Direct-Drive (Batteryless) Electrodialysis Separation using Flow-Commanded Current Control

An electrodialysis system controller is configured to be coupled to a power supply, and powered devices that include a pump, and an electrodialysis unit. The controller receives inputs including an input indicative of a flow rate through the electrodialysis unit, an input indicative of a concentration level of fluid in the electrodialysis unit, and an input indicative of a power differential (e.g., indicating a degree to which a power usage by the powered devices differs from available power of the power source), and provides outputs for controlling the powered devices, including an output for causing a variable current level to be applied in the electrodialysis unit, and an output for causing a variable fluid flow rate through the electrodialysis unit. The controller is configured to match the power usage to the available power, for example, to keep the power differential as small as possible, while maximizing the theoretical desalination rate of the electrodialysis system.