California Fights Drought With 96 Million "Shade Balls" 234
HughPickens.com writes: Katie Rogers writes in the NY Times that the city of Los Angeles is releasing 96 million plastic "shade balls" into the 175-acre Los Angeles Reservoir to help block sunlight and UV rays that promote algae growth, which would help keep the city's drinking water safe. Officials also say the balls will help slow the rate of evaporation, which drains the water supply of about 300 million gallons a year. The balls cost $0.36 each and are part of a $34.5 million initiative to protect the water supply. Shade balls are the brainchild of Brian White, a biologist with the utility who based the idea on "bird balls" that he observed in waterways near airport runways to prevent airfield bird strikes. The Los Angeles Reservoir, which holds 3.3 billion gallons, or enough water to supply the city for up to three weeks, joins three other reservoirs already covered in the shade balls. "In the midst of California's historic drought, it takes bold ingenuity to maximize my goals for water conservation," says Mayor Eric Garcetti who was at the Los Angeles Reservoir to mark the addition of 20,000 of the small balls to the lake. "This effort by LADWP is emblematic of the kind of the creative thinking we need to meet those challenges."
black balls (Score:5, Insightful)
To the extent the point was to keep heat away from the water, I wonder why they didn't go for something with a high albedo instead of black.
Re:black balls (Score:5, Interesting)
To the extent the point was to keep heat away from the water, I wonder why they didn't go for something with a high albedo instead of black.
My thought as well. I suspect it has to do with black plastic being more resistant to UV degradation.
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'High albedo' works two ways. Yes, during the day, it would reflect sunshine and reduce heat absorption. But at night it would tend to prevent heat already absorbed from escaping (reflects it back into the water). So at night black would be best, allowing more heat to escape. Google 'black body radiation'.
Water is already, in effect, a black body radiator, so IMHO the black-ball radiators would not be a bad solution because it radiates internal heat maximally and also is supposed to inhibit algae growth (as
Re:black balls (Score:5, Interesting)
I think, though, the first response to this thread nailed it - They chose black for the same reason power, phone, cable, and virtually every other type of exterior grade wiring comes primarily in black - UV resistance. Probably not a good idea to put 96 million rapidly deteriorating sources of pollution into a reservoir.
Re:black balls (Score:5, Funny)
Why limit ourselves to only one color? Make a bicolored ball, slightly heavier on the black side. There you go, efficient at blocking heat during the day but also efficient at allowing the water to radiate it away at night.
And then, if we can develop a mechanism to control areas of balls, using an XY grid of wires over the reservoir, we could selectively turn groups of balls (call them "pixels") white or black. Use this feature to spell out advertising messages to incoming airliners, and use the advertising revenue to pay for the scheme.
Brilliant! :-)
Re:black balls (Score:5, Funny)
Finally, the elusive step 3.
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Charge $300/ball.. PROFIT!
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"So at night black would be best, allowing more heat to escape. Google 'black body radiation'."
Sunlight is mostly visible and near-infrared (400-1500 nm), so white materials reflect most of it. Thermal radiation out of the surface is wide-band, peaking around 10 micrometers, 10 times longer than the received radiation. (Google Wien's law) Most materials except metals are excellent black-body radiators in that wavelength range. No need to use black paint.
Re:black balls (Score:4, Informative)
It looks like these balls were first mass produced to block light [plasticsnews.com], not to minimize evaporation, in order to reduce the formation of a carcinogenic byproduct of water chlorination of bromine-rich waters. So perhaps the color isn't ideal for its current role - but sufficient.
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They had to crank out a lot of these in short order.
Good, Cheap, Fast; Pick 2 comes into play here, with the selections biased toward 'Cheap' and 'Fast'. They settled for OK instead of 'Good'.
Re:black balls (Score:4, Informative)
To the extent the point was to keep heat away from the water, I wonder why they didn't go for something with a high albedo instead of black.
"... to help block sunlight and UV rays that promote algae growth,"
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(There exist opaque, bright white, UV-resistant plastic too.)
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IIRC, the balls also inhibit sunlight's ability to promote toxic chemical reaction with the water's surface.
If you add sunlight to a mix of bromide and chlorine, you get bromate... a suspected carcinogen.
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If you add sunlight to a mix of bromide and chlorine, you get bromate... a suspected carcinogen.
Hey, it's California. Everything not known to be a carcinogen is suspected to be.
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It's ok, they have a Prop 65 sign just outside the reservoir.
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The plastic is probably not very conductive so the heat is not bad.
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my guess is that they are not very conductive so the color is not much of an issue.
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It's hard for wind to rotate them when they're touching each other.
