Research Phase 2
Energy autonomous wireless 5G sensors
The aim of this study was to investigate the use of energy harvesting for the energy supply of wireless (5G) sensor platforms in industry. Based on market research on industrially applicable energy harvesters, various components and modules from different manufacturers were procured. Energy harvesting requires an energy source provided either by the process itself or from the environment. Typical energy sources are light, heat, or vibration. The energy harvester (EH) then converts these into electrical energy. A management system ensures the optimized supply of energy to the sensor system. For each EH there is a predefined resistance that defines the maximum energy conversion, the so-called Maximum Power Point (MPP).
Several experiments determined the MPP for different energy sources and manufacturer modules. The maximum energy outputs of the modules were then calculated. One of the vibration EHs achieved a value of 200 mW at 51 Hz. Other vibrations EHs provided values in the range of less than 1 mW to 65mW (module from the company Xidas). The temperature EHs achieved the lowest energy output, with a range of 0.37 mW at 140 °C temperature difference. The use of heat sinks on the EH in-creases the energy output by five times. Solar EHs produce indoor energy output in the range of 0.2 - 2 mW. Fluorescent tubes and LEDs were used as different light sources. The energy consumption measurements for the 5G transceiver Quectel RM500Q resulted in values in the range of 1 - 1.8 W.
Thus, energy-autonomous operation of a 5G sensor platform using EH is only possible if the transmission rate is correspondingly low and a battery is integrated for energy storage. However, an increase in the performance of EH systems as well as an increase in the energy efficiency of 5G transmissions is fore-seeable for the future.
This study provides a first insight into the current performance of EH and how it can be used to power wireless sensor platforms. By using EH, modern infrastructures such as sensor networks could be operated more energy-efficiently. This applies not only to 5G sensor platforms, but also to wireless sensor technology in general.