Sunday, 12 January 2014

Bountiful and Safe Energy - The Lure of Helium-3

We’re facing a lot of problems as a species: one of them is our ever-increasing need for energy, which is putting a huge amount of pressure on our environment. There’s no denying that we’re responsible for Climate Change, no matter what the politicians say - well, there is, as long as you choose to ignore the 9,135 scientists who are convinced our pollution is affecting the planet’s atmosphere, and listen to the solitary academic who says it’s nothing to do with us.

In our quest to find alternatives, we have those who still like to burn stuff, with shale gas being the latest exciting energy du jour among big companies and politicians, but definitely not among the general population. It’s ironic, for instance, that France has banned fracking in its territory, so French company Total is investing in the UK’s own fracking efforts.

But what are we to do? We’re constantly told that solar and wind technology aren't there yet (but frankly, if every roof had some panels and every garden had a wind turbine, I’m sure it would greatly alleviate our need to burn or frack anything, don’t you?), and nuclear power although highly effective (France derives over 75% of its electricity from it), is also fatally dangerous when things go wrong (Fukushima, anyone?)

In all the discussion, another form of non-polluting energy has popped up in recent years, Helium-3. What is it and could we ever use it to supply our gargantuan appetite for power?

What is Helium-3?

That's one big fusion reactor.
To say Helium-3 is uncommon would be an understatement. The nearest and biggest constantly running fusion generator that we know of, the sun, produces Helium by combining - or fusing - two Hydrogen atoms together. But the process isn’t perfect and one in every 10,000 comes out as Helium-3, a regular Helium atom which is missing a neutron. Despite this, it’s an extremely stable compound and if it has a half-life, it’s so long as to be irrelevant.

Closer to home, Helium-3 is as rare as it gets. It was originally seen as a waste-product from the creation of hydrogen bombs. These days, 15kg a year are recovered from decaying nuclear weapons. This is obviously not a sustainable means of production. It’s possible to create Helium-3 in other ways, but it’s not an easy process which is reflected in its price; although you used to be able to get a litre of Helium-3 for around US$150, current prices are closer to US$2,000-5,000. 
So it’s not something you’re going to find in any corner drug store.

Helium-3 is currently used for numerous diagnostic and security purposes, like greatly enhancing lung MRI imagery or as part of military equipment designed to check for nuclear cargo.

Extraterrestrial Activity

There's Helium-3 in them thar hills!
Our ozone layer filters out most radiation coming from the sun, and it is also believed to be responsible for deflecting any Helium-3 produced by our friendly neighbouring star away from us… but it does bombard our moon constantly. This discovery was made by analysing the rocks brought back from the Apollo missions (and some of you thought these missions were faked, tsk, tsk). In fact it’s estimated that there might be one million tonnes of Helium-3 on the moon. This may sound like a lot, but it’s still a pretty rare compound there as well: although Helium-4, the more traditional form of helium, can be found in 28 parts per million on the moon’s upper layer, Helium-3 is only there between 1 and 50 parts per billion, so it won't be as easy as picking up some lunar dust and bringing it back home.

On the contrary, it would be a huge undertaking, necessitating a base of operations and a factory of some sorts on the moon to make it feasible - which is why it’s very exciting that we've finally gone back to our natural satellite with the successful landing of the Chinese robotic rover Yutu (Jade Rabbit) as it could be a first step to this becoming a reality.

Fission, Meet Fusion

An experimental fusion reactor.
But why would we want to go to the extraordinary expense of starting any industry on another world? Because the potentials benefits are huge.

It’s estimated that 25 tons - a single payload for the now defunct Nasa space shuttle - could power the entire USA for a year. The entire lunar reserves could potentially power our planet for the next 5-10,000 years. Nothing to be sniffed at.

But how could we make use of Helium-3? Through nuclear fusion.

Currently, our nuclear reactors are fission-based, which means they take a large atom, like Uranium, and break it, releasing huge amounts of energy, but also lots of lethal radiation and hazardous waste which needs to be stored somewhere.

Our current experimental fusion reactors work by fusing two smaller elements, like Tritium and Deuterium, to create Helium, lots of energy, no waste, but also Neutron radiation, which is far from good.

The idea behind Helium-3 is that when fused with Deuterium, the only by-product is again Helium, no waste, but this time, just one loose high-energy Proton (harnessing this proton will produce the electricity we crave) 

Sadly, even though protons are the most abundant type of particle in deep space, it’s been recently found to be much more damaging than expected to DNA, the building blocks of life, so there’s really no such thing as a free and safe lunch.

Is this the key to bountiful energy in the future?

Well, I’m not entirely convinced. The initial expense will be tremendous, and once the compound is processed, returned to Earth and placed in a fusion reactor, we’re looking at a pretty big bill to pay back for all that original investment, so don’t expect cheaper prices for us consumers any time soon, but it will alleviate our obsession to pump carbon dioxide into the atmosphere, so that’s a big plus and failing a more homegrown solution, could be a good reason to check it out.

Moon Base Alpha, here we come. Maybe.

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