Geothermal energy is a renewable resource of power and heat for mankind, and is used today to generate clean electricity, for residential heating and cooling and in agriculture.
Being produced by the extreme heat radiated by the inner core of the planet, the geothermal resource is created when an underground reservoir of water is heated by the hot magma and turns into very hot water an steam.
The steam reaches the surface of the planet in different forms.
Natural Examples of Geothermal Energy
In nature, we can easily recognize the geothermal resource by watching a geyser in action, a hot spring or the hot lava produced by active volcanoes.
1. Geysers
Geysers can be found today in countries like the United States (in the Yellowstone National Park), Chile, New Zealand and Iceland, and are produced when an underground water reservoir is heated by magma (located a few miles bellow the reservoir), and keeps the water high above its boiling point.
Water heats near the magma, and a small amount of water trapped in channels leading to the surface, will squirt above the surface to release the pressure.
When the heat builds up too much, the boiled water overwhelms the pressure of the rock and produces an eruption of steam.
The steam quickly expands to more than 1,000 times its initial volume of water, and the eruption continues until the geyser is dried out or until the pressure of the water and the pressure of the rock go back into a balance.
2. Hot Springs
To explain what hot springs are, we first need to explain what is the water cycle on our planet.
Planet Earth is covered by a large volume of water in liquid form, and when the Sun heats this water, a process called ‘evaporation’ takes place turning the liquid water into water vapor.
Water vapors rise into the atmosphere to form clouds, and when it cools down produces rain or even snow through a process called ‘condensation’.
Rain and snow fall back down to earth as precipitation and this is the water cycle that takes place on our planet every day.
Some of the water that falls as precipitation goes into the ground seeping through porous rocks and feeding the underground water reservoirs.
The water in these underground reservoirs can stay there for a very long period of time, or can reach the surface under the form of springs.
If the underground water is heated by the inner core of the planet (through hot underground stones heated by magma), the spring becomes a hot spring.
Some hot springs have a temperature that is safe for bathing, while others are very hot, so they can’t be used for bathing.
Hot springs can be found today in countries like Iceland, United States, Bali, Turkey, Jordan, Italy, etc.
3. Hot Lava
Dormant, active or in between, volcanoes can be found all over the planet and are used by our planet to release some of the hot magma (molten or semi-molten rock) produced by the heat radiated by the inner core of the planet.
Iceland is a country with great geothermal resources reaching the surface under the form of hot water and steam (hot springs and geysers).
However, about a decade ago (2009), an Icelandic deep drilling project managed to unexpectedly break into magma 1.3 miles (2.1 km) below the surface.
Instead of abandoning the well, the team decided to pursue this opportunity and created a superheated geothermal power plant.
They’ve built a steel casing that was able to operate at a temperature exceeding 842°F or 450°C, and used this geothermal resource (hot magma) to produce clean energy.
This was more like a scientific experiment, but it proved that we can create magma-enhanced projects in the future that will help us to harness this renewable and clean source of power generated by the inner core of our planet.
Geothermal Energy Uses
In countries where the geothermal resource is available, this awesome, renewable and natural source of free energy provided by the inner core of the planet, is used to produce clean electricity in geothermal power plants, residential heating and cooling (geothermal heat pumps), and in agriculture (greenhouses).
1. Producing Clean Electricity in Geothermal Power Plants
The hot underground steam produced by the geothermal resource is captured by power plants and used to spin a turbine and produce electricity with the help of a massive generator.
The electricity produced this way is free and renewable, and is also part of the clean future that will follow.
2. Geothermal Energy for Residential Heating and Cooling
A good way of protecting the environment and lowering your energy bills is to use a geothermal heating and cooling system.
These systems use the geothermal resource (underground heat) to provide residential heating during the winter and residential cooling during the summer.
Such a system is called a geothermal heat pump system and relies on an underground loop system (a system of pipes buried underground) used to transfer heat in or our outside the house.
The earth surrounding the underground pipes always keeps a constant temperature between 50°F and 60°F (10°C and 15.5°C), and this heat is used to warm the house during the winter or is used to replace the hot air inside the house with colder air during the summer.
In contrast to an air-source heat pump, a geothermal heat pump will work fine during the coldest winters (when temperatures go below -4°F or -20°C) or the hottest summers (when the outside temperatures exceed 104°F or 40°C).
3. Using Geothermal Energy in Agriculture
The hot water coming from the underground is used in greenhouses to produce vegetables all year round.
The geothermal resource is used here to heat the greenhouse (hot water flows through heating pipes located at ground level).
To produce veggies all year round, the geothermal resource (hot steam) is used to generate clean electricity, which powers a few light bulbs inside the greenhouse used to replace the sunlight (when this resource is not available).
All plants in the greenhouse have plenty of light, water and heat, so the production of veggies can continue all year round.
Final conclusion
Geothermal energy is a natural and renewable resource of clean energy for mankind and is provided for free by the inner core of our planet.
Being a great source of natural power provided by the planet, it can help us to make the switch to clean energy much quicker.
