Can you imagine a day when your air conditioner will work on energy drawn from the depths of the earth? A new development by an American company may allow easier, safer, and cheaper drilling than ever before into the heart of our planet
By Yonatan Sher, Zveta - news agency for science and the environment
In recent days it has become difficult to survive outside the air conditioners, with the fireball in the sky boiling the air. A new development offers a cheaper and faster way than before to fight fire with fire: the Earth's core is as hot as the sun beating down above us, but it is precisely the one that may help us all turn on the air conditioning.
Using underground heat to generate steam and drive turbines enables the production of clean energy, throughout the hours of the day. The production of energy with low greenhouse gas emissions, such as nuclear energy or renewable energy, has become critical due to the increase in global temperature as part of the climate crisis, which many of us only remember on particularly hot days like these. Unlike other types of renewable energy, such as solar or wind, which depends on the time of day and the weather - the heat of the Earth's core is a constant, reliable and continuous source of energy that can satisfy the energy needs of all of humanity, at any hour and in any season, for millions of years.
However, until recently, the drilling process that could be used to reach sources of geothermal energy was expensive, slow, and terribly complicated: the deepest man-made pit that exists on Earth today is 12.2 kilometers deep, and it took 20 years to complete.
A new development by the American company Quaise makes use of technology that has so far been applied mainly in the study of atomic energy (Plasma heating for nuclear fusion reactors), seeks to resolve the described problems. That is to say, to allow drilling to a depth of 20-10 kilometers, in almost any point on Earth, in a procedure that may take only 100 days, and whose cost is up to 10 times less. will vaporize the rocks on the long way to the face of the earth. Sound like science fiction?
warm and deep
To understand the potential of using geothermal energy, you don't have to sail in your imagination, but in the ocean. In the second half of the last century, a small island country began to make use of the underground and boiling water that is abundant in its territory, for the purposes of heating and energy production: Iceland, which has since reached a state where About 30 percent of its electricity is produced in this way. Even in the United States, in countries like California and Nevada, geothermal electricity is already being used. Ormat Technologies International, founded by Israelis, There is a production capacity of over 700 megawatts of electricity in the USA And she is also active on the subject in countries such as Kenya, Indonesia and Guatemala. If so, the industry already exists, and it has been done Diverse uses; What is the uniqueness of the development in question?
"Geothermal energy production pays off mainly when the hot areas are close to the surface - up to a few kilometers - then you don't have to drill ten or twenty kilometers to reach them," explains Dr. Daniel Mader, a researcher and scientific consultant and one of the founders of the SP Interface company. According to Medar, these are usually areas that are located near deep geological fractures - such as those located between the tectonic plates that make up the earth's crust - areas that are frequent in earthquakes and volcanoes. Iceland is a good example of the principle in question: the island is located on the fault between the North American and Eurasian tectonic plates and A significant volcanic eruption occurs once every 5 years on average. "These are the places where the hot areas are closer to the surface, so you need to drill less to produce energy. About 40 percent of the cost of building a geothermal facility comes from the drilling. The deeper you drill, the more complicated, longer and more expensive the process becomes," Medar testifies.
In contrast to these unique places, in most areas of the earth, in order to reach the layers required to produce geothermal energy in large quantities - it is necessary to dig to a depth of 20-10 kilometers. at these depths, Conventional drills wear out quickly Due to the hot and hard rock with which they come in contact. According to Carlos Arca, the CEO of the Quaise company that develops the gyrotron - almost 90 percent of the time drilling at a depth of more than 5 kilometers is wasted on procedures of raising a worn drill bit from the bottom of the drill hole, replacing it and lowering it back down to the bottom of the hole. On the other hand, the gyrotron does not wear out: it is not in contact with the rock but produces radiation that vaporizes the rock itself, and therefore can work continuously. Reducing these times and costs may lower the price of geothermal electricity to a price as cheap as that of solar electricity (which originates from the sun's radiation).
In addition, drilling with conventional means requires the injection of special mud that maintains the pressure inside the pit, preventing it from collapsing. But at the high temperatures involved in geothermal drilling, the mud loses its thickness and therefore its effectiveness. According to the Quaise company, the gyrotron also solves the described problem: the device emits radiation that vaporizes the rock in the center, but the sides remain stable.
The danger: earthquakes
Not only economic or technical problems are solved with the help of the gyrotron. In 2006 The city of Basel in Switzerland suffered an earthquake with a magnitude of 3.4 on the Richter scale due to an experiment in the production of geothermal energy, and in 2013 another earthquake hit the city of St. Gallen in the country due to a similar project. The same was true in South Korea in 2017, when an earthquake with a magnitude of 5.5 on the Richter scale injured dozens and caused hundreds of millions of dollars in damage due to Activity of a geothermal energy plant. The common cause of these earthquakes is the use of high-pressure fluids in drilling near existing geological fractures. Therefore, while the use of geothermal energy is associated with the danger of earthquakes - the new technology seeks to solve this disturbing problem as well.
"Some say that the main reason for earthquakes as a result of drilling is that in the first place they try to drill in areas where there are tectonic fractures because there the hot areas are closer to the surface. These places are prone to disasters in the whole matter of earthquakes", explains Madar. ” Although this still needs to be proven, the company claims that its technology makes it possible to drill deeply even in places where the risks of earthquakes are lower. This may be the solution to the problem."
Where are you drilling next?
So far, the company, which raised $40 million and started with development in MIT laboratories, has drilled holes only about 90 centimeters deep, and only in the laboratory. At the same time, a kilometer-deep pilot project, near the Newberry volcano in the United States, is already planned for the next few years, given the successful operation of the technology outside the laboratory.
The ability to drill almost anywhere includes additional advantages, such as the possibility of using an existing infrastructure of steam turbines to produce electricity and electricity transmission that currently belong to polluting power plants. Until 2028, the company plans to restart the first power plant, which was based on fossil fuels (coal, oil or natural gas), on a new basis of geothermal energy.
Is this unique development, which enables the production of inexhaustible energy, almost anywhere in the world, using existing infrastructures - the long-awaited solution to carbon emissions, which are exacerbating the climate crisis? "If everything will be as rosy as they say, then in principle yes," says Madar, but also qualifies. "At the same time, we must also invest in other green technologies. We are not sure for sure that the development will be successful, nor do we have time to waste. We must act by all possible means to reduce our carbon emissions from now on."
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