Some of the questions I was asked were: ‘Where is our water going to come from?” ‘Is it going to be from desalination?’, ‘How much growth can we expect to see in desalination, and what breakthroughs if any in this area are we on the verge of?’
There was a very good session on water at the Always On Going Green Conference in San Francisco last week chaired by Christopher Gasson of Global Water Intelligence (GWI). I am going to borrow a little bit here from that session and from the GWI report “Desalination Markets 2007: A Global Industry Perspective’.
Desalination is a rapidly growing industry and there is no shortage of the raw material required. The Global Desalination industry is predicted to grow from 39.9 million m3/d at the beginning of 2006 to 64.3 million m3/d in 2010, and to 97.5 million m3/d in 2015. This represents a 61% increase in capacity over a five-year period, and a 140% increase in capacity over a ten-year period.
Beyond 2015, the rate of growth in the industry is expected to accelerate, as large markets such as the US, China and India will by then have established the financial and political models to pursue large-scale desalination projects. The rate at which the installed capacity increases is expected to move into double figures, and the annual increment to capacity is expected to increase by an average of more than 15% between 2015 and 2020.
To understand why desalination is so important, you first have to understand just how little of the world’s water is actually fresh water. If all the water on Earth were compressed to a single gallon, only four ounces would be fresh water. Only two drops would be readily accessible and human beings already use one of those drops. But about 92 percent of that single drop is used by agriculture and industry; just 8 percent goes to cities, towns, and municipalities. So for every gallon of water on the planet, only 8 percent of one drop is available for drinking, bathing, and other personal consumption.
A number of other factors compound this scarcity:
· Political & economic instability
· Uneven freshwater distribution
· Population growth in areas of limited natural resources
China has only 8 percent of the world’s fresh water to meet the needs of 22 percent of the world’s population, while Canada has 30 times more water and only 0.5 percent of the world’s population. While Global warming has no predictable impact on overall scarcity it is believed to increase the risk of both floods and droughts.
The good news is that costs for desalination have been dropping dramatically. Forty years ago the cost was $10 per m3. Now it’s down to $0.50/m3 (GWI). However 50% of the current costs are associated with energy use, and energy costs are only going one way. Given the huge impact that energy has on the cost of desalinating water, it is difficult to see how the industry can continue to deliver further significant reductions in desalination costs.
So what’s the next big thing going to be in desal membranes? Some say nanotechnology. Oak Venture Partners and Khosla Ventures clearly think so as they have just invested $15M into the UCLA spin-out company, NanoH20 to help them commercialize their Thin‐Film Nanocomposite (TFN) membrane system.
What NanoH2O are doing is very clever, they are nano-engineering the characteristics of the membrane so that it ‘wants’ to let water through’ and ‘wants’ to repel other contaminants. Its almost Taoist in principle, as opposed to trying to push water through a very small aperture with brute force, you are engineering that aperture so that its natural tendency is to let water pass through it and to repel other contaminants.
If desalination continues to increase, the water produced will have to be metered. Smart metering technology with remote on-line data collection is an area to watch.