Fusion and Clean Energy
The big science news of the week (possibly the decade, if not the century) comes out of the Lawrence Livermore National Laboratory in California, where nuclear physicists at the National Ignition Facility (NIF) finally managed to “ignite” a pellet of the hydrogen isotopes deuterium and tritium, releasing 54% more energy than they had to shove through the 192 lasers they needed to set off the fusion reaction.
This is the process that stars — including our own sun — use to power the universe, and humans have been able to replicate this ever since the first hydrogen bomb (named “Mike” — an auspicious name, if I do say so myself) was detonated in 1952. No: our problem isn’t initiating a fusion reaction; it’s always been in controlling the process once it gets going. While an uncontrolled fusion reaction may be fine for stars or a bomb, it doesn’t work at all for something more prosaic, such as generating electrical power.
The promise of fusion power is surely seductive: unlimited energy from a minuscule amount of raw materials that are cheap and readily available, no carbon anywhere in the circuit, and nothing worse than water vapor coming out of the exhaust pipe. Oh yeah… sounds like just what humanity needs to fuel our unending need for more and more electricity!
We can in large part thank Albert Einstein for defining this elusive goal and setting the frantic search for it in motion. We all know his famous equation (E=MC2), but what the heck does it mean? Einstein, with a well-deserved touch of vanity, once said that only six scientists on earth had a clue about the equation’s ramifications, and while I am surely not one of them, there is one take-away that seems obvious, even to my simple-minded approach to reality.
Let’s start by defining the terms (since there are only three, this won’t take long):
“E” is energy
“M” refers to the mass involved
“C” is the speed of light.
Since the speed of light is a constant, it can essentially be ignored in this equation — all it does is take the mass and, since the speed of light is squared, add fifteen or so zeros to the calculated energy value (this means that a small amount of matter contains an enormous amount of energy). Click here for an earlier post on Kinetic Energy that discusses the effect that a constant has on how an equation works.
Anyway, since we can ignore the C2 because it doesn’t affect the underlying basis of how the formula works, what we end up with is E=M.
Energy equals mass.
This is a profound statement and directly affects our version of reality, including the origins of the universe (called the Big Bang — another all-too-familiar moniker, but we’ll save a discussion of God’s own kaBoom for a later post).
Hydrogen is the simplest atom there is, with a single proton and electron. Deuterium is nothing more than hydrogen that has an additional neutron, with tritium bringing an extra two neutrons to the party (refer to the graphic, above, for all the important reactants and products).
In simple terms, the fusion process takes one atom each of deuterium and tritium, and combines them into a single atom of helium. And in the process, a massive amount of energy is also produced (this is where all those extra zeros come into play), along with a loose neutron to help fuel the chain reaction. This is what they successfully did at the NIF.
Good news all around!
So does this mean that we can say goodbye to the massive carbon footprint that the burning of fossil fuels is generating in order to run our electric carving knives? Probably not, at least in the short term. Yes… we have finally succeeded in a net energy gain from the fusion process, but this was only what’s called a “bench-scale” test — a full-scale electrical power plant will require scaling the fusion process up to production levels, and that will take a whole bunch more technology (not to mention a sure-fire way to control it).
But the first step has been made, and just about everything I’ve read indicates that this is the biggest step — from here it’s just a matter of fine-tuning. It’s like the moon-shots of the 60s. The big technological advancements were getting the rocket into space in the first place, and then slipping it back through the atmosphere without barbecuing the astronauts in the process. Once those steps were figured out, the rest was just a matter of putting in the time…
So what’s the expected timing for a commercial fusion-powered electrical generating plant? Well, some bullish predictions (likely based more on hope and politics than real science) say we’ll be there in ten years. Others say that timeframe is overly optimistic, and that we can expect it to take twenty to thirty years to get our microwave ovens burning hydrogen to warm up our afternoon cup of Joe.
The ever-present doomsayers are quick to add at this point that climate change will have caused irreparable damage by then, so why bother?
Personally, I say boo-hiss to the storm crows. My considered opinion, for what little it’s worth, is that fusion is a path of research that absolutely has value, no matter the delayed timing (and the unfortunate personal reality that I’ll likely be either slobbering in my oatmeal by then, or six-feet under).
I hate to miss the celebration, but my grandkids will absolutely love it.
