It's worth nothing that the economics of the labor to remove "old" solar panels, transport them, recycle them, and install new panels may not make sense. Current technology monocrystalline silicon stuff can be guaranteed to have 80% of its original STC (standard test condition) power output after 25 years. Usually at which time the panels will be long since paid off and whatever power they are making for the roof owner is free money.
80% of original test-conditions rated power is still a lot - if you were to theoretically install a 40kW rated array composed of about 112, 360W panels, that would still be a 32kW array after 25 years.
That depends on how much more efficient the new panels are, and how much they cost. You only have so much roof area, so if you can generate enough power with the new panels over the old ones to more than recoup the costs, it's worth it.
USA Interstate network has a total length of 77,556 km. A 1m wide strip of PV along the dividing barrier in the middle is, eyeballing the solar irradiance graphs, something like 77.5e6 m^2 * 1500 kWh/m^2/y = 116.250 TWh/y compared to USA annual use of about 25 TWh/y for all power not just electricity. Even accounting for PV efficiency, that’s basically enough from just one possible currently wasted location.
Obviously every country is different — my country, the UK, much worse annual average light, and higher population density, but the point still applies. Almost every nation can do this without worrying about land use.
The other is that you're estimating the energy of the sunlight that falls on 77.5e6 m^2 rather than the achievable electrical generation. The most efficient terrestrial solar panels are just a little above 20%.
Yes, we do. Covering the ground with solar panels means that land can't be used for other things, such as farming, or natural habitat.
I suppose if you want to just cover totally barren places like the Sahara with solar panels that would be OK, but there's political and engineering problems with that (transmitting power long-distance incurs losses, and getting power across the Mediterranean wouldn't be easy).
Perspectives can differ. One of the greatest soaring sites in Europe (Aspres in the French Alps) is fighting for survival against a solar farm. An irreplaceable loss, given the topology in the area. Which is also why a flat plateau at the top of a mountain is suitable for solar production. Economics wise of course a small bunch of glider pilots will not stand a chance against the inevitable economic needs of the area. So yes, a solar farm can be a land wart, depending on where you stand.
A coal power plant is also a central spreading point of ... well poison really (sulphur oxides are essentially poison). The ugliness of coal power plants just begins with their looks.
They've got large coal dumping grounds. They usually have a freight train station that had coal dumped all over it, so everything within 10 meters of it died. They just let all of this sit in open air usually, plus there's the massive amount of smoke, so you can smell them from kilometers away even when there is wind (and let's just not discuss when there isn't, just visit Beijing).
No one said coal was better or that we should even use it.
But commercial scale solar farms are fucking ugly they take spaces away from people and advocating for more of them at the expense of green spaces is terribly short sighted.
Put solar everywhere we already have ugly box buildings and roads don’t take up even more shared spaces some of them due to current laws are written can even be nature reserves because we’re green after all.
Having been in possession of more than my share of "used" panels, there are a few practicalities you need to be aware of:
•Used solar panels are off-spec and can't be teamed with other used solar panels properly. They become like two drunks trying to help each other down the street.
•Even used solar panels need mounting/racking hardware.
•Even used solar panels need inverters and wiring (frequently in values that are out of production).
•Used solar panels are a b*@#% to ship.
The glass, if intact, is the most valuable part of the solar panel for recycling purposes. This is followed closely by the aluminum frame.
The EVA (clear rubber) that encases the solar panels is garbage by the time the panel gets recycled. This is the part that turns brown and lets in moisture. I imagine incineration is the best path forward for this stuff, because after 30 years of cross-linking in the sun, it's not going to melt into a liquid.
The solar cells themselves are so enmeshed with the EVA that they turn into inchlong irregular shards attached to tabbing. There's no realistic hope for getting a commercial-grade panel out of them, even if you melt them down.
The tabbing is a valuable mix of tin, copper, and silver, as is the metallization on some cells, though you'd have to be talking tons of crushed cells to get a pound each of the metals. This should be a straightforward matter of crush and dissolve in chemicals, then throwing the stripped silicon into a smelter somewhere.
