The development of IoT instrumentation will always be strongly influenced by the properties of the power supply system. A large number of IoT nodes creates a danger of extra expenditures when changing the battery. For this reason, the development of supply nodes tends to prefer systems capable of battery-less operation, obtaining energy from other sources. This article deals with an alternative method of electrical energy acquisition form the excessive heat appearing in LED lighting fixtures utilizing large-area LED chips. A Peltier cell was used for the conversion of heat energy to electrical energy, connected as thermo-electric generator into the thermal chain.