thermodynamics

How hydrocarbon combustion releases energy as heat, the four canonical thermal cycles that convert that heat into mechanical or electrical work (Rankine, Brayton, Otto, Diesel), why combined-cycle gas plants reach 60% efficiency, and how carbon intensity scales with cycle and fuel choice.

The handful of quantitative concepts that make every energy debate readable — joules and watts, energy density, capacity factor, levelized cost of energy, exergy — and what each one is good and bad at communicating.