At the risk of destroying the basis of human civilisation Humanity must find ways and means for phasing out the use of fossil fuels before the end of the century. The EU aims at reaching that objective already for 2050.
Renewable energies – wind, sun, waves and tides – can do the job provided Humanity imposes substantial cuts on its energy consumption, which should be possible through a substantial increase of energy efficiency.
Renewable energies have benefited from rapid technological progress lowering production costs and making them almost competitive with fossil energies. But they continue to suffer from their inherent handicap of intermittence which can only be neutralised by big investments in energy storage.
The focus on energy efficiency and renewable energies has overshadowed the parallel effort to develop thermonuclear fusion for the generation of electricity which has been going on for more than 70 years
Copying the sun has made it possible to produce the hydrogen bomb. Why should it not alsobe possible to tame thermonuclear energy for the generation of electricity!
What appears simple in scientific terms poses huge engineering challenges. How to imitate the sun that contains the plasma by temperatures of 15 million degrees and very powerful gravitational pressures?
The basic answer lies in compressing deuterium and tritium hydrogen isotopes into helium through electromagnetism and much higher temperatures than in the sun,
For decades scientists have attempted to generate electricity this way.
In 1997 physicists at the Culham Centre for Fusion Energy have succeeded to generate 16 MW, but with an a input of 24 MW.
It is only in February 2014 that US scientists have, for the first time, been able to obtain a slightly positive yield.
The most ambitious international scientific programme for peaceful nuclear fusion ever launched, the “International Thermonuclear Experimental Reactor” (ITER) grouping USA, EU, Japan, Korea, India, China and Russia aims at generating fusion energy by 2028. It is extremely complex, due to diverging interests among the participants. In the fall of 2013 it was on the verge of breaking up when the US Senate refused to attribute additional financing after delays and cost- overruns, though the costs of €15 billion are only 10 times the cost of building one 500 MW off-shore wind park kin the North Sea.
Nobody is certain that by 2028 the gigantic machine will effectively generate more electricity than it consumes. But physicists will, in any case, be able to draw fertile lessons from their 15-year long cooperation.
And one day before the end of the century, they will most probably succeed.
When they do thermonuclear energy might become a crucial component of the future energy mix and contribute to the fight against climate change. The ultimate test will, however, not be the technical feasibility of a fusion reactor but the cost of generating thermonuclear electricity compared to much simpler and safer technologies.
Whatever the outcome of that research, thermonuclear fusion is unlikely to ever replace cost-effective technologies like wind, sun and waves.
Eberhard Rhein, Brussels, 16/5/2014Author : Eberhard Rhein