As the title says, why are so many solar panels erected on government bought farm land and not over car parks that are practically “wasted space”
I am from the UK and In this country I have never seen a car park that has solar panels over-the top, compared to when I lived in Australia, where most car parks also incorporated solar panel roofing which also provided shade. Along with optimising space.
As most people know the uk is a very small place with a very dense population so land is a very limited thing for us, so why don’t we follow in Australia’s foot steps and build solar farms/panels above car parks? Eliminating the need to buy large areas of land to put these solar panels and optimising the land thats already in use.
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We have them here. At work, there is about three acres of parking lot under panels. Also makes for a nice place to park on rainy days.
it’s same question as to why it isn’t built over any other building. Harder to access, harder to maintain, not that easy to expand. It is done but it has enough disadvantages that you aren’t automatically going to plop them on every car park.
In France all parking lots of 1,500 square metres or more must be at least 50 percent covered with solar panels.
I think maybe there isn’t enough sun in the UK to make it worthwhile.
Because car parks are privately owned and the people who own the land don’t want them used as solar farms, nor is the electricity generated by a car park’s worth of solar sufficiently valuable as to both cover the cost of installing them and offer the landowner enough financial incentive to change their mind.
Because nobody really needs or wants to park in the places where solar panel farms are built.
Solar powerplants need additional infrastructure to them, so building them above parking lots is often inefficient. Some countries and locations tend to have truly giant parking lots, it may be worth it then. But afaik, parking lots in the UK or the rest of europe are simple nowhere that size.
It’s more expensive
You then lock in that land as a parking lot and can’t put a building on it without having to buy out the solar project. Which is a pain in the ass for everyone involved
It is much less complex to build something on the ground rather than to build a structure people must pass safely under and then build on top of that structure.
And when I say complex I mostly mean expensive.
But also plenty of places have solar panels in car parks. Usually multistory ones. Or on the buildings.
The other issue is scale. A car park is small. Fields of solar panels can be multiples orders of magnitude bigger which makes it even more efficient.
Disclaimer: I agree with your assessment, but I’m gonna explain the why not.
Who owns the car parks? Are they owned by the Fed Gov? City Gov? Or privately owned? Who ever owns them, has to pay for the infrastructure and upkeep of these solar panels. If they are privately owned car parks, the private owners might not want that headache and additional costs. Also, just because you have solar panels, as a private owner, doesn’t mean the electrical providers will make a deal with you to accept your electricity. The costs might not be worth it for a car park owner.
Because if you’re a country finally getting off its ass to build a solar farm, youre more likely to opt to start with a few, really big solar farms rather than tons of smaller ones.
Later on you might decide it’s useful to create a network of smaller farms, but that requires actual initiative. No government has ever proactively pursued a project on the basis of “might as well”. If it happens, it’s because somebody pushed for it to happen.
A lot of the money goes into the frames that hold the panels up. it’s just more expensive if you need to put them 25 feet in the air and make sure the footings fit around the parking spots.
Plus, a big parking lot might be 20 acres, but solar farms are hundreds of acres.
couple reasons.
First, farmland is cheap and open to lay them out however you want. Car parks you need to navigate around the fact that cars need to still be able to drive around, light posts still need to light up the lot, storm drains exist and need to work properly. Any solar panel layout onto an existing car park is not going to be as efficient as a from-scratch set up on the farm field.
Next, car parks are more expensive for multiple reasons, you need to build the solar panels up higher so the cars can fit underneath, you need to make the structure that the solar panels sit on beefier because a car WILL eventually hit it. Which means bigger more sturdy beams are required. and you need to pay extra attention to electrical safety untrained people of the general public will be constantly walking underneath and around the panels. Unlike a field where you can put up a sign that says “high voltage do not enter” and not have to spend as much money.
Next, solar panels over car parks have an unfortunate byproduct, birds like to nest and land in them. Meaning the cars beneath solar panels routinely get covered in bird shit which doesn’t make people happy. Adding the blockers to prevent birds from landing on the beams costs more money.
and i’m sure there are other reasons. but the general answer is “farmland is cheaper and easier to do”
Besides all the reasons listed. The structure required is MUCH more expensive.
Building on bare land i can mount the panels on the cheapest structure possible. In some cases no concrete required!
Building on a parkade, now you need a civil engineer to draw up fancy solar archs which all need footings and cantilever calculations. Its a pain.
