RAIDE Atom: Economic Viability of a Price-Responsive Hydroelectric Edge-Computing Node for Renewable Curtailment Mitigation

Iberian electricity markets recorded over 740 curtailment hours in 2024 — structural surplus that transmission investment cannot resolve at competitive cost. This paper proposes RAIDE Atom, a modular 2 MW edge-computing node co-located with hydroelectric infrastructure, converting surplus energy into AI compute at M_net = 1,053–1,159 €/MWh (η_occ = 0.85, γ = 1; canonical Φ_B = 26.6× at full throughput; operational Φ_ops = 23.2× at γ = 0.875) — a 23×–25× multiplier over spot price, quantifying the Pigouvian gap between private and social value. A four-state demand-response automaton with sub-50 ms OMIE transitions achieves a 67× infrastructure cost advantage over HV transmission. Ten audited constants yield a canonical full-site payback of 1.3 years (regime occupancy) and a ramp-up-adjusted discounted payback of 3.1–3.7 years (IRR = 33.4%). Simulation over 8,759 real OMIE 2024 observations confirms Φ ≥ 16× under all simultaneous worst-case assumptions. Cross-validation at four Iberian nodes (Miranda do Douro, Alqueva, Belesar, Ricobayo) confirms consistent payback across scales, with drought sensitivity and WACC analysis confirming structural viability. Revenue at Miranda do Douro M0: 208.6 M€/yr (simulation); full-site M4: 1,502 M€/yr. Key invariants: Φ_B = 26.6× (canonical); M_net = 1,221 €/MWh; CAPEX = 337.5 M€; IRR = 33.4%; payback 1.3 yr (regime), 3.1–3.7 yr (DCF). Companion papers: C1 Invariant (theorem): https://doi.org/10.5281/zenodo.19520817 C2 Selection (framework): https://doi.org/10.5281/zenodo.19520816 Keywords: RAIDE, edge computing, hydroelectric, renewable curtailment, Iberia, OMIE, demand response, AI compute, economic viability, payback analysis, IRR, sovereign AI