REDstack develops blue energy technology

The Dutch have fought against water for centuries. However, now the Dutch are developing technology to work with water to generate ‘blue energy’. The Netherlands’ Afsluit dike is a tangible symbol of the country’s battle against the sea. The 32-kilometer dike is being rehauled to meet the challenges of the future. However, being a pragmatic nation, the Dutch are also transforming the dike into a sustainable energy dike while they are at it.


Aerial photo of the Afsluitdijk with the Blue Energy test installation.

Osmotic energy

The dike separates fresh water in the IJsselmeer lake from the salt water of the Wadden Sea. A company called REDstack is experimenting with generating energy by mixing fresh and salt water. The pioneering company wants to develop and commercialise this energy using Reverse Electrodialysis (RED) technology. When a small quantity of fresh water is added to salt water in a membrane pile (a stack), ‘osmotic energy’ is generated. This clean energy can be produced wherever rivers run into the sea, which where most of the world’s cities are located.

Next step

The principle of blue energy has been known for years, but the technology has never been exploited. Now experiments on a small scale by the Wetsus Institute (European Center of Excellence for Sustainable Water Technology and tests by Frisia Zout have shown the technique can be made viable. The next step is to optimalise the technology in the field. REDstack has built a demonstration installation which can be scaled up and commercialised. FujiFilm provided the ion exchange membranes used in the process.

Global warming

If this technology were to be applied worldwide it could potentially supply 80 percent of the world’s energy. What’s more the only waste product is brackish water which can be returned to the sea, This technology could seriously reduce CO2 emissions and help governments meet their targets to stop global warming.

National Icon 2016 shortlist

REDstack is one of ten companies shortlisted to become one of three National Icons for 2016. The three National Icons will be announced on the popular television programme De Wereld Draait Door on 18 October.