Used 240w modules built in 2010-2012 are worth $60-100 CAD at the moment in small quantities. There will be hundreds of thousands hitting the market (as long as they didn't hit the ground with careless removals) in ~2030+ as microFIT contracts in Ontario expire.

There is no clear path to switching these arrays to Net Metering, as of yet. Prepare for all sorts of unrecycled solar panels and potential loss of renewable capacity that is already installed.

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msandford 3 hours ago | parent | next [-]

Net metering is really, really smart when the installed base is small relative to the fossil fuel power plant capacity. But it doesn't scale forever. Once it gets up towards 20-40% of the fossil fuel capacity, it goes from an asset to a liability.

Suppose I have a 100MW gas turbine. And suppose there's 1MW of solar installed in my generation network. I don't really care if I sell 80MW at noon and 90MW around dinner time and 50MW through the night, or if instead it's 79MW at noon and 91MW at dinner and 51MW at night. The gas costs about the same irrespective of when I burn it so a bit of a fuel shift doesn't really matter.

But take that 1MW and turn it into 20MW and suddenly we go from 80MW at noon to 60MW at noon, 90MW at dinner to 110MW at dinner and uh oh. You see the problem? Whatever losses I endured at noon I don't get to make up for at dinner because my plant only goes up to 100MW and now we're not just shifting when we burn how much fuel, we're literally having to shift the power generation to a different plant.

Is this example precisely accurate? Absolutely not. But it helps you get a feel for the problem of net metering at scale. The grid can act as a battery for a few % of total generation, but by the time you hit some number, maybe 20% maybe 40% net metering turns from a cool math trick to a real cost on the grid.

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wat10000 2 hours ago | parent [-]

Net metering only makes sense as a way to incentivize solar installations. Looking at the economics, it's not something any utility would offer willingly.

It's like if the grocery store let you give them milk for a credit at full price. (Let's ignore the sanitary/health/quality issues that would come up.) You decide to buy a cow and you drink that milk. Sometimes you need more than your cow can give so you buy extra from the store. Sometimes you need less and you sell the extra to the store. Long term, you use as much as your cow produces on average, so you pay the store nothing. But the store has provided a valuable services to you and has incurred expenses in doing so. They have to keep the lights on and maintain a building and pay workers to handle your transactions but they make no money from you. The only way it would work at all is if they made enough money from their non-cow-owning customers to make up for it, and that can only take you so far.

	▲	hvb2 21 minutes ago \| parent [-]
		> It's like if the grocery store let you give them milk for a credit at full price. I know of quite a few places where through net metering you don't get full price, you get the wholesale rate for your production which is significantly less.

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pjc50 6 hours ago | parent | prev [-]

Could you elaborate on this? Why would people remove a working solar system?

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jandrese 3 hours ago | parent [-]

Buildings get torn down. Roof needs a replacement and the owner doesn't feel like it is worthwhile to redo the solar install for panels that only have 5 years of warranty left, or maybe they want to replace them with higher power models with a fresh warranty. There are any number of reasons why someone might need to offload otherwise functional solar panels.

	▲	mrguyorama 2 hours ago \| parent [-]
		Currently used solar panels are a hot commodity, with many groups selling them by the pallet, because 10 year old solar panels are still efficient enough to easily pay for themselves. Very few installations will care about specifically how many panels they want, they just want a nameplate output per dollar figure. Old inverters might not have a second life though.