Big solar panels are pretty cheap in bulk, adding the steel structure kills the bottom line HUGELY.
It’s definitely a missed opportunity to not put solar over carparking. The exact causes for why this is happening in your area, I can’t say, but it might be economics (carpark solar needs more expensive structures, is higher above the ground which makes cleaning etc more expensive too), it might be societal structure (eg some farmers are interested in leasing their land or have crops that can coexist with some shade, while carparks might typically be owned by a different kind of entity that is not involved or not interested), or it might be outdated zoning requirements that make it more onerous than it needs to be (though I would hope that’s the sort of issue that should be resolved by now.)
In other words, I would suspect mundane local reasons rather than a grand plan, and hopefully solar-covered parking will be coming to your area eventually 🙂
I can’t say I’ve ever seen a solar farm in a field in arizona. But plenty of parking lots have them. Usually big box retailers like walmart or Whole Foods, or office building complexes. I imagine those are the sorts of buisnesses that can afford the upfront investment.
As to why they build them on feilds, its probably because thats cheap, undeveloped land, not being used for anything else.
Installing solar panels on a building (maybe a school roof, or an office), makes sense as it’s small scale, reduces grid demand/energy bills during the day when the buildings are occupied, and can feed into the grid if needed because the building already has a grid connection.
Solar farms are a lot bigger scale, so they need their own substation as well as possibly an upgraded grid connection – which a car park wouldn’t necessarily have. A car park doesn’t have a great deal of need for electricity (beyond charging electric cars). If you cover the car park, you now need lighting. You’re limiting the height of vehicles that can use the car park. Also, farmland these days doesn’t always make much money, so the owners think it will be more profitable to have a solar farm. A car park is already making money.
There is benefit to intermittent shade for some crops. Iirc, they also help with weeds. Multiuser farming is becoming a bigger thing. Thematically, it’s a patch of land that produces using the sun as an input.
In California, it is common to build solar over car parks. School and Office parking lots are particular popular.
The cheapest installation is to put panels on an existing roof or on the ground. To put them on a car park, a roof would have to be built, and that’s not cheap.
It makes sense from a society point of view, but it dosen’t make sense from a profit point of view.
It’s cheaper to just put a solar panel on the ground than it is to build it elevated. That also makes it harder to get to if they need to be repaired or cleaned.
You would also need to make sure it’s strong enough to not only hold the solar panels, but withstand a car running into it.
If you’re building these big support beams to hold up the solar panels, that’s less room to park cars.
If you’re somewhere that needs lots of parking, you’re probably near buildings. If you’re near buildings, there are chances of shadows, which reduces the power you can generate.
Just buy a field somewhere more remote and run wires to where you need the electricity.
Most large scale solar projects in the UK are only economic because of subsidies.
The way most renewables projects get awarded subsidies is through auctions (Google AR5 for example). The projects the meet the technical requirements at the lowest price get built. The rest do not.
A project with huge economies of scale, on land that is cheap to install on and not shaded by buildings, is always going to win over an urban site of limited scale where it is considerably more expensive to install.
Plus, most car park owners don’t want their car park blocked by a power project that will invariably have to have a 15 year lease on the site minimum. It is an incredibly inefficient use of the land – given how expensive real estate is in the UK most car parks would actually add more value being converted into housing or commercial property. So if you want to intensify development of the site you would go that route rather than an uneconomic power project.
In the US I see parking lots with solar panels on them. It’s a case of the owner wanting to buy them.
I am actually a fabricator for exactly this in the US. My dad and I run a shop that manufacturers for Solar Mounts so it’s definitely possible and happening at least some what’s.
I see solar coverings over car parks all the time.
The main reason is cost.
Firstly, solar support frames over carparks are way more expensive than solar support frames for open space. Carpark framing needs to suit vehicle clearances and turning paths, withstand vehicle strikes and have anti-climbing measures. All your wiring needs to be underground while avoiding drainage pipes, sewers and anything else that’s buried. And you’re limited to the size and shape of the carpark, and in orientation of the panels. There might be buildings or trees that shade areas of a carpark, but are on a different property where you can’t do anything about it. And finally, there are usually hard limits on the total size of the array that can be connected to the electricity grid due to the capacity of the neighbourhood transformer.
Open space allows enormous freedom to array your panels at the scale, direction and spacing you want. You can run underground or overhead wires wherever you like. You can reconfigure the ground to drain in whatever direction you like. You can fence the whole array off and keep people away from it.
