Abstract: Power distribution is the most important part of smart grid therefore it is becoming increasingly important in recent years. In order to make the distribution network smarter and more reliable, numerous sensors located widely in the grid are required for data collection. These sensors are mostly wireless connected therefore powering these wireless sensors is a key problem the grid will encounter. Due to the work condition of the sensors, the power supply must be small, reliable, and maintenance free. These features eliminate the traditional battery from our choices. Recent explorations have been carried out to find alternatives. There are various sources of energy available in the power grid, for example solar energy, magnetic field energy, electric field energy, radio frequency energy. Harvesting power from these energy sources can potentially fulfill the power demand for the sensors. This paper will analyze the work conditions of the sensors and discuss the use of different power harvesting technologies in the grid.