Validate PyPSA models against physical/engineering reality - parameter ranges | topology | free energy | cost sanity (zero-marginal-cost electrolyzer = canonical bug). Triggers: check/review/lint/sanity-check a PyPSA network | pre-delivery checklist | is this plausible / does this look right | before solving for real decisions | suspicious results | zero or negative prices everywhere | one technology built without limit | storage cycling that beats thermodynamics | AC-feasibility of optimized dispatch (n.pf | n.lpf, explicit PyPSA context only). PyPSA only; stack ambiguous? VERIFY pypsa deps first.
