Electricity is something we use every day, but most of us have very little idea how it is actually generated. I think most of us have a vague notion that there is a power plant out there somewhere, probably burning something, because making something hot has something to do with making power. At least we’re pretty sure that it does. And some who might know a little more about how electricity is generated probably know that it has to do with making steam from those hot things that we burn…somewhere. But let’s be honest: most of us know very little about electricity and where it comes from. Even further than that, what even is electricity? We know that it comes out of the wall and makes things work, but it’s not at all like other things we deal with. It’s not a fluid like water, and it’s certainly not tangible like food or gasoline.
Because most of us know very little about electricity and how it’s made, it’s easy to believe myths or fantasies about how we might get more of it in ways that we hope will be safer or cleaner. But that leaves us open to being deceived in ways that will harm us in the future. It is very important for us to understand how we actually get electricity, and what electricity fundamentally is.
What Electricity Is
At its foundation, what we call electricity is the force that pushes electrons — tiny bits of matter found in every atom — through a conductor, usually a copper wire. We call the force that pushes those electrons voltage, and we call the amount of electrons that are moving current. We push those electrons against various loads, like motors or resistors, in order to make things move or to heat things up.
That’s why electricity isn’t a fluid like water. The physical component of electricity, the electrons, are tiny and are already present in whatever we’re connecting to the electricity. The electrons are already in the copper wires in your house. They’re already inside the motor in your blender. What you’re buying is the force to make them move. To move against a load. To do work for you.
That’s what you’re getting when you plug a blender or a hair dryer into the socket. You’re getting a force that will move the electrons inside those appliances in order to do something that you want. No force, and nothing happens. The blender sits there, not spinning. The hair dryer sits there, not blowing, with no warm air. The force to push those electrons is coming from somewhere else, and when you plug into the wall, you’re getting a little bit of that force — that voltage — that has been created somewhere else. And the amount of electricity you use is being metered and sold to you, probably on a monthly billing cycle by your local power company.
If it helps, think of voltage as pressure and current as flow. Water in a pipe has pressure pushing it and a rate at which it’s flowing. Electricity in a wire has voltage pushing it and a rate at which the electrons are flowing. The analogy isn’t perfect — electricity is not actually a fluid — but the intuition carries. High pressure moves a lot of water through a thin pipe. High voltage moves a lot of electrons through a thin wire. And in both cases, the pressure has to come from somewhere. Somebody, somewhere, is doing the pushing.
Where the Push Comes From
Almost every watt of electricity in the world comes from one physical phenomenon: a magnet moving past a coil of wire.
This is the discovery Michael Faraday made in 1831. When a magnet moves relative to a wire — or the wire moves relative to the magnet, it doesn’t matter which — a voltage appears in the wire. Connect that wire to a load, and electrons will flow. The stronger the magnet, the faster the motion, and the more wire in the coil, the more voltage you get. This is what a generator is. A rotating shaft with magnets on it, spinning past coils of wire, producing electricity for as long as something keeps the shaft spinning.
That’s it. That is how essentially all of the electricity in your house was made. The electrical grid of the United States is, at its heart, several thousand large rotating magnets, each one attached to a shaft, each shaft being kept in motion by something. The magnets themselves don’t do the work. They just translate motion into voltage. The real question — the one that actually determines everything about your electricity bill, your air quality, your energy security, and your country’s economic future — is this:
What is spinning the magnet?
Every argument about electricity generation, when you strip away the marketing and the politics, is an argument about what should be spinning the magnet. That’s the whole debate. Coal plants spin magnets one way. Wind turbines spin magnets another way. Nuclear plants spin magnets yet another way. The wire doesn’t care. The magnet doesn’t care. The electrons in your blender don’t care. What differs — what matters — is the thing that is providing the motion.
What Spins the Magnet
There are essentially three answers to the question of what spins the magnet.
