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New water-cooling solar panels could lower the cost of air conditioning by 20%
Most of us have heard of solar water heaters. Now there's a solar water cooler, and the technology may sharply lower the cost of industrial-scale air conditioning and refrigeration.
The new water coolers are panels that sit atop a roof, and they're made of three components. The first is a plastic layer topped with a silver coating that reflects nearly all incoming sunlight, keeping the panel from heating up in the summer sun. The plastic layer sits atop the second component, a snaking copper tube. Water is piped through the tube, where it sheds heat to the plastic. That heat is then radiated out by the plastic at a wavelength in the middle region of the infrared (IR) spectrum, which is not absorbed by the atmosphere and instead travels all the way to outer space. Finally, the whole panel is encased in a thermally insulating plastic housing that ensures nearly all the heat radiated away comes from the circulating water and not the surrounding air.
Researchers at Stanford University in Palo Alto, California, recently placed three water cooling panels—each 0.37 square meters—atop a building on campus and circulated water through them at a rate of 0.2 liters every minute. They report today in Nature Energy that their setup cooled the water as much as 5°C below the ambient temperature over 3 days of testing [DOI: 10.1038/nenergy.2017.143] [DX]. They then modeled how their panels would behave if integrated into a typical air conditioning unit for a two-story building in Las Vegas, Nevada. The results: Their setup would lower the building's air conditioning electrical demand by 21% over the summer.
(Score: 3, Insightful) by Sulla on Tuesday September 05 2017, @03:09PM (3 children)
It is applications like this that will start making a difference in lowering the carbon footprint. A possible 20% savings in power spent on air conditioning is a huge cost savings and they get to claim that they are green on top of everything else. The way to get people on board is to not call them evil planet murderers for wanting to drive their car, it is to invent tech to make their car not a problem to continue to use. Telling people to change will never work unless they are given an incentive to do so, I think we recently saw a study on here about how hope of monetary gain (sell as spending less on electricity) is much easier than selling impending doom.
Ceterum censeo Sinae esse delendam
(Score: 2) by JoeMerchant on Tuesday September 05 2017, @08:21PM
Yeah, this is real "green" technology, especially after the first idiot scrubs the mold off the panel with TSP and a thick layer of green algae grows back a week later.
🌻🌻 [google.com]
(Score: 1, Informative) by Anonymous Coward on Tuesday September 05 2017, @08:41PM (1 child)
While I agree that some tech can solve environmental problems, this device is probably not going to help much.
The relevant matter (which is rarely discussed) is net energy usage. How much is saved vs. how much is spent on adding this system (which is just a fancy radiator).
They're using plastic with lots of copper piping, that takes lots of energy to manufacture (although it should recycle better than old solar panels). Then there is the install and maintenance.
And how long does it last, it uses an active pump and piping so there are moving parts and water so probably less than 15-20 years before it all starts leaking and needs replacing.
Does 20% efficiency really offset all these energy costs for a complicated system that only produces 5°C? In most places you would be better off using ground coupling for lower temperatures, or using thermal storage to bank cold from lower night time temperatures. Or even more drastically not using the AC so much!
But this will probably sell, because you can show it off to your neighbors and boast about being green. Which is probably why they call them solar, they share that with many solar panel installations. Something I can point to and boast to the neighbors and say; look I'm green, I'm doing my part, while driving my single occupant SUV to the mall to participate in rampant consumer culture to the extreme and not making in real life changes.
(Score: 2) by gnuman on Wednesday September 06 2017, @04:23AM
1. It's copper pipes, so it's design life is far better than 20 years.
2. It can clearly operate as a passive system without moving parts.
I think they know what they are talking about here.
It's kind of amazing how simple solutions are immediately shouted down as impractical even if they are so much more practical than having 100% renewable power grid. This solution radiates heat away. It's simple and it has no maintenance issues. So of course, shout it down!