Hydrovoltaics

Hydrovoltaics (HV) is the conversion of energy using surface tension electrical potentials together with the thermoelectric effect combined with a photoelectric effect within nanomaterial cells. It is a form of natural energy harvesting exploiting various water cycle effects such as latent Sea surface temperatures, raindrops, windwaves, water flows, evaporation and so on.^[1]

A study realised by the Laboratory of Nanoscience for Energy Technology (LNET) at's École Polytechnique Fédérale de Lausanne (EPFL Switzerland) estimated that about one third of the solar energy arriving at the surface of the Earth is initially absorbed by water and that cost effective harvesting can be achieved by the use of various media such as carbon nanotubes, carbon nanoparticles, conductive polymers, and/or graphene.^[2]

When objects with a charged surface come into contact with water the charges on the surface of the water the electrokinetic effect attracts counter ions from the within the liquid, causing an electric double layer. This results in an exponential decrease in the electrical potential as the distance from the surface increases.^[3] It is expected that this potential difference could be usefully exploited in large bodies of water.