: Relies on both uranium and plutonium fuel, which are finite resources. While there are significant global reserves of uranium, the availability of high-grade ore and long-term sustainability are concerns.

Geothermal Energy: Relies on heat from the Earth’s crust, which is virtually a limitless & renewable resource. Geothermal reservoirs can sustain energy production for decades to centuries with proper management.

Environmental Impact

Nuclear Energy: Produces electricity with minimal greenhouse gas emissions during operation but poses risks such as radioactive waste generation, potential accidents (like Chernobyl, Fukushima, Three Mile Island), there are concerns about uranium mining impacts & nuclear proliferation (the spread of nuclear weapons).

Geothermal Energy: Generally considered environmentally friendly, with low emissions of greenhouse gases & pollutants during operation. However, there are localized environmental concerns such as land stability & potential release of naturally occurring toxins (like hydrogen sulfide) from geothermal fluids.

Safety and Risks

Nuclear Energy: High safety standards & technological advancements have reduced the likelihood of major accidents. However, nuclear accidents can have catastrophic consequences in terms of human health, environmental contamination, & long-term cleanup & mitigation efforts. In the history of nuclear energy we have had numerous disasters totaling dozens of events and thousands of lives lost since 1952. This does not include the amount of people who have died from radiation exposure from nuclear waste.

Geothermal Energy: Generally considered safe with minimal risks compared to nuclear energy. However, drilling & reservoir engineering carry some risks such as induced seismic activity (earthquakes), groundwater contamination (if not managed properly) which seems like this could be mitigated using cleaner materials & proper geological research. I could only find 2 articles that stated there were fringe accidents where a workers died from hydrogen sulfide gas in a separator rooms. 1 in 1998 & 1 in 2022.

Energy Production & Efficiency

Nuclear Energy: Provides a high energy density, with nuclear power plants capable of generating large amounts of baseload electricity continuously. However, nuclear power plants have long construction times, high capital costs, & the mentioned challenges of nuclear waste disposal with no clear solution.

Geothermal Energy: Provides consistent and reliable baseload power similar to nuclear energy (depending on the type of geothermal system) with good efficiency. Geothermal power plants have relatively lower operational costs once established but require suitable geological conditions for optimal energy extraction. So the limits of electricity produced by geothermal means is only limited to our ability to drill deep within the earth efficiently, harness the heat efficiently & building the power stations. Once we figure out how to tap into the existing geothermal energy from any point on Earth, we literally have limitless free energy.

Public Perception & Acceptance of Nuclear & Geothermal Energy

It seems very strange that while the obvious dangers & monumental costs of nuclear are known, nuclear seems to be the one getting the most attention (both good & bad). Nuclear energy also has billions of taxpayer dollars put toward nuclear development that often goes way over budget. It seems like were putting billions of dollars into something that doesn’t seem to be solving anything while geothermal energy gets a fraction of the investment & we wonder why geothermal isn’t developed.

Geothermal energy isn’t given praise or even much attention publicly in the scientific/engineering community considering its potential. Its seems like private companies are the only ones pushing geothermal energy. Why? Its like geothermal energy is being judged before its taken off. We’ve barely explored the limits & possibilities of geothermal energy. Look at how much progress has happened in the last 20 years alone of electric car technology after “sitting on the shelf” for over 100 years.

Closing thoughts on Geothermal & Nuclear Energies

In the end, we are essentially spending literally billions of dollars to re-create something that the Earth already does for us and then spend millions more trying to dispose of man-made nuclear waste which endangers future generations of people. While there have been developments in “micro-nuclear reactors” which are compact & supposedly more safe… this doesn’t solve the nuclear waste issue. In the times we are in the importance of addressing nuclear proliferation has never been greater since the Cold War. Humans should not have the ability to destroy the planet with weapons. If we continue using nuclear energy we continue making materials for our very destruction. Yes nuclear has a high energy density… but so does the Earth. Nuclear energy is still used to make steam & turn turbines like most other forms of energy generation. I would be all for nuclear energy if there wasn’t a nuclear waste issue & the obvious dangers associated with the technology. So is it worth the cost (both literally & figuratively)?

Geothermal energy taps into nuclear reactions that are already happening deep inside our Earth creating vast amounts of heat. Since this is energy that runs constantly regardless of the conditions & will always bee here so long as Earth is here… it seems like not tapping into this infinite & free energy source would be a great loss to humanity & humanity’s future. Having volcanic activity near the surface has made the pioneering geothermal technology much easier & faster for places like Iceland. The same thing can be achieved anywhere on Earth, we just have to drill deeper. If we can send people into space, build space stations & explore our universe… I think we can put some of our finest minds on how drill deep holes safely anywhere on Earth.

I think with geothermal energy, its going to be the same thing that happened with electric vehicles. It was a path we started on, it turns out it was the right path, but we made a wrong turn & went with different technologies. 100+ years later were suffering the consequences of those choices & now were trying to make up for them as fast as we can.

Jacob Haust

With a passion for design, electric vehicles, engineering and the environment, Jacob is combining his interests to help make the world a more sustainable place for generations to come. He went to University for Industrial Design where he understood materials, processes and manufacturing. This is a key part as a designer in order to understand what can and can't be done when manufacturing with certain materials and what materials to choose when designing for specific applications. So he has a fairly deep understanding of materials used in everyday products and the processes used to make them. As a kid he also lived in Iceland for years where he toured geothermal power plants and gained an appreciation for the engineering and sustainability of this energy source.

jacob haust


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