Desalination is considered an expensive and energy-intensive process. However, mega-projects are seeking to tap renewable resources to limit the cost and environmental concerns associated with this crucial process. In June 2022 ENOWA, the energy, water and hydrogen subsidiary of Saudi Arabia’s NEOM mega-project, signed a memorandum of understanding with French energy company Veolia and Japanese trading company Itochu to develop a reverse-osmosis (RO) water desalination facility fully powered by renewable energy. Slated for completion in 2025, the facility is expected to produce 500,000 cu metres of potable water per day, meeting 30% of NEOM’s anticipated water demand.

In a similar push for zero-carbon desalination, the Dubai Electricity and Water Authority (DEWA) signed a partnership agreement with Dutch start-up Desolenator in 2022 to develop a solar-powered desalination pilot project. The companies have installed a pilot plant at the Jebel Ali power plant and a desalination complex, which produces 1000 litres per day, with the potential to reduce the cost of desalinated water to $0.02 per litre. Although desalination costs vary considerably based on the source of water, technology and electricity prices, the global average ranges from $0.50 to $1.50 per cu metre. DEWA aims to produce 100% of its desalinated water from renewables and waste heat by 2030.

Global Capacity Expansion

Over half of the global population is affected by water scarcity. According to the UN Environment Programme, water supply could fall 40% short of demand by 2030 if water-management systems are not improved. As the costs associated with desalination decrease, the process will likely play a key role in meeting UN Sustainable Development Goal 6, which aims to “ensure availability and sustainable management of water and sanitation”.

Desalination is already widespread, with approximately 22,757 plants in operation globally as of October 2022. As of 2016 the MENA region accounted for 46.7% of the world’s desalination capacity, followed by the Asia-Pacific region (17.5%) and North America (12.9%).

Egypt has made significant strides to expand desalination capacity powered by renewable energy. In 2021 the country tendered 17, 25-year concessions from its sovereign wealth fund to construct solar-powered desalination plants. The plants themselves will be partially powered by renewable sources that, in combination with green financing, could lower production costs by an estimated 20-25%. The government is targeting an installed desalination capacity of 6.4m cu metres per day by 2050, up from 800,000 in 2021. Desalination should also support the expansion of industrial and residential development further away from the Nile River, in line with new urban development plans.

Local Solutions

Major progress has been made since the 1970s to lower the cost and energy usage of desalination plants, mainly through the introduction of membrane-based RO technology. The cost of desalinated water halved between 1980 and 2005, and promises to decrease further with the scaling of new technologies and renewable resources.

While fossil fuels power most desalination plants in the MENA region, the increasing use of renewable energy – coupled with plans for carbon capture and hydrogen production – should help many countries meet their emissions targets. Solar, in particular, presents a viable and increasingly affordable energy source for plants. KarmSolar, an Egyptian solar power and utilities company, is constructing a pilot solar-powered desalination plant at Marsa Shagra on the Red Sea coast with a capacity of 200 cu metres per day.

New technologies have the potential to diversify the power sources used in desalination. For example, Manhat, an Abu Dhabi-based start-up, has developed floating platforms that use sunlight to distil freshwater. In a zero-electricity process similar to the natural water cycle, sunlight evaporates seawater within a greenhouse-like structure, separating fresh water from salt crystals.