The first is falling water. A river, dammed, is a column of water with potential energy. Let it fall through a turbine, and the turbine spins, and the magnet on the turbine’s shaft spins, and you get electricity. Hydropower is the oldest form of large-scale electricity generation and still provides a substantial fraction of the world’s power. It’s elegant, it’s reliable, and it’s essentially all used up. Almost every river that can reasonably be dammed has been dammed. New hydropower at scale is not coming.
The second is wind. Moving air pushes a large blade, the blade spins a shaft, the shaft spins a magnet. This is also mechanical and direct, with no fire and no steam. Wind, however, is diffuse. A single coal plant the size of a shopping mall produces as much power as a wind farm covering a small county. Wind is also intermittent — when the wind doesn’t blow, the turbines don’t turn, and the electrons don’t move. We will return to this.
The third, and by far the largest, is heat. You take something, you make it very hot, you use that heat to boil water, the water becomes steam, the steam expands through a turbine, the turbine spins, and the magnet spins. This is a heat engine, and almost everything else you have ever heard of as a source of electricity is a heat engine. Coal plants are heat engines. Natural gas plants are heat engines. Oil plants are heat engines. Nuclear plants are heat engines. Geothermal plants are heat engines. Concentrated solar thermal plants are heat engines. Biomass plants are heat engines.
If most of the world’s electricity comes from heat engines, then most of the world’s electricity question is really a question about heat. Where does the heat come from? That is the question.
There is one significant exception to all of this, and it deserves to be named honestly: solar photovoltaic panels. Photovoltaics do not spin a magnet. They do not boil water. They are the one commercially significant form of electricity generation in the world that works by a completely different physical principle — a semiconductor effect that allows sunlight to directly knock electrons loose in a specially prepared material. This is a genuinely different way of making electricity. It’s worth knowing that it exists, and worth knowing that it behaves very differently from everything else. We’ll return to it in a moment.
But if you take solar photovoltaics out of the picture, what you’re left with is this: essentially all electricity on Earth comes from spinning a magnet, and the question of where electricity comes from is almost entirely a question of what spins the magnet — and most of the time, the answer is “heat.”
What Do You Want to Heat the Water With?
If you’re going to run a heat engine, you need a source of heat. That, and nothing else, is what the modern energy debate is actually about. Everything else is a consequence.
There are really only two options for generating industrial-scale quantities of heat: you can burn something, or you can split atoms. That’s the entire menu. Some sources of heat in the natural world — geothermal, solar thermal — are available in some locations, but neither of them can supply a large industrial economy at scale. Every large-scale heat source humans have ever used for electricity generation has been either combustion or nuclear fission.
Burning something means taking a carbon-containing fuel — coal, oil, natural gas, wood, biomass, garbage — and combining it with oxygen from the air. The chemical reaction releases heat, and also releases the carbon that was previously locked in the fuel as carbon dioxide into the atmosphere. The energy content of any chemical reaction, any reaction between atoms, is limited by the strength of the chemical bonds involved, which is to say the behavior of electrons. Every combustion reaction in the universe is governed by the same physics: electrons rearranging themselves as atoms are pulled apart and put back together into different molecules. The amount of energy you can get from a pound of fuel through any chemical reaction is determined by this same electron-level physics, and it is, as physics goes, not very much energy.
Splitting atoms — nuclear fission — is a completely different matter. When you split a heavy atom like uranium or thorium-derived uranium-233, you are not rearranging electrons. You are reaching into the atomic nucleus, which is held together by forces millions of times stronger than the forces between atoms in a molecule. When you break those nuclear bonds, you release correspondingly millions of times more energy per reaction. A pound of uranium contains roughly the same amount of energy as three million pounds of coal. This is not a slogan. This is a fact of physics, as fundamental as any in the natural world.
Everything else follows from this.
Why Energy Density Matters
The energy density of a fuel — how much energy you can extract per pound, per gallon, per cubic foot — is not an abstract technical property. It determines everything about what a power plant looks like, how much land it needs, how much material it consumes, how much waste it produces, and how much it costs.
