Possible Negative Environmental Impact

Although the use of salinity gradients is a considerably environmentally friendly method of obtaining electrical power, there are possible negative affects to be considered. There is at least one ways in which the use of this method of power production could harm the environment; the impact of the brackish water waste on the local marine and river environment.

Marine and river environments have obvious differences in water quality, namely salinity. Each species of aquatic plant and animal is adapted to survive in either marine, brackish, or freshwater environments. There are species that can tolerate both, but these species usually thrive best in a specific water environment. The main waste product of salinity gradient technology is brackish water. The discharge of brackish water into the surrounding waters, if done in large quantities and with any regularity, may alter the aquatic environment significantly. Fluctuations in salinity will result in changes in the community of animals and plants living in that location. However, while some variation in salinity is usual, particularly where fresh water (rivers) empties into an ocean or sea anyway, these variations become less important for both bodies of water with the addition of brackish waste waters. Extreme salinity changes in an aquatic environment may result in findings of low densities of both animals and plants due to intolerance of sudden severe salinity drops or spikes. The disappearance or multiplication of one or more aquatic organisms as a result of an influx of brackish water has the potential to cause ecosystem imbalance. The possibility of these negative affects should be considered by the operators of future large blue energy establishments. In general, the estimated impact of this technology is very limited to non-existent in comparison with current power production methods.