Blue-energy, renewable energy of the future?

Blue-energy, renewable energy of the future?

Jolanda Heunen - 24 February 2015

Renewable energy is the energy of the future. Sources such as the sun, wind, and tidal power are already well-known for delivering green energy, and now got company from a relatively new form: blue-energy.

About the author

Ms Jolanda Heunen
Jolanda Heunen is Editor Print & Online for Managing Aging Plants and 3D fab+print. She is also Conference Coordinator for the Managing Aging Plants (MAP) Europe 2017 Conference & Expo.
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Researchers from Utrecht University in The Netherlands recently announced that they discovered a way to triple the energy produced from blue-energy plants. This means a real breakthrough, and the simple innovation involved has led to renewed interest in blue-energy plants as a possible source to meet large-scale energy demands. Stainless Steel World News dived into the matter to explore the topic.

What is blue-energy?

Blue-energy is generated where fresh water and salt water meet. There are several ways to generate energy out of this, but we’ll stick to the way that is used in the test plant in The Netherlands, for this method seems to be very promising. At a site where a river flows into the sea you have the perfect spot to build a blue-energy power plant and this is exactly what has been done in The Netherlands. At the end of 2014, his Majesty King Willem-Alexander officially opened the first blue-energy power plant at the ‘Afsluitdijk’, in the north of the country. This is a test plant for which the Research Institute MESA+ from the University of Twente provided much knowledge. The technique that is used in this plant is based on eight years of work and the research is now continued and extensively tested in the plant. To get a better understanding of what exactly is being researched, let’s first have a closer look at the method behind blue-energy.

How does it work?

At the pilot installation in The Netherlands, fresh water from the inland sea IJsselmeer and salt water from the Wadden Sea is collected, stored, and filtered separately. The next step is to put a membrane between these two sorts of water. The salt water contains many more ions – charged particles that want to travel to fresh water. The membrane functions as a coffee filter, but then exactly the other way around: the water is stopped, while ions are allowed to pass through. In order to generate power, two sorts of membrane are used. One filters the natrium, and the other chloride, thus creating positively charged water on one side and negatively charged water on the other, which is comparable to a battery, with one side positively, and the other negatively charged.

Further research

The recent discovery that the University of Utrecht did is that by pre-heating the incoming fresh water the potential energy outcome can be tripled. This effectively means that it would be possible to provide one-third of the Netherlands of energy. For more information on the research behind this, please read the publication ‘Boosting capacitive blue-energy and desalination devices with waste heat’ in Cornell University Library.

In addition, researchers from the Membrane Science and Technology department at the University of Twente are making good progress in optimizing the membranes. Two researchers already obtained their Doctoral Degree in this field: Enver Güler developed a membrane that yields the highest energy to date, and David Vermaas optimized the way in which water passes through the membranes. Two new PhD candidates are currently working onwards from these developments.

The next step?

With the current low oil and gas prices it is hard to make any predictions, yet the future seems to look very bright for blue-energy. The considerable progress that has been made and the further research that is being conducted, indicate that blue-energy could very well become one of our major sources of renewable energy, which holds lots of opportunities for the steel business as well. At Stainless Steel World News we think this is not so much a question of if, but rather when, and we will therefore definitely keep a close eye on the matter.

Header image by Frank van Beek; source:

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