A large coal plant burns about ten thousand tons of coal per day. That coal arrives by the unit trainload. Every day, every plant. The mine that produces that coal has to dig up a proportional quantity of rock and earth. The rail infrastructure that brings the coal has to move it. The plant that burns it has to store it, handle it, pulverize it, blow it into furnaces, and dispose of the ash. The whole operation, from mine to ash pile, is an enormous industrial undertaking whose scale is dictated by the low energy density of the fuel.
A nuclear plant of equivalent output consumes a few tons of uranium fuel per year. Not per day. Per year. The entire annual fuel supply for a gigawatt nuclear reactor can arrive on a single truck. The waste, after the fuel has been used, amounts to a few cubic meters of material for a full year of operation. Not a few cubic miles of mountaintop removed. Not a few train-lines of coal ash. A few cubic meters.
Now consider the diffuse sources. Wind and solar are not heat engines in the conventional sense, and they do not consume fuel, so the comparison is different — but the physics of low energy density still applies. Sunlight arrives at the Earth’s surface at a power density of about one kilowatt per square meter, at noon, on a clear day, at the equator. Take any of those conditions away — clouds, morning, evening, latitude, season, weather — and the number drops, sometimes to zero. To collect a gigawatt of power from sunlight at even thirty percent efficiency requires several square kilometers of collector area, and the collectors have to be manufactured, transported, installed, maintained, cleaned, repaired, and eventually replaced when they wear out. Every square meter of that collector represents a footprint on the landscape that a higher-density source would not require.
Wind is similar. Modern wind turbines are large because they have to be — the wind is diffuse, so the blade has to be enormous to sweep enough air. A modern utility-scale turbine is the size of a fifty-story building, consumes hundreds of tons of steel and concrete and rare-earth magnets, and produces, on average over a year, a few megawatts. A single nuclear reactor, occupying a few acres, produces a thousand of them.
This is the physical reality behind the supposed “clean energy transition.” It is being proposed, in all seriousness, that we replace the concentrated energy sources that built modern civilization with energy sources that are, as a matter of physics, between one and five orders of magnitude less dense. This has consequences. The land consumed is real. The materials consumed are real. The mining required for the copper, steel, concrete, rare earths, and lithium is real. The environmental footprint of a wind-and-solar grid is not smaller than the footprint of a nuclear grid. It is, by virtually any physical measure, dramatically larger.
The Problem With Diffuse and Intermittent Sources
Let’s be blunt about this because the public conversation has not been.
Wind and solar cannot power a modern industrial civilization. This is not an opinion. It is not a political statement. It is a consequence of physics that would be obvious to anyone who has followed the argument from the beginning of this essay.
First, they are diffuse. We have covered this. To generate the same amount of power as a conventional plant, you need to cover vast areas of land with collectors that have to be manufactured, installed, and maintained. The materials consumed are enormous — more steel, more concrete, more copper, more rare earth elements, per unit of delivered energy, than any other source of power humans have ever used. This is not an improvement over the industrial footprint of the fossil fuel era. It is, by any honest accounting, a substantial increase.
Second, they are intermittent. The wind doesn’t always blow. The sun doesn’t always shine. This is not a problem that can be fixed by better engineering, because it is not an engineering problem. It is a problem of when the energy arrives. The wind delivers energy when the atmospheric pressure differential drives it, not when you want to run your air conditioner. The sun delivers energy during the day and more in summer than in winter, which has nothing to do with when electricity is needed. A grid that depends on wind and solar for a large fraction of its energy has to have something else, something dispatchable, waiting in the wings to cover for them when they fail — which is most of the time.
The something-else, in practice, has been natural gas. Every wind farm and every solar installation that has been built in the last twenty years has been built alongside natural gas capacity that can ramp up when the renewable source drops out. This is sometimes acknowledged, more often not, in the public conversation. The result is that the “renewable” grid is not actually running on renewables. It is running on natural gas with a veneer of wind and solar painted over the top, and the veneer is marketed as if it were the whole.