The "J-box" doesn't count for a lot of weight and is probably too old-fashioned to reuse, even if the plastic hadn't broken down and the contacts hadn't corroded. Best off cooking off the plastic and remelting the copper/tin metal portions.
You might find yourself in a position to say, hey, I'd gladly accept a used 3 ft x 5 ft solar panel that worked 50% as good as new, and was ugly. I doubt you would be in the position to take on 100 more, especially not being able to team them together.
It's not unusual to see brand-spanking-new panels at prices near $0.50/W. Shipping is starting to dominate the cost of panels, used or new.
You certainly wouldn't want to mix and match used solar panels with an existing install. It would be necessary to keep them together in series and parallel configurations somewhat similar to how they were originally installed. Or to break them up into smaller groups of the same consistent age and resell them to offgrid builders (eg: a guy who wants 8 x 60-cell panels for his off grid cabin somewhere).
And yes shipping will be truly a pain in the ass. A brand new pallet of 20 or 22 panels with the special plastic protectors in place, and wrapped up with plastic, is easy to ship. Individual loose panels are difficult to transport loose without damaging them, and labor intensive to move around.
One of the things you can do with used panels is re-use them for off grid applications. There are off grid PV charge controllers now (Schneider, others) which support up to either 600V or 1000VDC on the PV input side, and up to 4800W of panels per charge controller. You can build strings that are basically all of the panels in series together, simplifying the wiring, assuming that the panels are new enough to be also rated for 600V (US) or 1000V (EU) spec, mostly intended for feeding big inverters.
I wouldn't really say that shipping dominates the cost just yet. I recently bought a pallet load of high-efficiency monocrystalline panels (72-cell, 360W) at around $0.62/watt. The shipping for the pallet was about $350. The panels themselves were about $4500 FOB.
I've seen hobbyists/enthusiast groups get a van full of used panels for surprisingly cheap, which then was split between the members at meetups. Seems like people are happy to just see them gone, which makes sense if they're hard to reuse or repair at scale.
Sure, if I were in that position after 25 years, and I wanted to increase my kWh sold to the grid per month by buying new panels (let's imagine that a 1.99 x 0.99 meter panel in 25 years from now might be rated at 450W)... And I could make the math work for the ROI to pay off the new panels, I could sell the old panels in place as-is where-is, buyer to remove.
> The robots in Veolia’s new plant dissemble the panels to recuperate glass, silicon, plastics, copper and silver, which are crushed into granulates that can used to make new panels.
That still is a 8kW difference that, over decades, may offset the energy cost of recycling the old set of panels.
Also, keeping the old panels means you can’t reuse whatever those panels are mounted on for the new ones. That can make installing new panels alongside old ones more expensive, sometimes significantly more so.
This seems odd to me. Solar panels should last at least 30 years but we've been finding most just keep working, potentially for decades longer.
While the power they produce degrades with time, it's not enough to be worth junking the panel.
Basically no solar panels should be recycled unless they are completely non-functional or faulty.
My guess is this plant will be dealing almost entirely with damaged panels and not end of life panels. Or they hope to trick people into recycling perfectly good but old panels, which is not eco-friendly at all.
I have a solar panel that was hit by a falling rock (we're not sure how but it spiderwebbed the glass on the panel). I am a single sample but given the high number of solar installs, and the potential for mechanical damage (rocks, hail, etc) It seems like there might be sufficient material to support a recycling plant.
That said, most commercial installations price out the replacement as part of the life cycle management of their solar infrastructure. They will 'recycle' perfectly good solar panels like they recycle perfectly good computers. If you are running operations for a large physical plant this helps you spread the maintenance over time and avoid times where there is more repair work to do than you have staff to do it with.
Just like end-of-lease computers, it would seem to make the most economic sense just to auction off those replaced panels as working units (albeit slightly degraded).
I agree we should have some recycling capability. One of the things I think it will be used for is cheap panels that have failed entirely through encapsulation failure. If you follow the german photovoltaic industry there have been several large-scale grid feeding power plants that turned in all of their panels to the manufacturer for warranty replacement because the encapsulation failed.
