How low? Cell phone low? Clock radio low? Time and temperature display low? What devices would find it a suitable power source?
Probably more than enough for sensors like this. The internet of things is looking at harvesting ambient radio waves particularly Wi-Fi and 4/5G signals to power sensor nodes. Since both of those signals are pretty much everywhere urban and suburban now.
https://www.power-and-beyond.com/ultra-low-power-technology-for-battery-less-iot-sensors-a-885246/