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California wants to cover its canals with solar panels
- prax-mon 4y agoThis has been done in India[1]. Makes sense to try it out. 1: https://en.wikipedia.org/wiki/Canal_Solar_Power_Project https://en.wikipedia.org/wiki/Canal_Solar_Power_Project
- Steven420 4y agoThe skate community is not going to be happy about this
- larkost 4y agoI think they are mostly talking about the ones that carry water much (all?) of the year in the central valley, rather than the ones in L.A. proper. So I don't think skaters will have much to complain about.
- Animats 4y agoRight. The LA River is an emergency drainage system that isn't needed much. Last month, it was needed.[1] The California Aqueduct is usually kept full. Falling into the California Aqueduct is usually lethal.[2] 30 feet deep, steep banks, and a high rate of flow. It's fenced, but just with ranch fencing. [1] https://archive.is/2dbEI https://archive.is/2dbEI [2] https://archive.is/H52Jk https://archive.is/H52Jk
- buffington 4y ago> steep banks Not just steep, they're often vertical and not even remotely skateable even when dry.
- buffington 4y agoAs a member of that community, I am happy about this (and appreciate the consideration for our happiness - it's not something we're accustomed to). Forgive me for stating the obvious, but the kinds of canals we skate don't contain flowing water. Sure, there are rivers with engineered concrete river beds in metro areas that might have a smaller channel with water, but the skateable parts are dry (Santa Ana river, Los Angeles River, etc). Concrete river beds are also more of a novelty than they are enjoyable. The concrete is like corduroy. It takes a lot more effort to move, and when you fall, you leave smeared portions of yourself behind. The canals the article talks about are much smaller, and typically serve agriculture in Central California with edge to edge flowing water. When dry, those can be fun, but again, they're not the first on my list of fun places to skate (which isn't to say they're not fun, just not as fun as other places). They're full of debris, very rough, and lose their appeal pretty quickly. Personally, if losing those spots means more efficient use of water, it's a very small price and one I'm willing to pay.
- euroderf 4y agoA win-win-win situation. Doomed.
- wedn3sday 4y agoIn this case there's no eminent domain issues since the government already owns the land the canals sit in, which significantly reduces local governments abilities to stop the proposed projects. Additionally, since it will increase water availability its unlikely that farmers in the central valley will fight it.
- tempodox 4y agoI'm already waiting for creative NIMBY counter-arguments.
- Analemma_ 4y agoPeople can get weird about solar panel placement and constantly come up with terrible ideas like putting them on cars (not enough surface area for any real power) or roadways (no!). Does anyone know if this idea is one of those terrible ones or is genuinely feasible?
- oofta-boofta 4y ago> Does anyone know if this idea is one of those terrible ones or is genuinely feasible? They've done it India, a country notorious for red tape. Which begs the question: how long will it take California's bureaucratic ineptitude take to screw this up.
- wedn3sday 4y agoThe proximity to water cools the the panels which increases their efficiency, there's a lot of sq ft available, and the government already owns the land. It also decreases the amount of water lost to evaporation, and the amount of weeds/plant growth around the canals since there's less sunlight for them.
- vincnetas 4y agoif you use water to cool down the panels then you should not expect to lower the evaporation. I would say that this would increase evaporation as solar panels reflect less light than water. but this is just speculatio from my side.
- droopyEyelids 4y agowater underneath the panels will still evaporate to an extent, and cool the panels compared to panels above dry earth. The panels will shade the water and reduce evaporation compared to unshaded water.
- bugzz 4y agobut doesn't this ignore that a lot of the light now absorbed is become electricity instead of heat?
