The world economy is growing rapidly, and global energy demands are predicted to increase even more in the future. Energy is expected to get more expensive, in turn affecting the economic development. Energy demand can be reduced by employing efficient Energy Management Systems (EMS). The required infrastructure cost for EMS is often quite high, making it an unviable solution. However, new Internet of Things (IoT) based solutions can help to reduce the installation effort as well as cost significantly. Low-Power Wide-Area Networks (LPWAN) hold the solution to this problem. The goal of an LPWAN is to provide cheap nodes and communication distances of a few kilometers (5-10 km) with a low battery consumption rate (5-10 years). The data transfer rate is low, but the range and power consumption make it ideal for environmental data acquisition (samples per few minutes). The current wireless technologies, such as ZigBee, Bluetooth, and Wi-Fi, that are being used for wireless sensors are not suitable for industrial use where the number of connected devices is significantly higher, and reliability is of dire need. Therefore, in this work, a study of available LPWAN technologies is carried out which concludes in the selection of LoRa technology for communication in an EMS. Furthermore, we evaluate possible communication distances of the LoRa technology in an industrial area by conducting several range tests which result in significantly higher communication distances as compared to legacy WAN technologies. LoRa has proved to be a good start for adopting LPWAN, especially in applications such as energy management systems. Based on that, we present a system architecture for an EMS using LoRa as the underlying communication technology as well as a prototypical implementation of it. This implementation is furthermore integrated into the current EMS of Enisyst. LoRa-modulation combined with LoRaWAN communication protocol proves to be a base for a reliable and scalable system.