This study presents a flexible batch electrodialysis reversal (EDR) technology for low-cost solar-powered brackish water desalination. The system uses solar energy to desalinate groundwater, maximizing the use of available solar power and reducing reliance on batteries. The proposed photovoltaic-powered desalination system adjusts pumping and EDR power to match the availability of intermittent solar energy, achieving a 77% direct use of available solar energy—91% more than conventional systems—and a 92% reduction in battery reliance. In a village-scale case study in India, this system reduces water costs by 22%, making it competitive with existing on-grid reverse osmosis systems. The technology offers a sustainable solution to water scarcity in remote areas by reducing costs and carbon emissions. The study highlights the challenges of desalinating brackish groundwater in rural areas, where energy sources are unreliable. Solar energy is increasingly viable for water-stressed regions due to its declining costs. However, solar desalination systems must address the intermittency of solar power, often managed by costly batteries. EDR is more energy-efficient and has higher water recovery than reverse osmosis (RO), making it suitable for renewable-powered desalination. The study developed a flexible EDR technology that adapts to solar energy variability, potentially reducing costs for solar-powered desalination systems. The study tested a prototype PV-EDR system at the Brackish Groundwater National Desalination Research Facility, demonstrating its ability to produce freshwater efficiently. The system uses a real-time control strategy to adjust voltage and flow rate, maximizing solar energy use and minimizing battery reliance. The system's performance was evaluated over six days, showing a 33% reduction in operating time and a 54% faster production rate compared to conventional systems. The flexible system uses 77% of available solar energy, significantly improving desalination efficiency. The study also conducted a cost analysis, comparing the flexible PV-EDR system with conventional systems. The flexible system achieved a lower levelized cost of water (LCOW) of US1.66 m⁻³, a 22% improvement over the current state-of-the-art PV-EDR system and a 46% improvement over the conventional system. The flexible system reduces solar panel area, eliminates almost all battery capacity, and requires less operator time and labour costs. The study concludes that the flexible PV-EDR system is cost-competitive with on-grid RO systems, offering a sustainable solution to water scarcity in remote areas. The technology has the potential to reduce carbon emissions and brine discharge, enhancing water affordability and minimizing environmental impact. Future research should explore varied conditions and expand testing to different locations and feed salinities to further assess the technology's robustness.This study presents a flexible batch electrodialysis reversal (EDR) technology for low-cost solar-powered brackish water desalination. The system uses solar energy to desalinate groundwater, maximizing the use of available solar power and reducing reliance on batteries. The proposed photovoltaic-powered desalination system adjusts pumping and EDR power to match the availability of intermittent solar energy, achieving a 77% direct use of available solar energy—91% more than conventional systems—and a 92% reduction in battery reliance. In a village-scale case study in India, this system reduces water costs by 22%, making it competitive with existing on-grid reverse osmosis systems. The technology offers a sustainable solution to water scarcity in remote areas by reducing costs and carbon emissions. The study highlights the challenges of desalinating brackish groundwater in rural areas, where energy sources are unreliable. Solar energy is increasingly viable for water-stressed regions due to its declining costs. However, solar desalination systems must address the intermittency of solar power, often managed by costly batteries. EDR is more energy-efficient and has higher water recovery than reverse osmosis (RO), making it suitable for renewable-powered desalination. The study developed a flexible EDR technology that adapts to solar energy variability, potentially reducing costs for solar-powered desalination systems. The study tested a prototype PV-EDR system at the Brackish Groundwater National Desalination Research Facility, demonstrating its ability to produce freshwater efficiently. The system uses a real-time control strategy to adjust voltage and flow rate, maximizing solar energy use and minimizing battery reliance. The system's performance was evaluated over six days, showing a 33% reduction in operating time and a 54% faster production rate compared to conventional systems. The flexible system uses 77% of available solar energy, significantly improving desalination efficiency. The study also conducted a cost analysis, comparing the flexible PV-EDR system with conventional systems. The flexible system achieved a lower levelized cost of water (LCOW) of US1.66 m⁻³, a 22% improvement over the current state-of-the-art PV-EDR system and a 46% improvement over the conventional system. The flexible system reduces solar panel area, eliminates almost all battery capacity, and requires less operator time and labour costs. The study concludes that the flexible PV-EDR system is cost-competitive with on-grid RO systems, offering a sustainable solution to water scarcity in remote areas. The technology has the potential to reduce carbon emissions and brine discharge, enhancing water affordability and minimizing environmental impact. Future research should explore varied conditions and expand testing to different locations and feed salinities to further assess the technology's robustness.