What if there was an inexhaustible form of carbon-free, clean energy that was available 24/7, rain or shine, and was no larger than existing fossil fuel plants? Is that something you might be interested in? What I'm talking about is fusion energy. The easy joke is that fusion energy is the power source of the future and always will be, but what are its real prospects?. This is not a subject of unbiased speculation for me, I've devoted the last 35 years of my career to harnessing this tricky power source. So what have we been up to and where are we going?
Let's start at the beginning. Fusion is a form of nuclear energy that powers the sun and the stars and produces the elements of the periodic table by combing light elements into heavier ones. The discovery of fusion solved a vexing problem -- where did the sun's heat come from. After geologists figured out how old the earth was, there was no known mechanism that could keep the sun so hot for so long. On the sun, hydrogen fuses to produce helium, releasing a tremendous amount of energy -- more than a million times as much energy as when hydrogen is burned chemically. The hydrogen isotope we would use for a power source on earth is called deuterium and has one extra neutron in its nucleus, compared to ordinary hydrogen whose nucleus is a single bare proton. The deuterium extracted from 10 gallons of water would weigh about a 1/10 ounce and could supply enough electricity to last an average U.S. consumer about 15 years. And there's a lot of water.
Fusion reactions are slow until the fuel is heated to unimaginably high temperatures. At that point, the electrons in the fuel atoms are all stripped from their nuclei and the gas becomes a plasma, the fourth state of matter. The most promising approach for commercial fusion energy uses powerful magnetic fields to insulate this hot plasma from nearby material walls. Using these techniques, we've attained the necessary plasma densities and temperatures, over 300 million degrees, far hotter than the core of the sun. Experiments to date, have produced about as much fusion power as they consume and a simple scale-up in size would yield net energy production. ITER, an experiment to do just that, is under construction by an international consortium that includes the U.S..
The advantages of fusion energy go well beyond an abundance of fuel. The need for a carbon-free source should be obvious to everyone of course and by eliminating fossil fuels it also dispenses with other pollutants, as well as the hazards of mining, refining and transportation. How does it stack up to other alternate energy sources like wind or solar? Fusion would provide electricity in large central stations, simply replacing the heat from combustion with another energy source, so it would run all day in any weather, eliminating the need for expensive energy storage systems or expensive modification of the electricity grid. And unlike proposed forms of biomass energy, there would be no significant land or water use -- energy would not be competing with food for these precious resources.
How about fission, the nuclear power source we use now? Fission and fusion can claim many of these same advantages, but fission comes with some serious and all too apparent risks. Fission plants are fueled with enough enriched uranium to run for a year or two. The highly radioactive byproducts accumulate, which by themselves produce an enormous amount of heat that can't be turned off. The recent disaster at Fukushima was a consequence. When the earthquake and tsunami damaged the plant and all sources of electricity to run the cooling pumps, the reactor cores melted and released radioactive products into the environment. Some of these radioactive products are chemically volatile and biologically active -- they can move through the environment and accumulate in living organisms. In contrast, a fusion reactor would never have more than a few seconds of fuel in it at any time -- there is no way it could melt down. The metal structures that make up a fusion reactors would become mildly radioactive over time and would need to be isolated, but after about a hundred years, the materials could be recycled or buried -- no permanent waste disposal would be required.
Perhaps the most frightening aspect of a global fission industry is the risk of nuclear proliferation. The technology for enriching uranium for reactor fuel is largely identical to what is required to make a bomb (hence our concern with Iran's program). Alternately, only the tiniest fraction of the plutonium that is produced in fission reactors is needed to make a nuclear weapon. By comparison, the proliferation risks of fusion are minimal and easily detected. Fusion energy would pose little danger to the public health, to property or water supplies, nor would it threaten social trauma.
Fusion is the big winner in what economists call "external costs," costs that are borne by society as a whole and that don't factor into the costs of production. So why aren't we running our homes with fusion energy? Well, it turns out to be a very hard problem. We've made some dramatic breakthroughs and a lot of slow steady progress -- between 1970 and 2000, the energy produced by each pulse of a fusion experiment increased by a trillion times. Computational power increased over the same period by "only" a factor around a million. Of course, the semiconductor industry could sell individual transistors and make a profit, but fusion won't be profitable until it reaches full scale. Scientists working in the field agree that you could build a fusion reactor that produces a lot of energy, but whether in the end, fusion can be cost competitive and reliable is still an open question.
What's next? The steps required to harness fusion power are well known but will take some time and some money. The ITER experiment needs to be completed and operated. You'll read about cost overruns and schedule slips -- its multi-national management has been slow and inefficient. It would have been faster and cheaper if one nation had stepped up to lead by itself, but none did so we'll have to live with what we've got. We need to learn more about the behavior of hot plasmas, more about its interactions with material surfaces and more about the behavior of structural materials in a fusion environment. Fusion won't come cheap, but the costs need to be put into context -- in the U.S. alone, direct expenditures for energy are on the order of 1.5 trillion dollars per year, about 10% of the U.S. economy. We're spending less than 0.03% of that on fusion research. With a reasonable level of investment, the power source of the future could really be the power source of the future.
