by Jimmy Nightingale

Created on: February 18, 2011   Last Updated: February 21, 2011

Fusion power, or more accurately 'nuclear fusion' is the holy grail of power generation.  Or as nuclear physicist Dr Barry Green referred to it in a talk in October 2009, nuclear fusion is 'the philosopher's stone of energy'.  It is the technological advance much touted by climate change sceptics as one of the main reasons why a carbon tax or cap and trade mechanism or transition away from fossil fuels is not necessary.  The argument goes that technological advances, in say the realm of nuclear fusion, though it could come from any of the other range of alternate technologies, will provide baseload power generation at a cheap enough cost to obviate the need for fossil fuels at some stage in the not too distant future.

The idea of cheap, clean and almost limitless energy does sound appealing.  So what is nuclear fusion?

In simple terms, nuclear fusion is a thermonuclear reaction where two nucleii join to form a larger nucleus.  This process gives off energy.  If you look up at the sun, and only do this if you are wearing heavy duty sunglasses (and even then, glance off to one side and just look at it with your peripheral vision), it is an example of nuclear fusion.  Better still, look up at the dazzling display of stars at night.  Nuclear fusion is the energy souce which causes stars to shine.  When nucleii fuse, the form a nucleus with slightly less mass.  This difference in mass is released as energy in terms of Einstein's famous mass-energy equivalence formula E = mc².

So far so good.  But no.  As with anything that sounds too good to be true, nuclear fusion is only good 'in theory'.  To date, and ignoring the unsupported claims of breakthroughs in places like North Korea and Iran, in theory it remains.  In order for fusion to be harnessed for power generation, we essentially need to be able to contain the fury of a hydrogen bomb exploding (another example of nuclear fusion).  William Parkins, a physicist who worked on the Manhattan Project wrote a paper that was published in the prestigious journal Science in 2006 arguing that nuclear fusion would never be a practical source for electricity generation.  This is despite some four decades of research and around $20 billion in research spending.

With nuclear fusion, the devil lies in the detail.  The most promising developments in nuclear fusion revolve what is know as the deuterium-tritrium reaction, or the D-T fuel cycle. 

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