This chapter explores the transformative impact of 5G and beyond networks on local energy systems, emphasizing the potential benefits and addressing key challenges. It begins with an overview of the evolution of mobile networks, highlighting the technical requirements and services enabled by 5G technology. The role of communication systems in advancing local energy systems, facilitating real-time data exchange, efficient energy distribution, and enhancing system reliability is discussed. The chapter then examines how 5G-enabled technologies and applications can support localized energy systems, focusing on areas such as smart metering, dynamic pricing, energy theft detection, and blackout prevention. However, the integration of 5G networks introduces significant research challenges, particularly concerning cybersecurity, consumer privacy, and service scalability. To address these challenges, the chapter proposes potential solutions, including the use of advanced encryption techniques, federated learning, edge computing, and network slicing. By leveraging these innovations, 5G and beyond networks can support the development of secure, scalable, and efficient local energy systems, promoting sustainable energy management and resilience.