Fusion Power: Pros and Cons

There is no perfect energy source. Each and every one has its own advantages and compromises. This series explores the pros and cons of various energy sources.  Learn about other forms of energy generation here.

Nuclear fusion is the most basic form of energy in the universe. It is what powers the sun (pictured) and all of the stars. It is produced by a nuclear reaction in which two atoms of the same lightweight element, usually an isotope of hydrogen, combine into a single molecule of helium, the next heavier element on the periodic table.

Humans have successfully produced an uncontrolled fusion reaction to make the hydrogen bomb, in which all the tremendous energy of the reaction is released at once in a highly destructive manner. If the same amount of energy could be released gradually, in a controlled fusion reaction, which is what occurs in the sun, this could become the ultimate form of energy on Earth.

But creating a controlled fusion reaction has proven very difficult so far. Because the two hydrogen atoms have the same charge, they will electrically repel each other. The tremendous heat of the sun, which is somewhere in the neighborhood of 12 million degrees C, accelerates them to the point where their momentum overcomes the electric repulsion. Producing these kinds of temperatures in what is essentially a synthetic sun is a great engineering challenge. The elements are heated until they reach a plasma state. No material could possibly withstand such heat without melting, which is why the reacting elements must be suspended without touching the walls in the vessel. This can be done with either gravity, inertia, or magnetism, all of which are very challenging to create and control The resulting continuous reaction, known as a thermonuclear reaction, could then be used to create steam in a boiler which could then generate electricity using a conventional turbine.

The experimental reactors that are in use today all use deuterium and tritium as the main elements. Deuterium can be extracted from sea water. Tritium can be made from deuterium in contact with lithium.

Fusion research began in the 1950’s, in England. In 1968 the Russians created the first reaction in their Tokomak reactor, which utilized magnetic confinement. In 1991, the Joint European Torus (JET) reactor produced 1.7 MW. Two years later, the US-based Tokomak fusion test reactors (TFTR) produced 10 MW.  Today there are some 25 experimental reactors in existence. The most ambitious is the International Thermonuclear Experimental Reactor (ITER) currently under construction in France, which hopes to achieve 500 MW of output for approximately 1000 seconds. The earliest projected date for a commercial facility is not expected until around 2050.

If room temperature, or cold fusion could be developed, it would be much easier to implement and control. A pair of researchers, Pons and Fleischman from the US and England claimed to have demonstrated a cold fusion reaction in 1989, but the process could not be independently verified. Today, an Italian scientist, Andrea Rossi, claims to have a successfully created cold fusion system, but his results, which appear to contradict known science, have also not yet been independently verified.

No one knows when a successful continuous controlled fusion reaction can be achieved or even if it is ultimately possible. Billions of dollars have been and continue to be invested in research since the potential benefit is considered so great.

Pros of nuclear fusion

  • Clean energy. No greenhouse gases.
  • Virtually limitless fuel available. (The deuterium can be distilled from seawater and the tritium can be “bred” in the reactor.)
  • No chain reaction. Easier to control or stop than fission.
  • Little or no nuclear waste. Core remains radioactive for only 100 years. Possibly radioactive structural elements.
  • Very low fuel cost

Cons of nuclear fusion

  • Unproven at anything resembling commercial scale.
  • No full scale production expected till at least 2050
  • Commercial power plants would be extremely expensive to build
  • Requires extremely high temperatures. Difficult to contain
  • Could produce a net negative amount of energy
  • If cold fusion could be achieved, it would be much easier to implement.
  • The billions in research funding could be spent on renewables instead
  • Would remove any incentive for restraint in the use of energy.

In many ways, fusion power seems like the perfect energy source. It’s clean, it’s inexpensive, and it uses seawater as its fuel source. It’s the Holy Grail, it’s the pot of gold at the end of the energy rainbow, and it has no appreciable side effects, except for one: modern civilization on steroids.

If commercial scale fusion plants were to become a reality, we would have an unlimited, nearly free, clean source of energy. And if limited energy supply and climate change were our only problems, or, should I say the only geophysical constraints imposing themselves on our way of life, then that would be the happy ending to the story.

But here is where we need to step back and look at the larger picture. We need to look at the very question of energy consumption in the larger context of our planetary ecosystem and our survival within it. Scientists at the Stockholm Resilience Centre, have identified, not one, but nine planetary boundaries that define the envelope within which we must conduct our affairs if we are to avoid destroying our very source of sustenance. In addition to climate change, there is also biological diversity, nitrogen and phosphorus consumption and release, ocean acidification, stratospheric ozone, land use change, freshwater availability, aerosol loading, and chemical pollution.

