Environmental Energy
Research Collaboration

Reverse Electrodialysis

Electrodialysis (ED) is the process of the electrically charge induced diffusion of ions through ion selective membranes. It differs from osmosis, in that in osmosis, typically water diffuses through a non-selective but semipermiable membrane under pressure leaving the ions more concentrated in the original solution. In ED, this process is reversed. The ions are selectively attracted through selective membranes leaving purer water behind. This is potentially very efficient because usually water consists of the vast majority of the material, and the ions – usually pollutions are a small part of the solution.

If the process is reversed and fresh and salt waters are used as inputs, a process of Reverse Electrodialysis (RED) will generate electricity from salty or polluted water. It is exactly the reverse process of ED and will proceed with roughly the same efficiency – however measured.

The research project extends the known technology of Reverse Electrodialysis into a new region that will be commercially useful as a renewable energy resource.

Currently proposals are being made for the research and disclosure is not possible as patent protection is being sought.