A scientific milestone was achieved this month when, for the first time in a laboratory, a fusion reaction produced more energy than was needed to ignite it. This important result came at the Department of Energy’s Lawrence Livermore National Laboratory and its National Ignition Facility. It’s far from a commercial prototype – its giant lasers, for example, are very inefficient – but the result demonstrated the ignition of fusion fuel, which is the central requirement for commercially producing clean electricity.
Although fusion reactions power the sun and other stars, thanks to their enormous mass and gravitational pressure, controlled fusion on Earth has been difficult to achieve for many decades. The NIF result is exciting because when the journey from scientific demonstration to a commercially viable power plant is complete, the electrical grid will be revolutionized.
Why? Because just as wind and solar power, supplemented by batteries and long-distance transmission, are and will continue to be important in providing carbon-free electricity, a large-scale, compact, clean source of energy available when needed, regardless of the weather, opens ample opportunities for a reliable emission-free grid system. This will be essential for an energy economy free of greenhouse gas emissions. Nuclear fission, the foundation of today’s nuclear power, has exciting new technologies on the verge of implementation, but is challenged by the need to manage radioactive waste and concerns that some countries may exploit nuclear fission systems to gain knowledge about nuclear weapons. Nuclear fusion offers the benefits without those challenges, and widespread deployment would be a game changer.
Two technological approaches aim to navigate the path from the lab to the grid: compression of fusion fuel, usually forms of hydrogen, as practiced at the NIF; and the confinement of a hot plasma of fusion fuel, the nuclei plus the electrons that make up the light atoms, through a combination of magnets and accelerators. The latter is more prevalent and is progressing towards success, especially in privately financed companies. Investors have provided almost $5 billion private equity to various companies pursuing multiple fusion technologies, complementing considerable government funding earmarked for large-scale both compression and confinement projects. Most are betting that the lockdown focus will be on a commercially viable power plant first. (I belong to the board of directors of a company that develops such technology).
Nuclear fusion research has been going on for over 60 years, so why has it taken so long to show that net energy can be obtained from this process? Compression and confinement pathways need to achieve literally otherworldly conditions that meet and exceed those of stars. The NIF experiment compressed the hydrogen fuel to about 100 times the density of lead and at a temperature of about 100 million degrees Celsius, much higher than the temperature at the center of the sun.
Achieving these conditions is very challenging. The persistence of the fusion community over many decades is a testament to their ingenuity and the importance of the prize. Fusion is on track for a scientific demonstration before the end of this decade. The hope is that the next step, designing one or more pilot power plants and beginning deployment, can take place before the end of the next decade. This is an aggressive schedule commensurate with the scale of the climate challenge, and yet it would still add up to an 80-year journey. The public and private sectors must work together to sustain it.
Revolutionary energy technologies often have a long gestation period. The comparison with photovoltaic solar technology offers a guide. While there’s no official “start date” for solar PV, I have a personal one: I visited Bell Labs in 1961 as a high school student and saw the prototype for the Telstar satellite, which would go into orbit the following year. It was covered with photovoltaics that had been researched and developed by Bell Labs, without the pressure to meet the strict cost targets that would be required for commercial power applications. This puts the extraordinary technical challenges of fusion into context and reinforces a critical reality: the clean energy innovation challenge, by its nature, has been many decades in the making.
To meet widely accepted climate goals, we need to double the clock speed of the clean energy innovation process. The bipartisan commitment to energy innovation, from the discovery stage to initial deployment, was manifested in the remarkable legislative record of the past year: the Bipartisan Infrastructure Act, the Science and CHIPS Act, and the Inflation Reduction Act. This is encouraging, but it should hold even in the face of uncertain near-term macroeconomic conditions. Equally important, the federal and state governmentyes need to encourage private investment in clean energy research, development, demonstration and deployment by lowering barriers to bankability. Only by firing all cylinders in a synchronized manner, for fusion and for the broader clean energy portfolio, can we deploy energy, climate and security solutions faster, including for tomorrow’s breakthroughs like fusion.
Ernest J. Moniz is emeritus professor of physics at MIT and executive director of the Energy Futures Initiative, a Washington-based research group. He is a former US energy secretary and is on the board of TAE Technologies, a privately financed merger company.