Where river water flows into the ocean, the energy that is released is equivalent to the river water flowing over a dam 250 meters high, which is more than the height of the Hoover Dam in the USA. This energy release is due to salinity differences between the fresh water and seawater. The Logan Lab and others around the world are working to harness this salinity gradient energy using many different technologies.
Much energy is also lost as waste heat, commonly described as < 100 or 130 deg C. For example, power plants are typically only 33% efficient, and thus much heat energy lost as the temperatures become are too low for conventional electricity production using turbines. The Logan Lab is also examining new technologies to convert waste heat into electricity, for example by using thermal salts such as ammonium bicarbonate in reverse electrodialysis (RED) stacks, or in thermally regenerative ammonia batteries (TRABs).
There is only limited information on the older Logan Lab website on salinity SGE and TRABS. We have now developed a new new website on these technologies. Therefore, you might want to check out both.
Click here to connect to the new SGE & TRAB website at (http://sites.psu.edu/energyfromwater/)