REDstack’s goal is to develop and commercialise the reverse electrodialysis (RED) technology. REDstack originated as a spin-off company of the water technology institute Wetsus. The ‘Blue Energy’ research theme began at Wetsus in 2005, with the aim of generating energy from salt and fresh water. It soon became clear that there was a promising development, and it was decided by some research theme participants to establish REDstack. After nearly two years of preparation, a pilot installation with a maximum power capacity of 50 kW was built in Breezanddijk, the Netherlands, on the Afsluitdijk and officially opened by H.M. King Willem-Alexander of the Netherlands in 2014. A demo-pilot of 1 MW is foreseen in 2020.