A self-powered sensor device (100) is provided which comprises a wireless network unit (140) configured to enable a communication in a Low-Power Wide- Area Network (LPWAN), an energy converting unit (150) configured to convert a first physical quantity into energy, and an energy harvesting unit (110) configured to harvest energy from the energy converted by the energy converting unit (150), and to initiate a sending of a message via the wireless network unit (140) every time a predetermined amount of energy is harvested by the energy harvesting unit (110).