If you have a PV panel that isn't physically damaged and its encapsulation is still fine - it still has value even at 25 years of life... I'd happily buy a pallet load of used, physically fine condition 360W panels that when put on a STC flasher "only" produce 320W, at a very cheap $/watt price.
I don't think it's a trick. While I don't know the details about this plant, I've noted that a large number of solar panels are removed (and then disposed of) while they have some useful life left.
To be clear, I'm not saying people junk panels that are still producing.
But just for panels generating a standard "bucketed" wattage, a very small amount of damage can lead to a "defective" panel.
By removing the silicone and/or glass, the still-usable parts can be recycled into what you might call a "remanufactured" panel. Or, if the cells have been in service for a very long time, by taking apart the panel, the cells can be recycled as high-purity stock. (In other words, ground up and used to make new solar cells.)
None of this makes economic sense until it is being done at huge scale. Therefore, I expect this is plant is mostly an experiment, expecting that as the deployment of panels continues to grow exponentially, having a viable (and proven) recycling plant will grow in value proportionally to the panels.
> This seems odd to me. Solar panels should last at least 30 years but we've been finding most just keep working, potentially for decades longer.
What installations do we have data on that have been running since 1970 or so? You say they should last at least 30 years but may keep working decades longer.
> While the power they produce degrades with time, it's not enough to be worth junking the panel.
It's not surprising to me that they will fail, even before 30 years. I mean, they are outside, subjected to weather and thermal cycling. They are going to get hit by lightning, hail, and lots of freeze/thaw cycles. Almost everything degrades in that environment. Even the panel support structures themselves will get crooked on that time scale from soil moisture changes.
Soil moisture changes? Most panels are mounted on metal rails on roofs, presumably the structure isn't shifting so much that the roof's geometry is changing. Otherwise, yes, obviously exposure to the elements is hard on everything, though humans successfully maintain structures that are hundreds of years old.
I was talking about solar farms. I've started to see a few of them scattered around Colorado. The structure looks like something dug with a fence post hole digger. Old fences definitely show their age around here (as in they are crooked) due to expansive soils. Or maybe its mostly due to freeze/thaw in the ground.
The 1970s was when solar PV started to be used for RAPS (remote area power supplies), so there's a reasonable number of installations out there of that era. I wonder if any surveys of those have been done.
Sure, it's obviously not worth much - but the question is whether it's worth more as a less efficient but working panel, or as raw recycling feedstock material.
I wonder which technology they are using to remove the silicon and metal films from the glass. Two guys that used to work in the same shared office space had developed a process to do exactly that.
They stumbled opon it while experimenting with extremely bright and powerfull UV flash lights (couple of kilowatts for the fraction of a second). These powerful UV-bursts then remove films from surfaces due to the tensions introduced by the sudden heating. Building the first prototype in one of the guys basement involved some insane EE-hacking on their part such as manufacturing flash tubes to their own specs and building high voltage transformers to drive the flash tubes.
Last info I had was that they got founded and are trying to scale their process, opening a small experimental plant.
The only alternative to their technology that I know of is either throwing away the glass or melting everything and then recoup all elements. The former produces lots of waste and the latter needs huge amounts of energy.
Does anyone know what is the way to deal with dust and bird poo? I can imagine that the panels get dirty over the years which reduces their efficiency more than standard wear (less sunlight reaching the important layers). Is that accounted for in the numbers? Is there a study that provides insight on the maintenance required to run PV plant over 30yrs?
A whole lot of rain will pour down on those panels every year. You should be fine unless you live in a really dry and dusty area. Or if you have trees overhead which leave sticky leaves on your roof.
Involved in large scale, long term solar testing in the past:
I was almost always better to let the rain clean the panels in the field, even in some pretty dusty and arid climates.
The deciding factor was usually the labor cost of the cleaning. (Think very depressed labor prices) Even then the risk of damage from the cleaning ops might sway away from manual cleaning.
80% of original test-conditions rated power is still a lot - if you were to theoretically install a 40kW rated array composed of about 112, 360W panels, that would still be a 32kW array after 25 years.