It seems like it would be more effective to simply put all the solar panels in a field, and construct a cheap shade over the entire canal no? The supports in the picture are massive and don't look cheap. Also I would imagine the solar array uses more copper than a similar capacity array just built in a field. You can't daisy chain multiple miles of solar panels together, so you need an extra power line to run alongside the whole thing.
Put the solar panels in a field: The solar array uses less copper.
The shade supports don't have to hold up solar panels: Shade supports cost less.
The best reasoning they give is that California has insane permitting requirements, and it takes 1/6 the time to build on developed land compared to undeveloped land.
Anecdotally speaking, I have heard of a massive California solar farm in an undeveloped area that has serious vandalism problems. Junkies will find ways through the fencing at night, strip copper and other materials from panels, and cause thousands in damages and lost energy just to extract enough scrap for a fix.
Nothing short of a face-to-face security response will deter these criminals, so there it is a challenging cost-benefit balance. At least panels in parking lots and other developed spaces have the benefit of witnesses. I'm sure a 20 foot climb up a steel beam over running water is a decent deterrent as well.
First hand experience here - worked with a non-profit that has a tiny solar and battery installation for a light display, and we have had constant theft and vandalism problems with it. It's not even easy to get to - those meth-heads had to work to steal the lead acid batteries and copper wire...
Your takeaway is that every solar installation, regardless of size, now has an $80k/year minimum cost associated with its' mere existence because California can't get its' house in order?
That aint' gonna fly - you're going to have engineering requirements for a 100' span wither it's a shade structure or a solar panel. And don't even think about fabric shade sail types of things, nobody is going to want to replace those every 3 years.
>it takes 1/6 the time to build on developed land compared to undeveloped land.
> It seems like it would be more effective to simply put all the solar panels in a field, and construct a cheap shade over the entire canal no?
No because now you're using land that could be used for other things, which is exactly what this avoids. This takes existing land that loses water and costs money, and makes it lose less water and make money.
You are assuming that land is expensive and forgetting that building and maintaining panels over long a canal is harder than building over a large plot.
Harder but obviously not physically impossible either. From the image I can't imagine what the showstopper would possibly be. Technician on a little dinghy instead of a stepladder doesn't seem like a big deal. Presumably they make it where you can pull the panel off easily if you need to.
My understanding is that "The best reasoning they give" is the entire point. It such a huge issue that it drowns out all of the valid but smaller issues you are pointing out. And, the benefit to the water is just a bonus.
The cost of building that steel structure that will hold up against maximum in 100 year wind forces isn't cheap. Large PV panels make very good sails. The trusses look basically the same as you'd see in a large agricultural barn, horse riding arena, etc. Putting the PV panels on empty bare land at a height people can walk around and work with would be considerably less costly.
I would very much like to see a total dollar figure for the example "roof trusses over the canel" structure vs. how many panels it can hold.
It's already true that the ground mounting costs and labor to assemble the ground mount are a huge part of building a large scale PV system.
You know where the wind blows really damn hard in California? Virtually any open field you can imagine putting these otherwise. Mojave for example is damn windy. That is why they currently host massive wind installations there.
I'm well aware of that, thanks. Ground mount PV is still going to be considerably less costly than this. Partly because it's easier to build, partly because it has many competing companies that sell the basic aluminum rail/hot dip galvanized steel mounting pieces, partly because you can use relatively low cost contractors to do work like install its footings and bolt it together.
Having stuff at ground level that can be reached by people on foot or on a 6 foot step ladder also makes doing the electrical work a lot less costly.
> Putting the PV panels on empty bare land at a height people can walk around and work with would be considerably less costly.
What empty, bare land?
If its really empty and bare, there is a reason for it and that reason is probably a problem for building and maintaining PV, and otherwise you have to add the loss of the alternative uses of the land to the cost.
In the context of California, land that is not suitable for agriculture because it can't be irrigated, even though it's flat and somewhat accessible by road. California has plenty of it, go drive around near Twenty Nine Palms and you'll see it...
Spoken like someone who has never been to the mojave. This is the home to the largest wind turbine installation in the country. But again, if the worry is the solar panels acting like sails, probably not a great site given that wind.