In short, solar farms built on open ground allow the developer to have full control, making the installation as optimal, effecient and cost-effective as possible. You get a lot better bang for your buck.
Incidentally, solar in Australia is generally going to perform a lot better than in the UK simply because of the more favourable climate. You can get away with a semi-random arrangement of panels in Australia because it’s a sunny place. In the UK, it’s a lot harder to make solar financially viable, so sub-optimal installions in carparks have a much harder time making good sense financially.
It’s also never the government buying the land; the government doesn’t operate solar farms in the UK, and the fields are typically fairly low-value land leased from a farm – if it was used for sheep grazing it often can still be used for that even with solar panels in.
The UK has very little sun and a shortage of roofing labor. The numbers don’t work out.
Australia has a ton of sun so the numbers do work out.
If you’re building a roof over a parking lot (expensive), it may make sense to put solar panels (less expensive) on top of that roof. If you’re looking to generate power, mount solar panels cheaply on some cheap land without a lot of people and cars around complicating things.
I don’t have real numbers, but I’d be very surprised if the solar panels on massive steel supports at the (electric) comuter train station near my home cost less than ten times as many panels erected on some cheap desert land where they’d get more sun & generate more power anyway. They’re great because they keep cars out of the sun and generate some power on the side. They’re not close to being the cheapest way to generate power.
You are describing two systems which have different capabilities and uses.
Note: This is a generalisation and there are exceptions.
If you are building a solar system over something like a carpark you are generally installing smaller systems that provide power to a nearby consumer. Solar in carparks in Australia for example are usually connected as a supply to the shopping complex and feed the complex before feeding back into the grid. Think a scaled up version of residential solar.
A solar farm though tends to be a grid scale supplier. It has many more panels and usually have some kind of local storage system such as a large battery. The design of the inverter and the connection to the grid allows for what is called firming, which is where the phase of the network can be corrected by the solar farm, something you REALLY don’t want on smaller systems.
Also if you lived in Australia you must not have gone far outside of the main cities if you didn’t see the large scale solar farms built in farmland all over the place. Something like the Aldoga Solar Farm is a pretty run of the mill example, it’s being built about 20km outside of gladstone and is ~270,000 panels. Or you have the NewEngland Farm, near Port Macquarie which will be ~1.5 million panels when completed.
This is a aerial photo of NewEngland at the end of stage 1. It will be roughly 3 times the size when complete – https://acenrenewables.com.au/wp-content/uploads/2023/06/MicrosoftTeams-image-15-1536×1024.jpg
What are car parks next to usually?
The more dense (packed in) the population, the more dense (stupid) the government.
Solar farms need a lot of space. A small one is going to be at least 10 acres. Car parks aren’t big enough.
Much less expensive to build something cows or sheep need to pass under or hang around than a structure people need to walk and drive under.
Where I live, they are doing this.
The reason why they don’t do it more often is because it doesn’t make financial sense. You have to spend a lot of money building the canopy structure as well as buying/installing/maintaining the solar panels. It takes a long time (decades often) to see a return.
They are usually only done when there is a subsidy or when it is a requirement to get permits approved on an associated project.
Source – my dad builds these things and we talk about it.
Makes sense to me. The roof provides energy, shade, and cover from the elements. Who wants to come back to a hot car when the spots can be covered? It would probably help the cars by not needing to crank the A/C up to 11.
France is building them over car parks now as well.
It’s also a good idea to build them over canals and irrigation ditches as it both cools the panel and reduces evaporation.
Also, there are many reasons why land may not be suitable for housing, commercial, or even farming that makes a solar farm a good bet.
Having to worry about vehicle clearance means placing the panels higher than they would need to be in fields. This adds cost and complexity to the build and maintenance of the panels. If it has been considered, the extra cost probably makes this style a poor choice compared to farm land.
A couple of things which may not have been mentioned;
With a parking lot figuring out what to do with the power is more complicated and nearby office buildings may not need power on weekends and holidays.
Sometimes they are?
The small city I live in just outside Los Angeles installed solar panels over the car parks of:
The Library
Police Station
City Hall
And at least a dozen schools
..last year sometime.
I’m sure it costs more than installing them in an empty field, but the city already owned these properties and being close to LA land ain’t cheap.
Cheaper to do in a farm.
And there are solar panels on a lot of parking structures, in my city it’s not unusual to see solar panel structures providing shade for even open-surface lots (like this one).
