Arizona's solar-over-canal project will tackle its major drought issue

interestingengineering.com Arizona's solar-over-canal project will tackle its major drought issue

Arizona's solar-covered canal project is set to redefine energy and water dynamics as a sustainable solution for drought.

Arizona's solar-over-canal project will tackle its major drought issue::undefined

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Arizona and the entire South West don't have a drought problem. They have an aridification problem. While this canal project is a good move in general and we should have been doing it years ago, there is no solving the over-population of a desert. One look at Colorado River basin and its reservoirs is enough to know there is nothing we can do to fix it.
- With any luck pretty soon they'll look at alfalfa farming in the desert too
  
  Why the fuck are humans so stupid that we decided to grow one of the thirstiest crops in the fucking desert.
  
  They already do.
  
  Also, all those new Intel wafer plants near Phoenix.
- Yeah... but sometimes you've gotta accept that a band-aid is all you can do. While this doesn't fix the underlying problems, if it works it'll provide more water and low carbon energy, which is better than nothing.
  
  if it works it'll provide more water
  
  Unfortunately they will just use even more then, so the "shortage" will be maintained.
I really hope this works. Also: banning water-intensive farming in dumb places might help.
- It would definitely help because that is the main problem.
- What do you mean I can't farm on a fucking desert? What kind of communist dunghole is this?
Or we could put effort towards limitations of fossil fuels and fix it long term. Maybe both, but if we don't do former, only duct tape.
- Luckily this does both, to some extent. It's not as far as we need, but solar offsets dirty energy usage.
  
  I don't understand how it "offsets". If someone pisses in the pool and I do it behind a tree, that somehow gets rid of piss molecules in the pool?
  
  Doesn't Arizona get most of its energy from the giant nuclear power plant near Phoenix?
  
  My guess is that producing solar panels uses tons of fossil fuels. And they're pretty much used up after 10-20 years and needs to be replaced and the old ones ends up in a landfill.
Water Knife here we come
- Synopsys?
  
  Water scarcity causes societal collapse throughout the American Southwest. Well written book, interesting premise - just an all around enjoyable bit of fiction.
- YES! Such a good read!
- Good book :)
Open canal systems should be illegal. This is the dumbest shit we do. At least top 10 dumbest.
- As someone who knows nothing about canals (or what they are even used for), anyone want to explain why they are used, why they are dumb, and what we should do instead?
  
  Evaporation. You lose a phenomenal amount of water moving it by canal over large distances in an arid climate. Ideally you'd enclose the whole system to reduce loss but sticking a roof over the top helps to some degree and is less complicated.
  
  An irrigation canal like this is a big ditch to move water from a river to near farm fields. Without the extra water taken from the river, there wouldn't be enough water in the soil for crops to grow in the area.
  
  Being a big ditch open to the sky, the hot sun and dry air make a bunch of the irrigation water evaporate before it even gets to the field. So we went to all the effort of taking water out of the river just to waste it humidifying the nearby air.
  
  Why did we do it in the first place? Because it's way easier and cheaper to dig a ditch than to lay a big pipe, and I don't know if the US had any other water-delivery tech at the right scale when these were built.
  
  Hundreds of miles of shallow canals in the middle of the desert, where regular exceeds 120° f. The water evaporates very quickly.
  
  Imagine a canal which is 3 feet wide at the minimum. It contains a constant volume of water. This canal ultimately waters farm land. By way of example, California has the imperial valley which contains these canal systems. They feed desert farm land. The problem is these canals are often:
  
  open
  
  in a hot dry desert
  
  cheap
  
  Water rights have perverted water usage. People take cheap water which was grandfathered in by old laws and agreements and they waste it to evaporation. If you think "well the water isn't lost, just evaporated, right?" You'd be close, but slightly off the mark. The water is evaporated but it's transported often hundreds or thousands of miles from its original source. We are basically bleeding rivers to feed a desert. And deserts might as well be an infinite sink for water.
  
  We should not have farm land in deserts. But if we do, we should at least conserve the water we are using. Just because it's cheap doesn't mean it's good (not that you're implying that, just saying).
This idea is so poorly conceived. Imagine installing and maintaining something like this. How are those panels supposed to stay clean?The panels and the cover should both be built but they should not be the same thing. No current panels are engineered for this application so they would have to be custom made. Just getting the project to the point where the first panel could be installed would cost millions. We could get started now installing commercially available shade covers and ground mounted solar. Ground mounted solar is simple to clean, simple to maintain, and simple to replace.

I agree the idea looks like a great way to reclaim the space, reduce evaporation, and generate power I just think the money would be better spent on a plan the optimized for expenses and longevity instead of optimizing for novelty.
- I guess I missed it but how are these panels any different than typical ground based PV panels? Looks like, based on the rendering, they they are on some kind of rigid scaffolding over the canal. Not sure how that is different from typical installs?
  
  For sure cleaning them is a problem, don't have an answer to that. Hope that that is accounted for in the proposal.
They should try this at those retaining ponds where they filled them with black balls.
- There are several companies working on solar covers for reservoirs. I agree, seems like a win win. Reduce evaporation and have a large, level, "field" for solar arrays.

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