- cypherpunks01 4y agohttps://archive.is/vh8n8 https://archive.is/vh8n8
- toomuchtodo 4y agoTLDR Would reduce canal evaporation and add ~13GW of solar generation capacity (compared to the current ~20GW of current utility scale generation in the state). https://www.asce.org/publications-and-news/civil-engineering-source/civil-engineering-magazine/article/2022/03/solar-panels-over-california-canals-test-possible-joint-siting-benefits https://www.asce.org/publications-and-news/civil-engineering... https://www.nature.com/articles/s41893-021-00693-8 https://www.nature.com/articles/s41893-021-00693-8 https://app.electricitymaps.com/zone/US-CAL-CISO?wind=false&solar=false https://app.electricitymaps.com/zone/US-CAL-CISO?wind=false&...
- mdorazio 4y agoThank you for providing links! The first one contains a lot of the same doubts I have and points out that this is an exploratory project explicitly because the ROI is unclear. The second one is a bit strange. Here’s the actual paper [1]. And what they actually studied was “ To address this critical knowledge gap, we quantified the evaporation savings and financial performance of over-canal solar in comparison to over-ground solar on land adjacent to canals”. So they’re assuming leaving the canals uncovered and siting solar power plants on expensive ag land instead of covering the canals cheaply with traditional shade materials and using the savings to build power generation on cheap land elsewhere. Not very convincing to me. Personally, I think the net benefit will be negative, but I’d love to be proven wrong on this. [1] https://escholarship.org/content/qt8cj5j07p/qt8cj5j07p_noSplash_da7010b14e05c8089355f67e9f443a6f.pdf?t=qq63ir https://escholarship.org/content/qt8cj5j07p/qt8cj5j07p_noSpl...
- epistasis 4y agoThe most negative thing I see in that article: > At some point, the costs associated with conserving an additional drop of water exceed the benefits,” she says. But, she notes, if solar expansion is inevitable, then maybe hanging the panels over canals could tack on some extra benefits that might not come from building elsewhere. Which is only counting part of a positive, and excluding the value of the electricity. > cheap land elsewhere Not really sure where that's going to be in California, what are you thinking? And then if you use distant land, you have to pay for new transmission, which dwarfs the costs of solar panels and inverters. Solar hardware is incredibly cheap these days, and getting cheaper by the day. Putting solar panels instead of non-generating materials will miss out on all the benefits of how cheap solar PV has become. We should think about PV panels a lot like microcontrollers: so cheap that they can be thrown into all sorts of applications that would have been shocking 20-30 years ago.
- pimlottc 4y agoPrevent evaporation sounds like a good idea, but it seems like the payback for that alone must not be much, or else they would have been covered a long time ago (with non-solar-generating materials)? I'm not saying it doesn't make sense in conjunction with power generation, but that it's probably much less of a benefit.
- mikestew 4y agoSo there's not really a $20 bill on the ground, Mr. Economist? :-) There was no payback because the water kept flowing regardless. But past performance is no indication of future performance, and that realization is starting to dawn on at least a few folks.
- CydeWeys 4y agoThere already are reservoirs that are covered to prevent evaporation. See: https://en.wikipedia.org/wiki/Shade_balls https://en.wikipedia.org/wiki/Shade_balls
- hedora 4y ago1-2% of the water that goes into the canals is currently lost to evaporation: https://theconversation.com/installing-solar-panels-over-californias-canals-could-yield-water-land-air-and-climate-payoffs-158754 https://theconversation.com/installing-solar-panels-over-cal... So, reducing that is not going to have as big an impact as, say, improved irrigation techniques, or building more reservoirs. However, it will produce a lot of electricity. (Though probably less per dollar than putting the panels on top of failed farmland.)
- ortusdux 4y agoWhen I think of these canals, I think of large swaths of reflective white concrete. I wonder if bifacial panels would be a good choice?
- ehutch79 4y agoI'm confused. Reading many of the comments it sounds like preventing evaporation is the major reason for this. Given that it hasn't been done yet, evaporation must not be a major issue, so we shouldn't bother. I was under the impression that building more solar into the grid was the reason for putting up solar panels and preventing evaporation was a side benefit of their placement. Did I read this wrong?
- Denvercoder9 4y ago> Given that it hasn't been done yet, evaporation must not be a major issue, so we shouldn't bother. Because of the droughts and increased population, preventing evaporation has become a lot more important today than it was 50 or even 20 years ago.
