The big thing with renewables is that they don't really require ongoing fuel shipments. Spain is not a large producer of any of the major fossil fuels like oil, gas and coal.

While there are certainly issues with the supply chain of certain components of renewables, those effectively cease after installation. And even hydro is not totally immune from supply issues given increasing drought frequencies across the world.

You should read the report, its a good description of a complex system failing complexly. (well the reasons leading up to it failing were complex)

The interesting thing about spain's grid is that it doesn't have that much battery compared to say the UK (the uk has about 11 gwhr which is about enough to power the entire uk for around 20mins)

The Iberian grid has <100Mw (I know mixed units) battery at the moment. This is interesting because the economics of the iberian grid means that most solar plants are in curtailment (ie told to turn off) at solar mid day prices are normally negative, at 18:00 prices are very high.

There is currently a large lucrative market in grid scale batteries being paid to charge at solar noon and getting a 30-50% premium to release the power at peak.

There are only a few companies that are able to vertically integrate solar and battery, so it'll be interesting to see how the prices shape up in the next 5 years. I expect a bunch of batteries to be built and then sold as the market changes shape.