The GRADISAL project, which will be implemented over the next 24 months with an investment of 461,658 euros, is a pioneer in Spain and aims to test the feasibility of generating clean and renewable electricity using EDR (reverse electrodialysis) technology from the salinity difference between the purified effluent of a sewage treatment plant and the marine environment to which it is discharged. The feasibility of implementing this technology will be addressed in five important sewage treatment plants in Cantabria (San Vicente, San Pantaleón, Comillas, San Román de la Llanilla and Castro Urdiales) and aims to contribute to its energetic sustainability, enhancing the so-called circular economy. The project was presented at a press conference by Eva Díaz Tezanos, Vice-President and Minister for Universities and Research, Environment and Social Policy of the Region of Cantabria; Ángel Pazos, Rector of the University of Cantabria;  the director of the public company MARE, Rosa Inés García; Its director of Energy and Water Quality, Mónica Mallavia; and the director of Apria Systems, Pedro Gómez.