A Brief History of Energy

From the stone age to the space age

“In truth, only atoms and the void”

-Democritus 

Energy powers civilization. It runs our factories, propels our vehicles of trade and commerce, heats our homes and lights up our cities. In the broadest sense, the epochs of human civilization are delineated by the form of energy we harness to power our economies: the scale of our societies, the opportunities for growth, and quality of the average human life are all bounded by the abundance and availability of energy. Fusion power holds the promise to increase the available energy to power civilization by a million times over fossil fuels, without also increasing the risk of nuclear weapons. Power from the stars, to propel us to the stars. 

The Origins of Energy

The ultimate source of all energy we encounter in our lives is nuclear: solar, geothermal, hydropower, wind, tidal, and even oil and gas are downstream products of nuclear reactions which convert tiny amounts of matter directly to energy. There are two kinds of nuclear reactions which release energy: fission, when large atoms split apart; and fusion, when small atoms bind together, either transforming elements from one kind to another. The exchange rate converting energy to matter is the speed of light squared, contained in the famous physics equation E=mc², meaning energy is cheap when converted from mass in nuclear reactions. Consider, the explosion which destroyed Hiroshima weighed less than a gram. 

Fusion powers the sun, and stars ‘burn’ hydrogen in their stellar furnace into all the heavier elements we find in nature. We are mostly made of fusion ash, indeed stellar fusion is basically responsible for everything interesting and useful in the material world. Carbohydrates and sugars in the food we eat are built up by chloroplasts, using the energy from sunlight to transport electrons and build the base of the global food-chain. Radiated solar power has fueled the slow climb of cellular life up an energy gradient of complexity, starting with single-celled bacterium into the living breathing Earth we see today, and past generations of living things have been compressed, heated, and consolidated in the crust as oil, gas, and coal. Meanwhile, natural fission of elements like uranium, thorium, and potassium reactions produce heat inside the earth we can capture as geothermal power.

Although we associate nuclear fission with the post-war era in modern history, long before the Manhattan Project, nuclear fission powered the mythical forges of Hephaestus, hammering sword and armor for the Olympian Gods in a fiery smithy deep inside Mount Vesuvius. 

The Hydrocarbon Age: A Miraculous Inheritance

From the age of Homer (11,000 BC) to the age of Voltaire (~1750 AD) almost all of humanity lived in extreme abject poverty, a bad harvest away from destitute famine. In terms of energy, we were constrained to survive off the daily solar budget, the sunlight’s energy from dawn to dusk, and civilization was on a perilous footing. Indeed, the collapse of complex, large-scale civilization during the “Dark Ages” is now thought to be related to a small reduction in the total sunlight making it to the Earth’s surface. Civilizations living on the daily solar budget were in a poor position to survive an energy recession: reduce their energy income by a few percent and the Roman Empire falls. 

In England during the early 1700’s a rare alignment of geography, demographics, and arguably, the Protestant ethic of saving and investing in new competitive forms of commerce, saw the invention and adoption of steam engines powered by coal. In 1750 England was a comparable rival with Spain, France, Portugal and the Dutch republic; by 1850 it had become the most powerful empire on the planet, entirely fuelled by its industrial revolution, a geopolitical realignment driven by English industry running on hydrocarbons like coal, oil, and gas. 

What explains the dramatic social change enabled by the industrial revolution? At the molecular level hydrocarbons are a denser supply of energy, carrying 45 kilojoules per gram (kJ/g) compared to the mere 14 kJ/g carried by sugar. Both hydrocarbons and carbohydrates store energy as chemical bonds between carbon and hydrogen which is released when reacted with oxygen, creating carbon dioxide and water. For example, burning kerosene (C12H26):

C12H26 + 18.5 O2 → 12 CO2 + 13 H2O + energy (heat + light)

looks similar to the reaction describing the breakdown of glucose (C6H12O6) in the body,

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy (ATP)

The energy measured from burning kerosene sounds different to different professions but all equate to the same amount of heat and light - 7,500 kilojoules per mole to the chemist, 45 kilojoules per gram to the engineer, or 80 electron-volts (eV) per molecule to the physicist. This particular scale of energy, in the ten’s of volts, is something familiar to us as everyday consumers - it’s the same level of energy that powers our devices, from phones that run on 5V, your laptop that runs on 25V, or blender on 120V. 

Perhaps more important than the density of hydrocarbon fuels, was that unlike glucose it could be burned en masse - in large furnaces, combustion chambers, powering boilers, turbines and factories that transformed agrarian societies of windmills and draft animals into an industrial landscape of conveyor belts and row houses. Sugar powers the yoke, coal powers the crankshaft. 

