Blue energy, sometimes called ocean energy, is a term for the method of generating electricity through the convergence of both fresh and salt water. This energy can be extracted through a variety of means, including tidal power, current power, wave power, thermal energy conversion, and osmosis. Power may also be collected by harnessing the wind power associated with the body of water — usually the ocean.
A type of blue energy extracted by osmosis, also called salient gradient power, employs a large artificial semi-permeable membrane to create reverse electrodialysis from natural marine resources. The energy that results can be used to generate electricity. The only byproduct is brackish water. Brackish water is simply a combination of fresh and salt water which naturally occurs in an estuary.
This type of energy is only useful in certain geographical areas. The only way to create blue energy other than in a laboratory is at an estuary, where fresh water river currents and the saline tides of the ocean meet at the river’s mouth. Though the technology has been understood for quite sometime, manufacturing the membranes was far too expensive to become a practical energy alternative. Recently, more economical membranes have been developed which will allow blue energy technology to begin being implemented in suitable environments.
In addition to blue energy as it relates to reverse electrodialysis, there is also a company called Blue Energy. This company also provides alternative energy but their technology is slightly different. The power generated by the company harnesses the currents of the ocean’s tidal waters using a turbine. The turbine is similar to a windmill except that it works underwater. Harnessing ocean currents is more efficient and predictable than wind power, so it is a good solution for seaside communities.
The environmental benefits of the company as well as blue energy are invaluable. Since both technologies are renewable and do not emit greenhouse gases, the use of this energy where possible will help to reduce global warming and other consequences caused by burning fossil fuels. In addition, blue energy does not take up a lot of space like energy grids do, and ecosystems are not negatively affected as they are with mining and drilling for example.