When we think of clean energy we usually discuss wind, solar, hydro and geothermal.
Hydro and geothermal are extremely good sources of reliable energy, but they are of course location specific, meaning you either have access to it or you don’t.
Another type of clean energy that has enormous potential is wave, or ocean energy. However, as of writing, this potential is yet to be cost effectively harnessed. Although we are making great strides in this field, we can hardly include it as an energy game changer until we see much more substantial progress.
That leaves us with solar and wind energy. Solar can be split into several types, most notably photovoltaic solar energy and solar hot water. Aside from issues with efficiency, wind and solar share a common problem – availability. We can only generate power when the sun is shining or the wind is blowing, and that means that we cannot rely on them as a primary power source. Efficiency is constantly being improved in both areas, and breakthroughs in energy storage mean that both systems are on their way to usurping the dominance of fossil fuels. That day is still a long way off, so for now at least, it seems fossil fuels are in complete control.
But what about atomic power? What happened to the promise of clean, inexpensive and abundant energy that so many households in the 50s were seduced by?
While some may argue that nuclear fission is vastly cleaner than the burning of fossil fuels, incidents like Chernobyl and Fukushima are still very fresh in our minds. Indeed it is Fukushima that led to a dramatic shift in German energy policy which has set them on a path to completely phase out its nuclear reactors by 2022. Germany is certainly not alone in this decision, and with phasing out being the rule rather than the exception, we appear to be at the end of the era of atomic power.
This is where another player steps in – nuclear fusion. Nuclear fission generates energy by the splitting of large and unstable isotopes (atoms with the same number of protons but different number of neutrons) into smaller ones, which in turn go on to create a chain reaction. Fusion occurs when 2 light isotopes are combined to create a single heavier isotope, and a much vaster amount of energy. The major disadvantages of fission are the byproduct of radioactive waste, and the potential for the failure of containment of the chain reaction, such as happened in Chernobyl.
The reason it has taken us so long to turn to fusion is the extremely high temperatures and pressures involved. In order to successfully create a fusion reactor we need to heat and pressurize plasma to equal those found on the surface of the sun. Perhaps surprisingly, it is not achieving this heat that is the challenge, it is sustaining it.
Now it seems that feat is within our grasp. Scientists from 35 nations are currently building the International Thermonuclear Experimental Reactor (Iter) in Southern France. This vast and extremely complex undertaking is currently at around 50 percent completion, putting the team on course for their initial firing, when they will generate ‘first plasma’. This plasma will reach 150,000,000?C, which is ten times hotter than the sun, and then be contained in giant magnets that are cooled to -269?C. Should this test be successful, the team anticipate that we could see our first fusion reactors coming online by 2040.
Director general of ITER, Dr Bernard Bigot talked with no uncertainty about fusion being a viable energy source that will replace fossil fuels, going on to say that “[p]roviding clean, abundant, safe, economic energy will be a miracle for our planet.” This may sound very familiar to those that were sold on the idea of nuclear fission, but we will soon see whether the new atomic age can deliver where the previous one failed.
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