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The Renewables & Desalination Dilemma

Global desalination projects need to include renewable energy sources, despite the possibility of a negative rebound effect.

It’s an interesting fact that drinking seawater will only make you thirstier, because of all the salt. This is one of several reasons why being lost at sea would be profoundly unpleasant. Of course, if you could find a way to drink the water safely then dying of thirst would suddenly become the least of your worries. 

It’s an interesting fact that drinking seawater will only make you thirstier, because of all the salt. This is one of several reasons why being lost at sea would be profoundly unpleasant. Of course, if you could find a way to drink the water safely then dying of thirst would suddenly become the least of your worries. 

Jordan is the fourth driest country in the world and something about the tantalizing abundance of sea water seems to have tweaked the imagination of its national government. A $1 billion desalination project (turning sea water into fresh water) is now underway to provide water to farmers whose fields have, in the absence of irrigation, turned into deserts. Environmentalists are concerned with several aspects of the ambitious plan, not least the amount of energy it will take to produce so much clean water.

Historically, energy production has required water. Sometimes indirectly: oil extraction relies on the injection of water into the reservoir in order to maintain pressure. Sometimes directly: watermills and hydroelectric dams convert flowing water into energy. 

It’s been a pretty one-sided relationship, but that hasn’t been a problem to date. We’ve had lots of water and we’ve needed lots of energy, so the imbalance has been a non-issue.

Now we’re catching our first glimpses of a world where water needs energy as much as energy needs water. What that means is that the stakes in the global effort to increase renewable energy capacity just got higher.  

In Chile, the mining industry’s demand for water is so high that desalination projects are expected to increase by over 400 per cent by 2018. We could soon find ourselves in a position where energy needs water needs energy – an endless loop of consumption that amplifies a wide range of environmental problems.

Renewable energy has the potential to be the safety switch that cuts off this feedback loop before it does too much damage. If the source of energy is fully sustainable then, theoretically, it shouldn’t matter how much we use.

But human nature dictates a slightly different outcome. A recent Corporate Knights article outlines the concerns of several environmentalists that desalination through renewables will trigger a rebound effect. That is, energy and water use will increase due to reduced incentives to conserve, thus negating the positive impact of the sustainable energy source.

So what are renewables, then: a sustainable means of obtaining unlimited fresh water, or an anchor dragging desalinization projects down into an unsustainable spiral of runaway resource use?

Probably a bit of both, in the same way that eating too much of something – even a healthy food like carrots – will eventually kill you; inputs to the human body and the world economy both typically require a certain degree of balance, or else the systems fail. We can’t afford to go overboard on using renewables for desalination, because we have enough to deal with in meeting current demand for energy. Nor can we afford to ignore them, since desalination is already the only technology standing between some countries and mass starvation.

We’ll just have to brave the expected rebound effect as best we can. Add one more function that renewables will have to perform as they move to take over responsibility for meeting our collective energy needs.

A global population of seven billion is going to use almost everything in vast quantities, so we may as well do our best to mitigate the environmental impacts wherever possible.

The alternative would be throwing countries like Jordan an anchor. And that’s just not a palatable option.

Stu Campana is an international environmental consultant, with expertise in water, energy and waste management. He is the Water Team Leader with Ecology Ottawa, has a master’s in Environment and Resource Management and writes the A\J Renewable Energy blog. Follow him on Twitter: @StuCampana.