[droithomme]

> An explanation of the mechanics of how I'd have to pay somebody else to take my electricity (e.g., a negative rate) would be helpful.

Sure. Let's say you have a million people producing a glut of electricity on sunny days from 11am to 2pm, when there is not a lot of demand. So there's massive overproduction and you need to create a financial incentive to incentivize the overproducers to pull back. So you have negative rates. It's as simple as that.

How much you can charge has nothing to do with your cost. Your amortized cost of providing excess power every sunny mid-day might be extravagant. That is no matter as far as the market is concerned.

Solar energy production still costs a lot. But there's tons of articles claiming that it's now cheaper than pretty much every other energy source. Yes, it's cheaper to buy at noon in sunny areas during some months because of economics. That doesn't mean it's cheaper to produce and supply though.

[wisdomdata]

South Australian here - In South Australia keep in mind commercial scale solar is also generating against residential rooftop solar which is sold back via a feed in tarrif to the generator at a contracted fixed rate. The generators have to pay for (and take) this power. In some cases 20 year contracts where signed some time ago with feed-in tariffs much higher than what they ever should have been. This has resulted in early adapters making thousands in cash every year from residential solar (and still doing so). Everyone else is paying for it of course. Feed-in tarrifs available for contracts signed today are much lower, but some of these contracts still have a few years to run. Without more storage solar will continue to reduce reliability and add costs.