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Scaling is now the Target.................many technical problems have been resolved.
Very Exciting.....................ASAP Please !
I have heard a lot of nonsensical arguments for nuclear energy of any sorts, but this one takes the cake.
http://www.youtube.com/watch?v=ro5-QYqqxzM
A fusion-powered spacecraft fueled with proton-boron-11 can take us there to build permanent Moonbase to mine helium-3 as a fuel supply for clean nuclear fusion power plants on Earth.
The funny answer is that the GOP would come out against it and demonize it. Like they have done with all other forms of alternative energy.
There is no indication that we are having an energy problem in this country. There are plenty of indications that we are having a collective brain tumor, though.
I'm not sure if you'll answer this directly, but from my reading (and i'm just an average person), i get the impression that Fusion is still a long way off barring some ridiculous break through due to the cost. This leads me to think that LFTR should be the next step in our power process given the availability. I just feel like we're so hell-bent on our current system that we don't want to pay more money now in order to save money later. What's your thoughts on LFTRs and it's future in the alternate power world while we're potentially waiting on Fusion?
Thorium reactors can be made safe and plentiful.
They can also scale from something to power a single house, to a factory, to a city.
Until there are major new breakthroughs in the technology and costs, Fusion will be limited only to large installations.
I think Thorium cycle will provide an important bridge to a Fusion and Solar powered future.
We also need high density energy storage via advanced hydrogen, batteries, fuel cells or more exotic means.
I say hydrogen, because with all that Solar/Fusion electricity you can make all the Hydrogen needed.
Only then can we stop burning carbon fuels for power in vehicles and machines and clean up the planet.
And apart from that, letting power generation fall into the hands of a few private monopolies is just wretched public policy from any perspective. A grid of individual and small-scale neighborhood producers gives us a much more robust grid that's much less subject to both disruption and corruption.
http://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reactor
I have long thought that energy was the single most important issue that the entire world faces. Without sufficient amounts, readily available, the world will slowly drift backward to 19th century lifestyles, with violent wars to secure whatever remains of the traditional supplies. We will become a severely stratified world with the "haves" and those who truly have almost nothing - and the latter groups will include most of us.
Abundance, but from dirty and expensive sources, will pollute unacceptably large areas of the earth and the atmosphere.
Unfortunately, relatively few people seem to be really interested in conserving energy. Paradoxically, those who label themselves "conservatives" appear to be the least interested, as it seems to infringe on some "right to be wasteful" they feel they have, if they are encouraged to use anything that is more energy efficient.
I truly hope that major advances to this source can be made in the very near future. I think it would be the most important technological advance ever, bar none.
This sounds EXACTLY like wind power, except for the "no larger than existing fossil fuel plants" (noting that America has lots and lots and lots of empty room in which to put non-polluting objects). Wind power, which there is enough of, in many individual states in the United States, to supply all the kilowatt hours needed for the entire country.
For the U.S. to not be jumping into wind power is some kind of weird pretend-scarcity thing protecting coal and oil. Of course there is no need to turn off or discard existing fuel-burning power plants, you keep them on standby and use them whenever you feel like it...while we build up a national energy grid to get wind power shuttled everywhere as needed.
29 GIGAWATTS of wind power, EIGHT PERCENT OF THE ENTIRE COUNTRY'S ELECTRICITY is alread in Germany. Some perspective, the total amount of energy produced by coal in Ohio (which has the most coal-burning power generation capacity in the U.S.) is 23 gigawatts.
Also a straw man to say that the "only" way to distribute wind power is with superconducting power lines. Who said that all the wind power in the U.S. has to come from one central place? Germany is dealing with building lots of new distribution for wind power, expensive, but no superconductors. IEEE Spectrum: "[Germany] Transmission is no easy thing to build, however. The new lines will cost around €20 billion (close to $25 billion), and there will need to be some serious buy-in from the public and politicians alike..."
And exactly what is the "non-negligble environmental impact?" Air pollution? Radiation hazard? Mining for fuel? Nuclear material handling? Carbon dioxide or other greenhouse gas production?
Oh yeah, the visual pollution of windmills if you're crazy enough to put them where a hundreds of thousands of people have to view them daily. Man, that is just as big a problem as air pollution from burning coal...
1. Medical - for life.
2. Agricultural - for food
3. Fusion Energy - for power
Take a year's military budget and invest.
If we're going to accrue even more debt, we might as well spend the money in a way that will solidify the future: which is science.
Discoveries in one field often affect others without any foresight of doing so. So you have to fund them all.