There's a great article online in the Huffington Post about how desalination is not the answer for those of us responsible for water management planning. The author, Peter Hanlon, makes a great point about how much energy is used. In the case of San Diego, we'll use a lot more energy than our current practice which is to pump it out of the ground, and transport it thousands of miles for our use. Desalination means an increase in our water bills AND our electric bills.
He writes: "The process of converting salt water to drinking water is highly energy-intensive. In San Diego it takes eight times more electricity to produce about 325,000 gallons of water through desalination than it takes to pump the same amount of groundwater. Because desalinated water is so energy-dependent, water customers are vulnerable to rises in energy costs.
This is where desalination stumbles its way into the "energy-water nexus." In short, generating electricity requires a lot of water, while treating and moving water requires a lot of electricity. Desalination does not help to ease the burden of these interconnected demands, in fact it makes the situation worse.
Consider the added demand from a new desalination plant on the electric grid -- a grid fed by power plants that also require a tremendous amount of water for cooling. In other words, we're creating drinking water for one water-starved location using massive amounts of electricity generated with massive amounts of water somewhere else. Such a scenario raises an obvious question -- Does this make good sense?"
At Surfrider Foundation we say, "No, Mr. Hanlon, it does not." In fact, to us it sounds a big circular scheme that ends up raising our bills, and making us dependent on a big-green-house-gas-spewing desalination plant, when we could conserve, or recycle.
Energy costs are predicted to sky-rocket in the coming decades too, so it does not make good financial sense to "invest" in something so expensive, when a major component of the water production has a cost that is only going up.
Here's a novel idea: how about we re-use what we already transported and PAID for? Doesn't that make the most sense? I mean, WE ALREADY OWN THE WATER. So why are we dumping it in the ocean, only to turn around and PAY to desalt it?