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

L4sBot@lemmy.worldmod to Technology@lemmy.world – 440 points – Arizona's solar-over-canal project will tackle its major drought issue
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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.

Because entrenched, and exceptionally wealthy interests. Reading about how about in CA there are tons of Colorado River fed foreign owned farms growing alfalfa to export to the middle east is the definition of capitalist success...the profit of a commodity has been made the most efficient; acquired cheaply for something otherwise impossible with international arbitrage as the medium.

Every time someone asks people in the southwest to take shorter showers show them this: https://www.foodandwaterwatch.org/2022/02/24/california-water/

We should probably update the dictionary so the word 'greed' is synonymous to dumb, stupid, ect. Cuz it sure seems that greedy people just have a super low IQ.

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.

The "one more lane" of water supply.

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.

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.

Doesn't Arizona get most of its energy from the giant nuclear power plant near Phoenix?

Well they're part of a larger grid. Any clean energy on the grid will be cheaper than dirty, so will be sold to offset dirty even if Arizona was 100% clean.

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?

You only need a certain amount of power. (In fact, you can't generate more power than is needed, or you cause massive issues.) If this adds extra energy generation but doesn't add demand, generation somewhere else will be taken offline. This will be whatever is cheapest, and green energy is nearly free after construction, so it'll be dirty energy that isn't running anymore.

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.

It takes energy to produce them, sure, but it's way less than even just the production needs for coal or natural gas. Not to mention that's a one time carbon cost (per lifespan which is close to 30 years these days) vs ongoing emissions. And additionally, as the energy mix where the panels are produced cleans up, the carbon footprint of the panels go down as well! Is it the perfect solution? No, but there is no silver bullet to get off fossil fuels. Solar is just one part of that transition and it is exciting to see more groups exploring the solar/shade synergy (there's some cool shaded farming solar experiments going on that also make use of the solar panel's shadow for additional benefits!)

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.

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.

Are there not enough areas of the US that get rainfall suitable for growing the needed food?

There probably are, but Saudi Arabia owns a bunch of land in Arizona and decided it was the perfect place to grow alfalfa, a very water intensive crop. That said, some farming does make some sense even in the desert, since it is almost certainly cheaper to have local produce than to need to import everything from places that have an abundance of water, even if that means building canals to water them.

Almost everything West of the Colorado Rocky mountains is very arid and requires extensive irrigation.

Everything except for the Pacific Northwest, and only the area west of the Cascade mountain range in Oregon and Washington.

The US has lots of land that doesn't require irrigation, but also lots of land that can grow crops if irrigated. Some of that land in California is some of the best farmland in the whole country, growing things that prefer California's Mediterranean climate (similar to parts of Australia's southwest coast).

We have the technology and have had it for a while. But we don't have the laws and habits of dry countries so US water laws are a wasteful mess.

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).

it contains a constant volume of water

This guy has never been to the Phoenix area :P we even have rivers with no water, too! Bring the whole family, camp out and have imaginary marco / polo by the hill infested with scorpions, only a half-mile from the city dump! Bring your RV so you can feel like a complete moron with the other people who thought it was a great idea to buy a mini house on wheels that gets 6 miles to the gallon. And if you are early to rise, you can make Laughlin a day-trip to lose all your social security check by dusk, before sauntering back to the depression-rut of a life you have carved out for yourself. Because living in a desert with a large elderly population, just-barely-enough power during the summer even though there is a fucking nuclear power plant 20 miles out of town, and has been in a drought for my entire life while everyone waters their lawn 3 times a week, never felt so good!

Oh sorry I got mixed up with my "fuck off and stop moving here" speech. Give me 10 minutes.

I've been to Phoenix and I agree. I don't understand why they waste so much water.

Hundreds of miles of shallow canals in the middle of the desert, where regular exceeds 120° f. The water evaporates very quickly.

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.

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.