To my eye if you were putting up a few hundred or more of those steel structures, and it didn't require a redesign of the canal retainment around it, it could be built quite economically.
Every extra pylon structure built, especially the first dozen, will be cheaper and easy to produce and install.
How about hanging solar panel vertically on tall buildings covering every floor except the first few to prevent vandalism
As the earth moves the sun would only hit one side and lose efficiency but right now it's "free space" not being used otherwise
They even make flexible solar panels now that can bend and move with the wind and don't need a stiff frame, slightly less efficient but volume makes up for that
Clean them the same way automated window washers work on skyscrapers
Shame they never came up with the solar paint solution, yet
The best explanation I've heard is from a PV installer. He said, "Every try to get a suntan standing up?" Seems you lose too much sun exposure to make it worthwhile.
I didn't try to get a suntan, but I have gotten tans while standing up. It's called working outdoors (and not properly covering up, which I'm paying for now).
That said, the economics of vertical installations have changed. The cost of panels keeps going down, and as it does it's starting to make sense depending on your location and how you're orienting your vertical panels. Remember, almost all solar panel installations will be suboptimal unless they include a mechanism for tracking the sun. The question is how bad is suboptimal, what's the cost of the panels and what's their energy yield?
Distance from the equator helps. As does if it snows where the panels are, then vertical simply not having snow on them plus the reflection of the snow helps quite a bit in winter.
What's the lifetime of a "cheap shade"? And the cost to renew it over the same lifetime? And the cost of paying for other land?
... likely less than the ~$13/W this cost to install, but that included NRE for three different styles of panel mounting. Standardizing would cut costs significantly.
Yes, I'd like to see the "cheap shade" that could span as far as shown in the pics as well as survive strong gales. It wouldn't be like a cheap shade in your back yard.
There are solutions like this to most of Californias big intractable problems, and they're not done because some California laws and/or regulations make it impossible.
This is one reason I now live in Nevada, where pretty much everything is legal...
>It seems like it would be more effective to simply put all the solar panels in a field, and construct a cheap shade over the entire canal no?
Yes, absolutely. But if you try and do that kind of stuff and the regulators show up and kick you right in the dick. "You got a permit to put panels on this land?" "Where's your SWPPP?" "Where's your environmental impact assessment for shading that canal?". And HN cheers.
But if you say you want to cover the canal with solar panels out comes the rubber stamp because that's what the powers that be want to "incentivize" this week.
Does the success of populists make a little more sense now?
I seriously doubt that you can chain even 1/4 mile of panels together without destroying things. Thats already puting thousands of volts and hundreds or thousands of amps through the silicon. If you are making it all parallel you still need wiring between panels that can handle that. The cabling doesn't go away, it just moves.
Wouldn't there still be supports in a feild of solar panels? Are you sure that those supports + the supports for the shade material are going to be less material than the supports for this?
Most shade material wears out pretty quickly. Will their replacement result in more expense, more waste, etc than just putting the solar panels?
Shade material is generally pretty heavy, is it really going to need significantly less robust support? Weight aside, how much of the load those supports are rated for is due to the actual weight of the panels, and how much is for forces from things like wind?
"Thats already puting thousands of volts and hundreds or thousands of amps through the silicon."
In a typical string of solar panels design, you'll get tons of volts but not a lot in amps - current cell maximums top out at ~11A and the connective MC4 wiring can't handle too much more current than that, so what you end up with is like a 1,000V 10A string on one MPPT connection into the inverter.
A solar panel is 4 feet or so on the long side. Theres 250+ of them in a string 1/4 mile long.... at 48 V/panel, you get to 12KV. even if it's topped out at 10A thats still 120KW... you need a hefty cable to carry that panel to panel. Which is the core of the point I was making.
Amps determine how hefty a cable needs to be, not volts. Volts mostly determine how thick the insulation needs to be.
14 gauge wire is basically all you need to carry 10A safely for an extended period of time regardless the voltage. It doesn't matter that you are carrying 120KW.
