Seeing this non-stop on Reddit, now seeing it migrated here lol.
It is stalking me like my intrusive thoughts to become a hermit in the woods.
also, agrivoltaics is a thing. Judiciously placed solar panels can reduce ground heat and water use through evaporation, which can be beneficial for growing crops.
Wow, super cool and obvious once you see it.
The left part is only true if the roofing has to be built explicitly for the panels. There are already covered parking lots, I can’t see any downsides in just adding panels on top.
And I doubt that it requires longer cable runs than panels somewhere on a field.
Don’t get me wrong, I’m all for solar and wind. Put those panels everywhere possible, the more the better. I just don’t get why even having this discussion.
The structure for solar panels is much heavier than for pure sunshade, as a person will have to walk on it to install and maintain the panels. You also have to deal with the associated health and safety regulations for working at height and live electricity, as well as probably pay more for insurance since there is an increased risk of fire.
Why 1 purpose when 2 purpose possible?
Fuck cars, sure, but solar panels on roofing is smart.
And for roof solar, we are not running out of space for them anytime soon. Plenty of buildings still haven’t install them.
I agree, multiple land use is the way forward. Solar panels for their own sake is seldom good enough land use, even if may be cheaper to set up.
Do you think that they build roofs that can’t support people walking on them?
Yeah, I do, and I have good reason to, because I am a structural engineer and have designed them myself on occasion. A lot of these canopies over car and bike shelters are just a sheet of plexiglass.
Where are you designing these that they don’t need to support hundreds of pounds of snow or rain, or stand up to hail?
Northern/Western Europe.
Hail bounces off, rain flows off. For a very light duty structure like a smoking shelter, bike shelter or trolley corral, they sometimes have a curved plexiglass roof that snow can just fall off or be blown off. A person is a much more intense load than snow (a person’s whole weight can be on one foot). The frame might take it, but the cladding may not.
Usually they are just a product off the shelf.
My parents just bought and installed a small off the shelf carport, it has its own built-in gutter system and the ability to hold 100s of pounds on its metal roof. Nobody is covering cars with plexiglass, that would literally defeat the purpose of having shade.
I’ve seen the plexiglass ones he was talking about
Here’s one for sale in Denmark, where I am, and where it snows. Polycarbonate instead of PMMA. Same thing. I wouldn’t stand on it.
https://dancovershop.dk/products/carport-arizona-2-89x4-95m-palram-canopia-gra
Get an opaque sheeting if you want to keep UV off. Point stands.
Which are a canopies or awnings not a roof.
Fuck off lmao. A canopy is a roof.
No it’s not, if you asked to have a roof installed and someone installed a fucking canopy over your house, you’d be pissed.
This is like asking for a truck and they show up with a station wagon and tell you well it’s got foldable back seats.
Words have meaning.
Yes, when they’re called “awnings.”
Which isn’t really a roof, it’s just a cover.
They don’t build parking shade roofs to support the weight of being covered in panels, though. That has to be planned for. A typical panel that’s around five and a half foot by a bit less than 3 and a half foot weighs around forty pounds. Having like two of those on your covered spot at your house would probably hold fine. But to a large parking area will add a huge amount of weight.
Shade canopies or awnings…but yea solar is heavy.
Yes. It doesn’t need to be 1 contiguous roof, gaps big enough to fit a ladder are ideal.
spoiler
That’s more of an awning than a roof though. Plus that picture shows that this was specifically designed with the panels. As those are just straight solar panels and not roofing that’s had solar installed to it.
Awnings are fabric lol. This is a roof made with solar panels, a solar roof.
And those panels are not light weight…so someone could walk on them if they wanted.
Do not walk on solar panels.
They likely won’t be able to take the additional weight of the solar panels, according to code anyway.
Because we let the morons have power and now we’re all paying for it
I’ve also noticed Lemmy seems to have zero understanding of farming/plants/farming infrastructure and can’t understand that nearly all food crops require FULL sun and building an opaque canopy over crops that need FULL sun will absolutely decimate that crop, you can’t just grow plants on vibes they require very specific things, especially cultivars that humans have designed to make huge fruiting bodies, that takes SO MUCH ENERGY (sun)!