Third, and most importantly, they do not reduce the cost of electricity. The experiments have been run. Germany’s Energiewende — the most ambitious wind and solar buildout ever attempted by a major industrial economy — has produced some of the highest electricity prices in Europe, a dependence on Russian gas that has repeatedly humiliated the country diplomatically, and a continued reliance on coal. California, pursuing a similar strategy, has the highest electricity prices in the continental United States and routinely experiences rolling blackouts during heat waves. Texas, which has pursued a similar strategy with different politics, had its grid fail catastrophically during a winter storm in 2021. These are the three most aggressive renewables economies in the Western world, and the results are consistent.
Storage is supposed to solve this, and it doesn’t. Batteries exist and they are useful for smoothing out short-term fluctuations — a few hours, maybe a day. But storing seasons of energy, which is what a wind-and-solar grid actually requires in high latitudes, is not something any battery technology in existence can do at remotely affordable cost. The lithium required, the cobalt required, the nickel required, the manufacturing capacity required — the numbers, when you work them out, are absurd. This is not a problem on the verge of being solved. This is a problem that physics does not permit to be solved at the scale required.
The proponents of a wind-and-solar-and-batteries future have had thirty years to demonstrate that their approach can work. They have been given trillions of dollars. They have been given public enthusiasm, regulatory preference, and the benefit of every possible doubt. What they have produced is electricity that is more expensive, less reliable, and no less carbon-intensive than what it was supposed to replace, because the natural gas that is actually keeping their grids running is still burning.
It is time to be honest about this.
The Concentrated Alternative
If you’ve followed the argument to this point, you understand that the physical properties of an electricity source matter. Concentrated sources produce electricity with small footprints, few material inputs, and high reliability. Diffuse sources do the opposite. Intermittent sources, regardless of their energy density, require dispatchable backup, which means they are not really doing the work — the backup is.
There is one source of electricity that is genuinely concentrated, genuinely dispatchable, genuinely reliable, and genuinely carbon-free at the point of generation. It produces heat the way other heat engines do, but the fuel is so energy-dense that a thermos-sized quantity of it can power a typical American household for a lifetime. The material inputs are small. The land footprint is small. The waste, properly handled, is small. It can run through the night, through the winter, and through the calm days when the wind doesn’t blow.
That source is nuclear fission.
The United States, having invented this technology and having pioneered its civilian application, has spent the last fifty years progressively dismantling its institutional capacity to build it. Other countries have continued. France built out its nuclear fleet in the 1970s and 1980s and produces some of the cleanest and cheapest electricity in Europe. South Korea has built nuclear reactors on schedule and under budget for decades. China is currently building dozens of reactors and is on track to pass the United States as the world’s largest nuclear energy producer within the decade. The technology works. The economics work when the regulatory framework is sensible. What has gone wrong in the United States is not the physics. It is the politics.
But even granting all of this, there is a further point. Not all nuclear reactors are the same. The nuclear technology the United States actually deployed — the light-water reactor — is a half-measure. It was chosen in the 1950s for reasons that had relatively little to do with being the best available civilian power technology. It was chosen because it was the technology the Navy had developed for submarines, and because the federal government wanted to standardize. It works. It produces electricity. It has run reliably for decades. But it uses less than one percent of the energy in the uranium it is fed, requires its fuel to be manufactured into solid ceramic pellets clad in expensive metal tubes, operates at pressures a hundred and fifty times atmospheric so that the water doesn’t boil, and leaves behind solid radioactive waste that the country still hasn’t figured out what to do with after seventy years of trying.
It is not a bad technology. It was just not the best available one. And the best available one was already demonstrated, at Oak Ridge National Laboratory, in the 1960s.
The Molten-Salt Reactor
Between 1965 and 1969, a team at Oak Ridge operated a reactor unlike any other reactor before or since. Instead of solid fuel pellets, the fuel was dissolved in a molten fluoride salt that circulated through the reactor like blood through a body. Instead of high pressure, it ran at essentially atmospheric pressure, because the salt does not boil until above 1400 degrees Celsius. Instead of requiring a shutdown to refuel, it could be refueled while it ran. Instead of waiting for the fuel to develop problems from radiation damage, the fuel was a liquid that could not develop cracks or swell. Instead of requiring elaborate emergency cooling systems to prevent a meltdown, it was already melted — the salt was designed to be liquid — and the reactor had a simple passive safety feature in which a frozen plug of salt would melt if the reactor overheated, draining the fuel into an underground tank where the reaction would stop on its own.
