Robust benefit optimization for virtual power plants with incentive compatible control rights transfer for user-side storage

User-side battery storage often struggles to be profitable when revenue is restricted to time-of-use arbitrage, motivating business models that can unlock additional value through coordinated operation. This paper proposes a virtual power plant (VPP)–controlled framework in which users retain ownership of their energy storage systems while transferring charging and discharging control rights to the VPP under an incentive-compatible compensation mechanism that guarantees non-decreasing user net benefit. On this basis, a VPP profit-maximization model is developed to co-optimize thermal generation, wind and PV utilization, and aggregated user-side storage, subject to portfolio power balance, mode-dependent state-of-charge dynamics, rated power limits, and cycle-life-related degradation costs. Renewable curtailment penalties and settlement rules are explicitly embedded, enabling storage charging to be shifted toward renewable-rich periods and discharging to be scheduled in high-value periods while maintaining user participation constraints. Case studies demonstrate that coordinated control improves renewable-energy absorption, reduces wind/PV curtailment, and increases portfolio profitability, while a feasible compensation band is identified to support contract negotiation and tariff design. The proposed framework further provides implementable guidance on when to activate control rights, how to hedge against forecast uncertainty, and how compensation levels affect participation and value sharing, offering a practical pathway for aggregating distributed storage at scale.