Gasification and combustion of de-oiled Pongamia Pinnata seed cake is done to produce higher energy biomass waste heat “syngas” for generating power using hybrid thermoelectric generator (TEG). A test rig is fabricated and experiments conducted with synthetic oil (Therminol-55) as the heating fluid under water and air-cooled methods. The hot side temperature is varied from 200 - 250ºC while the coolant temperature is maintained at 30 oC for both water and air respectively. Experimental results showed 22.27% enhancement in electric power at a constant hot side temperature of 250 ºC under water cooled method. In addition, simulation results for the above mentioned conditions using artificial neural networks (ANN) tool in MATLAB also agreed well with the sample experimental results. The performance parameters such as open circuit voltage, maximum output power and matched load resistance are forecasted using ANN upto maximum possible hot side temperature of 350ºC. Further, the financial evaluation of Biomass gasified-thermoelectric system ($0.0018/kWh and in terms of Indian currency is ₨ 0.0676/kWh) is found to be almost negligible on comparison with other available renewable energy technologies.