Energy Optimal Control of a Multivalent Building Energy System using Machine Learning Topics: AI-driven approaches for smart buildings; Algorithms for Reduced Power, Energy and Heat; Energy Management Systems (EMS); Optimization Techniques for Efficient Energy Consumption; Power Consumption; Smart Energy Storage; Urban Monitoring and Optimization In Proceedings of the 10th International Conference on Smart Cities and Green ICT Systems SMARTGREENS - Volume 1, 57-66, 2021