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  • Category: Tech

China's total seawater desalination capacity has reached 3.077 million tons per day, according to the Ministry of Natural Resources (MNR). This capacity is equivalent to meeting the daily domestic water needs of approximately 15 million people.

Scale and Growth

As of the end of 2025, China had 167 seawater desalination projects in operation nationwide, with a combined daily capacity of 3.077 million tons—an increase of 221,000 tons per day compared to 2024. Compared to 2020, the total capacity has grown by 86.4%.

Among these, 68 projects are classified as large-scale facilities with a daily capacity of 10,000 tons or more, accounting for 2.85 million tons per day—over 90% of the national total.

The projects are distributed across 10 coastal provincial-level regions: Liaoning, Tianjin, Hebei, Shandong, Jiangsu, Zhejiang, Fujian, Guangdong, Guangxi, and Hainan.

Technology and Self-Reliance

A major driver of this expansion has been the localization of core desalination equipment. China has achieved breakthroughs in three key components of reverse osmosis (RO) desalination: RO membranes, high-pressure pumps, and energy recovery devices, gradually achieving independent controllability.

A fully domestic RO desalination demonstration line with a single-unit capacity of 30,000 tons per day has been built. Domestic RO membrane performance is now essentially on par with comparable foreign products and has been applied in large-scale projects in Tianjin, Shandong, and other regions, with exports beginning to reach overseas markets.

RO technology remains the dominant method, accounting for 70.54% of China's desalination capacity in 2025.

Key Applications

Industrial Water Supply: The world's largest petrochemical-supporting desalination complex is located on Yushan Island in Zhoushan, Zhejiang Province, serving a 40-million-ton-per-year refining and petrochemical base. Using domestically developed dual-desalination technology, it supplies over 515,000 tons of freshwater daily and more than 140 million tons annually, with water quality meeting high-end industrial standards.

In 2025, Zhoushan's total desalinated water supply reached 170 million tons, with over 160 million tons used by large-scale basic industries such as petrochemical refining and shipbuilding—both figures ranking first among prefecture-level cities nationwide. Desalinated water now accounts for 73.5% of the city's total industrial water use.

Island and Residential Water Supply: In Zhejiang's Zhoushan Archipelago, islands like Huni Island—which have no rivers and rely on rainfall—now receive stable freshwater through desalination projects. Construction began in December 2024, and stable supply was achieved by October 2025.

Coastal provinces including Shandong, Zhejiang, and Hainan have expanded desalination infrastructure, enabling more than 30 remote islands to achieve full water supply coverage and ending their dependence on water shipments.

Policy Target

In July 2026, the National Development and Reform Commission, the Ministry of Natural Resources, and the Ministry of Water Resources jointly issued the Seawater Desalination Industry Development Action Plan, aiming to promote the large-scale utilization of desalinated water.

The plan sets a target of reaching a total national desalination capacity of 4.5 million tons per day by 2030, with new capacity of at least 1.5 million tons per day. This includes 1.3 million tons per day for coastal cities and 200,000 tons per day for islands.

Outlook

As China enters its 15th Five-Year Plan period, the desalination industry is moving toward high-quality, green, and international development. According to Xiang Wenxi, director of the MNR's Institute of Seawater Desalination and Multipurpose Utilization (Tianjin), the sector has evolved from meeting domestic demand to exporting technologies and equipment overseas, transitioning from domestic innovation to international engagement.