China Unveils Pioneering Seawater-to-Hydrogen Plant Slashing Freshwater Costs

China’s new Rizhao facility converts seawater and industrial waste heat into low‑cost fresh water, green hydrogen, and mineral brine. Producing hydrogen without desalination, it delivers cheaper water than many global plants. The project showcases an efficient, low‑carbon model for coastal industries, supporting China’s clean‑energy transition and demonstrating a promising approach to sustainable water and hydrogen production.

China has introduced a landmark water‑and‑energy facility in Shandong province that may reshape how coastal regions secure freshwater and clean fuel. The pilot installation, located in the coastal city of Rizhao, uses seawater and low‑temperature industrial waste heat to generate inexpensive fresh water and green hydrogen, according to provincial media reports published Saturday.

The facility has been running continuously for more than three weeks, producing high‑purity hydrogen without relying on traditional desalination or drawing on scarce freshwater supplies. Operators report that for every 800 tonnes of seawater processed annually, the system yields approximately 450 cubic metres of high‑grade fresh water suitable for residential consumption or industrial cooling.

In addition to freshwater, the system produces 192,000 standard cubic metres of green hydrogen each year and around 350 tonnes of mineral-rich brine, which can be used in marine chemical manufacturing—forming what researchers describe as a “one-in, three-out” circular production model.

The hydrogen output requires roughly 4.2 kilowatt-hours of electricity per cubic metre, enough to power a fleet of 100 buses for nearly 3,900 kilometres annually. The reported overall water-production cost stands at just two yuan (US$0.28) per cubic metre, significantly undercutting other Chinese desalination initiatives. By comparison, a waste‑heat‑powered desalination project in Jinan produces fresh water at roughly four yuan per cubic metre, and residential water in Beijing is priced at five yuan per cubic metre for typical household usage.

Internationally, the Rizhao plant delivers fresh water at a price far below many established desalination leaders. While Middle Eastern countries such as Saudi Arabia and the United Arab Emirates have achieved some of the world’s lowest desalination costs—generally under US$0.50 per cubic metre—many global facilities remain far more expensive. The largest U.S. desalination plant, the Carlsbad facility in California, produces water at an estimated US$2.21 per cubic metre, according to a 2021 study from Arizona State University.

Researchers say the Shandong project’s innovation lies in its direct use of natural seawater. Conventional electrolysis systems require high‑purity water because minerals and salts found in seawater can damage catalysts and corrode equipment. To overcome this, the Rizhao facility employs corrosion-resistant materials and water‑conditioning technology that allow seawater to be used in its raw form.

The system also harnesses low‑grade heat generated by nearby steel and petrochemical operations. Instead of using dedicated cooling units, the plant repurposes this waste heat to create high-quality fresh water for electrolysis, improving efficiency and lowering operational costs. The overall energy-utilisation rate is reportedly more than 20 percent higher than that of standard freshwater electrolysis units.

Experts involved in the project say the facility demonstrates a new model for carbon-neutral hydrogen production tailored to China’s coastal industrial landscape. Li Jiawei, a researcher at the Laoshan Laboratory in Qingdao, noted that the system aligns with the nation’s push to integrate energy generation with existing industrial hubs, particularly those with access to seawater and large amounts of waste heat.

Qin Jiangguang, a senior engineer at the same laboratory, described the project as an early glimpse into a future where coastal cities can “draw energy from the sea” while simultaneously producing vital water resources.

Local officials say the model offers a pathway for port-based industrial centres like Rizhao to cut emissions while expanding green economic opportunities. By converting waste heat into fresh water and clean hydrogen, the facility could help accelerate regional energy‑transition goals and strengthen China’s position in next-generation water and hydrogen technologies.