Fusion breakthrough a magic bullet for energy crisis ?  

The NZ Herald has an enthusiastic article on a form of "fusion (known as Aneutronic fusion) - Fusion breakthrough a magic bullet for energy crisis ?.

A Florida based research team, however, may have found a solution to the world's energy woes that could provide a clean and near limitless supply of energy in as little as a decade.

Global energy production and consumption is a complex beast and many nations remain heavily reliant on a lethal mix of oil and coal, both of which are finite, and have huge impacts on the environment.

While there is much conjecture on just how long oil and coal reserves will last, the stark reality is that they will both eventually run out.

In the 1950s, many thought atomic energy would allow humanity to dodge the energy crisis, with newly nuclear fission reactors providing an affordable and near limitless supply of energy.

More recently however, incidents such as the Chernobyl meltdown, the growing pile of incredibly toxic nuclear waste and the spectre of rogue nations manufacturing weapons- grade plutonium have taken the shine off nuclear fission.

With the energy requirements of developed nations continuing to grow, and developing nations gaining a serious appetite for energy consumption, demand will soon outstrip supply, and many predict that massive economic and social impacts are probable.

Thankfully, a new type of nuclear fusion energy generation technology holds the potential to provide a cheap and clean source of energy without toxic radioactive waste or the environmental impacts of oil or coal.

Unlike nuclear fission, where the nucleus of an atom is split to release energy, nuclear fusion uses the same process as our sun and works by fusing atoms together to release of large amounts of energy.

Nuclear fusion generates energy leaving little to nothing in the way of by-products, and uses fuels that are plentiful but far less dangerous than the uranium used with conventional nuclear fission reactors.

Whilst physicists have generated nuclear fusion reactions, doing has involved creating the earthbound equivalent of a small star, which in turn has required ultra-strong magnetic fields to contain superheated gases many times hotter than the surface of the sun.

Unfortunately, doing so has tended to consume almost as much energy as was being generated by the fusion reaction. Creating a nuclear fusion reactor that is commercially viable and able to output surplus energy beyond sustaining its own reaction was thought to be at least 20-30 years away.

Thanks to work being done by a group of physicists at the University of Florida, all things fusion related could however be set to change in as little as a decade.

Where conventional fission reactors use uranium which can be refined to make nuclear weapons, the University of Florida's concept uses hydrogen and an isotope of boron called Boron 11, both of which are abundant on earth and can't be used to make atomic weapons.

When fusion reactions occur in the heart of a star such as our sun, atoms are subject to intense heat and pressure which stops the atoms from repelling each other, allowing them to fuse.

To date, experimental fusion projects have largely been focused on generating intense heat so they can fuse, and containing the super hot gases from this reaction consumes most if not all of the energy being produced by the fusion reaction.

The University of Florida have taken a different tack, by putting hydrogen and boron fuel into an accelerator that fires them towards each other at incredibly high velocities. When the hydrogen and boron 11 atoms smash into each other, they fuse, producing fast moving helium nuclei whose motion is converted into electricity.

This new process is clean, highly efficient and most important of all, simple. The output of the new reactor is electricity with its by-product being the same helium gas used to make voices squeaky and party balloons float, so there's no toxic radioactive waste to dispose of.

Initial calculations also show that this new type of fusion generation could produce clean electricity at similar levels but far more cheaply than oil or coal.

In the US, a different approach known as inertial fusion is being perused at the National Ignition Facility (NIF) in California and the Z-Machine in New Mexico. If Iter is like a conventional power station burning fuel for days or weeks at a time, the inertial projects share more in common with the combustion engine.

NIF blasts tiny pellets of deuterium-tritium fuel with a single 500-trillion-watt laser beam. This is a big number; about 1,000 times the power consumption of the United States.

This gargantuan short-lived laser pulse causes the fuel pellet to collapse and detonate, producing a mini-star for a fraction of a second.

The Z-machine takes a different approach, channelling half a trillion watts through a spider's web of hair-thin wires surrounding the fuel pellet. The result is much the same: a big crunch known as a Z-pinch and the birth of a star.

If a steady stream of mini-stars can be created, then a power station could be constructed. The Z-machine has already achieved fusion in a test run, and NIF hopes to follow in its footsteps in 2010. The challenge will then be to smooth the rough edges of the technology in order to mass-produce economically viable, reliable power stations.

This is no mean feat, but there seems to be no fundamental reason to doubt that it is possible.

When fusion is mentioned, a common reaction in some circles is to say, "It's always 30 years away, so let's not invest too heavily".

In fact, the fusion engineers of 2009 are speaking of building the final generation of experimental reactors now.

If they succeed, Iter and her sisters should be capable of putting electricity on to the grid some time in the early 2030s. This long-term and final solution to the energy crisis depends of course on sustained public investment at current or preferably significantly increased levels.

This is a challenge that I believe we must confront now, and not tomorrow. At some point in the future, we will generate our power by nuclear fusion; there is simply no other way to deliver the trillions of watts needed to make life comfortable for all the citizens of our planet.

To this statement nobody objects. The question is therefore not "if" but "when", and it is my view that the "30 years away" argument simply doesn't wash.

John F Kennedy used to tell a story about a French general who asked his gardener to plant a tree. "What's the rush?" replied the gardener. "It will take 30 years to grow."

The general looked him in the eye, and said in an urgent tone: "Thirty years? Then you had better plant it immediately."