C5: RAIDE at National Scale — Floating Photovoltaics, Green Hydrogen, and AI Compute Co-production at 82 Portuguese Hydroelectric Nodes

This paper provides the first national-scale validation of the RAIDE framework across all 82 eligible Portuguese hydroelectric nodes, using primary data from SNIRH/APA (reservoir areas and volumes), IGP (geodetic coordinates), REN/EDP annual generation reports (2019–2024), and PVGIS-SARAH2 (irradiance, JRC). The structural multiplier Φ_ops = 23.2× (operational; canonical Φ_B = 26.6×) is confirmed to hold universally for all 82 nodes, and the IST invariant Σ(0)_ops = 21.18 ≫ 1 is verified consistently with the domain-invariance property established in C1. Three IT scenarios are evaluated: S1 (conservative, 462 MW from historical spillage), S2 (design scenario calibrated to Miranda M4, 2,817 MW), and S3 (alternative conservative, 2,135 MW). Under S2, aggregate compute revenue reaches €20.4 B/year, with 504 M€/year from floating photovoltaics (FPV, 13,546 ha, calibrated to the Alqueva 41 ha pilot) and 38.6 M€/year from co-located PEM green hydrogen (563 MW, 7.7 kt H₂/year). All 82 nodes satisfy the C2 screening criterion (Φ_ops ≥ 10×), confirming 100% national eligibility. Total CAPEX is 28.2 B€ with mean simple payback of 1.4 years. DCF analysis of the top-10 nodes (C4 Economic Model v2.0, WACC = 10%, empirical ramp-up) confirms IRR = 25.8–30.0% and discounted payback of 4.3–4.9 years. The paper includes per-node PEM electrolyser dimensioning operating during the 774 h/year of zero-or-negative OMIE prices recorded in Portugal in 2024. This paper is part of the RAIDE series: C1: A Structural Invariant — DOI: 10.5281/zenodo.19558936 C2: A Four-Axiom Framework — DOI: 10.5281/zenodo.19558932 C3: RAIDE Atom — DOI: 10.5281/zenodo.19558933 C4: RAIDE Network — DOI: 10.5281/zenodo.19559468 C5: RAIDE at National Scale (this paper) — DOI: 10.5281/zenodo.19559402