The proof of this is in EV charge cables. Those bad boys can carry up to 350kW. Yet the cables are often thinner than you might expect. How do they do this? It's by using high voltages (around 900V) which cuts back the amps to around 300->400.
Tesla's chargers peak (or used to) around 600V which has required them to have much beefier cables to handle the high current.
I get that. I'm pretty skeptical that 120 KW going through the last panel doesn't cause damage, and in the "multiple miles chained together" (to quote op) many MW going through the panel at the end of the chain doesn't run into some sort of issue in the real world. Even small percentage losses turn into a lot of heat or other issues at that scale.
If it doesn't why not just make the whole 100 mile stretch of canals discussed a single very long daisy chain of panels, and still address the concern of the OP in terms of extra material for conductors?
I'm sure it could be done, but it would cost a fortune. My understanding is the canals were built to distribute water to farmers, and conservation/evaporation wasn't really much of a consideration because California had plenty of water back then.
BTW, I used to swim in those same canals around Modesto and Turlock as a kid. So gross.
> Even though the canal is fenced in, “we have instances where we have cars go into the canal — we’ll have people go into the canal, and animals go into the canal,” Allen said, describing some of the challenges they faced as an urban water district.
>“What Turlock is doing with their projects is very impressive, but we have a different-looking canal system going through our service area,” Allen said. They are looking to put their canals into pipes to avoid evaporation, instead.
Umm, if you can completely enclose it in a pipe then why in the heck couldn't you put an 8-10' tall roof over it?
Typical local government (and I worked for one): "We didn't do it that way when I got here and it sounds like a lot of work and will be a change so let's rationalize doing nothing"
When you read lines like "California’s extensive network of canals and aqueducts is the lifeblood of the state, providing clean water to populous cities and expansive farms that wouldn’t otherwise have it." you have to ask how we ended up with these canal systems, what the tradeoffs are in a landscape setup this way rather than one where water infiltrates the ground and stays hydrated, and who owns water rights in California.
(note: I'm not trying to totally bash the solar panel project nor some of the key figures involved who've done great work like Dustin Mulvaney, but do think we should think about how we ended up here)
I thought this was a pretty awesome video to provide the lore on how water got to Southern California. Growing up in Pasadena I heard the name Mulholland and Eaton (as in canyon) all the time but never realized they were so instrumental in the founding of the city and all the wild shenanigans that went into getting the water from up north to LA.
In searching YouTube history for it, I see I also stumbled across this project too: Why Aqueduct Solar Solves 2 MASSIVE Problems https://youtu.be/EVBacmPfQ6E (about 9 minutes in it gets into the engineering challenges mentioned else comment about wind loads and such).
Are there any risks of mercury settling into the water system over time from coal power plants?
Are there risks of heavy metal and tire contaminates from vehicles leaking into the water system over time?
Are there risks of dust blown contamination from the megatons of shit humans leave everywhere we go leaking into the water system?
The answer is everything has risks, the risks from solar panels are unbelievably tiny in relation to all other pollution sources and I have to deal with a bunch of redneck solar panel haters that have bought in to massively overblown risks around them.
Maybe, but ideas like that are what you all will use to eventually turn against solar and seek to ban going off grid as you see a disparity between those who can afford to buy solar and those who can't. Why's that a problem? Those who can will go off grid and those who can't will be left on a grid that they can't pay for, and it will crumble. We are already seeing the beginnings of this in California.
oof, that is a crap ton of steel. I doubt those panels will ever harvest enough energy to offset the energy use to produce both the cells and supports.
I imagine with cells in that configuration, lifting wind loads are significant which is why it's overbuilt like that.
Perhaps some laminate timber for the cross supports?
Lastly, the US has got to start eating seasonally. The water problem in the southwest is all agriculture: people want to grow baby spinach in January. Unless we figure out a way to create a crap ton of energy cheaply so we can supply industrial sized flows without worrying about the energy cost, we use far more water than we should in California and Arizona.
Electricity is incidental (and a nice benefit) to the goal of "reduce evaporation of water from the irrigation canal and improve water quality".
