PHOS, the double lamp that combines light and fire

Among the different forms of energy harvesting, i.e., the process through which energy from ‘unconventional’ sources is found and utilized, there is also thermoelectricity, which studies the different phenomena of conversion of heat into electricity and vice versa that occur in all materials. For his thesis project in Product Design at the IED in Cagliari (2021), Gabriele Onnis experimented with thermoelectricity and developed a stable lighting system – called PHOS – that exploits this phenomenon: thanks to heat, electrical energy is produced and stored to activate the luminaire.

“It took almost a year of personal experimentation to come up with a thermoelectric stable open flame system,” Gabriele recounts. The designer collaborated with Veil Energy to develop the thermoelectric system – a technology company based in Bolzano, founded by engineer Marianna Benetti and Klauss Kress – while the system’s evolution was realized in collaboration with engineer Paolo Gobbato. The goal was not only to achieve a stable system but also one that fulfilled thermal, thermoelectric, functionality, and design requirements.

How PHOS works

PHOS consists of two bodies: the bioethanol burner (fuel produced by the fermentation of biomass) and the lamp. The former, thanks to the thermoelectric unit, produces heat which is then converted into electrical energy. This energy, stored and produced by the power unit, is used to operate the lamp. The designer wanted to design two separate elements that had a strong connection during operation.

“The functionality of PHOS is based on the use of Peltier cells, electronic components capable of developing a temperature difference between its two surfaces when an electric current passes through them. This phenomenon is reversible due to the Seebeck effect: in fact, if the cell is subjected to a temperature difference, it behaves like a voltage generator. To keep this temperature difference constant, the cell is coupled to a heat sink and a cooling fan.”

PHOS starts with the energy production unit (the bio-fireplace), consisting of:

  • a stainless steel upper body housing the thermoelectric system,
  • a borosilicate glass cylinder enclosing the flame,
  • a lower steel body housing the bioethanol burner.

The heat is converted into electrical energy by the thermoelectric system enclosed in the upper body. By means of contact points between the base of the burner and the lamp handles, the two bodies come together, allowing the former to transmit electricity to the latter to charge its battery in about 100 minutes. Once charged, the two bodies can also be separated and used independently. The lamp has an adjustable cone diffuser with a switch and LED light.

With PHOS, Gabriele has designed a self-sufficient lighting system for the domestic environment: two transportable light sources, where fire and light are inextricably linked and where thermoelectric energy is produced, stored, and utilized. PHOS currently exists as a single working experimental prototype and has been selected from among the 100 projects in the ADI Design Museum’s temporary exhibition dedicated to Italian designers under 35 “Italy: a New Collective Landscape”, curated by Angela Rui with Elisabetta Donati de Conti and Matilde Losi, which will be presented at the HKDI Gallery in Hong Kong from 19 January to 19 May 2024.

To discover more projects by designer Gabriele Onnis, visit his website and follow him on Instagram!!

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