Nuclear fusion is the future

By Roger Highfield

James Hansen Photo: PA

'It's time to stop waffling so much and say that the evidence is pretty strong that the greenhouse effect is here." With that warning to the US Congress in June 1988, the Nasa climatologist James Hansen focused the minds of politicians on a danger that, until then, many of them had treated with scepticism.


A few days later came the first international conference to discuss man's impact on the Earth's climate, in Toronto, to which I had been packed off by The Daily Telegraph's then editor. I watched as scientists tried to persuade government representatives, legal experts, economists and industrialists that the time had come to take the threat seriously.
Two decades later, the waffling goes on. Over the past few days, about 15,000 delegates have expended vast amounts of carbon dioxide to attend the giant climate-change jamboree in Copenhagen. Hansen himself says that any agreement likely to emerge will be so deeply flawed that it would be better to start again from scratch.
Yet at a conference event I am chairing on behalf of the EU, to discuss research on low-carbon technologies, we will be hearing about a process that could allow us to escape the whole carbon trap. Prof Sir David King, a former chief scientist for the government, now of Oxford University, will remind us that the most radical solution to the underlying problem (and yes, climate-change deniers, there is one), remains the same as two decades ago: nuclear fusion.
Sceptics joke that this is the fuel of the future – and always will be. Commercial fusion, they gleefully point out, is as far away now as it was in Toronto, and as it was half a century ago, when Sir John Cockcroft, one of the great nuclear pioneers, began an article in New Scientist with the words: "It has long been the ambition of scientists to emulate the Sun."
Fusion is the process by which the Sun, and other stars, transmute matter, transforming hydrogen into helium to release colossal amounts of energy. The fused nuclei are a fraction lighter than their atomic ingredients, so – according to Einstein's famous equation E = mc² – that tiny loss of mass results in a colossal release of energy. Harness that release in an efficient way, and the world's energy needs are solved: near-infinite power, almost no harmful by-products.
An international consortium known as ITER ("the way" in Latin), is about to start building a prototype fusion reactor in Cadarache, France, at a cost of £6 billion. Critics argue that given the difficulties involved, that sum could be better spent on solar power, using the fusion reactor that nature has already given us. The challenge is indeed vast: in the core of the Sun, huge gravitational pressure allows fusion to take place at about 15 million C. In man-made devices, the temperatures need to be above 150 million C, a temperature that no material on Earth could withstand.
The solution came from the Soviet Union in the late 1950s: a doughnut-shaped device called a tokamak. This uses intense magnetic fields to hold the reacting plasma away from the furnace's walls. Prof Steven Cowley, director of the Culham Centre for Fusion Energy, home of one of the leading fusion test plants, says the biggest hurdle lies in creating the technology needed to use it, such as developing walls that can withstand unbelievable pummelling by subatomic particles and cutting the cost of the superconducting magnets that will confine plasma 10 times the temperature of the sun's core.
At America's Tokamak Fusion Test Reactor in Princeton, the Joint European Torus in Culham, and the JT-60 in Japan, scientists have come tantalisingly close to the break-even point at which the device releases as much energy as is required to get the fusion going. Such is the cost of constructing a proper prototype, however, that the ITER Council includes all the world's leading powers: China, the EU, India, Japan, Korea, Russia and the United States. The research they are funding could transform the lives of billions of people, and of future generations.
Will it work? Although the plan to put the experimental fusion plant into operation by 2018 looks unrealistic, and risks a costly overrun, we should, by February, have a date for it to burst into action. ITER's objective is to release 10 times as much energy as is used to initiate the reaction: if 50 MW is put in, ITER will generate 500 MW.
The hope is that ITER will pave the way for a demonstration power plant in the 2030s, which will feed energy into the grid by the middle of this century. Meanwhile, research will continue in other installations worldwide. If the gamble pays off, the last quarter of this century will see the end of the age of carbon, and usher in a future of almost limitless potential.

from: telegraph.co.uk