Tiers, thresholds, and trade-offs: Policy design for U.S. 45V hydrogen credits

An uncertainty-aware optimization framework is applied to evaluate and refine the U.S. IRA 45V clean hydrogen production tax credit. A plant-level database of prospective U.S. hydrogen projects is coupled with techno-economic and life-cycle analysis (TEA–LCA) under Monte Carlo simulation to derive distributions of levelized cost of hydrogen (LCOH) and greenhouse-gas (GHG) intensities. Incentive designs are optimized across two accounting scopes—gate-to-gate (GtG) and well-to-gate (WtG)—and three functional shapes—four-tier step, linear, and reciprocal—by minimizing the production-volume-weighted standard deviation of net LCOH under a same government expenditure constraint. Across average government expenditure 0–2 $/kgH2, the WtG-Step consistently delivers the lowest market fairness metric. In low-expenditure regimes (below 0.6 $/kgH2), WtG attains the same fairness as GtG with about 25% less expenditure. Applied to the probabilistic U.S. plant dataset, the enacted 45V policy implies a mean expenditure of 0.82 $/kg (3.6 billion $/yr) and a fairness metric of 0.55 $/kgH2, comparable to an optimized WtG–step design at the same mean expenditure (≈0.49 $/kgH2). The policy's four-tier thresholds also closely align with the optimized locations, jointly suggesting that 45V is near-optimal for the market-fairness objective under the study's assumptions and dataset. Policy implications are twofold: For countries relying on domestically produced hydrogen, adopting a WtG scope improves market fairness. A four-tier step provides a robust default, while reciprocal-style front-loading can accelerate early deployment of low-carbon, high-cost technologies; mid-tier slopes can act as micro-levers that encourage operational decarbonization without conferring windfall gains.