Our ability to create and harness fire has led to our remarkable proliferation and the development of our civilisations over the millennia. However, from burning wood to splitting the atom, our endless quest for energy has created some unwanted consequences for both the environment and the creatures living in it.
This is why fusion power is the holy grail of energy production. We’ve been talking about it since the 1950s and the world’s scientists have been working tirelessly on it, but are we any nearer to this goal?
There are lots of reasons to pursue fusion – fission power, also known as nuclear power, involves dangerous by-products and the threat of disaster; fossil fuels pollute the environment and grow ever more finite by the day and wind, solar and wave power may not be enough for everyone.
Fusion will neatly by-pass all of these problems and produce more power than we’ll know what to do with.
What is fusion?
Fusion is the same process as the one that goes on in the sun and all other stars. The nuclei of hydrogen and helium atoms fuse to make heavier ones – hydrogen becomes helium, for example – releasing energy as a by-product. Up to ten times as much energy is released through fusion than through fission, but there’s no radioactivity, no other forms of pollution and the raw materials are common and easily available.
So what’s the hold-up?
Despite their best efforts, scientists still haven’t reached the break-even energy point when fusing atoms. This is where there’s as much energy coming out of the reaction as there is going in. Obviously we want more coming out than goes in, but right now, we’re nowhere near this. However, there are three types of reactors and processes being developed and refined.
Magnetic confinement fusion
Rather than mechanical or laser compression, hugely powerful electromagnetic fields contain and confine a ball of superheated plasma. This plasma can be detected and monitored by specialist sensors developed by companies like Andor.com and once the plasma ball is hot and compressed enough, fusion occurs in it. This method has been used since the 1950s and often runs neck-and-neck with inertial confinement fusion as they head to the break-even point. It’s a case of making the process less expensive – both in energy and monetary terms – if this method is to deliver the results we want.
Inertial confinement fusion
This involves a pellet of hydrogen that’s compressed by lots of lasers around it. This compression generates heat and pressure and causes the hydrogen nuclei to fuse into helium nuclei, releasing a big burst of energy. At present it takes way more energy to operate the lasers than is gathered from the fusion, but there is a new laser that can emit 2 quadrillion Watts of power with each pulse, so this could be a breakthrough for the break-even point!
Magnetised target fusion
This is a crossover of magnetic and mechanical methods – superheated plasma is confined magnetically, then pistons compress it further, causing fusion. It’s a clever hybrid, but sadly it hasn’t come close to ICF or MCF yet and research progress seems to have stalled in recent years.
Don’t stop believin’
There are always pessimists who claim that fusion is permanently 30 years away, but they’re wrong. The decades of hard work have brought us closer to this break-even point, and many technical hitches have been solved along the way. We’re inching ever closer.