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" The water is nowhere near boiling temperature, so evaporation cannot happen due to heat."
It doesn't have to be boiling to evaporate.
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The water is nowhere near boiling temperature, so evaporation cannot happen due to heat.
Then care to explain how evaporation can happen in the dark?
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Look up "vapor pressure" on Wikipedia and have your mind blown.
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... totally insane homeless people, and startup tech firms.
But you repeat yourself.
Balls? (Score:2)
A ball is a sphere. It casts a circular (ovoid) shadow at best. The overlap between balls probably means you're only covering about 80-90% of the surface at best. I suppose they don't mind losing that to allow the water level to rise and fall and have the balls move over each other.
But, to be honest, I can't imagine that's it's not cheaper to just buy a cover of some kind? Getting those things back out is going to be great fun - and expensive - if they get covered in algae, say.
We've been saying to leav
Re:Balls? (Score:5, Interesting)
They reportedly considered a floating shade cloth, but found this to be a cheaper solution when all costs were factored in.
Why is it cheaper? Don't ask me. But it reportedly is.
IMHO, the "ideal" solution would probably be to use the area over the water for productive purposes, such as floating sealed algae farm or floating solar farm [google.is], so that you're both stopping evaporation and getting a secondary benefit with the same system. But the overhead times and costs would obviously be much higher for that.
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Because the company that makes them is owned by a close friend of the guy who decided to use them? ;-)
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Re:Balls? (Score:4, Informative)
My guess would be that these are easy to transport and deploy. Pulling a cloth over means getting a boat and keeping it lined up. Also needs to be transported in one piece. Balls can be loaded into a dump truck, driven to any point around the reservoir, and just dumped in. They'll spread out by themselves.
And plastic balls are very cheap. These don't even need to be particularly good quality. Stamp them in a mould, glue two halves together, you're done.
Re:Balls? (Score:4, Informative)
Why is it cheaper? Don't ask me. But it reportedly is.
The balls require no maintenance, aside from replacing lost or stolen balls. Nothing is really going to be damaging them out there besides the elements, which will work on them only slowly due to their nature. A cloth would just be an algae-growing substrate mat.
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Thoughts I had:
1. Balls might be more durable than cloth - if something lands on the balls, they simply shift out of the way, then back. The cloth might tear or be pulled to the bottom with whatever. Stand up to rain/hail better.
2. Cheaper - a 'floating shade cloth' might end up costing more per coverage, after all, it needs to be woven from thread and somehow made to float
3. Easier to place. As shown in the video, you can pretty much just dump the balls, with cloth you'd actually need to place it. T
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The overlap between balls probably means you're only covering about 80-90% of the surface at best.
Those numbers would be if the sun is overhead all the time, but it's at an angle the vast majority of the time and the balls do have height.
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96 million balls at $0.36 each?
I reckon you can get a very big tarp, and supports, and structure, for that.
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Anaerobic wasteland ? (Score:5, Insightful)
Is there a risk that they just turn the lake into an anoxic wasteland (sulfides are quite toxic) if they do this ?
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Reservoirs often have fish and in some cases quite large ones since people aren't allowed to fish on them unless they have special permits.
Re:Anaerobic wasteland ? (Score:5, Informative)
It is a concrete reservoir used to hold TREATED water. There is nothing in it.
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During the filming of the 1989 movie 'The Abyss' James Cameron used black beads to cover the big tanks he was using for filming. Blooming algae often reduced visibility to 20 feet (6 m) within hours [wikipedia.org]. Over-chlorination led to divers' skin burning and exposed hair being stripped off.
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Probably. It also reduces the release of oxygen into the water by algae and cyanobacteria. But it also reduces consumption of oxygen by living matter too.
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Bold ingenuity? (Score:5, Insightful)
"In the midst of California's historic drought, it takes bold ingenuity to maximize my goals for water conservation," says Mayor Eric Garcetti
Or you could, you know, tell all those rich idiots who insist on acre-sized green lawns in the middle of the desert "tough luck".
Re:Bold ingenuity? (Score:5, Insightful)
Or you could tell the almond farmers, who use about 10% of the entire water supply, to take a hike.
Or you could float the price of water and the problem would solve itself within a few months.
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Or you could float the price of water and the problem would solve itself within a few months.
We tried that here, in a similar semidesert-like environment when our reservoirs were running dry. The wealthier citizens (most prolific users of water) still kept their landscaping and lifestyle with an extraordinary ability to absorb the budgetary increase and/or drill private wells to rob from a depleted aquifer. Like most measures of austerity, it has a greater impact on the poor and middle classes.