> The duo went on to start Solar Aquagrid, an advocacy firm dedicated to reimagining aging canals, and partnered with the Turlock Irrigation District, UC Merced and the California Department of Water Resources to cover small sections of Turlock’s canals with solar panels. The new “solar canal” provides shade to limit evaporation and generates power all in one neat package. They call it Project Nexus, and it operates at the intersection of the state’s need for clean water and energy.
> ...
> But the canal site hosts more than just panels. Bales said they “have instruments out there to measure temperature, relative humidity, wind speed, incoming radiation, outgoing radiation, and a prototype instrument to measure evaporation directly.”
> When it comes to algae, the panels helped. “Last year when we drained the canal at the end of the irrigation season, there was a physical line on the sun side of the canal that had algae growth and then not algae growth from where the shade was,” Weimer said.
That it's green energy and can help supply the power demand is a bonus.
Steel takes about 4.750 kw-hours to produce per kg.[1]
A 450W solar panel will make roughly 562 kwh a year in California.[2]
So one panel running for one year offsets 140kg of steel production, roughly.
Thats an I-beam based structure so it's weight efficient and a heck of a lot more then 1 solar panel are going to fit on it.
Judging from a local steel supplier[3] and some span tables it looks like you'd need about a 360mm or so I-beam to bridge a 115 ft (30m) channel (the structure looks more efficient then that though) so call it 50kg per meter. So one span is probably ballpark 1500kg of steel.
A 450W solar panel is about 0.7m wide, the structure is fully covered so call it 42 panels per span offsetting the energy production of a little over 5900kg of steel per year (and it doesn't look like we're putting one solid I-beam per row of solar panels either since I see lightweight spanning channel in there).
Furthermore at the end of the steel structures lifespan it will be recycled in a manner that is far more energy efficient, requiring only 25% of the total energy. And that's in the case it wasn't from recycled materials in the first place.
According to my searches, steel production is something like 6-8 MWh/ton to extract, refine, and shape. A solar panel lasts 25 years at up to 80% effiency. This thing produces 1.7MW at peak. so call it 3 MWh/day average to account for a lot of adverse conditions over the lifetime. Thats 27000 MWh... so unless we are looking at more than 3000 tons of steel (we aren't) the steel production is accounted for. A panel takes something like 1.9 MWh equivalent in energy.... and again we aren't looking at 13K solar panels in this pilot.
So yes, in fact this does generate far more energy than goes into its production.
Put the solar panels in a field: The solar array uses less copper. The shade supports don't have to hold up solar panels: Shade supports cost less.
The best reasoning they give is that California has insane permitting requirements, and it takes 1/6 the time to build on developed land compared to undeveloped land.
Nothing short of a face-to-face security response will deter these criminals, so there it is a challenging cost-benefit balance. At least panels in parking lots and other developed spaces have the benefit of witnesses. I'm sure a 20 foot climb up a steel beam over running water is a decent deterrent as well.
First hand experience here - worked with a non-profit that has a tiny solar and battery installation for a light display, and we have had constant theft and vandalism problems with it. It's not even easy to get to - those meth-heads had to work to steal the lead acid batteries and copper wire...
One prisoner costs the California taxpayer $125k/yr, all in.
Maybe the company should foot the bill for a security guard instead of asking the taxpayers to subsidize their business.
https://wallethub.com/edu/drug-use-by-state/35150
Your math implies polar winter. Solar would be a bad investment.
In remote areas if you only guard at night they will go in the day.
Looks like the vandals will have to move along to somewhere else to score some copper.
That aint' gonna fly - you're going to have engineering requirements for a 100' span wither it's a shade structure or a solar panel. And don't even think about fabric shade sail types of things, nobody is going to want to replace those every 3 years.
>it takes 1/6 the time to build on developed land compared to undeveloped land.
This is not something you can just ignore
No because now you're using land that could be used for other things, which is exactly what this avoids. This takes existing land that loses water and costs money, and makes it lose less water and make money.
I would very much like to see a total dollar figure for the example "roof trusses over the canel" structure vs. how many panels it can hold.
It's already true that the ground mounting costs and labor to assemble the ground mount are a huge part of building a large scale PV system.
Having stuff at ground level that can be reached by people on foot or on a 6 foot step ladder also makes doing the electrical work a lot less costly.
