Introduction
China’s northern provinces grapple with severe water shortages, driving innovation in desalination. The Rizhao facility, operational since late November 2025, marks a milestone by integrating low-grade waste heat (8–38°C) from nearby steel and petrochemical plants with direct seawater electrolysis [2][3][G1]. Validated by Laoshan Laboratory, it avoids traditional reverse osmosis pitfalls like brine waste and freshwater needs for hydrogen production [2][3]. Provincial reports confirm three weeks of continuous runs by December 7 [G3]. This pilot exemplifies China’s “Dual Carbon” goals, producing outputs from 800 tonnes of seawater annually: 450 m³ fresh water, 192,000 standard m³ green hydrogen (at 4.2 kWh/m³ energy cost), and 350 tonnes brine [1][2]. Power efficiency exceeds conventional electrolysis by over 20% via corrosion-resistant catalysts [3]. Coverage from SCMP and others highlights its edge over Middle Eastern plants [2][3][G1].
The “One-In, Three-Out” Technology
At its core, the Rizhao plant employs a circular model: seawater enters, yielding three outputs without grid power or pre-desalination [1][4][5]. Thermal desalination uses industrial waste heat, followed by electrolysis for high-purity hydrogen—eliminating cooling units and boosting efficiency [3][G2]. “This redefines the water-energy nexus,” notes Good News Network, emphasizing no ocean-dumped brine [4][G11]. Laoshan Lab aligns it with coastal industries, enabling zero-carbon hydrogen [2][3]. Unlike energy-intensive zero-liquid-discharge systems, it achieves “positive yield” economics [G1]. X users like @ChinaScience echo this, linking to Shandong pilots [G17][G19].
Cost Efficiency and Global Comparisons
Fresh water costs RMB 2 ($0.28)/m³, undercutting China’s tap water (3–5 yuan/m³) and rivals: Saudi Arabia below $0.50/m³, California’s Carlsbad at $2.21/m³ [1][3][5][G4]. Hydrogen adds value, with outputs equivalent to fueling 100 buses yearly [2]. Analyses predict 50–70% desalination savings via waste heat [G1][G10]. Hydrogen Exchange.io calls it a “global hydrogen economy reshaper,” undercutting imports by 40% [5][G14]. Yet, pilot-scale limits full benchmarking; state media dominates reports [G3].
Economic and Environmental Impacts
Economically, brine sales (for aquaculture, chemicals) turn waste into revenue, supporting China’s 20M-tonne green H₂ target by 2030 [G1]. Environmentally, it prevents 142B m³/year global brine dumping, cuts CO₂ via fossil H₂ displacement, and uses no freshwater [G1][G11]. Trends show brine minerals market hitting $10B by 2030 [G1]. X discussions praise tech transfer to arid nations [G15]. Balanced view: Sinopec pilots in Qingdao build momentum, but scaling needs brine markets [G18][G13].
Social Media Insights and Expert Views
X activity (Dec 14–16, 2025) shares SCMP articles with positive sentiment (~100–1,000 engagements), lauding “circular economy” [G1][G17]. @SinopecNews highlights related seawater electrolysis [G18]. Experts like those at Hydrogen Central see 30% green H₂ cost drops [G13]. Critically, older threads warn of fouling risks [G15]. Planet Keeper analysis notes geopolitical edge for China over EU/Australia freshwater-dependent tech [G1].
Challenges and Scaling Opportunities
Scalability hinges on mineral purity, fouling, and industry proximity [G1]. Independent audits are needed beyond Dazhong Daily [G3]. Opportunities: offshore plants for Middle East/India, “desal farms” with renewables [G1]. Shandong targets 15+ GW by 2030; exports via Belt & Road loom [G1]. Constructive paths include Tianjin/Yantai pilots and global brine valorization studies [G2].
KEY FIGURES
– Fresh water production cost: RMB 2 ($0.28) per cubic metre{1}{2}{3}{4}{5}
– For every 800 tonnes of seawater processed annually: 450 cubic metres of ultra-pure fresh water, 192,000 standard cubic metres of green hydrogen, 350 tonnes of mineral-rich brine{1}{2}
– Hydrogen production energy cost: 4.2 kWh per cubic metre{2}{5}
– Hydrogen output powers 100 buses for 3,840 km annually{2}
– Power utilisation rate: over 20% higher than conventional freshwater electrolysis{3}
– Saudi Arabia desalination cost: below $0.50 per cubic metre{3}{5}
– California largest desalination plant cost: $2.21 per cubic metre{5}
RECENT NEWS
– China launches cheapest desalination plant in Rizhao, Shandong, producing fresh water at $0.28/m³ plus green hydrogen and brine (Dec 2025, Source: chinaeconomicreview.com){1}
– Chinese desalination plant in Rizhao makes fresh water cheaper than tap water, powered by seawater and waste heat, operated over three weeks (Dec 2025, Source: scmp.com){2}
– China desalination tech in Rizhao cheaper than Middle Eastern plants, uses corrosion-resistant catalysts (Dec 8, 2025, Source: thestar.com.my){3}
– Cutting-edge Rizhao facility generates pure water and hydrogen from seawater using steel foundry waste heat (Recent, Source: goodnewsnetwork.org){4}
STUDIES AND REPORTS
– Laoshan Laboratory: Validates zero-carbon hydrogen paradigm aligned with China’s coastal industries, leverages waste heat for seawater electrolysis{2}{3}
TECHNOLOGICAL DEVELOPMENTS
– “One-in, three-out” circular economy: seawater input yields fresh water, green hydrogen, mineral-rich brine; powered by low-grade waste heat from steel/petrochemical plants, direct seawater electrolysis with corrosion-resistant catalysts{1}{2}{3}{4}{5}
– High-purity hydrogen from seawater without prior desalination or freshwater; eliminates traditional cooling units, boosts power efficiency >20%{3}
MAIN SOURCES (numbered list)
- Reports launch of Rizhao facility with key outputs and costs {1}.
- Details facility operations, statistics, and hydrogen yield {2}.
- Compares costs, describes tech innovations and Laoshan Lab input {3}.
- Highlights waste heat use and cost advantages over Saudi/California plants {4}.
- Analyzes “one-in, three-out” model and industrial implications {5}.
- Covers Rizhao plant powered by seawater and waste heat {6}.
