China’s Massive Effort to Purify Seawater Is Drying Up
Stalled projects and underperforming plants have hampered China’s desalination plans.
The site of a seawater desalination plant that could provide up to one-third of the water consumed by Beijing’s households lies about 200 kilometers southeast of the parched Chinese capital. In 2014, China’s state news media reported that the facility, to be located on the shores of Bohai Bay, would be completed by 2019, contributing to the three million tons of fresh water per day of desalination capacity that China wants to have built by 2020.
Since then, the planning of this facility has been touch and go: it’s been approved by the provincial development agency and listed as one of the major projects in China’s initiative to build a supercity around Beijing, but it’s still far from certain when the construction will begin.
After an initial boom—from 2006 to 2010, China’s desalination capacity grew nearly 70 percent each year, according to government statistics—China missed its target of producing 2.2 to 2.6 million tons of desalinated water a day by 2015. As of December last year, China’s total installed capacity was 1.03 million tons a day, according to the China Desalination Association.
China has much to benefit from more abundant freshwater resources. Government statistics show that by 2030, the water shortage in China’s coastal areas will reach 21.4 billion cubic meters, despite water conservation efforts and the massive South-North Water Diversion Project, which pumps 25 billion cubic meters of water per year from the Yangtze River in southern China to the north China plain via two routes that are each more than 1,000 kilometers long. Of China’s 669 largest cities, at least 400 already suffer from water scarcity. Water security also underpins the economy, since 93 percent of power generation in China relies on water, according to China Water Risk.
But challenges abound in China’s ambition to bring more desalination capacity online. Because of its energy-intensive nature, desalination is expensive—while most Chinese pay less than 50 cents for a ton of tap water, the average price of desalinated water in China is 75 cents to $1.20 per ton. This means the water is a hard sell for urban water authorities, and local governments are often reluctant to commit to building desalination plants.
“When there is a drought, local officials and enterprises all come to see us and say, ‘We want to desalinate seawater,’” says Wang Zhi, director of the Key Laboratory of Membrane Science and Desalination Technology at Tianjin University. “But if there is sufficient rainfall the next year, they will drop the idea and invest their money in other things first.”
Indeed, the demand for seawater desalination grows and wanes as the levels of local surface water and groundwater fluctuate from year to year, putting future projects on hold. There are mismatches between supply and demand for existing plants, too. The pilot phase of the proposed plant for Beijing currently produces 3,000 to 5,000 tons of fresh water a day for a local coal-fired generator—even though it was built to produce 50,000 tons a day.
“The rapid development of the entire seawater desalination industry in China will not happen unless most of the desalinated seawater can enter municipal water supplies,” says Fan Zhifeng, senior engineer of the seawater desalination division at Shanghai Electric. “But currently that’s not the case.”
In an effort to prioritize the already dwindling freshwater resources, the Chinese government rolled out a new policy a few years ago: new water-intensive industrial facilities in the coastal areas cannot draw local surface water and are required to provide their own water supplies. As a result, over 60 percent of the desalinated water produced in China is for industrial use, often in the form of individual plants for generators or oil refineries along the country’s east coast.
For northern China, the South-North Water Diversion Project has made seawater desalination seem less urgent. Some Chinese officials and scientists have questioned the sustainability of the project since it has forced hundreds of thousands of people to relocate and spurred environmental concerns such as destroying the ecology of the southern rivers. The choice between desalination and water transfer is a complicated one, as “desalination must likewise be designed so as to minimize negative impact on marine life” by diluting and diffusing the concentrated salt water discharged back into the sea after the fresh water has been extracted, says John Lienhard, director of the Center for Clean Water and Clean Energy at MIT.
Sensing that desalination is a technology-driven industry, China has called for at least 70 percent of domestic innovation in desalination equipment. That’s still a long way off. According to a government document released in 2012, of the 756 desalination-related patents registered in China, only 15 percent had Chinese intellectual property.
Chinese scientists say they first use foreign equipment and then do their own research in order to catch up. “We import for the first phase, and then we do it on our own,” says Xie Lixin, deputy director of the Tianjin University desalination lab, which boasts research on nearly all the major desalination technologies including distillation and energy recovery.
For foreign companies eyeing the potential of China as a desalination market, this means the picture is not all rosy. Located on the outskirts of Tianjin, the Beijiang Power and Desalination Plant is the largest desalination facility in China. It was designed by Israel Desalination Enterprises, or IDE Technologies. Many Chinese companies go to the plant to try to imitate the design, says Wang Shuangcheng, general manager of IDE Technologies’ China office. “It’s a big market, so they think, why should it be dominated by a few foreign companies?”