What empty, bare land?
If its really empty and bare, there is a reason for it and that reason is probably a problem for building and maintaining PV, and otherwise you have to add the loss of the alternative uses of the land to the cost.
Have you been to Death Valley, my friend? All of Southeastern California is empty, barren land. Death Valley, Mojave Desert, etc.
Every extra pylon structure built, especially the first dozen, will be cheaper and easy to produce and install.
As the earth moves the sun would only hit one side and lose efficiency but right now it's "free space" not being used otherwise
They even make flexible solar panels now that can bend and move with the wind and don't need a stiff frame, slightly less efficient but volume makes up for that
Clean them the same way automated window washers work on skyscrapers
Shame they never came up with the solar paint solution, yet
The best explanation I've heard is from a PV installer. He said, "Every try to get a suntan standing up?" Seems you lose too much sun exposure to make it worthwhile.
I didn't try to get a suntan, but I have gotten tans while standing up. It's called working outdoors (and not properly covering up, which I'm paying for now).
That said, the economics of vertical installations have changed. The cost of panels keeps going down, and as it does it's starting to make sense depending on your location and how you're orienting your vertical panels. Remember, almost all solar panel installations will be suboptimal unless they include a mechanism for tracking the sun. The question is how bad is suboptimal, what's the cost of the panels and what's their energy yield?
I suspect it's more of a "hassle ain't worth it to lose 20%" type situation.
Could absolutely be worth if you can make that 20% back dodging permits because it's not flagrantly visible on the aerials like roof panels are.
... likely less than the ~$13/W this cost to install, but that included NRE for three different styles of panel mounting. Standardizing would cut costs significantly.
This is one reason I now live in Nevada, where pretty much everything is legal...
Yes, absolutely. But if you try and do that kind of stuff and the regulators show up and kick you right in the dick. "You got a permit to put panels on this land?" "Where's your SWPPP?" "Where's your environmental impact assessment for shading that canal?". And HN cheers.
But if you say you want to cover the canal with solar panels out comes the rubber stamp because that's what the powers that be want to "incentivize" this week.
Does the success of populists make a little more sense now?
I seriously doubt that you can chain even 1/4 mile of panels together without destroying things. Thats already puting thousands of volts and hundreds or thousands of amps through the silicon. If you are making it all parallel you still need wiring between panels that can handle that. The cabling doesn't go away, it just moves.
Wouldn't there still be supports in a feild of solar panels? Are you sure that those supports + the supports for the shade material are going to be less material than the supports for this?
Most shade material wears out pretty quickly. Will their replacement result in more expense, more waste, etc than just putting the solar panels?
Shade material is generally pretty heavy, is it really going to need significantly less robust support? Weight aside, how much of the load those supports are rated for is due to the actual weight of the panels, and how much is for forces from things like wind?
In a typical string of solar panels design, you'll get tons of volts but not a lot in amps - current cell maximums top out at ~11A and the connective MC4 wiring can't handle too much more current than that, so what you end up with is like a 1,000V 10A string on one MPPT connection into the inverter.
14 gauge wire is basically all you need to carry 10A safely for an extended period of time regardless the voltage. It doesn't matter that you are carrying 120KW.
The proof of this is in EV charge cables. Those bad boys can carry up to 350kW. Yet the cables are often thinner than you might expect. How do they do this? It's by using high voltages (around 900V) which cuts back the amps to around 300->400.
Tesla's chargers peak (or used to) around 600V which has required them to have much beefier cables to handle the high current.
If it doesn't why not just make the whole 100 mile stretch of canals discussed a single very long daisy chain of panels, and still address the concern of the OP in terms of extra material for conductors?
BTW, I used to swim in those same canals around Modesto and Turlock as a kid. So gross.
62% is pretty respectable for the size of California (same electricity consumption as Spain). I did not know this.
this part of the claim is carrying a ton of weight here... Zero-carbon sources could include carbon dependent sources with paper offsets.
[1] https://www.autonocion.com/us/arizona-solar-panels-irrigatio...
