The upside in the unknown realms of the desalination equation is rapidly gaining more potential as technology jumps forward in unexpected leaps. Are we at a point now, or will we be there soon, of wondering what effect large (mega) scale desalination and irrigation would have on global warming?
Even in a lower-tech world, desalination has had a huge role. Currently, there are 13,800 desalination plants operating in the world, producing a total of about 12 billion gallons of water a day. That, according to the International Desalination Association.
Consider: About 15-20% of the Earth's non-polar land surface is considered desert. Many of these areas could be spectacularly transformed if only they had access to cheap, plentiful water.
The problem with desalination is that, up until now, it has been an extremely energy intensive and, therefore, expensive process.
Two recent announcements have provided more reason to believe that larger scale desalination is already on the horizon.
(KACST), has already begun a solar-powered project that will supply 30,000 cubic meters of clean water per day to 100,000 people in the city of Al-Khafji. The KACST project is leveraging a new technology developed with IBM to allow more intense heat to be harvested from the sunlight and also foresees other innovations, such as proprietary new membranes developed for the reverse osmosis process.
Back on the other side of the planet, a Vancouver company, Saltworks, is continuing to dazzle specialists from the Middle East to Australia with its own unique version of solar-powered desalination.
Saltworks' breakthrough process uses far less energy than conventional systems. Saltworks' Thermo-Ionic™ desalination technology harnesses renewable energy sources such as dryness in the air and heat from the sun - to provide sustainable, low cost, desalinated water with minimal environmental impact.
Besides requiring only 20% or less energy than conventional desalination, other advantages of Saltworks' process include that it does not release a concentrated saltwater brine as a by-product and in fact, it could even use the brine produced by other desalination plants.
All that remains is for Saltworks to prove that its technology can be scaled up. Their initial Vancouver test plant will produce (or is producing) 1,000 liters of clean water per day.
Given that both of these new desalination processes use considerably less energy than previous technologies, it now becomes more interesting to project the potential and consequences of very large scale desalination. Indeed, there are sure to be further technological improvements in the near future. Deserts may be transformed - but at what price or benefit? Would a green Sahara accelerate global warming - or discourage it? The Aswan Dam in Egypt has wreaked havoc with the desert environment in unexpected ways. Now is the time to consider the large picture of desalination.