I find them on Flea bay and Dumbtree.
There are LOADS of them here for sale that are only 2-3 Yo. People are either upgrading their systems and want to get all the same panels or they are insurance jobs. Only one panel needs to get damaged and they will again replace the lot to make sure they all perform right.
I'm hoping to get some this week from a guy that has a heap of them. 5x 225W panels for $200. More like .25C a watt and they are good quality Tier 1 panels to start with. From the pics on the ad, I'm not even sure these things are used. Seem to all be from boxes in pallets so unless a solar farm somewhere either closed down or upgraded, I'm thinking these things could be in fact new.
I'm going to check the seller out and what his stocks and panels are with a view to buying in bulk and reselling them myself. My father lives in the country so If I can make some money taking them to where he is and on selling them, might pay for the trips I was going to make anyway.
There are ship loads of these used panels around here, just some sellers are more realistic than others. People advertise used gear all the time for more than they can be bought for new. Obviously they bought a system 5 years ago and are going on a second hand price for what they were worth then, not what they can be bought for new new now which is less than what they want for old 150W panels that are out of date with current technology.
I posted recently about these used panels being so cheap, I would look at using them to build a veranda/ patio cover out of in the future. I crunched some numbers and worked out that even when placed in a less than ideal angle and orientation, the difference in price between doing a covering in panels and in normal roofing material would be paid for well and truly under 2 years. By the 5 year mark I'd be ahead on the cost of the whole structure that I wanted anyway. I looked at a couple of houses on teh weekend and both would be good for this One had perfect orientation and the ability to get the right angle and the other was near orientation and I could get a good winter angle.
If they didn't happen to be facing near the right direction and I could get some decent tilt on the things, I'd still be laughing. I'd look at these primarily as a backup or add on but they could work real well in an over kill system.
They may not even be needed on sunny winter days but on hot summer days and cloudy ones, the extra panels would be awesome.
The affordability of off grid in suburbia is becoming closer all the time here. I see 30Kw battery packs being advertised for $3k With 2 year warranty.
Storage as well as generation is affordable. Biggest cost is going to be inverters and Charge controllers.
With a 30 Kw reserve, All I'd need is the lister or a diesel genny for a battery charger to run to cover the maybe 2-3 weeks a year of continuous wet weather we get and maybe a week of odd days I'd have to top up and that would be it.
People always talk of rising power prices but they have shot up so much here in the last few years I don't think they can go much further. The power companies have to know that they are near if not at the tipping point where people are going to start investing in serious consumption reduction even on grid and a proportion are going to bail all together. You'd have the DIY'ers, the green washed and just those that will sink money into avoiding getting screwed on principal just to start with. Many home builders now are throwing in 5Kw solar packages to their packages and the overall energy consumption of houses is falling anyway.
I don't really subscribe to the theory of spiralling power prices because where I am, I don't think there is too far they can go before they start going backwards.
We'll see though. Plenty of places pay more than what we do here so there is still margin to go yet. Don't think it's going to worry me although it might be wise to stock up on these used panels while they are still cheap and everyone else doesn't wake up to them.