Buildings cast shadows, roads kick up dirt that will cover the panels, its a lot harder and more expensive to get planning permission to build something like that in an urban enviroment.
It’s not a bad idea to do it if we run out of space elsewhere, but were not close to that.
I work for a company that builds grid scale solar farms in the UK and we get this question a lot.
The short answer: Rooftop solar is great for whoever owns the building but terrible for adding energy to the national grid. It’s a bit like the difference between buying an electric car or getting public transport. Rooftop solar and ground mounted solar solve two different problems.
The full(ish) answer:
Before answering, there are a few things to clear up.
Firstly, solar farms are rarely on government bought land. Nationality significant infrastructure projects (NSIP) are not common. In most cases, farmers or other rural landowners lease land to energy companies (for very good money) and the company must reinstate the land at the end of the lease.
Secondly, and this is important, solar farms use up almost no space at all. About 0.01% of available land is covered by solar. About a sixth of what is used by golf courses. Solar also has an incredibly light footprint. Only a few % of the land they are on is physically disturbed by the installation.
It is also near impossible to get planning permission for a solar farm on productive land. Maybe there was feedstock (food for cows, pigs etc ) growing there before, but that’s not worth much to the farmers and has almost no impact on food security. The farmer won’t lease productive crop land anyway, nor would we want it.
Many of the other reasons have been covered, but if you are ever wondering why there is a solar farm or wind turbine or gas fired power plant somewhere, the answer is 99% because there is an available grid connection nearby.
Our grid is old and needed upgrading decades ago. A grid connection date for a new solar farm could take 10 years to get. Seriously.
We generate electricity wherever we can plug it in and wherever the landowner will lease us the land.
Anyway I accidentally wrote a huge essay. Hope that helps!
Edit:typo
I see them everywhere in Los Angeles. I wonder if it’s a cost issue for the building owners, relative to the electricity it yields. The UK is obviously not the most ideal place for solar panels. The building I used to work at had covered parking for hundreds of cars, all covered with panels, and they said it only provided like 5% of the power. It was a TV studio so definitely a very power intensive place. But one thing I’ve learned is that concrete work is really really expensive and you probably have to tear up a lot to go from an uncovered parking spot to building the covers into concrete, and all the wiring.
The answer is cost. A car park solar system costs at least twice as much as a system just mounted in a field.
Its simply a question of cost.
Because the first thing you need to do is to build a huge damn structure large enough for cars and possibly trucks to pass under while supporting a solar farm on its top.
It also needs to be sturdy enough to be able to withstand accidents without having everything come crashing down and potentially harming bystanders.
This structure will cost alot. and the maintenance of the panels will be more expensive since they arent at ground level anymore, so harder to reach for cleaning etc.
In Australia (South Australia) it’s become more popular to have solar panels over car parks, especially shopping centres. It’s row of parking bays has panels on the top
Talking about the big-box-store lots found through the suburban blight — It seems like the folks that make the rules for lot minimums haven’t gotten around to including solar panel minimums in said lots.
The companies don’t invest heavily in their locations anyway and do as much as they can to convince local legislators that their buildings and plots are worthless. There’s no incentive to build them.
For one, vandalism. Every time you throw a rock at a solar panel, you just cost the owner $5K.
For another, car parks are hot, and solar panels are worthless in hot environments.
Third, why would they? Solar costs far more than it generates. A supermarket with a parkinglot covered in solar panels costs tens of millions to produce, then they cost thousands of dollars a month to keep in operation.
You can say there are government subsidies, but in the near future the government will charge you a tax for even having a solar panel to the tune of thousands of dollars a day.
In case you ever wondered why the government demanded we have gas powered cars and fossil fueled houses to begin with. You pay a big fat, juicy tax bill for every one of those things, which you don’t even see becsause the taxes are hidden in the purchase price.
My company was looking into it a few years back but was denied permits by the city for whatever reason. This was in Texas. Near DFW. Theory is power company didn’t like us going net zero and shut it down.
The UK is neither very small nor very densely populated. Where do people get this rubbish from,?
Part of the problem is you’re overvaluing farm land. In the United States, we use 30 million acres of prime farm land to grow corn for ethanol, added to gas it makes up just 5% of the overall energy mix.
That land with solar panels can produce far more electricity than the country requires.
So the better question is why do we waste so much farmland on inefficient things?