Desalination Cost Curves Are Improving

Reverse osmosis (RO) desalination has achieved a 90% cost reduction since the 1970s and now operates at 0.4–0.7 kWh/m³ for seawater desalination in best-in-class plants — down from 10+ kWh/m³. The Sorek B plant in Israel, operational since 2023, produces water at ~$0.40/m³, competitive with marginal supply costs in many stressed regions. The remaining bottleneck is brine disposal — the concentrated saltwater byproduct is increasingly regulated and expensive to manage. Mineral extraction from brine (lithium, magnesium, potassium) is being piloted as a value recovery mechanism that could turn a liability into a revenue stream. Pairing RO plants with intermittent renewable power as a flexible industrial load is the energy-water nexus play — running high during solar peaks, curtailing during peak demand periods.