One of the key issues with the Internet of Things (IoT) is energy consumption. This type of network is mainly composed of connected objects supplied by an unreliable power source. Wi-Fi HaLow is one of the telecommunication technologies that proposes to connect IoT objects by providing energy optimization mechanisms. It allows the integration of a full IP stack and the implementation of recent security mechanisms. In this article, we introduce power consumption measurements performed on the first device available on the market. In our study, we integrate the current consumed by the power amplifier in transmission phase, and we qualify the power-saving mechanisms. We then propose an analytical model to determine the energy consumed by a sensor node depending on the carried payload. Finally, we validate the use of this technology in IoT application in terms of energy consumption.