Desalination can Help Solve our Water Woes, but not without Clean Energy

Source: Prodes Project

Source: Prodes Project

As drought continues to grip Texas and many other Western states, one of the solutions often discussed (and pursued) to overcome water scarcity is desalination. Simply put, desalination, or desal as it is most commonly called, is a process that removes salt and other minerals from salty (brackish) or seawater to produce freshwater for drinking and agriculture. This technology seems like a no-brainer option for addressing the state’s water woes, but the problem is that desalination uses a lot of electricity and the majority of Texas’ electricity comes from coal and gas power plants, which require copious amounts of water to generate that electricity. It doesn’t make much sense to use water to make water, especially when there’s an alternative in Texas’ abundant renewable energy resources.

Texas is the national leader in wind energy and has the greatest solar energy potential in the U.S., yet neither of these resources are being widely deployed for desal plants despite recent studies pointing to vast opportunities. Not only do these energy resources produce negligible carbon emissions, but they also consume little to no water, unlike fossil-fueled power plants. Furthermore, if we look at where brackish water sources are located compared to where the wind and solar energy potential is in this state, the overlap is pretty clear. This synergy should not be ignored.

Let’s desal water when the wind blows and the sun shines!

Solar energy coupled with a desal plant provides economic, health, and seasonal benefits. Foremost, as the price of solar panels continues to fall each year, the investment for building solar-plus-desalination plants looks bright. And one company, WaterFX, is already ahead of the curve. WaterFX uses the sun’s heat to filter salty water and is about 30 times more efficient than similar facilities. Currently, the company has a pilot project right in the heart of California’s agricultural heartland and is able to provide about 14,000 gallons of water a day.

Solar provides a vast and inexhaustible energy supply and doesn’t emit harmful air pollution, making it the perfect alternative to dirty fossil-fueled power plants currently used to desalinate water. It also safeguards the health of our community members and future generations. Plus, Texas has no lack of sunny days, especially during the summer months, when the need for water is highest. But solar power isn’t the only resource available in Texas.

A recent study by the Webber Energy Group at the University of Texas at Austin found that wind energy could power desal plants at night, when wind blows the hardest, and store the water for the next day’s use. Some areas in Texas are already testing the waters, so to speak. Seminole, located in the Texas Panhandle, has a demonstration project underway to desalinate brackish water from the Dockum Aquifer using the region’s abundant wind energy. The water will be integrated with the city’s existing water treatment and distribution system for municipal use. The partners for this project, Texas Water Development Board and Texas Department of Agriculture, aim to complete this $1.6 million effort by August 2014. Texas Tech University’s National Wind Institute, a powerhouse wind energy research program, is on board to manage the project.

Texas’ Water Crisis Requires a Suite of Solutions

The drought in Texas is, by any definition, dire. When people are reduced to taking “spit baths” and lake levels have dropped to as low as 26 percent full, all options need to be on the table. But being more efficient with the water we have now is what we should do first—just as with electricity.

There are currently 46 brackish desalination plants and an estimated 2.7 billion acre-feet of brackish water in Texas—enough to cover the entire state with 15 feet of water. While desal seems like an obvious solution for solving the state’s water woes, providing enough freshwater to meet Texas’ current needs for 150 years is not that easy. Aside from addressing the energy-intensity issue of treating all that salty water, there are other problems that need to be resolved, specifically around property rights, groundwater districts, and waste, if we are to begin addressing this complex challenge from a holistic viewpoint.

First, we should focus on conservation and water reuse. Desal can be part of the solution, but it shouldn’t trigger us to think that we have an infinite supply of water just because we can make more.

Our second best solution should be to find ways to treat and move water that are not water-intensive themselves, such as taking advantage of renewable energy to maximize new, freshwater resources.

Just as there is no silver bullet to solve climate change, there is no single solution to solve water scarcity problems either. It requires a suite of options that must be undertaken with thoughtful urgency. As Legislators from all corners of Texas prepare for the upcoming 2015 legislative session, the eyes of Texas will be upon them, looking for innovative, cost-effective plans to keep our faucets running.

This commentary originally appeared on our Texas Clean Air Matters blog.

This entry was posted in Clean Energy, Energy Efficiency, Energy-Water Nexus, Renewable Energy, Texas. Bookmark the permalink. Both comments and trackbacks are currently closed.

One Comment

  1. Posted May 14, 2014 at 9:49 pm | Permalink

    might be more efficient to simply use straight distillation by the sun instead of generating electricity to power pumps to force fresh water across an expensive membrane that has to be chemically cleaned and and can see only water that has been pretreated.
    Kate, please send an email address, I have been working on something that may be of interest to you.
    Robert Pulliam