Thermoelectric generator using water gas heater energy for battery charging

This work deals with the design and a prototype implementation of a maximum power point tracker (MPPT) for a thermoelectric (TE) module aiming to improve energy conversion efficiency in battery charging. This system uses TE devices that directly convert heat energy from a water gas heater to electricity to charge a battery. The TE module exhibits a non-linear I-V characteristic and its maximum power point varies with the change of its surfaces temperatures. A SEPIC (single-ended primary inductance converter) DC-DC converter is applied and controlled by a microcontroller and to achieve the maximum power point tracking it is used the perturbation and observation (P&O) algorithm. The microcontroller will also control the charging process of lead-acid battery making an autonomous system that is used to feed the necessary electronics that controls an autonomous gas water heater system. The objectives of this work are to study the principle of TE power generation and to design and develop a TE battery charger that uses heat of a water gas heater system making an autonomous electrical system. The two different charging stages of a lead-acid battery lead us to a good interface board. Finally, experimental results performance of the first stage of charge using P&O MPPT algorithm are presented and compared with the results achieved with the direct connection of the TE module to the battery.