Desalination Should Be A Last Resort

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“One of humankind’s worst tragedies is currently unfolding in the Horn of Africa, and it is caused by the absence of water. Two years of failed rain, and subsequent drought and famine, is responsible for the daily deaths of roughly 2,000 people in Ethiopia, Kenya, and Somalia.

According to the Director of Yale’s Environmental Engineering Program, water scarce countries like these in Africa and the Middle East can achieve greater water security by developing desalination plants. However, as you might have guessed, this conviction does include a rather large caveat.

De-salting the sea

Menachem Elimelech also told PBS that even the most advanced desalination technologies, which are becoming increasingly necessary in countries like Israel, Singapore, and Spain, still use three times as much energy as conventional water treatment.

There are two kinds of desalination technologies at work in the world. The Gulf Countries such as Saudi Arabia and Kuwait, which have been hydrating their citizens with desalinized water for decades, still rely on archaic thermal desalination plants that boil water and condense the resulting steam in order to produce potable water.

This process uses a lot of energy.

But even new technologies such as reverse osmosis, which involves blasting seawater at very high pressure through molecular-sized perforations in a plastic membrane that captures all but 0.05% of the salt pumped through it, is energy intensive.

The most advanced desalination plant requires as much electrical energy to produce 1000 liters of clean water as 30 100 watt lightbulbs left on for an hour. If this doesn’t seem a lot to you, consider this: Israel’s fifth desalination plant along the Mediterranean produces 500 million cubic meters of water every year. A cubic meter is equivalent to 1,000 liters.

That’s a lot of lightbulbs, particularly for Israel, which has very few of its own energy sources with which to power these plants. But even oil-rich nations have to exercise caution.”

Read more: Green Prophet