Performance of the first reverse electrodialysis pilot plant for power production from saline waters and concentrated brines

This work reports experimental data collected for the first time on a full-scale RED pilot plant operated with natural streams in a real environment. The plant - located in the South of Italy - represents the final accomplishment of the REAPower project (www.reapower.eu). A RED unit equipped with almost 50m2 of IEMs (125 cell pairs, 44x44cm2) was tested, using both artificial and natural feed solutions, these latter corresponding to brackish water (≈0.03M NaClequivalent) and saturated brine (4-5M NaClequivalent). A power output up to around 40W (i.e. 1.6W/m2 of cell pair) was reached using natural solutions, while an increase of 60% was observed when testing the system with artificial NaCl solutions, reaching up to ≈65W (2.7W/m2 of cell pair). The unit performance was monitored over a period of five months under, and no significant performance losses were observed due to scaling, fouling or ageing phenomena. Such results are of paramount importance to assess the potential of the technology, towards the successful development on the industrial scale. A scale-up of the pilot plant is planned through the installation of two additional RED modules, with an expected power output in the order of 1 kW.