ELECTRON (rEsilient and seLf-healed EleCTRical pOwer Nanogrid) focuses on the critical vulnerabilities in Electrical Power and Energy Systems (EPES), which are increasingly exposed to cyberattacks, privacy breaches and data-related attacks due to the growing digitisation and interconnectivity. Securing these systems is vital for societal well-being, economic stability and national security, as potential disruptions can lead to catastrophic effects, including widespread blackouts, financial losses and risks to essential services. Therefore, ELECTRON delivers a new security and safety ecosystem that combines both cyber and energy-related security countermeasures in order to detect, correlate, prioritise and mitigate large-scale attacks against energy domains in a timely manner. To this end, ELECTRON first introduces a collaborative risk assessment framework that combines dynamic risk assessment, cybersecurity certification, and energy honeypots that act as security controls. Second, ELECTRON provides a set of anomaly and intrusion detection systems orchestrated by a Security Information and Event Management (SIEM) system. These detection systems leverage both Federated Learning (FL) and Fully Homomorphic Encryption (FHE) in order to counter privacy concerns. Third, ELECTRON provides both threat exploration and information-sharing services, enabling energy stakeholders to stay one step ahead of zero-day threats. Next, ELECTRON integrates attack mitigation mechanisms, including Software-Defined Networking (SDN), grid reconfiguration, intentional islanding schemes and grid restoration. Finally, following the EU regulations, including (a) the General Data Protection Regulation (GDPR), (b) the European Union (EU) Cybersecurity Act and (c) the EU AI Act, to enhance security awareness and preparedness, ELECTRON introduces advanced training and certification platform that leverages cutting-edge augmented reality (AR) and virtual reality (VR) technologies. To conclude, ELECTRON as a whole was validated successfully in four large-scale use cases that integrate all the stakeholders of the energy chain.