>“What Turlock is doing with their projects is very impressive, but we have a different-looking canal system going through our service area,” Allen said. They are looking to put their canals into pipes to avoid evaporation, instead.
Umm, if you can completely enclose it in a pipe then why in the heck couldn't you put an 8-10' tall roof over it?
Typical local government (and I worked for one): "We didn't do it that way when I got here and it sounds like a lot of work and will be a change so let's rationalize doing nothing"
Build Soil has some interesting threads on this:
- https://bsky.app/profile/buildsoil.bsky.social/post/3lmeddjd...
- https://bsky.app/profile/buildsoil.bsky.social/post/3mkzybkk...
(note: I'm not trying to totally bash the solar panel project nor some of the key figures involved who've done great work like Dustin Mulvaney, but do think we should think about how we ended up here)
https://www.youtube.com/watch?v=x-RGL15Skuo
In searching YouTube history for it, I see I also stumbled across this project too: Why Aqueduct Solar Solves 2 MASSIVE Problems https://youtu.be/EVBacmPfQ6E (about 9 minutes in it gets into the engineering challenges mentioned else comment about wind loads and such).
Are there risks of heavy metal and tire contaminates from vehicles leaking into the water system over time?
Are there risks of dust blown contamination from the megatons of shit humans leave everywhere we go leaking into the water system?
The answer is everything has risks, the risks from solar panels are unbelievably tiny in relation to all other pollution sources and I have to deal with a bunch of redneck solar panel haters that have bought in to massively overblown risks around them.
I imagine with cells in that configuration, lifting wind loads are significant which is why it's overbuilt like that.
Perhaps some laminate timber for the cross supports?
Lastly, the US has got to start eating seasonally. The water problem in the southwest is all agriculture: people want to grow baby spinach in January. Unless we figure out a way to create a crap ton of energy cheaply so we can supply industrial sized flows without worrying about the energy cost, we use far more water than we should in California and Arizona.
> The duo went on to start Solar Aquagrid, an advocacy firm dedicated to reimagining aging canals, and partnered with the Turlock Irrigation District, UC Merced and the California Department of Water Resources to cover small sections of Turlock’s canals with solar panels. The new “solar canal” provides shade to limit evaporation and generates power all in one neat package. They call it Project Nexus, and it operates at the intersection of the state’s need for clean water and energy.
> ...
> But the canal site hosts more than just panels. Bales said they “have instruments out there to measure temperature, relative humidity, wind speed, incoming radiation, outgoing radiation, and a prototype instrument to measure evaporation directly.”
> When it comes to algae, the panels helped. “Last year when we drained the canal at the end of the irrigation season, there was a physical line on the sun side of the canal that had algae growth and then not algae growth from where the shade was,” Weimer said.
That it's green energy and can help supply the power demand is a bonus.
Fair. But the almonds and alfalfa would like a word, especially since the alfalfa is shipped around the world for others to consume in some way.
So while it's definitely agriculture as a serious source, it's not just the US as the driver of that source.
A 450W solar panel will make roughly 562 kwh a year in California.[2]
So one panel running for one year offsets 140kg of steel production, roughly.
Thats an I-beam based structure so it's weight efficient and a heck of a lot more then 1 solar panel are going to fit on it.
Judging from a local steel supplier[3] and some span tables it looks like you'd need about a 360mm or so I-beam to bridge a 115 ft (30m) channel (the structure looks more efficient then that though) so call it 50kg per meter. So one span is probably ballpark 1500kg of steel.
A 450W solar panel is about 0.7m wide, the structure is fully covered so call it 42 panels per span offsetting the energy production of a little over 5900kg of steel per year (and it doesn't look like we're putting one solid I-beam per row of solar panels either since I see lightweight spanning channel in there).
[1] https://solar.lowtechmagazine.com/2009/06/how-much-energy-do...
[2] https://www.cahomesolar.com/feeds/blog/solar-panel-energy-pr...
[3] https://www.mascotsteel.com.au/wp-content/uploads/2018/10/st...
While I agree those steel supports are large, that seems insanely wrong to me, but not an expert so curious if someone with more info could comment.
So yes, in fact this does generate far more energy than goes into its production.