One hour of sunlight has enough energy to power Earth's energy for the whole year. Why is sunlight so strong? It comes from a reaction called nuclear fusion.
This process, which has the potential to generate eternal energy, is considered to be the holiest of the energy industry, and several world's brightest thoughts will have to be developed.
In a conversation with the BBC at the end of 2016, the famous British physicist Stephen Hawking, who died in March last year, said that the technology that makes it possible to create nuclear fusion is the most promising for humanity.
"I would like to see the development of fusion energy"He answered and consulted with an idea that could change our society the most.
"Nuclear fusion would be a source of practical energy that would give us an inexhaustible amount of energy without polluting or causing global warming," he said.
Unlike traditional atomic energy produced by separating atoms – a process known as fission – this new energy source is formed by joining, that is by combining atoms.
More specifically, it combines hydrogen to produce helium, a reaction that releases huge amounts of energy, just as it happens in the Sun.
The idea is essentially to create "microelements" on Earth.
The race to reach the holy grail
Today it exists more than 25 private companies To this end, some of them were funded by some of the world's best-known entrepreneurs, such as Bill Gates (Microsoft), Jeff Bezos (Amazon) and Peter Thiel (PayPal).
The first private project was Tri-Alpha Energy (or TAE Technologies), based in California, the United States of America, which existed for two decades.
One of his most famous investors was Microsoft co-founder Paul Allen, who died in October last year.
The heavyweight in this sector is Commonwealth Fusion Systems, a momentum created by six professors from the prestigious Massachusetts Institute of Technology (MIT).
Although it was only formed a year ago, it is considered one of the most ambitious projects, as it wants to create a prototype of the reactor for 2025.
Gates and Bezos are two of those who finance this venture, along with other well-known entrepreneurs, such as Richard Branson and Michael Bloomberg.
Also some oil companies are starting to bet on the future without fossil fuels. According to the agency Bloomberg, Italian Eni SpA led a group that invested $ 50 million in March in Commonwealth Fusion Systems.
But some experts believe that the project, which is unlikely to be promoted, is not in the private sector.
It's a call International Thermonuclear Experimental Reactor (ITER, for its acronym in English), built in Cadarache, in the south of France, with a budget of 23,000 million US dollars.
In this scientific experiment, 35 countries took part in more than three decades ago.
Those responsible for assessing ITER will produce a comprehensive reactor by 2050.
Several countries are also developing their own initiatives. Last April, the BBC could access capacity in Anhui Province, China, where scientists from this country claim to be more advanced than their peers in the United States, the European Union (EU), Japan, South Korea and Brazil.
But all these projects face the same problem, which is strange that we do not achieve nuclear fusion.
It's a big challenge how to create more energy than to spend in the process.
Fusion is dependent on heat to very high temperatures in excess of one hundred million degrees. In this state, matter is called plasma.
Unlike the Sun, the Earth has no conditions for maintaining heat in plasma. In order to achieve this, plasma should be insulated from other materials. For that, something special ring-shaped camerasawith tokamakom.
Tokamak They use powerful magnets to create a magnetic field that preserves plasma isolation. The problem is that today these cameras consume more energy than they create.
The solution that companies like Commonwealth Fusion Systems warn is the use of better magnets, and the truth is that no one has been able to overcome this major obstacle.
Some, like Tesla's creator, Elon Musk, believe that investing in the creation of better solar panels and batteries to capture solar energyinstead of wasting money, trying to reproduce a star.
However, IP Group Plc, an investor, said to Bloomerg that even though fusion energy lasts longer than desired, many innovations created for this industry need to be developed they are very profitable.
"Research companies patented many of their creations, from software that simulates plasma burning to 150 million degrees Celsius to a new type of magnet that has medical applications," reports Bloomberg.
Meanwhile, we will have to wait to know if the desire for unlimited and clean energy can be achieved with Professor Hawking.