Harnessing the Sun

The Holy Grail of nuclear fusion may soon be within reach

The world’s insatiable demand for energy is rapidly altering the economics of its production. As the price of crude oil rises, exploration in inhospitable seas and frozen wastes becomes profitable. Gas, too, becomes more valuable as an alternative, and the breakneck rise in production has transformed the economies of countries such as Qatar and Bolivia. But accelerating demand, especially from China and India, is also driving up carbon emissions. All this has therefore spurred the search for new sources. Research into ways of producing hydrogen fuel cells for cars has already come close to resolving the main drawbacks. But for basic electricity generation, scientists have long dreamed about harnessing an entirely new and virtually limitless energy source: nuclear fusion, the process that drives the Sun.
The physics have been understood for at least two generations. When two types of hydrogen atom, deuterium and tritium, are fused to make helium, they release vast quantities of energy. And since deuterium can be produced in almost limitless amounts from seawater, while tritium is a byproduct of the reactor itself, the potential fuel is available everywhere. Moreover, unlike nuclear fission, atomic fusion produces almost no radioactive waste, with reactors giving off little more that a hospital X-ray machine. Until now, however, there has been an almost insuperable drawback: fusion takes place only at temperatures of tens of millions of degrees. Not only was the technology to produce such heat rudimentary, but the energy needed to do so was greater than the energy released by the fusion process.

But this Holy Grail may soon be within reach. Scientists have developed lasers that generate the required extreme temperatures, and a prototype for Hiper (high energy laser fusion research) may be built in Britain in the next five years. A team of British scientists has been given European Union approval, and a civilian programme, building on work done by a US military laboratory, could develop a network of fusion generators that may provide an alternative source to conventional energy supplies.

The Times (London)