I see this problem a lot too in people asking about prepping, there doesn’t seem to be a well educated prepping community on Lemmy and the amount of people giving out advice like a backyard garden will sustain you as a food source in an emergency is not only wildly ill informed but dangerous for those taking the advice
For panels mounted as depicted, I’m with you 100%. I do want to mention though that vertically mounted panels seems to increase harvests and from the farmer (singular) I’ve spoken to who is testing this with the help of academia I’ve understood that there is a debate about moisture retention. And as far as I’ve seen, there are more than university coming to the same conclusions. Having said that, we’ve still to see this tested large scale…
Yep, gotten into that argument, got downvoted into oblivion by pointing out that covering 80% of the space above crops with sun-blocking solar panels might, you know, affect the crops.
Was confidently told that crops only need about 4 hours of sunlight, lol.
However, you can easily replace all corn farms that were used for ethanol production and produce more energy per unit of land
I genuinely wish we could disable the upvote and downvote counters. Its 99% group think and it isn’t healthy for the discussion.
I mean all of that is big ol fat case depends. Like elevation distance from equator, time of year, what crop and at stage of development.
Half of their points make no sense
Just convert every biofuel field into a solar field. Boom, year round power output and way more efficient than growing plants to burn.
Then work on replacing every car with electric.
Eventually it will be more cost effective to retrofit old structures.
cool cool cool, except cities have 25% of their space taken up by parking lots, and land that has solar panels like on the right are pretty much stuck being just solar.
pavement does not need to be heated by the sun. and putting up a solar field needs to include the cost of the land, where as parking lots do not
If your city is 25% parking lots, you have a much deeper problem that solar panels won’t solve
I think it’s called North America.
Yeah, that’s the name of the problem.
The USA has corn fields specifically grown to be turned into FUEL. These crops are a waste. These fields can be used for solar instead.
i mean yes. but this isn’t about those problems specifically. but the average american city is apparently 22% parking lot upon a quick look.
if we are going to have nearly a quarter of a city as dead land, might as well as put up solar panels and lessen our dependency on destructive forms of power generation.
I feel that you may not have read the whole thing. This post is in support of elevated solar panels.
seems kinda ambiguous. because usually when someone says “it’s time to correct the record” the image they post is usually the corrected record… or at least the posters intention is elaborated at least a little
“both have their place”
“but they are not the same” which points to the main pictures meaning of “it’s more expensive to build parking lot solar panels then fields for solar panels. the cost being the pointed to difference.
That’s fair, I do agree the point should have been more prominent. I didn’t realize until the end that it was supporting both which is why I suggested you may not have read all of it.
I remember seeing this image (or one like it) and the post was flooded armchair engineers talking about how bad parking lot solar is and I assumed the “fix” was adding the conclusion at the end.
yea i was torn as to what the op’s meaning was, and just took a stab with how i saw things.
It depends on the city I believe, midwest cities have the land to expand so they can have more parking lots. New York though doesn’t have single layer parking areas as profusely.
The parking lot economics don’t figure if you’d be building a shelter for the lot anyway. Its hardly custom engineering, theres like 3 designs I see everywhere.
In places that get heavy sun/rain, it’s quite common.
I may live in a country that doesn’t do this but I’ve never seen a parking lot with a shelter. If there is, it is used to park cars in top.
Theres a different type for cars.
Yeah we don’t have many of these either here 🤷
Same back home. I am constantly thinking about how much of the cities and towns would need to be leveled to park the number of 2-wheelers I see if everyone drove cars; this tiny cafe would need 7-10,000 sqft for just the 20 bikes here now, and the parking area is half full, and then there’s parking across the street.
They also don’t factor in the greenwashing of using solar panels to cover wasteful cars, when it would be much better for the environment to not have a parking lot to put solar panels over.
