Electricity generated with water, salt and a three-atoms-thick membrane

phys.org

42 points·EugeneOZ··4 comments

Looks like there is something wrong with numbers. Article says 1 square meter will be enough to produce 1MW of energy. But, 1MW of energy will be surely enough to desalinate water for covering 1 sq. m., isn't it?

So, place it at sea-side and get "infinite" amount of energy.

But, more probable, author of the article confused 1MW and 1mW.

The paper seems to be here, although all I'm getting back right now is long load times and a generic error page:

http://www.nature.com/nature/journal/vaop/ncurrent/full/natu...

I found a copy elsewhere (won't link, piracy, etc) and it does indeed claim an estimated density of 1 megawatt per square metre.

There definitely seems to be something missing here, because another paper I found (http://www.ijesd.org/papers/243-B20001.pdf) claims a typical reverse osmosis plant processing seawater uses 3-10kWh to desalinate a cubic metre of seawater.

They don't have any information on water consumption (which I'm really curious about), but the break-even point on energy consumption is ~333m^3/hr and, as a layman, that seems like a pretty high flow rate for how they describe this working.

Someone should email the authors of the paper for clarification.

Other potential problems are the life span of the membrane, and how to keep it clean. I would imagine that seawater is full of impurities that would cause havoc with a membrane in real world use.

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