<p>The transition to inverter-based renewables reduces grid inertia, compromising frequency stability. Concurrently, the upscaling of wind turbines intensifies structural fatigue. To address this dual challenge, we propose a “Structure-Grid Synergy” framework that redefines wind tower gravity energy storage (WTGES) as a multi-functional system combining active tuned mass damping with inertial support. Using high-fidelity simulations across scales from 300 kW to 101 MW, we demonstrate that WTGES reduces grid frequency deviations by 11–16% while suppressing tower displacement by 62.4%. This damping effect significantly mitigates dynamic fatigue loads, establishing a theoretical upper bound of a nearly 50-fold extension in tower service life under idealized assumptions. Techno-economic analysis reveals a low power-specific cost of 247–607 USD kW⁻¹, though energy storage costs remain high (2611–5807 USD kWh⁻¹) due to physical constraints. Global technical assessment identifies a technical upper bound for hosting capacity of ~200 GW, translating to 4.8 GW of effective inertial power but limited energy storage (0.25 GWh). By value-stacking frequency regulation revenue with potential reduced structural maintenance, WTGES shows promise as an infrastructure-compatible pathway for enhancing grid stability and structural resilience in next-generation wind power systems.</p>