The whole world is facing challenges for energy supply due to the economic developments, increasing population because of the decrease in oil/gas reserves. Therefore, in current decades, alternative energy sources are in focus to fulfil the energy gap between energy demand and supply. Wind, solar, and biomass are good and sustainable energy sources but – have high installation costs. Henceforth, to find out the cheap, clean, safe, and adequate energy sources is still a prime challenge for the researchers. Power generation by using membrane technology is the new achievement in this list. From the last few decades, pressure-retarded osmosis (PRO) is involved to generate the power, and it offers the opportunity for utilizing osmotic pressure gradients for a wide range of applications. Generating power from the PRO is an emerging platform technology that produces high electric power. In this research area, the membrane science community has expanded huge attention, currently, polymer composite, and nanocomposite membranes are involved in osmosis power generation application. In this chapter, we discuss the treasured insights and tactics for the fabrication and design of highly active antifouling materials and membranes for pressure-retarded osmotic power generation.