A recent CNBC video story on ocean desalination technologies, one of several options being explored to address world water shortages, featured Prakash Rao of Lawrence Berkeley National Lab (Berkeley Lab). Rao, a research scientist within the Lab's Energy Technologies Area, conducts analysis of large-scale desalination, focusing on its energy implications. He has co-authored research, for example, that looks at the energy use and potential energy savings opportunities associated with U.S. seawater desalination systems.
One out of three people today don't have access to safe drinking water, and some estimates suggest that more than half the world's population will be living in water-stressed areas by 2050. The CNBC story examines the pros and cons of turning to seawater to address this issue.
Oceans hold most of the planet's water, yet the salinity makes it undrinkable. While desalination removes the salt, on a commercial scale it faces hurdles in terms of energy intensity, cost, and environmental impacts. Ocean water desalination, Rao says, can be up to 25 times more energy intensive than other freshwater approaches. And disposing of the leftover brine can be harmful to marine life.
Experts agree that desalination is not a panacea, but that it can be one tool among many in ensuring safe water supplies where they are needed. Rao says, "One of the benefits is it's a fairly stable and known process, particularly for dealing with ocean water. You can be confident that it will supply you water when you need it."
The Berkeley Lab-led National Alliance for Water Innovation was recently awarded a five-year, $100-million Energy-Water Desalination Hub by DOE (pending appropriations) to address water security issues in the United States.