This paper presents systematic studies of the renewabale energy [RE] technologies and focuses on thermoelectric (TE) technology. The invention of a new equipment is applied to thermoelectric modules (TEM) and demonstrates important capabilities such as in-situ characterization of I-V curve, P-V curves, and TE efficiency. Many variales are invetsigated in order to maximize the output of TE power. Experimental data show that the TE power output is scalable/ additive for multiple TE systems. Multi-stack structures are invetsigated in order to improve the TE efficiency. One of the hightlights of this paper is to generate a large output of TEPG system up to 1kW power. The TE technology is one of the most important RE technologies that has advantages of being renewable, possessing low-noise/ no-moving parts among other features, and having versatile and special applications with TEM. Several sets of the thermoelectric power generation (TEPG) systems are developed with various TEMs for many different applications. Finally, the TEPG is characterized for the experimental investigation and data analysis, followed by summaries and conclusion based on the data.