LCOH Hybrid Model: Capacity-Weighted Blended Levelized Cost of Hydrogen — Derivation, Sensitivity Analysis, and Cost Tier Reference (PEM + Al–Water, 70:30 Split)

Transparent computation of the capacity-weighted blended LCOH for a hypothetical hybrid PEM electrolysis + Al–water thermochemical hydrogen production system (70:30 baseload:peak-shaving split). Contains: base case inputs and sources, step-by-step equations, full sensitivity analysis (±30% Al scrap price, ±25% solar LCOE, 60:40 and 80:20 capacity splits), robustness summary, and five-pathway cost tier reference. IMPORTANT: All values are model-based projections derived from separately published cost ranges; they have NOT been validated against integrated pilot-scale systems.