- ehutch79 4y agoI get the reason for preventing evaporation. > Reading many of the comments it sounds like preventing evaporation is the major reason for this. That's the important part of the paragraph. I'm not asking about the evaporation, so much as why that's what everyone seems to thing the point of building the solar panels is? I would expect they were going to build them anyways, and the prevention of evaporation seems to be a bonus. But reading the other comments, it would appear that's a wrong assumption.
- epistasis 4y ago> Given that it hasn't been done yet, evaporation must not be a major issue, so we shouldn't bother. Do you really believe this? It reminds me of the joke about an economist that doesn't pick up $100 off the ground, because if it was a real bill, somebody else would have already picked it up.
- comte7092 4y agoHaven’t you heard, markets are always efficient! In all seriousness, people really seem to gloss over the “in the long run” part of that hypothesis.
- nostromo 4y agoJust cover the canals as cheaply as possible. And then put solar panels where it makes sense to put them. Sometimes that might be over the covered canals, but often not.
- hedora 4y agoThat doesn't sound very instagrammable. You'd clearly never make it as a politician.
- mdorazio 4y agoThe fact you got downvoted for saying this shows how little critical thinking is going on around here. If people think this is a good idea, show us the numbers: how much would this cost including running all the cabling, building substations, linking into the grid, adding scaffolding spanning the canals, all for hundreds of miles. Compare that to $1800/kW installed for a normal solar power plant [1] and however much basic shade tarp or shade balls would cost to provide the same evaporation benefit. And no, I don’t believe “the government already owns the land” is a good argument here. We’re talking about comparing to land cost for a power plant literally in the desert, of which there is an awful lot in Southern California. [1] https://www.eia.gov/todayinenergy/detail.php?id=48736 https://www.eia.gov/todayinenergy/detail.php?id=48736
- buffington 4y agoIf I were to guess as to the motivations of those who downvoted, it'd be because of this statement: > Just cover the canals as cheaply as possible. Covering the panels as cheaply as possible is probably not worth the cost. Covering the canals with something that produces energy tips the scales to make covering worth it. Then there's this part: > And then put solar panels where it makes sense to put them I agree with that, and wouldn't consider that worthy of a downvote. But without an explanation of "where it makes sense to put them", it's not very constructive. Your reply, however, is far more constructive. It probably doesn't makes sense to cover every possible square inch of canal without considering the costs and benefits, or without considering the costs and benefits of alternative solutions. Keep in mind, the idea isn't only to produce energy. It's about reducing evaporation and maintenance of uncovered canals. Covering panels with just about anything other than solar panels helps reduce evaporation and maintenance, but that's it. If you can cover it with something that can produce energy, then the cost of covering the canals can be offset by the energy produced. Emphasis on "can", because as you point out, it's not as simple as slapping panels down and calling it a day.
- jwagenet 4y agoAt what point is preventing evaporation a bad thing? I realize that we have already done quite a bit to change when and where water evaporates, but doesn’t moving where, if ever, the water evaporates affect the local water cycle?
- undersuit 4y agoLocal water cycles are already affected though. This is water that has been released from reservoirs and aquifers. Covering the canals with solar panels isn't like covering a natural river and interrupting it's water cycle. It could mean we have less need to use the reservoirs and aquifers... moving the local water cycle to a more natural state.
- CydeWeys 4y agoPreventing evaporation on your aqueducts and canals definitely isn't a bad thing though. That water is precious and you want to lose as little of it as possible.
- ehutch79 4y agoI'm pretty sure a giant concrete channel has a much larger effect on local water cycles
- rascul 4y agoAre there fish or anything in these canals? Could the solar panels have an affect on their habitats?
- pvaldes 4y agoBird poo is a big problem to solar panels, and aquatic birds release a lot of very sticky product and will try to land in the panels to rest. This is -the- problem IMAO. They will need to find how to spray and clean the panels routinely or the panel efficiency will decrease a 30% in no time.