Energy harvesting for smart city applications

The 'smart cities' concept is now becoming a reality: cities are increasingly connected and intelligent, with rapid advances in diverse areas including transportation, utilities, and municipal services. These can allow services to be delivered more efficiently and reliably, enriching residents' and visitors' experiences, and the data generated can be used for innovative new applications. While many sensors enabling these applications can be grid-powered, there is an increasing need for autonomous distributed or wearable sensing devices, which may also perform edge analytics. While these systems are typically powered by batteries so that they can be deployed quickly and cheaply, this comes with the cost of periodic battery replacement. This paper surveys the state-of-the-art in smart city sensing applications and considers their future directions, focusing on the power demands of sensors, and considerations for using energy harvesting.