According to the analyses these folks have conducted, we need to respect all of these boundaries in order to maintain the comfortable living conditions we enjoy now. Unfortunately, we may have already crossed the first three.

We must confront this reality, as we engage the question of how to manage our energy future, because energy is so inextricably tied to our impact on all of these. If we didn’t have access to the tremendous amount of energy we expend every day, we wouldn’t be anywhere near any of these boundaries. Energy consumption has always gone hand and hand with material consumption, resource depletion, and environmental pollution. While it’s true that fusion power would not produce these things directly, it would enable them to continue unabated, giving mankind unprecedented power to do harm as well as good.

If we are going to move to a more sustainable, lower impact way of living on this planet, we need to do a lot more than substitute a clean and renewable source of energy for the ones we are using now.

Most of the projections for a renewable energy future involve a healthy dose of conservation as well as efficiency. That implies some level of re-examination of our current way of life, in everything from how much we consume to how we lay out our cities, how we move around, and how we feed ourselves, just to mention a few areas.

If someone were to walk up and hand us the keys to nuclear fusion power tomorrow, I’m not at all sure that we would have the wisdom or the maturity to reign in our consumption, once we no longer needed to. Yet if we don’t we are likely to put increased pressure on a number of these planetary boundaries.

There is one further and perhaps more immediate concern about the fusion scenario. It is not expected to be commercially available until somewhere around 2050. If you believe the projections on climate change, we pretty much need to have our energy house in order by then, with a dramatically lower carbon footprint that needs to begin dropping yesterday. The DOE has forecast that the US can meet 80% of its electricity demand from renewables by that time using existing technology while Denmark will be fulfilling 100% of its total energy needs with renewables by then.

Given that the fusion approach, will not, failing any miraculous breakthroughs, be ready by the time we need it, which is very soon if not now, it could be argued that it makes more sense to spend those billions of research dollars on something that will be.

What about other energy sources?

[Image credit: Image editor: Flicker Creative Commons]

RP Siegel, PE, is an inventor, consultant and author. He co-authored the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water in an exciting and entertaining format. Now available on Kindle.

Follow RP Siegel on Twitter.

RP Siegel

RP Siegel, author and inventor, shines a powerful light on numerous environmental and technological topics. His work has appeared in Triple Pundit, GreenBiz, Justmeans, CSRWire, Sustainable Brands, PolicyInnovations, Social Earth, 3BL Media, ThomasNet, Huffington Post, Strategy+Business, Mechanical Engineering, and engineering.com among others . He is the co-author, with Roger Saillant, of Vapor Trails, an adventure novel that shows climate change from a human perspective. RP is a professional engineer - a prolific inventor with 52 patents and President of Rain Mountain LLC a an independent product development group. RP recently returned from Abu Dhabi where he traveled as the winner of the 2015 Sustainability Week blogging competition.Contact: bobolink52@gmail.com

8 responses

  1. It is interesting that this article has spotted magnetic fusion and even the immensely unlikely “cold-fusion” (there’s no such thing as a “free lunch” in physics or nature)… but has missed the technology most likely to be the first to succeed in harnessing fusion for energy production… Inertial Confinement Fusion (using very large lasers).

    Have a look at what is happening at the National Ignition Facility (NIF) in Lawrence Livermore, California.  Scientists there are now getting really close to scientific “Proof of Principle” for laser fusion.  That will be a huge achievement when it happens, but from there the work will start to turn a demonstration of the fact that it works into a functioning economically viable fusion energy power plant…. something that industry can roll out across the world. 

    Fusion Energy is very hard to do and this work costs a lot of money but, given that the fuel supply will be effectively inexhaustible (on the human timescale)… well worth the effort and the relatively short wait.

    What we need now is the vision, the courage and the tenacity to achieve fusion… as soon as it can be done.

    In our ignorance, the human race currently spends more money each year on “ring-tones” for mobile phones than it does on fusion energy research.  If we are not smart enough to change that we really don’t deserve to master fusion… nor do we deserve to survive as a species for the long term.

