Heating energy harvesting is based on Peltier effect, what means that even not very large temperature difference permits to use it for energy harvesting. The Peltier effect is the presence of heating or cooling at an electrified junction of two different conductors and is named after French physicist Jean Charles Athanase Peltier, who discovered it in 1834.There is a big variety of applications, it is to way effect, you can use it as energy generator and as heat pump. In our case we are speaking about the electricity generation, the good examples are the heat of human body or burning camping fire. It permits to produce electricity for wireless devises solutions and applications. One can charge mobile phone and lightening equipment, volume of charging depends on the heating source and temperature differences, as well as on the solution efficiency.