Mobile phone company European Telco Orange has
introduced a phone charging prototype — a set of thermoelectric gumboots or
Wellington boots with a 'power generating sole' that converts heat from the
wearer's feet into electrical power to charge battery-powered hand-helds.
The
boot was designed by Dave Pain, managing director at GotWind, a renewable
energy company. Pain said the boot uses the Seebeck effect, named after
physicist Thomas Johann Seebeck, in which a circuit made of two dissimilar
metals conducts electricity if the two places where they connect are held at
different temperatures.
"In the sole of the Wellington boot there's a
thermocouple and if you apply heat to one side of the thermocouple and cold to
the other side it generates an electrical charge," Pain told Reuters
Television. "That electrical charge we then pass through to a battery
which you'll find in the heel of the boot for storage of the electrical power
for later use to charge your mobile phone."
These thermocouples are
connected electrically, forming an array of multiple thermocouples
(thermopile). They are then sandwiched between two thin ceramic wafers. When
the heat from the foot is applied on the top side of the ceramic wafer and cold
is applied on the opposite side, from the cold of the ground, electricity is
generated.
After a full day's festival frolics music lovers can plug their
phone into the power output at the top of the welly and use the energy
generated throughout the day to charge their phone. But the prototype boot does
have one drawback. You need to walk for 12 hours in the boots to generate one
hour's worth of charge.
