This article presents an experimental analysis of the use of signals transmitted by Wireless Local Area Networks (WLAN) based on the IEEE 802.11b/g standards for Radio Frequency Energy Harvesting (RFEH) applications in indoor environments employing a Quasi-Yagi Rectenna (QYR) topology. This analysis is a crucial point to distinguish the use of the IEEE 802.11b/g standards for ambient RFEH applications and contributes to the debate on the use of different types of energy available for free in modern society. For it, a dedicated setup, developed in a controlled environment to avoid any external interference, was built to carry out the programmed measurements. The results obtained indicate that IEEE 802.11b/g standards have great potential for applications in RFEH, with the IEEE 802.11b average power four times higher than IEEE 802.11g at the rectifier output.