The book offers a study of the concepts, existing technologies, and design principles necessary for energy harvesting to be applicable in creating perpetual and infinitely operating wireless sensor nodes and sensing devices. It emphasizes the application of developed practical implemented energy harvesting systems like building, automotive, etc. The book describes how energy harvesting can complement the limitations of legacy batteries in emerging applications. The various sources of energy that can be harnessed, and the integration of cutting-edge energy generation, storage technologies, and power management techniques, are discussed in basic terms. The most recent advancements and developments in energy harvesting systems are covered in detail; including methods of performance enhancement and advances in both low-power electronics, as well as how these optimized EH-WSN systems are successfully integrated into real-life deployments/applications.