Abstract: There is provided a self-powered energy harvesting system for harvesting electrical energy from the environment for feeding a load, the system comprising a first energy harvester for generating first electrical energy having a first input voltage from the environment; a first local storage unit for storing the first electrical energy after conversion; a passive startup circuit connected to the first energy harvester for harvesting, converting and storing the first electrical energy inside the first local storage unit; a second energy harvester for generating second electrical energy having a second input voltage from the environment; and an active circuit connected to the first local storage unit, to the second energy harvester and to the load for extracting and using the first electrical energy stored in the first local storage unit for harvesting, converting and directing the second electrical energy to the load, the second input voltage being insufficient for operating the active circuit.