New certification framework prioritizes hydrogen bus backup over buildings in zero-emission hubs

A new research paper from Yifan Wang on arXiv (2607.00585) tackles a critical question for zero-emission mobility hubs: how to balance hydrogen bus reserves with building backup power during grid outages. These hubs combine EV charging, hydrogen bus operations, and stationary conversion equipment for nearby critical buildings. The paper introduces a Mobility Safe Adaptive Reserve Certification framework that uses a physics-hybrid building-load model, split conformal reserve calibration, and adaptive conformal inference to handle seasonal drift. The key innovation is a mobility-first scheduling rule that protects post-event bus service before assigning hydrogen to buildings.

Evaluation across 495,221 real EV sessions, AC Transit bus data, and EnergyPlus simulations under 66,816 outage scenarios showed stark results. A mobility-blind hydrogen-export policy served 39.2% of building demand but protected buses in 0% of cases, causing a 426.7 kg mean bus-hydrogen shortfall. In contrast, the certified mobility-first policy achieved 100% commitment delivery, 100% bus protection, and zero mean shortfall, while still serving 20.5% of critical-building demand. Adaptive conformal inference also improved winter coverage from 0.687 to 0.891 overall. The findings prove resilience value depends on service-aware certification, not raw export capacity.