Converting osmotic energy into electrical energy in the cycle, based on charged droplets growth and coalescence

Abstract

Low-grade heat with temperature difference 20-80 C is one of perspective sources of renewable energy. It may be as natural temperature difference (for example, vertical temperature gradient of the ocean or temperature difference between the air and the water), geothermal or waste heat. The way of converting low-grade heat into electrical energy based on solution distilling in a temperature gradient (in fact, converting heat energy into osmotic energy) and further electricity generation in a concentration galvanic cell has attracted much attention lately. The process of concentration galvanic cell activity is very slow, so we developed a concept and made calculations for the process of electricity generation based on coalescence of charged droplets. This process could be divided into two stages: charged drops growth (osmotic energy converts into surface energy) and charged droplets coalescence (surface energy converts into electrical energy). This process appeared to be not so effective as electricity generation in a concentration galvanic cell. However, it is a more rapid process. Besides, it is possible to use any solution, including non-electrolyte solutions.