A method, system and tag for low power radio frequency communication are described. In one embodiment, the RF tag comprises: a radio, an energy harvesting unit operable to convert incident RF energy to direct current (DC), a storage unit to store recovered DC power, one or more sensors for sensing and logging data, and a microcontroller coupled to the energy harvesting and storage units, the one or more sensors and the radio, the microcontroller operable to wake up from a sleep state and cause the radio to communicate, sensed data from at least one of the one or more sensors while powered by energy previously harvested and stored by the energy harvesting and storage unit.