ABSTRACT
Nowadays, photovoltaic (PV) panels and thermoelectric generators (TEGs) constitute the most important direct current energy transducers that can be used to harvest energy from the environment and power an autonomous sensor node. They generate a direct current and voltage for constant operating conditions. This chapter presents a description of these energy transducers and their associated energy conditioning circuits. An energy conditioning circuit is used to transfer energy from a PV panel to a storage unit, that is, a battery or a (super) capacitor. Two types of energy conditioners can be distinguished: the direct coupled and the maximum power point trackers. TEGs are used to provide electric energy from a temperature difference between a heat source (hot side) and a cold ambient (cold side). The electrical behavior of the TEGs can be approximated by a Thevenin equivalent circuit.