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We tried that here, in a similar semidesert-like environment when our reservoirs were running dry. The wealthier citizens (most prolific users of water) still kept their landscaping and lifestyle with an extraordinary ability to absorb the budgetary increase and/or drill private wells to rob from a depleted aquifer. Like most measures of austerity, it has a greater impact on the poor and middle classes.
Was there a sliding rate? IE $0.01/gallon for the first 1000 gallons/month. $0.10 for the next 1000 gallons. $0.25 for the next 1000 gallons...
This is how electricity is normally billed, so most homes get one rate, commercial buildings with banks of lights burning all day get another rate, and factories using plasma cutters all day get a different rate.
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We have a law in California that restricts government agencies to charging for only the actual cost of service. Tiered rates were tried but the courts just struck them down. Bad for conservation but good for limiting pricing shenanigans. It is a hard problem.
Re:Bold ingenuity? (Score:4, Insightful)
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I'm not opposed to that (Score:3)
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but I'd rather see more desalinization plants. The trouble is shade balls were probably pretty cheap. If you think California lacks the political will to tell their 1% to back off on the water usage try getting the tax raises through needed to support desalinization plants.
Taxes don't need to be raised, the water bill would go up slightly. Last I read it was something like $30 a month to the average residential water bill in order to add a desalination plant to the local supply mix. Costs of desalination have come down quite a bit.
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Or you could, you know, tell all those rich idiots who insist on acre-sized green lawns in the middle of the desert "tough luck".
how about we tell all those idiots who insist on a city-sized sprawl of assholes in the middle of the desert without capturing any water worth mentioning even though enough rain falls on it in the average year to serve 100% of their needs "tough luck"? I'm tired of draining California dry so that socal can have water it should never have had.
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" I'm tired of draining California dry so that socal can have water it should never have had."
Uhh, except there is plenty of geological evidence that SoCal had much more vegetation and was not so much desert as recently as a few hundred years ago.
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Uhh, except there is plenty of geological evidence that SoCal had much more vegetation and was not so much desert as recently as a few hundred years ago.
That doesn't really have any bearing on what I'm saying. The water that it's getting now would never have got there without help. If it weren't causing problems then who cares, but it is causing problems further north, so we should care.
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Or you could, you know, tell all those rich idiots who insist on acre-sized green lawns in the middle of the desert "tough luck".
how about we tell all those idiots who insist on a city-sized sprawl of assholes in the middle of the desert without capturing any water worth mentioning even though enough rain falls on it in the average year to serve 100% of their needs "tough luck"? I'm tired of draining California dry so that socal can have water it should never have had.
I don't like sprawl and we could be a lot smarter about collecting water. That said, 80% of our water goes to agriculture which gets water dirt cheap (pardon the pun.) Now try convincing the ag-lobby to pay their fair share for water and related infrastructure (capture, desalination, etc...)
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We have tried many, many times to build new water storage in SoCal only to be slapped down by the environmental lobby EVERY time. They always find a slightly differently colored bird or worm and declare the area protected. They publicly state that the goal is to prevent any new construction of any kind. Not very reasonable people...
Ball water. (Score:2)
That is all.
Old Balls (Score:3)
Make that 2008: http://www.popsci.com/holly-ot... [popsci.com]
Let's add some BPA to the water! (Score:2)
So more of our boys can grow boobs. That's just great.
PT Barnum at work... (Score:2)
...every minute...
Just use the water (Score:2)
The summary says the reservoir has enough water to supply the city for three weeks. So instead of spending millions to preserve the water, use it up. Let the other supplies have a break for a few weeks, and then you don't have to worry about the empty reservoir.
Nothing New Under The Sun (Score:3)
Thirty years ago, I was living in Sweden, where it was already nothing new that you cover an outdoor swimming pool with ping-pong balls to prevent heat losses and related evaporation. How come this was news, and a great stroke of genius, in California?
As an aside, they don't interfere with the use of the pool at all. You can dive in through them.
Idiots messing with things know in other fields (Score:4, Insightful)
They are creating an environment for an algae bloom that are starting to cause problems everywhere.
The algea blooms, which are not truly algae but are cyanobacteria, use less light(lower wave length) want low oxygen environments with lower water turbulence. And they are creating that.
Once cyanobacteria bloom starts, it's very difficult and costly to control. It' has very few natural predictors, I don't know of any freshwater ones, and worse yet, cyanobacteria can create toxins that have killed dogs running through it.
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I was wondering if anyone else were to point this out. There are many bacterium types that actually work with chlorophyll type-f and can absorb in the IR wavelengths and are anaerobic.
This is a poorly-researched idea.
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Yea, we've got pretty resistant bacteria, now days.
I have to deal with these things in hydroponic nutrient tanks.
