The Future of Energy ― Hydrogen, Fusion, and Beyond

Last time, we watched how the planet-wide challenge of climate change is pressing humanity to graduate from fossil fuels after three centuries in the lead role. The great shift of decarbonization, swaying though it does between ideal and reality, has surely begun to move.

So, after those fossil fuels, with just what force will humanity drive its civilization? In this final chapter, I want to lay out several signs now quietly growing, and survey the future of energy. Hydrogen, a new carrier; the challenge of nuclear fusion, trying to build a sun on the ground; the evolution of the technology that stores power; and the question of energy security ― of ‘who holds’ that power. Each is still on its way, and none can yet yield a clear conclusion. Yet as the continuation of a long story that began with an ape who took hold of fire, let us look at its outline together.

Burns and Leaves Only Water ― Hydrogen, the Carrier

In the context of decarbonization, one thing often spoken of with hope is ‘hydrogen.’ Burn hydrogen, and it emits no carbon dioxide; what remains afterward is only water ― and so it has drawn attention as a source of power to replace fossil fuels.

That said, hydrogen calls for a little care. Hydrogen scarcely exists on Earth on its own, and must be produced using some form of energy. Its meaning for the environment changes greatly depending on that ‘way of making.’ Make it from fossil fuels, and carbon dioxide is released; make it by splitting water with electricity from renewable energy, and it becomes hydrogen with almost no emissions, it is said. The latter is called ‘green hydrogen’ and is drawing hopes. In other words, hydrogen has less the character of an energy source in itself than that of a ‘carrier’ for transporting and storing the power one has made. Many challenges to overcome ― the cost of production, and the technical difficulty of transporting and storing it ― are reported to still remain.

Building a Sun on the Ground ― The Long Challenge of Fusion

And when speaking of the future of energy, the one told as an especially great dream has been ‘nuclear fusion.’

The nuclear power generation we saw in Episode 6 used ‘nuclear fission,’ splitting heavy atomic nuclei to draw out energy. Fusion is its reverse, fusing together light atomic nuclei like hydrogen to produce energy. This is the same principle by which the sun shines. For that very reason, fusion has often been described as ‘building a sun on the ground.’ Deuterium, its fuel, is said to be obtainable from seawater, and the possibility of being freed from struggles over resources is spoken of as well.

The realization of fusion is by no means simple. To fuse atomic nuclei, one must create on the ground a state of ultra-high temperature rivaling even the sun’s core, and must keep it confined stably and continuously. Because it has long been said for years that ‘it will be realized in a few decades,’ there are also deep-rooted voices warning against excessive hope. Even so, in recent years the assembly of ITER’s main body ― the international-cooperation experimental reactor under construction in France ― has advanced, private firms have entered one after another, and the competition in development is reported to be widening worldwide. Whether it can reach commercial power generation is still unclear, but a dream humanity has long pursued is taking on a touch of reality, little by little ― such, it can be said, is the stage we are at.

Storing Power, Guarding Power ― Storage and Security

In thinking about the energy of the future, what is indispensable alongside the glamorous new technologies are two challenges that look more humble. One is ‘storing,’ the other ‘guarding.’

Renewable energy can make electricity only when the sun shines and the wind blows. For that very reason, the technology of storing the power one has made becomes decisively important. The performance of the batteries used in electric vehicles too has risen year by year, and their price is said to have fallen, but the technology to store cheaply and for a long time the vast amounts of electricity needed to sustain society as a whole is still on its way of being sought. Pumped-storage generation, hydrogen, various new batteries ― the competition among means of storing power will shape the future.

However fine a technology of generation may be born, if it cannot be stored and stably guarded, it does not become a force to sustain civilization. The energy of the future takes shape only when three things come together: the technology to make, the technology to store, and the mechanism to guard.

From Fire to Fusion ― The Story of Humanity and Power

Through this series, we have traced the long road by which humanity took hold of power.

From the day an ape gathered around fire and gained warmth and light, waterwheels and windmills aided human and animal labor, coal turned the Industrial Revolution, electricity lit the world, oil drove the twentieth century, dams and transmission grids sustained nations, the atomic fire brought dream and dread at once, wind and light became a new option, and decarbonization presses for a graduation from a three-century lead role ―. The history of energy is the history of humanity continuing to seek ‘a greater force,’ and at the same time, the history of continuing to face the blessing and the calamity that force brings.

Hydrogen, fusion, storage, and the still-nameless technologies that await beyond ― they lie in the continuation of this long story. Whether they will save humanity or give rise to new hardships ― we do not yet hold a certain answer. What history teaches us is that every force, without fail, has its light and its shadow, and that whether one makes that force a blessing or a calamity rests not on the technology itself but on the choice of the human who takes hold of it. Fire gave us warmth and was at the same time a force that could burn everything to the ground. The force we take hold of next, surely, will be the same.

With what power will humanity drive the next civilization? The ones to give that answer are the people who will live the future, and we ourselves who live the now. Rather than rushing to an easy conclusion, to keep holding this question while accumulating each single choice ― that, perhaps, is our responsibility, inherited from the ape who took hold of fire.

To all readers who have kept company with this long, long journey from fire to fusion, my heartfelt thanks. If this story has become an occasion to turn your thoughts to the true nature of the power that has lit our feet, and to its light and shadow, there is no greater joy than this. The story of power has no end. The one to write its next chapter, surely, is you.

【A World History of Energy: From Fire to Fusion — End】