It sucks that for the past 50-100 years, places have been built somewhere on the scale between favoring cars to outright hostile to any other form of transportation. On the plus side, most of these places are so shoddily built that it is cheaper to tear them down than to maintain them. So destroying suburbia and replacing it with walkable neighborhoods is actually quite profitable for everyone except the car industry, not to mention beneficial for everyone living there.
I don’t think suburbia even needs to be destroyed and left fallow; anything with a motor smaller than a car works fine with car infrastructure, as long as there’s not shittons of cars. It can just be densified by building regular parks or buildings where the parking lots were if the use of cars were restricted. My current motorbike gets 100mpg, my old one 160, and there’s some electrics I’ve seen that easily keep up with traffic.
Unfortunately, and I learned this relatively recently, motorcycles are worse for GHG emissions than cars because of catalytic converters (and probably just better combustion in general).
Agreed on electric, though.
Euro 3 went into effect in 2007, nearly all bikes made in the last 20 years have cats.
As far as combustion goes, there’s way more variability between a nc750 revving to 6500, a Ducati reving to 16500, and a Honda Wave with 110ccs displacement. You can probably get a lot of answers.
Even the worst, most pollution inducing motorcycle on the planet doesn’t hold a candle to my 90s truck.
Hell, even most modern trucks are better despite being massive, considering the improvements to fuel efficiency and such…
Arguing a motorcycle is worse because one specific area of its carbon footprint is slightly higher than cars depending on model of both is weird to me.
And I don’t remember the last time I saw a motorcycle without the obvious cat hugging the engine before it winds to the muffler. Note: usually the motorcycles I get to see close are people who are more environment conscious than your average redneck. I’m sure the shop down the road specializes in removing them. I KNOW they offer “diesel tuning services” to let people “roll coal” so it wouldn’t surprise me…
I saw a few in Osaka, but yeah its quite rare even on 90s bikes.
spoiler
Do you have any links to any recent info? This link makes it seem like its still not great, bit it like to see actual hard data.
https://gearjunkie.com/motors/motorcycle-vs-vehicle-emissions
My Aldi just put roofs over part of their parking last year. And then they put solar panels of the roof… of the store. Because yeah, there’s way more space on the roof than on the parking and I bet it’s 10x easier to put solar panels there.
It’s way easier.
Aside from initial install (crane), it’s effectively the same as the right side of the image with the added benefit of not taking up any land
I like to look at parking solar more like balcony solar. It’s free real estate. Throw a few solar panels up here and there. Put a few on the existing light poles on the parking lot and/or around the perimeter. It’s more about integrating small additive power generation to existing infrastructure than trying to extract maximum Kwh per square foot like field solar.
My company has a very green mission statement, and they did the solar parking lot right before COVID. After they built it, they realized that the design basically funneled snowmelt down to directly between every car, and the cooler ground froze it almost instantly.
So 80% of the workforce went remote during COVID, and the ones that stayed couldn’t park in the lot during winter because it was an icy deathtrap.
If only somebody would invent…
…a gutter!
This doesn’t necessarily fix the problem. If the ground is at -5 ° Celsius after a cold winter night and the snow melt is dripping drop for drop from the panels it refreezes before it can reach any gutter.
I was being facetious, BUT, if it freezes before making it to the gutter, how is it an issue on the ground…?
Okay, I guess I took all that a little too seriously again—sorry about that.
If I’m picturing the situation correctly, the meltwater is dripping from the panels (or from the frozen gutter) onto the ground below—in this case, the parking lot. Since the ground is frozen, drop by drop a layer of ice forms, gradually turning the entire parking lot into a skating rink… if cars start sliding or people fall flat on their faces when getting out, no one wants to be held liable, which is why the idea is unpopular in climates with long, cold winters.
The raised gutter should carry the melted water away from the parking lot.
Start with existing empty roofs - parking garages, malls, office buildings, schools, apartment complexes, warehouses, industrial buildings, etc. Once we’ve run out of those empty spaces, we can start talking about where to build free-standing ones, but hopefully we won’t need as many.
