Pinpointing secure and reliable methods of renewable-energy generation remains a challenge for policymakers, energy analysts, industry experts and researchers alike. Indeed, it has become increasingly apparent that no "one-size-fits-all" approach to this dilemma exists. This thesis therefore examines a relatively unknown form of small-scale renewable energy generation, namely micropower energy harvesting, which offers a novel and innovative solution to the clean-energy crisis by enhancing energy security, curtailing energy consumption and reducing material and installation costs. Micropower energy-harvesting devices harness the power of energy sources widely available in the ambient, including chiefly mechanical, thermal, solar and magnetic energy, and transform it into useable electricity. As the power output of micropower harvesting modules is in the microwatt to milliwatt range, these technologies can replace or augment the lifetime of batteries in ultra-low power devices, such as wireless sensor networks (WSNs), but have the potential to reclaim waste-heat from the tailpipes of automobiles, to power medical implants and to reduce the conventional power consumption of everyday devices such as mobile phones and laptops, offering numerous benefits to the developed and developing world. Although energy harvesting already constitutes a viable option for WSNs, the results of this thesis reveal that limitations in power output are currently preventing large-scale implementation. Nevertheless, policy-based conclusions and recommendations are offered, and a summary of near-future technological readiness levels and areas of future application, in both industrialized and developing nations, is presented.