This is why wind and solar are good partners with hydro. They're more unreliable due to weather but if you have the wind or sun available to generate more power than you need, you can use the excess power to pump water uphill into a hydro lake and store it for later. So even though it's a lossy operation as you say you're basically getting it for free. And like the video showed, hydro is very responsive to short term load demands so if the wind falls off you can quickly start up a hydro plant, as opposed to something like coal or gas which takes much more effort to start/stop.
Theoretically you can put wind/solar much closer to urban centres but in reality the NIMBYs don't want them either near cities where they can be seen or in remote areas which are typically areas of natural beauty.
I would guess due to a design flaw in the market rules (or the rules for the interaction between different national markets).
I think most large windmill turbines are designed to be able to be feathered to limit electricity production - they need some way to not fail when winds exceed generator constraints - but maybe designs use wind stalling or other dynamics to prevent that? Alternatively they could build dumping loads close to the wind power - e.g. warm some seawater with big resistors!
Edit: I love the quote "Wind farms in West Texas earlier this year were paying utilities to use their electricity on particularly gusty days because they can still earn $22 a megawatt-hour in federal tax credits." LOL.
Theoretically you can put wind/solar much closer to urban centres but in reality the NIMBYs don't want them either near cities where they can be seen or in remote areas which are typically areas of natural beauty.