I’m confused by the title. Are you saying the stuff in the picture is wrong or misrepresenting reality, or the opposite?
the picture is correct, there’s a common post that does the rounds every now and again that says we should put solar panels over car parks instead of building dedicated solar farms, this image provides reasoning as to why dedicated solar farms are a good option, while also recognizing that solar panels over car parks also have their place
my personal opinion on this is, new solar panels should be installed in dedicated sun-tracking solar farms, and older/recycled panels are ideal for car parks, flat roofs, etc.
It stems from people having a shit idea of how much space there is in the world, too. Yes, too much of our infrastructure is car centric, but holy fuck buddy there’s a lot of land out there that doesn’t have anything on it right now.
Unused land isn’t useless land. Every bit of land, grass, tree, rock currently has a place and destroying/changing it has consequences. We can’t just assume that unused (by humans) land is usable (by humans) land, like white settlers have a habit to do
Nah, you’re just not understanding the scales we’re talking about. That’s ok, most people can’t wrap their heads around it.
I think you can’t really handle what “human activity” means and how it affects everything, but if you’re advocating for preservation of literally human life on the planet, avoiding diseases spread and all, it’s something you should get yourself acquainted with
Ah, false dichotomy. Now I understand.
Makes sense. 👌🙏
This!
There are many NIMBYs that are against using fields for solar, and make the suggestion of covering car parks for it instead.
The purpose of this image is to explain the economics and design reasons for each option.
Thank you.
Very confusing title phrasing, still.
I think they’re saying the picture is wrong. Assuming you have the same amount of space, placing solar panels on the ground, or paving the ground and putting the solar panels on the roof of a car park, assuming also the same number of solar panels, it should generate about the same amount of energy. What do the solar panels care if they’re a few meters off the ground? Plus, the car park can lease or rent its spots and generate revenue that way as well.
It didn’t say anywhere about generating less power. It said it is more expensive per watt, which it is.
Okay. How so?
I get there’s an up-front cost of building more stuff. You have the solar panels in both pictures, but the one on the left has a car park as well. I also said they can lease/rent out the spaces. Which means it’s less expensive over time as those costs pay for themselves.
The car park itself is going to generate the same money with or without the solar. Consider that irrelevant for this discussion.
Building the solar over the car park only really makes sense if you have absolutely nowhere else to put it. The land for solar is usually very cheap, compared to the cost of constructing a large gantry that is designed for vehicular impacts. If you need to do any repair, maintenance or replacement, you have to contend with all the cars in the carpark, or absolutely nothing in a field. You also need to do it at height (i.e., with a crane or lift), which is much more complex than just driving out with a van and doing it on the ground.
The only instances that I would recommend doing this are:
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You are already building a gantry for shade.
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You have a green target for the development and cannot achieve it with only rooftop solar on the buildings.
I don’t see how the car park revenue is irrelevant. But, we’ll table that — neither of us are winning anyone over given the context the OP framed this shit in. Call it “agree to disagree.”
You’re 100% right about the maintenance of the panels, though. I feel like there’s probably an easy way to do it, like have an access ramp and a way to get a golf cart up there. But, it’s a stretch and you made a good point, so that point goes to you.
Side note: Anyone know why indented lists drop the first letter? I’m not seeing the “Y” that should be at the start of those bulleted items, or the bullets, dashes, or numbers. (I still knew what you meant. I’m bitching about the tech that runs this site.)
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When over a parking lot, you can’t have supports columns every few feet. So now you’re spanning with a beam, then you need bigger columns, and bigger foundations. Construction of that is also more complicated requiring concrete, cranes, etc. It all adds up.
You could also be aggressive with the design in the field because if it tips over in a storm, who the fuck cares. You just pick it up and redo it.
Of course parking solar needs extra structure, is more expensive. They would’ve built a roof if not, with or without solar.
It cancel the heath trap that parking lot are too
Some places have plenty of open space that nobody sees. Solar farms there are usually fine. Some places are beautiful countryside with hills between small villages. The nimbys are probably right. Quite ugly, unless they are somewhere you can’t see. Additionally, industrial buildings and city rooftops should be used, as well as car parks if you can keep the costs low.
