> Yes, the point with selling electricity is that you need to guarantee that you will deliver some fixed amount of electricity

Surely this can change, no? You'd just have to sell it at a cheaper rate to make up for the fact that the other side has to ramp up/down other sources to accomodate your changes in volume.

Electricity in most networks is bid on usually just two or three hours into the future, for 30min windows of electricity. (Biding starts up to a day or two before, but the auctions usually only close and hour or two before the 30min block starts).

It’s pretty easy to predict the amount of wind two or three hours into the future, wind doesn’t just “stop” without any sort of warning. (At least not when you’re dealing with wind over 100s of square KM in the middle of an ocean).

So selling renewables into the grid isn’t that hard, even across grids. But you might not be able to command the same premium that a more “reliable” source could.

> the point with selling electricity is that you need to guarantee that you will deliver some fixed amount of electricity.

No you don't. Electricity is sold at spot prices in real time. At that is how I and most people in Norway buy theirs.

It should be possible to reduce the likelihood of prices going negative by continuing to improve the interconnectedness of the various national grids in Europe.

> Yes, the point with selling electricity is that you need to guarantee that you will deliver some fixed amount of electricity. If you depend on wind power plants how this guarantee can be given? What if wind stops.

Real-time bidding for prices already works at some places, but we need to modernize the whole electric system of the world. Smart grid was always part of the renewable solution.

> Maybe it would make sense to build huge bitcoin mining data centers and mine bitcoins in case of surplus. Hardly useful, but given current coins rush could be profitable. Better than paying producers for not producing energy.

It's already happening, but with all the negative conotations of Bitcoin mining, it's generally easier to listen to interviews with people working at energy companies than to discuss it on internet forums.

On a wholesale level, electricity prices are highly dynamic already, and highly demand based.

Aluminum smelters. If you have lots of cheap power you can always smelt. The raw materials are everywhere and everyone needs aluminum products. Fill the pots and spark up the electrodes as soon as power gets cheap.

https://en.wikipedia.org/wiki/Aluminium_smelting

Yes, all true. But, you also need to keep the "pots" quite warm (at least 960 degrees C) in order for the electrolyte to be liquid. Keeping them that temperature while not actually producing any product (while electricity is expensive) is a waste. The article you cite says that the Australian smelters that are used to iron out changes in electricity demand can't be switched off for more than 4-5 hours, or they may be damaged by the liquid solidifying.

You can get a better price if you can guarantee availability, but there is also a market for variable supply.

In particular those investing in utility grade batteries are playing the low price/high price arbitrage game.

Blockchain, obviously. /s