The area of smart energy systems and technologies (SEST) has witnessed both impressive growth and significant investments in recent years. Smart energy systems and technologies are enabling more efficient management of energy usage and supply and better planning for outage response and recovery, as well as the integration of heterogeneous technologies such as electric vehicle networks, renewable energy systems and connected consumers. Nonetheless, major research questions and engineering challenges remain, in particular in the light of increasing data streams from different parts and components of energy systems, as well as the need for enhancing their physical and cyber resilience.