How Can We Get Cheap, Clean Power From Nuclear Fusion?

Forbes FEB 28, 2017


What are the most important unanswered questions in natural science that are likely to be answered by 2025? originally appeared on Quora: the place to gain and share knowledge, empowering people to learn from others and better understand the world.

Answer by Matthew J Moynihan, PhD in ICF, Fusion Blogger, on Quora:

Nuclear Fusion offers the world: cheap, abundant, zero-carbon electricity. It also expands the supply of electricity. Consider that:

  1. Fusion could curtail climate change by replacing fossil fuel plants.
  2. Fusion energy enables cheaper more abundant clean water.
  3. Solar and wind have not touched the 80% dominance of fossil fuels.
  4. Fusion has the potential to power spaceships.

Despite all the hoopla around solar and wind, fossil fuels are still 80% of the world’s energy sources. They have been burned for at least the last 200 years, through communism, socialism, capitalism and democracies. They have been burned through times of peace and of war. Fossil fuels are very hard to displace, but fusion has the potential to really displace them.

I argue that fusion development is about where human powered flight was in the early 1890’s. Namely:

  1. Most people consider it impossible.
  2. The public is not paying attention.
  3. Fusion is so new, that we have no clue what a plant looks like.
  4. Many wild ideas are being tried.
  5. Net power has not happened yet; we are pre take off.

Net power would be the Wright Brother’s first flight of fusion – it has not happened yet. For many decades fusion has been promised. But, within the past five years, fusion has been fundamentally changing:

  • Fusion is now being attempted in Silicon Valley style startups. Billionaires like Paul Allen, Jeff Bezos and Peter Thiel have all started funding fusion startups in the past few years. These trailblazing companies include (1) Tri Alpha Energy and (2) General Fusion.
  • The National Ignition Facility has failed. This has been the primary focus of the US fusion effort for the past twenty plus years. NIF failed to get ignition. The DOE recently admitted it will may never, ever work. This represents a massive shift in fusion research, not seen in decades. I argue this means that we are now willing to put funding into lots of new fusion concepts. This will take US fusion research fundamentally new directions.
  • Fusion has moved from ivory tower researching into the garage. Today, there is a growing amateur fusion movement. Kids, hobbyists and teenagers can fuse the atom in their garage. This was recently featured in the Washington Post. Today, there is even a high school club with access to a fusion device. The Northwest Nuclear Consortium is a high school club with regular access to a fusion device, they came first in the world at the Intel International Science and Engineering fair and have won over $600K in college scholarships.
  • Many more approaches are being tried; and yes, many of these ideas will fail. There are now dozens of small and large startups getting into the game – with dozens of different ideas. Some of these groups have off the wall ideas. These ideas are mapped out below, with machines in blue. One radical example is Lockheed Martin, which is trying to get a diamagnetic plasma to reject the outside field [1].
  • The internet is helping. It is standardizing fusion knowledge and information from many more sources, to many more people and all at a much faster pace than ever before. It is also allowing the growth of fusion advocacy groups like the Fusion Energy League – which have sprung up, to advocate for fusion power research.
  • The press is taking more of an interest. Fusion was even on the cover of TIME magazine, in November 2015. There have been recent articles on “new” fusion concepts in the BBC, Gizmodo, Science Magazine and MITs’ Technology review.
  • Congress is taking an interest. In 2015, Rep. Alan Grayson introduced “The Fusion Innovation Act of 2015” this bill went nowhere – but, in 2016 he re-introduced the bill and got a hearing on the house floor.
  • Venture Capital is also taking an interest. On May 2nd, a panel of fusion experts were invited to speak to a global conference of investors at the Milken Global Institutes’ annual meeting. What is exciting, is not who they invited, but how many other innovative companies could have been invited.
  • Finally, the need for clean cheap energy sources is getting stronger with each passing year. Investors are lured by the prospect of cracking this problem. Whomever does it, will get filthy, stinking, rich.

To get net power, we need to beat the energy balance. Here it is for a plasma-based fusion machine:

People turned this into The Lawson Criteria – but I find it easier to explain by walking through the original power balance.

  • Fusion: Thus far, research has focused on increasing the fusion rate. This leads to giant, expensive machines. These are far away from net power. The goal is to get atoms to slam together. If this happens, they can fuse. Some of the mass is lost, it becomes energy through e = mc^2. This makes more energy than any other process known to mankind.
  • Conduction: Conduction is the loss of mass. The mass touches surfaces and it lost. Energy leaves with this mass. You can steer plasma with magnetic and electric fields; you can even get plasma to make fields with self-contain it. So there is a great deal of room for improvement.
  • Radiation: Radiation is the loss of energy as light. Plenty of energy leaves the plasma cloud as light. This includes visible, x-ray, infrared and ultraviolet. There may be ways to “tune” plasma or the fields to lower these losses.
  • Efficiency: Efficiency is how well we capture the energy. This may be the most unexplored concept in fusion. Efficiency means either lower the amount of energy to run the machine or/and raise the amount of the energy we get out.

These ideas are all over the spectrum, from tokamaks being the most proven and highest funded – all the way out to ideas which will totally fail.

Here are some more approaches, that I have not already mentioned.

  • The levitating dipole approach at MIT.
  • The plasma liner experiment at LANL.
  • Penning Trap Fusion.
  • The Polywell at EMC.
  • The Dynomak approach at the University of Washington
  • Magnetically Insulated fusors from the University of Sydney
  • The stellorator.

Sure many of these ideas will fail, but if one hits net power, it will fundamentally change human civilization, forever. Fusion is coming along much faster than folks realize. It also has the potential to make a much wider and deeper impact on human civilization than most appreciate.