Powered by this rich, abundant hydrocarbon inheritance, starting in 1850 human civilization flourished, and the world’s population more than doubled. This growth was despite the relatively small degree of penetration of hydrocarbon-enabled industry throughout the world as a whole - largely confined to Western Europe, and areas of North America - the rest of the world still lived on the meager solar diet. After 1950, the industrial revolution found its way into every corner of the earth, and the population of the Earth more than tripled. Even more significantly, the fraction of humanity in abject poverty reduced by an order of magnitude, from 95% to less than 10%. 

Despite the stigma in modern culture, coal, oil, and gas is responsible for lifting humanity out of lives that are nasty, brutish, and short, and sending them into glittering cities of steel and glass. This hydrocarbon inheritance was formed over millions of years of methodical and diligent savings of fusion-powered solar radiation, captured by chloroplasts as sugars, powering animals, compressed by geology and time into hydrocarbons, enabling industry and science to colonize every corner of the world, invent antibiotics, vaccines, and ultimately  probe the structure of matter itself - the atom. 

The Nuclear Age: An Unfinished Business

The 20th century saw the completion of the industrial revolution worldwide and with the adoption of hydrocarbons human societies flourished across every measure, from literacy to infant mortality. Yet with industrial society came industrial warfare, the most brutal and apocalyptic of which was ultimately terminated by a weapon heralding the next age in energy production and consumption. After Hiroshima we lived in the nuclear age, with immense productive and destructive potential. In terms of energy density a fuel like uranium is 2 million times more dense than kerosene, 80 million kJ/g to gasolines 40kJ/g. Humanity had tapped into a scale of energy previously unimaginable. 

Compared to the chemical bonds broken by burning kerosene in engines or sugars in our bodies, the energy binding together nucleons - protons and neutrons, the constituents of atomic nuclei - is far, far higher. and are measured in million electron-volts, or MeV: for fission reactions, 200MeV per reaction; for fusion reactions, on the scale of 10MeV per reaction. Although fission wins out for raw energy released per reaction, the enormous size of uranium atoms compared to hydrogen means that on a per-kilogram basis, hydrogen fusion is between 2-10x more energy dense than fission. 

At the start of the nuclear age there were many optimistic projections that nuclear power could soon provide our economies with energy ‘too cheap to meter,’ however after several high-profile reactor meltdowns like Chernobyl, the omnipresent threat posed by nuclear weapons during the Cold War, and massive lobbying by the oil and gas industry, there developed a vast reserve of negative public sentiment against the widespread adoption of nuclear power. Regardless of the lobbying agenda, the reality is that a country that can produce nuclear fission power can also produce nuclear fission bombs, and therefore has the power to destroy the planet or a large fraction of it. Fission power, having assumed the throne as rightful king of the energy landscape, brought with it the nuclear sword of Damocles.

The Future of Energy: Fusion

Fusion energy is different. Nuclear fission requires extracting and refining uranium, a rare ore run through an expensive and tedious process, which can also be used to produce the raw material of nuclear bombs. The fuel for fusion energy is most often humble hydrogen, specifically a form of hydrogen called deuterium which contains one proton and one neutron (there is also tritium, which is one proton and two neutrons) - a substance which can be extracted from ordinary sea water where it makes up one in every 5,000 hydrogen atoms. Burning the deuterium from one gallon of sea-water in a fusion reaction produces the same energy as burning 300 gallons of refined gasoline. The promise of nuclear fusion is therefore threefold: 

1. A clean, pollution-free energy source

2. Readily accessible reserves of fuel that would last humanity millions of years

3. No risk of catastrophic meltdowns or proliferation of apocalyptic weapons. 

Fusion energy has the promise to save our planet, and indeed civilization, from ourselves.

Fusion energy from the stars began the ponderous climb up a chemical energy gradient to give us complex organic life, and our utilization of complex hydrocarbons has propelled us from a life that is nasty, brutish and short, towards one filled with glittering steel cities and lives of abundance. For the briefest moment in living history, fission now powers a scattered, all-to-few societies with cheap, reliable power; yet hangs over us the nuclear sword of Damocles - a country with nuclear fission power is a country with nuclear fission bombs. For the great majority, we are beholden by the vicissitudes and geopolitical strife caused, and causing, the fluctuating price of hydrocarbons - our captured, one-time inheritance of fusion energy from ages past. 

The quest to develop fusion energy is not a flash-in-the-pan excitement of venture capital seeking returns in the zeitgeist of the moment, nor is it driven by a military-industrial complex trying to arm itself for the next, and perhaps last, world war. It is the earnest striving of a scientific few on behalf of all mankind to free us from the iron limit on our prosperity, wealth, and abundance: energy. Time and time again energy production has been the king-maker and -breaker among human civilizations. Regardless of the method ultimately used or the company which first brings it to market, it has been fusion energy from the stars which let life flourish on the planet Earth; and it will be fusion energy wrought by human hands on our terrestrial, aqueous globe that sends life out among the stars, to flourish in an age of available, affordable, and boundless power production. 

The next article in this substack is the Fusion Energy Landscape, giving a comprehensive overview of humanity’s quest to harness the ultimate origin of energy.