[gwd]

> The business or land owner doesn't have to pay for it. Just let whoever put the panels up provided they provide x watts to charge cars.

Which sort of begs the question, why isn't this already a thing? Why aren't there companies going to businesses which own parking lots and saying, "Let me lease the air above your parking lot. I'll install and maintain the frames and the solar panels, manage the connection to the grid, the whole lot; I'll pay you $x per meter per month, and your customers have shade."

[l1tany11]

I think it’s just way more expensive than you’d want. The schools here in California do it, and the steel superstructure is huge. Having done some steel moment frames for housing—let’s just say the cost isn’t in the panels. The moment arm for wind loads etc is not in your favor. My guess is you’re paying the cost of >10-20 panels to get 1 installed. Let’s call it a 15x cost multiplier. Even rooftop solar, which has a way worse multiplier (~4x) than power stations (2x?) can be hard to justify for some. You’re much better off covering the roof of the Walmart in panels than the parking lot. Which is why that is the case.

Yeah it’s a better use of land, it keeps the cars shaded, but no one seems to have figured how to do it economically. Even in Southern California where it’s very sunny, and power is very expensive. I just don’t think it’s anywhere close to being economical. And in other markets the economics are almost certainly worse.

[galaxyLogic]

> no one seems to have figured how to do it economically

Mass-production is the key to economies of scale. Government policies can play a huge role in steering us towards goals like that.

Why is America so rich? Because of car-industry. And why is car-industry so prominent? Because of the interstate highway system.

[MadcapJake]

There is a company working towards this that I believe has been mentioned here on HN before: https://www.legends.solar/get-early-access?grsf=texm9h (Feel free to lop off my referral code).

I'd argue that this is likely more challenging than it seems, with city/state/county building codes, plus just building on existing dense spaces, and add to that any grid/utility policies and associated costs to play ball

[Schroedingersat]

Probably a combination of insane zoning and tax laws that would make owning a parking lot that does something productive cost 10x as much as it yields and that landlords are as a rule stupid, petty, and greedy and demand a large enough share and dealing with them is so volatile that noone wants to take the risk.

[galaxyLogic]

Exactly. We need better laws

[galaxyLogic]

> why isn't this already a thing?

Perhaps the Inflation Reduction Act subsidies will, or should, make it a thing.

Government subsidies (incentives) is a good thing if it can save the planet and prevent the devastating floods and forest-fires and drought that is killing us now.