Burning Oil to Make Fresh Water

By Yonatan Neril

Where does our water come from? A reservoir? A stream? A river? I recently visited the building site of the world’s largest desalination plant, at Soreq, in the center of Israel. They have built a huge tunnel to transport seawater from the Mediterranean Sea and turn it into fresh water. People think that desalination is the great solution to the world’s water problems, especially here in the Middle East.

In recent years, hundreds of desalination plants have been built around the world. The U.S. has dozens of plants, Algeria has 15, and Israel five. What few people realize is that all of these plants burn fossil fuels in order to produce clean water.

In the Jewish teaching, it is stated, “Who is wise?  The person who sees the long term effect of their action.”(Tractate Tamid, 32a) Desalination technology solves the short term problem of water scarcity, but exacerbates the long term problem of climate change. That’s because in order to make freshwater from seawater, you need to use energy. A lot of it. In the case of powering seawater or brackish water desalination plants, most of the energy used is from burning gas and coal, causing climate change. But why is desalination such an energy-intensive process, consuming at least 75.2 TWh per year, almost 0.4% of global electricity consumption?

During the process, billions of gallons of water are forced through pressure treatments, consuming an average of 10-13 kilowatt hours (kwh) per every thousand gallons. There are many variables in calculating specific energy costs for this technique, depending on the geographic region, degree of salinity, and more. A minimum energy consumption for seawater desalination of around 1 kWh/m³ has thus been determined. The cost of desalinating sea water – including infrastructure and energy – is also usually higher than fresh water from rivers or water recycling. Desalination costs in 2013 ranged from US$0.45 to $1.00/cubic metre. In 2014, Israeli facilities like Soreq were desalinizing water for less than US$0.40 per cubic meter. However, the cost of untreated fresh water in the developing world can reach US$5/cubic metre. In the US, supplying only desalinated domestic water would increase domestic energy consumption by around 10% – around the energy used by refrigerators!

So what can we do to use water more wisely and reduce demand for desalinated water? We can conserve water! For example, wash your car less. Turn off the faucet when you are washing dishes or shampooing your hair. Use more efficient dishwashers. Eat less meat, as raising livestock is incredibly water-intensive. Steam your veggies instead of boiling them.

Another way to use water wisely is by capturing rainwater. Many people could learn how to capture rainwater and use it for irrigating home gardens, not for drinking. For example, in Jerusalem, 24 schools participated in a rainwater harvesting project. Projects like these reduce demand for piped and desalinated water. Installing the right equipment can save up to 5,000 liters of water a year! And just imagine how green your garden could grow!

And at an even bigger level, consider the 12 million people living west of the Jordan River. They could replace the current system of flush toilets with composting toilets. How do these toilets work? They treat human waste through the decomposition of organic matter into odorless compost or humus. Most composting toilets use no water for flushing and are therefore called dry toilets – another great resource for conserving water.

This system might seem a bit radical — but it’s a better solution than building desalination plants that burn fossil fuels in order to make fresh water from seawater… Why pollute our earth with something you will just flush away in your toilets!