DesertGrid Solar Desalination System Goes Live in Saudi Arabia: Producing Both Electricity and Fresh Water From Sunlight and Seawater

DesertGrid Solar Desalination System Goes Live in Saudi Arabia: Producing Both Electricity and Fresh Water From Sunlight and Seawater

On June 1, 2029, Saudi Aramco and ACWA Power's jointly built DesertGrid integrated system began commercial operation at NEOM city. The system deeply couples concentrated solar power with seawater desalination technology, using the same mirror field and thermal system to simultaneously produce electricity and fresh water — 500,000 tons of water and 800 MW of electricity daily.

At DesertGrid's core is a concentrated solar array of 1.2 million heliostats. These mirrors focus sunlight onto a central tower receiver where molten salt is heated to 565°C. The high-temperature molten salt has two destinations: part drives a steam turbine for electricity, while another part converts seawater to fresh water through multi-effect distillation.

Efficiency Breakthrough

In traditional approaches, power generation and desalination are independent systems with significant energy waste. DesertGrid's innovation integrates both processes within the same thermal cycle. Low-temperature exhaust steam from the turbine (approximately 120°C) directly enters the first-effect evaporator of the desalination unit, achieving cascaded thermal energy utilization.

This coupled design achieves an overall energy utilization rate of 78%, approximately 30% higher than independently operated power and desalination systems. While producing 500,000 tons of fresh water daily, DesertGrid also delivers 800 MW to NEOM's grid, serving approximately 200,000 households.

Economic Benefits

DesertGrid's desalinated water cost is $0.35 per cubic meter — 60% of Saudi Arabia's current reverse osmosis desalination cost. The levelized cost of electricity is 2.1 cents per kWh, lower than any other power generation method in Saudi Arabia.

Saudi Energy Minister Prince Abdulaziz bin Salman stated at the inauguration: "DesertGrid proves Saudi Arabia possesses not just oil, but inexhaustible sunlight and seawater. This project is a benchmark of Saudi Vision 2030."

Technical Challenges

DesertGrid's biggest technical challenge is sandstorms. Saudi desert regions experience approximately 30 to 50 sandstorm days annually, and mirror soiling significantly reduces concentration efficiency. The project team developed an automated cleaning system using micro-robots to clean heliostats individually at night.

Another challenge is brine discharge. Desalting 500,000 tons of seawater daily produces concentrated brine that could severely impact Red Sea marine ecosystems if discharged directly. DesertGrid includes a brine concentration and mineral extraction system that recovers lithium, magnesium, and potassium from brine, converting waste into byproducts.

Global Replication

ACWA Power has announced plans to replicate the DesertGrid model in the UAE, Egypt, and Morocco. The three projects' combined capacity is expected to reach 3 GW with daily fresh water production exceeding 1.5 million tons, potentially becoming the mainstream solution for water scarcity across the Middle East and North Africa.