Power is the rate, not the total
Energy is a quantity (joules, kilowatt-hours). Power is a rate — the joules-per-second the machine is moving right now. We measure it in watts. A watt is a joule per second.
Run a 1 W bulb for a year and you used 8,760 Wh. But for thinking about civilization, the year-of-bulbs framing is noisy. The cleaner question is: how big is the pipe? The answer for the pipe is in watts.
- 1 GW — one large nuclear reactor.
- 500 GW — the United States, average continuous draw. Peaks above 1,000 GW on hot days.
- 3,200 GW = 3.2 TW — the entire global electric grid.
- 19,400 GW = 19.4 TW — total human civilization, electric plus everything else.
The scoreboard
Earth's power rating, as a single machine:
- Total civilization power: ~19.4 TW. Cars, factories, heaters, lights, livestock, planes.
- Electric power: ~3.2 TW. The grid. The wires. The clean part of the machine.
- The gap: ~16.2 TW. Heat. Fire. Fossil fuels burned for warmth, motion, and industrial process heat.
Only 16% of the machine runs on electricity. Anyone who says we are close to a clean energy transition is rounding aggressively.
Why we burn things
The reason for the gap is not stubbornness. It is energy density.
- A 50-pound backpack of gasoline drives a car ~300 miles.
- A 50-pound backpack of lithium batteries drives a car ~5 miles.
Electricity is hard to carry. Hydrocarbons are easy. We pay for that ease with the 16.2 TW heat slice and everything that comes with it.
Closing the gap means two things, both hard:
- Lighter batteries (so we can carry electric power).
- Bigger wires (so we can move electric power).
What this implies for AI
AI compute is currently a small slice of the electric grid — ballpark 0.1 TW out of 3.2 TW. But it is doubling every two years. The bottleneck is not transistors. It is wires. A frontier training run that wants 1 GW of continuous power has to find that GW on a grid that is already serving everyone else.
The next two pages are about that grid: where the 19.4 TW actually goes, and how far we are from a civilization that doesn't need to burn anything.