Solar electricity is now the cheapest form of new generation in most of the world. Iron-air and sodium-ion batteries are entering commercial deployment at price points that begin to make multi-day grid storage viable. Enhanced geothermal is moving from demonstration to deployment in Nevada and Utah. The underlying physics of energy is no longer the constraint. The constraint is who owns the wires, the meters, the storage, and the rights to the sun and the wind.
Energy is the foundational falling cost, because it sets the floor under every other falling cost in this section. Compute is electricity. Water purification is electricity. Vertical agriculture is electricity. The price of a kilowatt-hour, and who collects rent on it, structures everything else.