Improved energy storage system & unit commitment scheduling

System operators must schedule sufficient controllable generation ahead of time to compensate unavoidable realtime mismatches between the production and consumption of electricity. If energy storage (ES) facilities are required to provide such flexibility, the technical constraints on the operation of ES must be taken into account in this scheduling problem, which is typically not done in deterministic models. Stochastic optimization enhances the procurement of flexibility, but may require more computational resources. This paper proposes an improved deterministic model for the co-optimization of controllable generation and ES, accounting for the technical constraints of the ES system and arbitrage opportunities with conventional reserve capacity. In a case study, the proposed unit commitment (UC) model is shown to yield significant operational cost reductions without affecting the systems reliability, while the increase in calculation times is limited.