    Let’s hope we are smart enough to overcome short-term greed, political expediency and the compulsion to rest easy on the current availability of cheap and easy energy for the short term.  One look at current trends in fuel prices tells us that energy won’t be anything like this cheap for long.

    Perhaps what we need now to achieve this huge step is not “politicians”, but “Statesmen” !!!


  2. Thanks James,
    I did mention the three types of containment (gravity, inertia, magnetism) early in the piece. I know there is a lot of great work being done on this all around the world. I have, in fact, toured the laser fusion lab at the University of Rochester and came out very impressed. It was not my intention to write a comprehensive technical overview, but rather to try to describe fusion power in the context of the broad energy picture for this series.I am not against fusion research per se, though I do have concerns as I mentioned about our ability to bring it online in time to make the difference we need. Clearly there are tough choices to be made in the area of energy, which is probably why we still have no energy policy. We do need to narrow the field and then invest and regulate to ensure the timely success of whatever choices we’ve made.

  3. The great European experiment, Desertec, is begging the World Bank for billions in loans to expand its grid requirements without a return on investment. That is not the way banks survive. Now this author is asking for billions for existing technology that has already been developed and in production. If the renewable utility needs money, get it from the customer. Government subsidies should be for development of new innovative technology. To solve all the planetary problems, we actually need more energy available, not less. I prefer fission/fusion nuclear power and believe governments around the world should be investing in them. Renewable (wind and solar) is already a proven technology and should be self-sustaining like the energy they use.

  4. We need to look at -electrical fusion- do a google search for the “plasma focus device”
    This truly IS the future of energy. With a fraction of funding that other sources get they would be up to commercial production in a short time!

    1. Fusion means we can use the same total energy but use less from sources which end up putting a greater proportion of carbon in the carbon cycle into the atmosphere (like fossil fuels do). This is because if there is more CO2 in the air there is a net increase in the energy in our global system because more energy comes in from the sun than goes out into space ie. the greenhouse effect.

      If all our fossil fuel use was replaced by fusion then zero CO2 would enter the atmosphere and the energy from the sun would equal the energy lost to space so global temperatures would cease to rise.

      Since fusion energy would probably be cheap we would probably end up using more total energy effectively got from nowhere (ie. converted from mass in the fusion process). Would this lead to rise in global temperature? I guess this must depend on:-

      – How much extra total energy is used
      – How much of the energy used ends up heating the atmosphere eg. increased use of air conditioning as opposed to ending up causing chemical changes so the energy is stored latently in chemical bonds
      – Whether that increase in energy is significant

      Who will do the sums?

  5. Mr. Cox is the only one here looking in the right direction with regard to fusion. We did this calculation in 1975 at UCB in a class called Energy and Society for the Environmental Studies Major, and the conclusion with numbers available then was that getting nuclear fusion, and having everyone on the planet using energy at a US rate ( which is what everyone would want to do) would generate enough waste heat to cause the global temperature to rise several degrees, thus, in effect, doing what CO2 emissions are doing now. The earth is a black body radiator, and the nuclear fusion energy (which would be generated on top of whatever comes in from the sun) in the end all becomes heat energy, which must be radiated to space at low-energy long wavelengths (function only of temperature and area and emissivity). We already dump the daily input of solar energy (plus any extra burned fossil fuels’ energy) at the temperature we are at now, and the only way to dump more energy is to raise the black-body temperature. Unfortunately, there are now several billion more people than in 1975, and they all want good things like those in the US. I came across this article while searching for an update to our 1975 calculation, and haven’t had any luck yet. Everyone still talks about fusion as the Holy Grail of energy. It isn’t by our calcs in 1975, unless the some of the energy from the fusion could be bound up in sequestering CO2 out of the atmosphere to lower what has been going in. Energy conservation and use of renewable solar is the only viable method currently. We are a spaceship, and waste heat must be shed. Now, if we could build some giant radiator panels in space, and get waste heat energy to them to radiate, we would have increased our net surface area.

    1. Solar energy includes solar, biomass, wind, and to some degree tidal energy, to the degree tidal energy includes energy from wind driven waves and ocean currents. Otherwise tidal energy is using energy from the earth-moon gravitational system, which has other long-term effects. Any wide spread use of solar will affect local weather and climate to some degree, because it involves shifting the energy around the surface of the earth from where it normally is absorbed/reradiated, which is what our weather really is, an attempt by the planet to balance energy on the planet, as the poles are in energy deficit, and the equatorial region is in energy surplus.

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