Nuclear fusion shows promise as a source of clean, abundant energy that could power the world. Now fusion researchers at a national laboratory in the US have achieved something that physicists have been working towards for decades, a process known as “ignition”.
This step involves extracting more energy from fusion reactions than is supplied by a laser.
But how close are we to generating energy from fusion that can power people’s homes? While ignition is just a proof of principle and the first step in a very long process, other developments are also in the works and together they could spark new enthusiasm for the practical implementation of fusion.
First of all, it’s important to recognize that the latest result is indeed a real milestone.
Researchers at the National Ignition Facility (NIF) in California fired the world’s largest laser at a hydrogen-filled capsule, causing it to implode and triggering fusion reactions that mimic what happens in the sun.
The fusion energy released by the implosion was greater than that contributed by the laser, a colossal feat considering that just a few years ago the NIF laser could only extract about a thousandth of the energy contributed.
However, the laser had to be supplied with around 10,000 times more energy than the light energy it generated.
It can only be run once a day. And each destination is so exquisitely designed that each costs thousands of dollars.
To make a reactor for a working power plant you would need a laser that produces light energy at a much higher efficiency (tens of percent) and successfully fires at targets ten times a second, each target costing a few pence or so.
In addition, each laser shot would have to emit many times – maybe 100 times – more energy than was supplied.
In fact, very little research has been done on fusion “reactors,” in which neutrons from the reactions would help power a steam turbine to produce electricity. But there are other reasons for hope.
First, while NIF took more than a decade to achieve ignition, scientists have independently developed new lasers over the same period.
These use electronic devices called diodes to transfer energy to the laser and are very, very efficient, converting a good chunk of the electricity from the grid into laser light.
Prototype versions of such lasers have been shown to operate at speeds of 10 times per second, which would be required for them to be useful in fusion.
These lasers are not yet of the size needed for fusion, but the technology is proven and the UK is at the forefront of this type of research.
Also, the fusion approach used by NIF scientists has some known, inherent inefficiencies, and there are several other ideas that could be much more effective.
No one is absolutely sure these other ideas would work as they have their own unique problems and have never been tried on a large scale.
Doing this would require hundreds of millions of dollars in investment for each of them, with no guarantee of success (otherwise it wouldn’t be research).
But now a fresh breeze is blowing: the private sector.
Various very long-term funds have started investing in new start-up companies that are promoting fusion as a commercially viable energy source.
Given that it was private industry that revolutionized the electric car market (and the rocket industry), perhaps this sector of the merger could also provide the “kick” it needs.
Private companies can work much faster than governments and respond quickly to new ideas when needed.
Estimates of total private financing in this sector are now in excess of $2 billion (approximately Rs. 16,500 crore) peanuts compared to the $2 trillion (approximately Rs. 1.65 billion) in revenue generated by the oil and gas industry generated every year.
There is still plenty of room in the market for high risk, high payout players.
The latest results show that the basic research works: the laws of physics do not prevent us from achieving the goal of unlimited clean energy from fusion.
The problems are technical and economic. While fusion may still be too far away to solve problems on a decade or two timescale, recent progress will at least fuel enthusiasm for solving one of humanity’s great challenges.
