Generating energy on a large scale by mixing salt and fresh water is both technically possible and practical. The worldwide potential for this clean form of energy — ‘blue energy’ or ‘blue electricity’ — is enormous. However, it will be necessary to work actively on several essential technological developments and to invest heavily in large-scale trials.

On 3 November, Jan Post is presenting his research during his doctorate dissertation on this subject from Wageningen University.

The principle of generating electricity by mixing salt and fresh water, taking advantage of the difference in charge that results, has been known for more than 100 years. It was first tested in practice in a laboratory in the 1950s. There are two methods for generating blue energy: pressure-retarded osmosis and reverse electrodialysis.

Post, in his research, has focused mainly on the latter because it is the more attractive method of generating energy from sea and river water. With his research into the practical applicability, techniques and preconditions for large-scale energy generation from salinity gradients, he was the first to demonstrate that very high yields are possible. In the laboratory, it is possible to recover more than 80% of the energy from salinity gradients; the technical feasibility would be 60-70% and the economic feasibility a little lower than that.

There are differences among continents: the technical potential in Australia (65%) or Africa (61%) is greater than in South America (47%). There are also considerable differences between rivers — there are 5472 large rivers worldwide. These differences depend on the salt concentration in the rivers and seas, temperature, and environmental factors. The Rhine is one of the most ‘energetic’ rivers in Europe.

Read more . . .

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Tags: blue energy, energy generation, generating electricity, river and sea, salinity gradients, salt concentration

This entry was posted on Sunday, November 8th, 2009 at 11:35 am and is filed under Consider This, Cutting-edge Research, Innovation, Project Energy, Science Digest / Science Daily, disruptive innovation, environment. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.