View YT video below to see the two
different versions of the Peltier lamp: 
cube shaped, or with curved edges.

Energy harvesting with Peltier elements

To convert heat into electricity this lamp uses two stacked TEC1-12706 Peltier modules in series. One side of the compound is heated by a candle flame while the other is cooled with a fan. A DC/DC boost converter type LTC3105 raises the output voltage from the Peltier modules to a suitable level for operating a USB LED lamp model Jansjö from IKEA. A puzzling feature of this design is the fan being powered also by the electricity generated by the Peltier modules. Despite this, the power available to the USB lamp equals or even exceeds the value obtained without the fan.