How Does Geothermal Energy Work
When you ask "how does geothermal energy work?" you are asking how to capture energy that is produced naturally. There are both advantages and disadvantages in how geothermal energy works and can be used.
To understand how geothermal energy works you must understand what geothermal energy is. This is heat energy that has been in existence since the earth was formed. It is a natural and renewable energy source.
How Does Geothermal Energy Work Inside the Earth
The earth's core generates geothermal energy and this core has a higher temperature than the surface of the sun. The heat is produced by radioactive particles which decay and release energy through that process. Though this decay occurs naturally in rocks, the construction of the earth leads to thermal energy production.
The Earth is composed of several layers and you would need to dig 4000 miles into the surface to reach the center of our planet. At its core, the Earth's temperature can only be estimated and is believed to be at least 7200 degrees Fahrenheit. The heated core was a result of billions of tons of hot mass that collided, meshed, collapsed and reformed as the Earth was created more than 4 billion years ago.
The central core of the earth is made up of two layers - hot melted rock called magma and a central core of iron. Around the core a layer composed of magma and rock is about 1800 miles thick. The crust of the Earth is the land we live on. The depth of the crust varies from 3-5 miles deep on ocean floors to 15-35 miles deep on land.
The crust layer of the Earth is broken into pieces under the surface. When you think about it, this makes sense as the Earth's crust is curved so it's natural for seams (faults) to occur. The broken pieces are referred to as tectonic plates and in areas where these fault lines naturally occur, the hot magma and heated rocks are closer to the surfaces we live on.
These fault lines are the cause of seismic activity (earthquakes) as the edges of various tectonic plates bump together and shift. Because the surface layer is thinner near the fault lines, this is also where you find hot geysers spewing steam and water in the air, volcanoes, and hot springs. These fault lines are also where geothermal energy can be tapped and harnessed to produce electrical power.
Without a Power Plant
For centuries, people have found ways to use geothermal energy. Geothermal reservoirs are large areas of land where heat from the Earth's core escapes through porous rock and fault lines and where underground reservoirs are heated and can be accessed with wells.
Areas near a geothermal reservoir might drill wells and direct the water under the floors of homes in a town to provide heat. Hot springs have become famous in some areas. The water in this springs bubbles to the surface from an underground geothermal reservoir. Often these waters have high mineral content.
There are sulphur springs and mineral baths that for centuries were advertised as "healing waters". It is said that the first commercial use of water was when innovative businessmen began charging for people to submerse themselves in hot springs and turned those pools into resort areas.
Where do You Find It?
The answer to "how does geothermal energy work" is simply that the energy that naturally occurs can be accessed by tapping into the heat in areas known to be geothermal reservoirs. In these places, the heat is closer to the surface and it's possible to reach the hot water and steam located far beneath our feet.
These hydrothermal sites can be used for industrial practices that require heat. Using this heated water or steam to heat greenhouses is a common application in many parts of the world. It's possible to warm your home with direct use of naturally created hot water or steam.
The most recent application of how geothermal energy can work is to use the heat source to create electrical power. The process itself is not highly complex but there are concerns and questions.
The basic process when you ask how does geothermal energy work is that deep wells drilled into areas known as geothermal reservoirs allow us to pump hot water and steam from deep in the earth to the surface. Using turbines and generators, we capture the energy of that heat and convert it to electrical power. The water is then cooled and injected back into the earth through another deep well.
Issues and Question
There are concerns about environmental impact in areas where geothermal power pants are built. These areas are along known fault lines and prone to earthquakes. In some cases, drilling deep wells miles below the Earth's crust may increase seismic activity in a region. It can also transmit energy along a fault line and cause earthquakes in other areas.
Pollution is not a hazard as the toxins naturally occurring in the earth are returned to the earth when the cooled water is injected into the waste wells after the energy has been released. Cost is a problem as this is an expensive energy producing plant to build. Over half of the cost of a new geothermal plan is in the planning for well location and in safety studies.
These are not attractive installations and more resemble an oil field than a power plant. This lack of aesthetic value can be problem in areas of residential development. However, one feature of how geothermal energy works is the requirement to locate these along fault lines so relocating a plan is not always an option.
Perhaps one of the greatest advantages of how does geothermal energy work is the sustainability. The core of the earth is gradually cooling but that is a slow process occurring over billions of years. The production of electricity using thermal processes requires some balancing so that the heated water and steam are not removed faster than they can be reheated.
Over production in some areas has reduced the temperature of the magma and rock in certain geothermal reservoirs. This is not an insurmountable problem as reducing the amount of water pumped out of the ground may allow the reservoir to once again reach previous higher temperatures.
The basics of how does geothermal energy work is that hot water and steam are drawn from wells drilled miles deep into the Earth's surface. The heat is removed and used to create electricity and the cooled water is then returned to the deep reservoir.
