Solar-powered electrodialysis. Part 2. Design of a solar-powered, electrodialysis system for desalting remote, brackish water sources. Final report

The critical components in the design of a solar-powered, electrodialysis (SPED) plant have been evaluated and technology developed to combine ED equipment with a photovoltaic (PV) array. The plant design developed in Part II is simplified from the Part I design in three areas. First, the system uses a flat-panel PV aray rather than PV concentrators. Second, the system voltage is maintained at the voltage corresponding to the peak power output of the array which is essentially independent of the level of solar insolation. The third simplification is in the flow diagram for the plant where the number of pumps and variable flow valves has been reduced to two of each. The proposed system is expected to provide a reliable supply of fresh water from a brackish water source with minimum maintenance. In certain applications where grid power is unavailable and fuel costs exceed $.40 per liter, the solar-powered plant is expected to provide lower cost water today.