The future of desalination lies in efficiency, not just expansion
By 2030, global water demand is set to outpace supply by 40%. This isn't a distant crisis; it's unfolding now. Falling reservoir levels and rising populations are forcing utilities to look beyond traditional freshwater sources. Desalination has emerged as the most reliable solution, but it comes with a significant challenge: it’s energy-intensive.
Already, desalination accounts for roughly 26% of all energy used in the global water sector. As capacity expands globally, the question isn't whether we need desalination, because we do. The question is whether we can afford to deploy it inefficiently.
Water and energy are not separate challenges. They are deeply interconnected systems where decisions in one domain directly impact the other. Every step of water production requires energy, and energy generation itself also requires water. This mutual dependency - the water-energy nexus - means that inefficiency in desalination doesn't just inflate operating costs; it also undermines broader decarbonization efforts and strains already-stretched energy grids.
If “reduce and reuse” methods were adopted across all relevant processes in light industries, water use could be reduced by 50–75%
Integrating energy management into water planning is no longer optional. Scaling desalination without efficiency considerations increases energy costs, as well as undermining decarbonization goals.
The potential for efficiency gains is substantial and proven. In 2024, the Canary Islands Institute of Technology achieved a world record in seawater reverse osmosis energy efficiency at its DESALRO 2.0 experimental plant, breaking the 2.0 kWh/m³ barrier with consumption of just 1.86 kWh/m³. That is the equivalent of 25% lower energy consumption than conventional desalination facilities.
If all existing desalination plants worldwide were retrofitted to operate at 2.0 kWh/m³, the potential energy savings would be 247 TWh (equivalent to Spain's total 2020 electricity consumption), financial savings of €34.5 billion, and carbon emissions reductions of 111 million tons of CO₂. This example proves that the efficiency opportunity isn’t theoretical. It’s measurable and scalable.
The principle of efficiency should apply all across the industry, though, not just in the production of water, but at the end of its cycle. Industrial water reuse should become the standard practice. Across industries, from food and beverage to pharmaceuticals, water typically flows in one direction: in, through, and out. This one-way street needs to become more circular, where we “reduce and reuse” water.
In fact, if “reduce and reuse” methods were adopted across all relevant processes in light industries, water use could be reduced by 50–75%. This is equivalent to the annual water consumption of 67 million EU households. These efforts not only conserve water but also reduce the energy required for pumping, heating, and treatment, delivering cost savings and emissions reductions. As pressures on water systems grow, integrating reuse into core operations is emerging as critical for both resilience and competitiveness.
Operators and utilities need to shift from viewing energy and water waste as an unavoidable cost to treating efficiency as a core design principle. The water-energy nexus demonstrates a practical reality: efficiency in one system supports efficiency in the other.
Those that embrace an integrated approach to water and energy use will not only meet their decarbonization targets but also gain lasting operational advantages, reduce costs, and strengthen resilience in a resource-constrained future.
The technology is available. The business case is established. As water stress and desalination demand continue to grow, the question for utilities is whether to incorporate efficiency from the start or face higher costs and missed opportunities in the years ahead.
