A tracking device (100) comprises a power module (102) and a tracking operations module (104). The power module (102) includes two electrical power storage cells in the form of a super-capacitor (110) and a rechargeable battery (112); an energy harvester (106) for generating electrical power to charge the electrical power storage cells (110, 112) and a power management controller (108) arranged to control charging of the first (110) and second (112) power storage cells. The tracking operations module (104) includes a GPS module (122, 124) for receiving data about a location of the tracking device (100); a GSM module (126, 128) for transmitting the data about the location of the tracking device (100); a motion sensor (136); and processing means (118) arranged to: detect movement of the device (100) based on an output of the motion sensor (136); and manage receipt and transmission of the data about the location of the tracking device (100).