Re:Idiots messing with things know in other fields (Score:5, Interesting)
They are creating an environment for an algae bloom that are starting to cause problems everywhere.
And yet, they've been using shade balls since 2008 without incident. (See Ivanhoe reservoir.) You'd think that would be an easy problem to spot.
Similar Technique used by James Cameron in 1989 (Score:5, Interesting)
For the 1989 Movie The Abyss [wikipedia.org] James Cameron shot the underwater sequences for the film were shot at an unfinished Cherokee Nuclear Power Plant, situated outside Gaffney, South Carolina, which had been abandoned by Duke Power. Two specially constructed tanks were used. The first one held 7.5 million US gallons (28,000 m3) of water, was 55 feet (18 m) deep and 209 feet (70 m) across. At the time, it was the largest fresh-water filtered tank in the world. Additional scenes were shot in the second tank, which held 2.5 million US gallons (9,500 m3) of water. The filmmakers had to figure out how to keep the water clear enough to shoot and dark enough to look realistic at 2,000 feet (700 m), which was achieved by floating a thick layer of plastic beads in the water and covering the top of the tank with an enormous tarpaulin.
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"How many Olympic-sized swimming pools(OSSPs) does that make?
Based on a nominal depth of 2 m, this is 2,500,000 L (550,000 imp gal; 660,000 US gal) [wikipedia.org] or, in terms of cubic volume, 2,500 m3 (88,000 cu ft), as is commonly quoted. So Cameron's big tank was the equivalent 11.36 OSSPs and the smaller one held 3.79 OSSPs.
I was ready to rip on this due to bad reporting... (Score:4, Insightful)
You have to love how they use gallons as a unit of measurement because it gives a really big number - 300,000,000. But in water terms, that's actually very little. That computes out to just under 921 acre-feet, which is the standard unit of measuring large quantities of water. Not so impressive-sounding now, so let's see what the actual costs are. Divide the $34,500,000 cost by the number of acre-feet and then again by the expected lifetime of the balls - say, 20 years. You wind up with $1,900 per acre-foot. This is a lot of money, but California residents and normal businesses normally pay around $1,000 per acre-foot. If you amortize the cost of these balls over the total water going through the system it's still a bit pricey but not insane when you consider the effects of droughts. For example, in Carlsbad, California they are building a desalinization plant with guaranteed annual sales at a cost of just over $2,000 per acre-foot.
Of course, real sanity would address the real causes of the "drought" - the fact that the two groups that use 85% of California's water pay nowhere near this much. Government pays $0 per acre-foot and wastes a breathtaking amount of water. Big agriculture pays around $10 per acre-foot (the small organic farms I buy my produce from still pay the two-orders-of-magnitude-higher residential rates). I'm all for agriculture - California is an amazing place to grow food and provides a huge percentage of the fruits and vegetables consumed in the US - but the artificially low prices have been abused by some farms and orchards. There is still a lot of flood irrigation being used (and some farmers were actually growing rice in the desert). A massive amount of alfalfa is being grown in the desert and then shipped to China, because at the subsidized water prices this is actually cheaper than China growing their own hay. Sit back and bask in that insanity. The government has dumped as much as a third of California's water supply for various environmental purposes - you could argue the costs and merits of this except for the fact that none of these projects are having their desired effect, so all of that water is just pure waste (around 33% of state water usage). And then they threaten to fine us if we water our lawns more than twice a week (> 5% of state water usage).
So anyway, for once, the black balls are the government doing something expensive but not completely stupid. But the fact that this is even necessary due to government stupidity and a breathtakingly colossal mismanagement of a valuable natural resource sort of makes it all moot in the end. There is no shortage due to drought - there's a shortage due to bad policies.
Why plastic balls? (Score:3)
Why not use a thin layer of biodegradable oil as has been proposed to weaken hurricanes [physicsforums.com]? That would prevent evaporation and cost a lot less, I'd imagine. I doubt the oil would cause problems since the water is likely drained from below the surface. The only downside is the possible damage to wildlife.
Couldn't it make things worse? (Score:2)
I know nothing, but when I put a ball into a bowl of water, it naturally rolls around in the gentle current. Like a ball-point pen, the ball picks up some water, spreading it over the ball.
Wouldn't that thin layer over a sunny ball evaporate faster? And would the over-all wet-ball surface simply be a larger surface area than the otherwise planar surface -- also contributing to greater evaporation?
And if the entire body of water is only good enough for 3 weeks of water, then isn't this kind of "conservatio
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2. The real key is that the interstitial spaces are reflux zones, that let the evaporating water condense and run back into the pool.
