Harvesting energy from evaporating water

[wolram]

What do you guys think of this concept.
https://www.sciencedaily.com/releases/2017/09/170926125154.htm

 

[berkeman]

Interesting idea. I tried skimming the article (TL/DR), but couldn't easily figure out what kind of structure or mechanism is used to harvest the power. Can you point me to that part? Thanks.

 

[OmCheeto]

I think it was probably a fun mathematical recreation.
google google google

Yup! Lots of maths.
Potential for natural evaporation as a reliable renewable energy resource [Nature Communications]

I think their economics teacher would give them an F- for not including even a mention that "this might be expensive".

Might have a "niche" market though.
The rains have finally started here, so I may devote some time between now and July, to study this idea.

 

[gleem]

Might have a "niche" market though.

A really small niche to be sure currently a prototype has an average power output of 0.3 mWatts/m² with a target of increasing it to 0.03w/m² .



The only body of water I can off the top of my head think might be worth covering with this device is the Great Salt Lake with an area of 4400 km². It would generate 132 MW of power. which might power about 10,000 houses if it could generate 0.03W/m². They say it could be made more cost effective than solar which I cannot see since solar manufacturing cost is currently less than $1/watt. and about $3/ w installed. Seeing that they would try and use as much water surface as possible how would they contend with or share the water with birds and other aquatic life.?

 

[berkeman]

Seeing that they would try and use as much water surface as possible how would they contend with or share the water with birds and other aquatic life.?

Yeah, the Environmental Impact Reports would seem to be a show-stopper for most of these projects...

 

[gleem]

For people with sufficient property a shallow pond of about 0.8 acres would be adequate for an average house in an area that does not freeze although you would need uncovered aisles in the array to repair or service the individual units.. Not knowing how they are going to scale up the device from the prototype there could also be other issues for example the louvers have to be able to compete with wind either preventing them from opening or closing as well as survive damage from gusty conditions. Having exposed mechanisms to the environment may require significant maintenance.

 

[OmCheeto]

A really small niche to be sure currently a prototype has an average power output of 0.3 mWatts/m² with a target of increasing it to 0.03w/m² .
...

Hey! That's an old paper. Wolram's link took me to a paper just published. hmmmm...

Your source paper:
Scaling up nanoscale water-driven energy conversion into evaporation-driven engines and generators
Published online: 16 June 2015
Xi Chen, Davis Goodnight, Zhenghan Gao, Ahmet H. Cavusoglu, Nina Sabharwal, Michael DeLay, Adam Driks & Ozgur Sahin

Wolram's source paper:
Potential for natural evaporation as a reliable renewable energy resource
Published online: 26 September 2017
Ahmet-Hamdi Cavusoglu, Xi Chen, Pierre Gentine & Ozgur Sahin

hmmm...

Is this common for people to rewrite their ideas every two years, and switch names around, so that no one notices?

 

[gleem]

Your source paper:
Scaling up nanoscale water-driven energy conversion into evaporation-driven engines and generators
Published online: 16 June 2015
Xi Chen, Davis Goodnight, Zhenghan Gao, Ahmet H. Cavusoglu, Nina Sabharwal, Michael DeLay, Adam Driks & Ozgur Sahin

Interestingly another article from the MIT Technology Review dated Sept 26, 2017 says the same thing. The article referenced by @wolfram is a theoretical justification for the optimism for this technique but the reality the prototype specs do not appear to have changed and thus actual implementation does not appear to have progressed from 2015.

An additional issue is the fact that the device depends on a rapid change in humidity as the louvers open. This situation does not exist in areas of high relative humidity routinely found in the southeastern states or when there is significant rain. The warm arid regions of the country seem to be the best location for the use of this device.

Before the champagne is poured we need to see a fully operational system capable of powering a standard home for a substantial time under varying weather conditions.