Energy Harvesting in Smart Cities

Abstract

Smart cities rely on a plethora of sensors at various locations in urban environments to collect data so that the living standard can be improved using the information gathered. Wired sensors that have limited flexibility and high installation costs are less attractive. Wireless solutions are flexible and low cost to install but their requirement of regular battery replacement introduces a high maintenance cost. By endowing wireless sensors with energy harvesting capabilities to harvest energy from the environment such that they can be energy self-sufficient, the maintenance cost associated with battery replacement can be eliminated, which is a more sustainable and environmentally friendly approach for the realisation of smart cities. This chapter reviews the core elements of an energy harvesting powered wireless sensor system, from the energy harvesters that harvest the energy to the power management circuits that convert the harvested energy into a form that is usable by the wireless sensors, and finally the wireless sensors that collect and transmit data. Kinetic energy is abundant in urban environments due to the dynamism in cities that comes from high human activities. Therefore, this chapter focuses on kinetic energy sources that are available in urban environments and their associated energy harvesters. For the power management circuit, particular attention will be on its key subsystems to achieve a high performance circuit. Finally, the features that make a wireless communication technology suitable for the applications of smart cities with the available energy sources will be reviewed with some example applications given.