Energetic idiot index
I_E = actual cradle-to-gate energy ÷ thermodynamic floor. The joules-based, "above Musk" lens: how far the actual energy to make a unit sits above the minimum the physics demands for the same atoms (mining, reduction, purification, crystal growth, fab). Each side carries a citation or a labelled estimate.
Full cradle-to-gate energy per leading-edge wafer
2,300×
medium confidence
Actual · Fab electricity per wafer (company avg)
7,200 MJ
cite ↗ semivision-tsmc-power-2024
Floor · Thermodynamic floor (Si in one wafer)
3.1 MJ
cite ↗ nist-quartz
The full chip stack burns ~2,000–3,000× the thermodynamic minimum for its silicon — vast headroom, the energetic industrial-explosion signal.
Metallurgical silicon smelting (per kg Si)
2×
high confidence
Actual · Submerged-arc furnace electricity
43 MJ
cite ↗ si-energy-exergy
Floor · Reduction enthalpy ΔH
24.6 MJ
cite ↗ nist-quartz
The smelting step is already close to its floor (~2×) — the silicon-winning chemistry is near-optimal. The waste is all downstream.
Siemens polysilicon purification (per kg)
78,000×
medium confidence
Actual · Electronic-grade Siemens energy
Floor · Ideal separation work
0.005 MJ
est.
Purification is the single most thermodynamically wasteful step — ~78,000× the ideal separation work. The biggest energetic opportunity in the stack.