What is geothermal energy? What's up Engineering Lovers, my name is Igor Felipe and today I want to talk about geothermal energy, a renewable energy source that has the potential to break our dependence on fossil fuels. Geothermal energy is heat that comes from the earth's subsurface.
It is contained in the rocks and fluids beneath the Earth's crust and can be found even in the Earth's hot molten rock, magma. The term geothermal is a portmanteau of "earth" and "heat" in Greek, and refers to the waste heat from molten rocks formed within the Earth's interior billions of years ago. Geothermal energy converts this natural heat that percolates deep underground into electricity.
To produce energy from geothermal energy, wells are dug in underground reservoirs nearly a mile deep to access steam and hot water, which in turn are used to drive turbines connected to electricity generators. There are three types of geothermal power plants, dry steam, flash and binary. Dr steam is the oldest form of geothermal technology and takes steam from the ground and channels it to be used to directly drive a turbine.
Flash plants use high-pressure hot water into cold, low- pressure water, which generates steam that turns a turbine. Binary plants pass hot water through a secondary liquid with a lower boiling point, which turns into steam to drive the turbine. Geothermal energy is used in more than 20 countries.
The United States is the largest producer of geothermal energy in the world and is home to the largest geothermal field. Known as “The Geysers” in California, the field extends over 117 square kilometers and comprises 22 plants, with an installed capacity of over 1. 5 Gigawatt.
The energy source is also predominant in Iceland, where it has been used since 1907. Describing itself as a “pioneer” of geothermal energy, the country produces 25% of all its energy from five geothermal plants and this is due to the 600 sources hot springs and 200 volcanoes in the country. Geothermal energy is a sustainable, renewable, carbon-free form of energy that provides a continuous, uninterrupted supply of heat that can be used for either residential heating systems or generating electricity.
Geothermal energy produces only one sixth of the CO2 produced by a natural gas plant and is not an intermittent source of energy like wind or solar. Its potential production can reach at least 35 Gigawatt and go up to 2 Terawatt. Humans have been harnessing geothermal energy for thousands of years.
Ancient Romans harnessed its powers to heat rooms, bathe and even treat skin conditions in Pompeii. Today, the oldest geothermal field in the world at Larderello in Tuscany in Italy still generates 10% of the total global geothermal energy supply. The World Energy Council estimates that geothermal energy has the potential to supply more than 8% of the world's electricity needs.
But it still has the status of being somewhat risky, accounting for just 0. 3 percent of installed renewable energy capacity globally, mainly due to seismic risk, extended trial phase and high upfront costs. On paper, geothermal energy sounds too good to be true.
Our planet will likely provide heat for millions of years, and unlike solar and wind, geothermal does not rely on unstable weather above ground. Geothermal brought Iceland out of economic ruin in the 1970s, allowing the country to stop expensive fossil fuel imports to generate its own electricity and heating. Today, nine out of ten Icelanders live in geothermal-heated homes.
This is due to the fact that Iceland is a volcanic island. But not all countries in the world have this characteristic, of having the heat of the earth just a few meters below your feet. In these cases, a little more depth is needed.
And when we need depth, we have to use an enhanced geothermal system called EGS, or enhanced geothermal systems, which is a type of deep geothermal system designed for less tectonically active regions. The EGS works by injecting water at high pressure into the bedrock of the Earth, where it absorbs heat from these “hot rocks”, before being recovered through a well drilled into the ground. Unlike conventional geothermal systems that collect heat from porous rocks where hot water naturally flows, EGS needs to artificially engineer this permeability.
The technology was first tested in New Mexico half a century ago, but has only made incremental gains these days. The EGS could, in theory, unlock countless heat reserves from almost anywhere in the world. The IEA, the International Energy Agency, estimates that the heat flowing into the first few kilometers of the earth's crust is equivalent to more than two million times the world's total energy consumption annually.
It is estimated that by 2050, each of Switzerland's 26 cantons is on the verge of running on partial geothermal energy, with the aim of phasing out nuclear energy, which currently supplies 40% of Switzerland's energy needs, and replacing fossil fuels. That's right, Switzerland, a country nestled in the Alps. According to the Swiss Federal Energy Office, which invested $60 million in geothermal projects in 2020, Switzerland already has the highest concentration of heat pumps per square kilometer in the world, supporting almost 15% of Swiss home heating systems.
and offices. But heat pumps are under the umbrella of “shallow” geothermal, which harnesses the heat emanating from the earth's crust between 1. 5 and 400 meters below ground.
“Deep” geothermal projects like the EGS, on the other hand, require drilling to depths of 5,000 meters. However, there are drawbacks to the power source. Despite the low production of CO2, geothermal has been associated with other emissions such as sulfur dioxide and hydrogen sulfide.
Geothermal plants have also been the cause of mini quakes in the areas where they operate and they also have a high initial cost of construction. And you, do you think that extracting heat from the ground and using it for heating and energy generation is an interesting way to obtain renewable energy? Leave it here in the comments.
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