Solar desalination uses sunlight to remove salts and impurities from saline or brackish water, producing freshwater for drinking, irrigation, or industrial use. It pairs solar energy—either as heat or electricity—with water purification technologies to reduce reliance on fossil fuels and extend access to water in sunny, off-grid, or energy-constrained locations.
Solar desalination is not a single device but a range of approaches: direct thermal systems that evaporate water using solar heat, solar-driven membrane processes where photovoltaic (PV) electricity powers pumps and membranes, and hybrid setups that combine heat and electricity. Each type suits different water quality, scale, and budget needs.
Key benefits include:
Common trade-offs are intermittency (sunlight varies daily and seasonally) and the need for storage or backup power to ensure continuous supply. Systems may require pre-treatment for highly turbid or contaminated water, and disposal of concentrated brine needs careful management to avoid environmental harm.
Overall, solar desalination offers a sustainable pathway to expand freshwater supplies, especially in arid, coastal, and island settings where both sunlight and saline water are plentiful. Choosing the right approach involves balancing local water demand, solar resources, maintenance capacity, and budget.