3. Not sure where you were going with the "getting more water..." comment
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When was the last time you put a ball in a bowl of water? I just tried it with a ping pong ball and the ball didn't roll at all. Even with the water running.
Typical LA (Score:2)
Great fun! (Score:2)
Are we in Norstrilia? (Score:2)
In the Cordwainer Smith book Norstrilia [wikipedia.org], the protagonist buys Earth, and is astonished when he comes to visit that the rivers are not covered, that evaporation runs rampant -- unlike back on his home world of Norstilia. Over the three decades I've lived in California, and especially over the last few years, that part of the book seems more and more like reality.
Simply Reduced Surface Area! (Score:2)
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Read the article not the summary.
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Ping Pong Balls are typically nitrocellulose. Which makes them very flammable.
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Oh noes! They could set the lake on fire!
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You say that like the point is to save money rather than water. You can't drink money. Crops don't do too well on it either. And California is rapidly losing their traditional imported water sources since surrounding states are mostly faced with the same drought and are increasingly unwilling to sell their own water.
So, the options are:
Conserve water
Buy more water at prices sufficiently elevated to tempt surrounding states to sacrifice their own dwindling water supplies
Start building desalination plants
Re:Expensive... (Score:4, Insightful)
Yeah, let's just fling any old kind of plastic on top of our water supply without checking that it won't rot in the sun and leach whatever chemical its made of into the water, or melt into a sheet that starves the water of oxygen, or chokes the local wildlife. Oh, and you'll have to get them painted black first.
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Ping Pong Balls are made of Nitrocellulose. Very fun to light on fire.
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BUT ping pong balls are less than 1 inch in diameter, so you'd have to use about 20 of them to replace each one of the larger black balls. Now the cost savings doesn't look quite so dramatic.
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Do you have any idea how hard it is to find a BPA-free rubber duckie?
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There are no fish, the water has already been chlorinated which is why they are using the balls in the first place.
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The rich entitled pricks continue to waste water by the millions of gallons because "they pay taxes", and therefore, deserve water more than poor people who want to drink it.
So you don't think the people paying to develop and extract a resource ought to have the first right to use it? Lets face it California could not sustain the populations it does without massive water infrastructure. Local availability in terms of aquifer and the naturally present surface water would not even come close.
If it was not for the people paying taxes, all your poor would be forced to leave! Deny the best their right to the top and you'll have no best left. That won't work out well for the mass
Re:Could save more water even cheaper (Score:5, Informative)
Rich people watering lawns is not the problem. Residential water use, ALL residential water use in California, accounts for about 4% of our annual use. It is unrestricted use by big agricultural concerns that use OVER 80% of our water. They still flood fields for christ's sake!!! Their is no incentive for them to use modern water wise farming practices since they have "senior rights" going back centuries. We can't even pass a law restricting them so now we grow rice in flooded fields. Just stupid.
Re:Solar shade or solar oven? (Score:4, Informative)
Water is already a near-ideal absorber of sunlight, so the black balls shouldn't change much in that respect, except to keep much more of the heat on the surface. They are also quite likely much better heat radiators, which should be even more helpful since the heat will be more concentrated (hotter) and thus radiate far more rapidly.
I also don't know that wind would be a problem - it sounds like they're trying to pack these pretty tightly, so it's not like they're going to be able to freely roll around the surface and lift a film of fast-evaporating water. It'll take a heck of a wind to rotate them against each other, especially considering they're almost completely shielded from the force by their upwind fellows. So most of the time I would suspect they would remain relatively stationary, with their top surfaces getting very hot, and their plastic construction largely failing to conduct that heat down to the water's surface.
I do agree that white balls (preferably a beyond-visual solar white) would seem to be a considerably better solution at first glance, but I can think of several possible confounding factors:
- Longevity: As a rule plastic breaks down rapidly in direct sunlight. These are probably carbon-black, which I suspect is is about as good as it gets for both cost, UV protection, and non-toxicity. Alternate UV-protective dyes are likely to be more expensive, less effective, and more toxic. Plus the faster degradation would increase clean-up and replacement costs as the balls degrade.
- Costs: these balls are already mass-produced for other reservoir-related purposes: a new design would add at least some design and retooling costs
- Testing (money and time): these balls have already been used in reservoirs and thus (hopefully) the health and safety issues have received at least some study. Reformulate the balls and you'll need to do those studies again.
All out of hot air (Score:2)
Oh, I should also add another wind-related benefit: All those balls will almost completely shield even the exposed surface of the water from the wind - which should dramatically reduce evaporation rates. Wind being one of the major contributors to evaporation rates.
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The balls are good for 10 years, at which point they will be collected and recycled.