Monday, July 23, 2007

Limitless Clean Energy

The venerable Brit scientist and creator of the Gaia theory James Lovelock is a strong proponent of nuclear energy. He sees reactor power as the sole viable alternative to fossil fuel energy in existence today. Lovelock, however, also sees the best long-term hope for mankind in a developing form of nuclear energy, fusion reaction.

"Along with many other scientists throughout the world, I knew that nuclear fusion energy, the nuclear combustion of hydrogen, was the ultimate clean ad everlasting energy source, mainly because we knew that this was what empowered the sun and other stars. Most of us still thought that we were a long way from realizing fusion in practice. It just seemed impossible that the conditions inside the core of the sun, with temperatures over 100 million degrees, could be arranged here on Earth on a practical scale as part of a power station.

But in February 2005 the director of the Culham Science Centre, Professor Sir Christopher Llewellyn Smith, invited Sandy and me to visit and view their Tokomak reactor, and to learn about their recent experiences using it and the prospects for fusion energy. We were amazed and delighted to discover that their fusion reactor had proved itself by sustaining for two seconds a nuclear flame that burnt deuterium and tritium, isotopes of hydrogen, and generated sixteen megawatts of energy.

As a scientist I was intrigued by the thought that there in front of me was a large toroidal flask within which temperatures far above those of the hottest part of the sun's core had been sustained for a couple of seconds. The temperature of the burning mix of hydrogen isotopes was 150 million degrees.

The deuterium fuel used for fusion energy is unlimited in availability. It constitutes 0.016 per cent of water and is easy to extract [while the fusion reaction itself produces tritium].

The nuclear waste of a fusion reactor is the harmless non-radioactive gas helium, and there are no long-term radioactive wastes. The metal parts of the reactor become mildly radioactive as a consequence of the neutron flux, but this is a minor disposal problem.

Noting that France is about to build the next large thermonuclear reactor which will be producing power for that country's grid, Lovelock lamented the failure to back Kyoto: If Kyoto had been influenced more by the pragmatism of scientists and engineers and less by romantic idealism, we might soon have harvested fusion energy. As it is, even given good will, it may take twenty more years before it begins to heat our electric kettles or run our word processors.

Which brings us to Vancouver and General Fusion Inc. which has already lab tested its own hot-fusion device and is now raising capital to produce a prototype fusion reactor. General Fusion is developing a patent-pending technology, MTF fusion, which it hopes to turn into a prototype reactor by 2010. Let's hope it succeeds but, even then, it would probably take at least another decade before fusion power became a significant contributor to our power grid.

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