Runs the actual project physics against a real 90-day winter (Dec 2017–Feb 2018)
recorded at 2,715m in the Georgian Caucasus, with an added 8-day storm worse than
anything in the real record. Storage starts full on day 1 — the assumption
being summer surplus already topped it off before winter began. Switch storage type
to compare hydrogen against Li-Ion or LiFePO4 batteries, using real 2026 pricing and
real cold-weather capacity derating for each.