According to the Daily Mail, a startup from the Massachusetts Institute of Technology plans to develop a new "wave drill" (English name: wave drill), or wave drill for short.
The company claims that the drill can penetrate to a depth of 20 kilometers underground, so that humans can use "inexhaustible and inexhaustible" geothermal energy, and more importantly, these energy sources are clean energy.
Does that mean that even without controlled fusion technology, humanity will trigger a new energy revolution?
Wave drill bit technology
The energy problem has been plaguing us since the birth of human civilization, and the essence of every industrial revolution is: the energy revolution.
The first industrial revolution was ostensibly the use of steam engines, but in fact humanity began to use coal extensively;
The second industrial revolution was the widespread use of oil and electricity.
Due to the background of global warming, in recent years, human beings have begun to universally pursue clean energy.
For Earth, 99% of the main source of energy comes from the Sun. Coal and oil, for example, are fossil fuels that existed tens of millions or even hundreds of millions of years ago in the form of plants and animals that were largely backed by the food chain.
Regardless of the type of food chain, it mainly relies on the photosynthesis of plants as the main source of energy, and this photosynthesis still relies on solar radiation to work. Solar radiation, on the other hand, comes mainly from the nuclear fusion reactions of the Sun's core.
Therefore, many people are convinced that the ultimate solution for the future of energy is controlled nuclear fusion. Many countries and regions around the world have invested heavily in this regard, but there is still a long way to go before controlled nuclear fusion is fully rolled out.
"Quaise Energy" took a different approach, hoping to extract energy from geothermal heat. This is because 4.6 billion years ago, during the formation of the Earth, because the nebula material that makes up the Earth gathered together under the action of gravity, the potential energy was converted into internal energy and stored in the Earth's interior for many years, making the temperature inside the Earth extremely high.
Therefore, geothermal heat can be said to be a great gift from the earth to mankind, but this gift is not so easy to enjoy. If you want to develop geothermal resources, you are essentially drilling the earth's interior and then building a drilling platform that can continuously obtain geothermal heat.
For human beings' existing technology, the depth of drilling is really limited. To date, the deepest drilled to date was the Odoptu OP-11 well at a depth of 12,345 meters, followed by the Ashokhin oil well with a depth of 12,289 meters, and the Kola ultra-deep borehole at a depth of 12,289 meters.
It is not difficult to find that the depth of these wells is maintained between 12,000 meters and 12,500 meters, which is more than 6,000 times different from the radius of the Earth of 6371 kilometers, which is equivalent to just digging a very shallow layer. So the question is, why can we only dig such a deep?
Mainly because of equipment problems. Previously, in the process of drilling, when the depth reached more than 7000 meters, there was often a loss of drill bit overheating, a drill bit falling off or a broken drill pipe.
Therefore, drilling to about 12,000 meters is already the limit. Therefore, human beings do not regard geothermal heat as one of the important energy sources in the future.
However, Quaise Energy recently raised a $40 million funding to make a "wave drill" on their drawings.
The company claims that this drilling system is different from before, it does not require a complex mechanical drill bit, but after drilling into the bedrock, it uses a cyclotron to emit high-power millimeter waves downwards, which can heat the rock in front of the drill bit to melt and evaporate, somewhat similar to the principle of high-energy lasers.
Since the drill bit is not in contact with the rock during the whole process, it is more conducive to heat dissipation, and the drill bit and drill pipe are not so easy to damage or break.
How is electricity generated?
The company plans to drill to a depth of 20 kilometers, about 7,700 meters deeper than previously recorded. When Korra's ultra-deep drilling reached about 12,000 meters, the temperature had reached between 300-400 degrees.
If the hole is drilled to 20 kilometers, the temperature must be at least 400 degrees. The company's research found that the temperature here should be around 480 degrees. As for how to use the energy here, in fact, the use of traditional power plants similar "boiling water" mode can be, 480 degrees of boiling water is still a breeze, which can achieve the use of geothermal heat.
The company also came up with a detailed planning timeline:
In 2024, the first rig, a full-scale hybrid rig that combines traditional mechanical rotary drilling and millimeter wave drilling, will be completed.
In 2026, the first super-thermally enhanced geothermal system will be built and 100 megawatts of thermal energy will be obtained from a handful of wells.
In 2028, a traditional fossil fuel power plant will be converted into a geothermal steam power plant.
The company also claims that this geothermal power generation is not only a clean energy source, but also impossible for humans to run out, which can be said to be the ultimate solution to energy shortages. So the question is, is geothermal really inexhaustible for humans?
Geothermal resources
The total amount of geothermal heat of the earth is basically about 10% of its own gravitational combined energy, which can probably reach the order of 10 ^31 joules, which is still not a decay situation, if humans use it uncontrollably, it is no problem to use it for 60 billion years, and the sun is about 6-7 billion years later, so it is not used up until the destruction of the solar system, and the geothermal heat cannot be used up. So in a way, geothermal heat is infinite for humans.
According to the study, geothermal resources within 10 kilometers of the outermost layer of the Earth's crust can reach 125.4 billion coke heat, which is equivalent to 2,000 times the total heat generation of coal produced in the world and 170 million times the total coal reserves.
To add, geothermal heat, like oil, is unevenly distributed. This time to dig is 20 kilometers deep, and it has not yet been fully determined what the total amount of geothermal resources 10 kilometers further down is, but because it is deeper and the temperature is higher, it will only be more, not less. This is not counting the situation of digging deeper after the future development of technology.
According to a study by the Massachusetts Institute of Technology, they found that the geothermal resources that technology can extract at this stage exceed 2 * 10 ^ 24 joules, which can be used by humans for at least thousands of years.
Not only that, but these geothermal resources are renewable. This is because the extracted geothermal heat is low relative to the total heat of the Earth's interior, and deeper geothermal heat is replenished. So, theoretically, humans could continue to use geothermal heat at the depths of the Earth without having to fully drill into the core of the earth.
The total amount of geothermal heat is enough for human use for more than 60 billion years, and decay is also providing additional geothermal resources. Therefore, geothermal heat is theoretically comparable to the existence of controlled nuclear fusion technology. However, it is also the same as controllable nuclear fusion technology, the technical threshold is very high, and there is still a long way to go before it is truly commercialized.