You’ve heard of grid parity, and now it’s time to meet pipe parity. The Energy Department’s Lawrence Berkeley National Laboratory has just launched a major research initiative that tackles the water-energy nexus, with a strong focus on energy efficient desalination. Echoing the Energy Department’s SunShot initiative goal of achieving grid parity for solar power, the new program aims at making desalination as inexpensive as water from natural sources.
Pipe Parity And Water Desalination
The new Berkeley Lab water desalination program aims at reducing costs by a factor of five, so the lab is not interested in incremental improvements over conventional reverse osmosis technology.
Reverse osmosis has been favored since the 1950s partly due to its relatively low use of energy, but the emergence of low cost clean power is opening up other options. For example, Berkeley lab will be looking at forward osmosis, using heat derived from geothermal sources.
Among other emerging and existing technologies that will get a second look from the lab are membranes based on graphene, and something called capacitive deionization (CDI) that seems to solve every problem all at once. According to the lab, CDI has a low-cost, low-energy profile:
CDI uses an electric field (operating at a few volts) across a water channel to attract and trap charged dissolved solids, including salt, in a porous electrode. Polarity is reversed to release the solids, regenerating the electrodes to begin the cycle again. The process does not require pressured water (as in reverse osmosis, or RO), a membrane that can become fouled (as in RO and electrodialysis), or energy intensive heating of water (as in thermal distillation).
The lab will also be looking at “entirely new paradigms” leveraging nano-engineered materials.
The China Connection
While US-China relations have grown a bit testy over the South China Sea, all is quiet on the desalination front.
The desalination part of the lab’s new water-energy initiative dovetails with an existing $64 million collaboration between the US and China, called the Clean Energy Research Center for Water Energy Technologies. The US end of it is focused on solutions specific to California’s ongoing water problems, though presumably there is the potential for application elsewhere.
Okay, so the statement is really long and detailed, and the part about water desalination comes at the tail end, but still:
Under the new energy-water track of the CERC, the United States and China will work together to discover an array of innovative technologies to alleviate pressures on water resources and management related to energy production and use. The United States has also announced five projects to study the feasibility of using salty water – or brine – from CO2 storage sites to produce fresh water.
Those five water desalination projects were announced last September. The $7 million pot of funding is going to explore different pressure and flow management strategies for CO2, an approach known as “plume steering.”
More Water-Energy Nexus Projects
The new Berkeley Lab water-energy initiative has two other main areas of focus. A second key area is in hydroclimate and ecosystem predictions, recognizing that “the climate, ultimately, is the source of all water.”
Part of that effort involves whittling down the scale of global climate modeling to a resolution of one kilometer. At “neighborhood level,” that scale provides much finer detail than the current level of about 25 kilometers.
The third area will explore “water banking” and other strategies for managing groundwater.
All together, the three parts of the water-energy initiative can be compared to energy generation (desalination), storage (groundwater), and distribution (climate modeling).
To get many more details about the initiative, you can visit the lab’s Water Resilience page.
The lab’s press materials don’t bring up food, but we’re guessing that will come into play somewhere down the line. The integration of food into the water-energy nexus is already being explored elsewhere around the globe in ambitious projects like Sahara Forest and Masdar City’s desert aquaculture project.
Image: via Lawrence Berkeley National Laboratory.
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