If you’re describing nearly free and unlimited electricity as a problem, you may want to reconsider some things.

It’s a very capitalist way of thinking about the problem, but what “negative prices” actually means in this case is that the grid is over-energised. That’s a genuine engineering issue which would take considerable effort to deal with without exploding transformers or setting fire to power stations

Home owned windmills, solar panels and battery storage solves that.

Edit: Look at this awesome diagram of how it’s done for a hybrid setup that’s about $400 on Amazon.

PIKASOLA Wind Turbine Generator 12V 400W with a 30A Hybrid Charge Controller. As Solar and Wind Charge Controller which can Add Max 500W Solar Panel for 12V Battery.

How, exactly, does that solve anything? It’s not like we can add some kind of magic residential cutoff system (that would just make it worse) and residential distribution is already the problem! Residential solar is awesome (tho home batteries are largely elon propaganda…) but they only contribute to the above issue, not solve it.

I don’t see why home batteries are propaganda. Those prices are plummeting and they have decent payback times in some markets.

The reasons for getting solar is the same reasons for getting batteries.

Because home batteries, while provisionally useful in the same way as a standby generator (though the generator is going to be far more eco friendly than the batteries over their respective lifetimes), is a vastly inferior solution to the implementation of even local grid scale solutions. Also because there is essentially 0 infrastructure designed to handle said batteries, they wear out quite quickly at home scales (unless you’re using uncommon chemistries, but if you’re using iron-nickle batteries you’re not the target audience here) and because Elon popularized them with his “powerwall” bullshit entirely to pump the stock value of Tesla’s battery plant (which is it’s own spectacular saga I encourage you to look up, it’s a real trip).

Batteries in the walls are useful in niches, but the current technology which uses lipo/lion/lifepo4 chemistries is inherently flawed and a route to both dead linemen and massive amounts of E-waste. They could be useful potentially, but as it stands, it’s really bad right now.

provisionally useful in the same way as a standby generator (though the generator is going to be far more eco friendly than the batteries over their respective lifetimes)

A generator can provide backup power for unlimited time if fuel is available, but it is highest cost power in the world. Batteries can be charged/discharged every day, displacing dirty energy. A generator is either rarely used or eco destructive.

If you assume what’s being compared is the platonic ideal of both technologies then you’re largely correct, but removing them from the context of the real world (where: high density battery chemistries still wear out quickly, biodiesel is common, the supply chain is a major contributor of greenhouse emissions, the need for power backups is infrequent, and where grid power is still in large part supplied by fossil fuels) isn’t very useful. Local-grid scale battery storage is the best solution we have for direct energy storage, and it’s very much maturing rapidly, but home units are still restricted in the above and additional countless ways. Ignoring those issues doesn’t work; implementation doesn’t particularly care about theory.

home units are still restricted

LFP batteries are the right home solution (Sodium Ion soon enough). US is tariff/capacity/policy restricted. Utility monopoly restricted if you want to export to grid, or use your EV as V2G. Utilities are also protected from off grid choices, and are changing their pricing with extortive fixed portions of utility bills. Biodiesel is not a sustainable (worse than ethanol if produced intentionally) solution.