Fusion power is a long way off despite breakthrough

Fusion research proves it could become our next main energy source in the future, though not anytime soon.

Don’t get your hopes up too much. Last December, an important step in making fusion power a reality was achieved — but that doesn’t mean that fusion is right around the corner. Although this was the first time a man-made fusion experiment produced more energy than it consumed, it was done using a complicated, expensive and difficult-to-scale setup. We might see fusion energy within our lifetimes, but it probably isn’t right around the corner.

The Lawrence Livermore National Ignition Facility (NIF) in California, the site of the breakthrough, is essentially a giant laser amplifier. By using some of the largest and most powerful lasers ever constructed, they were able to superheat a capsule containing hydrogen isotopes to achieve fusion ignition — i.e. to produce more energy (3.15 MJ, or 875 Watt-hours) than the lasers consumed (2.05 MJ, or about 570 Watt-hours). However, before fusion becomes viable for large-scale energy generation, there are myriad challenges to overcome.

Actually harnessing that energy doesn’t seem like it would be too much of a problem — just boil some water to spin a turbine. However, some energy loss would take place. In order to be feasible as a power plant, a fusion reactor would need to be able to operate unimpeded for days at a time. To put that into context, the experiment which produced fusion ignition lasted for a fraction of a second and only occurred under precisely-controlled laboratory conditions, using a gargantuan laser array targeted at a cryogenically cooled chunk of deuterium and tritium about a millimeter in diameter.

It is also worth noting that although the energy produced by fusion exceeded the energy consumed by the lasers, this does not include the energy consumed by the environmental controls in the experiment or the electricity consumed by the building as part of normal day-to-day operations. Scaling this experiment up one-to-one so that it produces energy in the megawatt range would create challenges with laser amplification, cooling, etc. which we haven’t even begun to address. To replicate this experiment, design and build a demonstration reactor and then begin wide-scale implementation of fusion power would take decades at least, if we are being optimistic.

Fusion has a reputation for having been “30 years away for the last 70” and although this is an important milestone, it’s far from the first and it won’t be the last before the technology is ready to produce energy. Fusion is sometimes seen as a “silver bullet” that would effectively solve global energy problems, but if the history of nuclear fusion research is any indication, then there are barriers to practical fusion power that we haven’t even discovered yet — and placing our hopes in fusion power, if anything, could detract from more practical and readily-available methods that we could use to wean ourselves off of fossil fuels, like light-water reactors (LWRs). Although this is an important development and perhaps one which could attract some more attention (and investment) to the hurdles ahead, fusion could be 30 years away for another 70.

Post Author: Dominic Cingoranelli