which led to the concept of thermoelectric refrigeration [19]. Today,
the commercial types of TECs consist of P-type and N-type blocks of
semiconductor materials.When electrons pass through P-type to Ntype
semiconductors, cooling effect occurs.
Thermoelectric coolers (TECs) have no moving parts, so, they have
a long life. They are noiseless, simple, compact in size, easy controllable,
suitable for low capacity or case in which the energy cost is not
the main consideration. These equipments can operate in any position,
and they have no any leakage problems. TECs can efficiently
work with photovoltaic panels due to the low-voltage requirement,
and they can accept a power supply directly from PV panel. Because
the performance of Peltier devices is almost independent of its capacity,
they have definite advantages for cooling small enclosures. So
many manufacturers use them for cooling cold boxes especially
when the power source is 12 V. The thermoelectric devices are also
insensitive to movement, so they are attractive for use in portable devices
[