Systems and methods may provide for an energy harvester to power a mobile device. The energy harvester may include an energy harvesting portion to generate electrical power. At least one sensor may measure an environmental condition relating to generation of electrical power by the energy harvesting portion. A controller may generate a signal based on the measured environmental condition by the at least one sensor to the mobile device. Alternatively the signals from the at least one sensor are place in a memory on the energy harvester. In one example, the controller determines the power generated by the energy harvester and the controller signal includes this power information.