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Entrepreneurial Water: Desalinating 900 Ft. Deep in the Ocean; 54 DXW Desalination Plants could Supply Water to All of SoCal (Aguanomics)

Feb.11, 2009 in Water Technology

(Feb. 11, 2009, Aguanomics)

On Monday, I visited DXV Water Technologies, a start-up with a new technology for desalination.

I met with Michael Motherway (president), Curt Roth (VP engineering), and Diem Vuong (inventor), and we discussed their technology, markets and other issues of supply and demand. Here’s one write up [PDF].

I HIGHLY recommend that you listen to this MP3 of our conversation (just over an hour; 55MB). It’s rambling and rambunctious and full of interesting details from the world of “entrepreneurial water” — often an oxymoron.

Their technology uses off the shelf micro filters in a new (patent pending) configuration that is placed 270m underwater in the ocean. The hydrostatic pressure at that depth is enough to push fresh water through the filter, at such a slow rate and yield that there is no energy required (energy is necessary to bring the water onshore) and entrapment of biological beasties and brine concentrates are minimized.

Their system can use any size filter to get water that’s clean of not much (for prefiltering) to water that’s free of endocrine disruptors (the current bad-boy of water quality). [The second slide is slightly fuzzy but it shows the relationship between pore size and what's filtered. Vuong said that IF their filter hole was as big that of a straw, then a virus would be the size of a bus and an endocrine disruptor would be the size of a softball, i.e., still blocked from passing through.] The system can also be used to clean fresh water and/or reclaimed water for consumption.

Because DXV’s system uses 1/3 the energy of current systems, it produces water at half the total cost (capital costs are the same), i.e., $0.50/m^3. DXV’s cost will ALWAYS be lower than on-shore, high-pressure desal because both technologies use the same filters. It’s the method of holding the filters that differs.

Here’s the money quote:

We can get 50MGD (56TAF/year) from an 11 acre installation. Given a SoCal urban demand of 3MAF, that means that 54 of these systems could supply all of local demand [ignore price for now]. The footprint of 54 installations is less than one square mile in the ocean.DXV is looking for $1-2 million to run a fresh-water pilot of their technology. Tell them I sent you :)

Bottom Line: Technology CAN lower the price of supplying water, but remember that the easiest way to end a shortage is to increase prices to reduce demand. Raising prices also generates revenue instead of costs.

(Original Post Here)