This was the Molten-Salt Reactor Experiment, or MSRE. It operated for more than four years. It was fueled first with uranium-235, then with uranium-233, demonstrating that a thorium fuel cycle could actually work in a real reactor. The physics was proven. The chemistry was proven. The engineering was proven. The only thing missing was a follow-on reactor design, a thorium-fueled breeder that would turn abundant natural thorium into a virtually inexhaustible fuel supply.
That follow-on reactor was cancelled in 1972 by the Atomic Energy Commission, for institutional reasons that had very little to do with the technology’s merit. The man who had led the program, Alvin Weinberg, was fired from his position as director of Oak Ridge for continuing to advocate for it. The reactor sat in a building at Oak Ridge. The technical reports were archived. The knowledge began to scatter as the people who had built it retired.
And there, for thirty years, the matter rested.
What had been abandoned was not just a reactor design. It was an entire alternative nuclear future. The molten-salt reactor, particularly one fueled by thorium rather than uranium, has advantages over the light-water reactor that are not incremental but categorical. It runs at high temperatures, which makes it more efficient at producing electricity and also enables industrial process heat applications that a low-temperature water reactor cannot touch. It runs at low pressure, which eliminates entire categories of accident risk. It uses its fuel with essentially complete efficiency rather than throwing away ninety-nine percent of it. It produces a waste stream that is a small fraction of the volume of a light-water reactor’s waste and decays to background radiation levels in a few hundred years rather than hundreds of thousands. It uses thorium, which is four times more abundant in the Earth’s crust than uranium, and which every country in the world has in quantity.
In short: the best civilian reactor technology ever demonstrated is a technology the United States built, proved, and then walked away from. The country has spent fifty years running the second-best option while the best option gathered dust.
What This Means for You
Come back to the blender. Come back to the hair dryer. Come back to the outlet in your wall.
The electrons in the wire of your blender are ready to move. They have been there all along. What you are paying for, every month, is the force that pushes them — and that force was generated somewhere else, by something spinning a magnet, powered by something producing heat, fueled by something that was either burned or split.
You have a stake in what that something is. Not as a matter of virtue-signaling, not as a matter of which lawn sign you plant, but as a matter of what your electricity actually costs, how reliably it actually arrives, what it does to the air you breathe, what it does to the land around your town, and whether your country is energy-independent or vulnerable to the whims of people you never elected.
The honest answer is that the best available choice, by essentially every measure that matters — cost, reliability, land use, material use, waste production, safety, carbon emissions, fuel availability — is a technology the United States invented and abandoned. The thorium molten-salt reactor is not science fiction. It has been built. It has been operated. Its physics is settled. Its chemistry is settled. What remains is the institutional and political will to build it again.
Understanding what electricity actually is — a force that pushes electrons through a wire, a force that had to be generated somewhere, by something spinning a magnet — is the first step toward understanding why the choice of what does the spinning matters. Once you see that choice clearly, you see that the public conversation has been lied to for a generation about what the real options are. The diffuse intermittent sources that have been sold as the future of energy are not the future of anything. They are a very expensive distraction, propped up by natural gas, that has delayed for thirty years the deployment of the technology that could actually do what they have promised to do and cannot.
Energy literacy is civic literacy. Once you understand how electricity is actually made, you understand why the choices being made about how to make it are not choices you can afford to leave to others. They are decisions that will shape the country your children live in. The country that invented the thorium molten-salt reactor still has, in its laboratories and in its archives and in the remaining U-233 inventory at Oak Ridge, everything it needs to finish what it started.
The electrons are waiting in the wire. The question is still: what is going to push them?