Interesting. I don't recall ever reading about this limitation (lack of turbine inertia to stabilize frequency) before.
There was not enough inertia to contain the frequency shift and inverters dropped out, widening the gap between supply and demand and worsening the frequency deviation. This caused other equipment to disconnect, quickly leading to a cascading blackout. The process was too fast for grid operators to take action to contain it, due to the lack of inertia.
It's really not been a problem before, when almost all electricity was made with big, constant speed, spinning turbines.
I have raised the issue previously in this thread, many times, and as far back as
June 2018; My first mention of grid stability as a problem for renewables on this forum was
in a thread about Solar Power in California, back in July 2017.
Grid stability services provided as a byproduct of constant speed turbine generators, need to be separately (and expensively) provided by other means in high wind and/or solar grids.
Most of the much hyped battery "storage" facilities are incapable of storing any worthwhile amount of energy, but are useful for increasing the stability of the grid.
Inertia is one of the best stability providers, particularly as it comes along for free with nuclear, hydro, gas, and coal power plants. But in its absence, someone has to supply stability services as an add-on.
Alternating current at grid scale is not just a matter of "Gigawatts in = Gigawatts out", And is even further from being a case of "Energy Generated in a given week = Energy Used in that week", but that's the highest level of electrical engineering "understanding" that most politicians and lobbyists can bring to the debate.
The advocates of high renewables (and even 100% renewables) grids have been warned of this issue, and have been ignoring it, for decades.
They also ignore the fact that a kWh isn't a fixed value commodity, but is rather a time dependent service. If you use 1kW every hour, and you generate 24kWh of solar electricity every day, the 3kW you generate between noon and 1pm are worth
far fewer ¢ than the 1kW you consume between midnight and 1am. Indeed, the kWhs you generate are likely of
negative value if you live in a place with lots of solar power. This is concealed by retail contracts that pay a price that is decoupled from the wholesale price of electricity.
Solar power generating householders here in Queensland often feel ripped off because they sell for 4¢/kWh, but buy for 35¢/kWh (for example); But the reality is that this price difference is probably unfair in the opposite direction*, and represents a subsidy of solar panel owners by consumers without solar panels. That is, the better off people, who own a house, are being subsidised by the less well off people who rent, and/or live in an apartment.
And claims of "this facility/city/factory/home/etc. uses 100% renewable electricity" are almost certainly an exaggeration, a misapprehension (or to be blunt, a lie) in almost every case - unless the system is entirely disconnected from any other generation technology for the duration of the period being claimed.
My house has 10kW of solar panels on the roof, and I generate slightly more power per year than I consume, but even if I had a home battery (there's an entire thread worth of good reasons why I don't, shouldn't and wouldn't), my power will go out if the mains trips in the middle of a sunny day, simply because the inverter cannot generate 50Hz AC without a mains connection providing a frequency to map to. Totally off-grid solar power systems do exist, but are FAR more expensive than the ones installed in most domestic suburban settings.
* Whether those prices are acually "fair", or how "unfair" they actually are, depends on exact generation and useage patterns compared to wholesale prices, and are (I suspect deliberately) hard to get a handle on.
Willow Island disaster - a cooling tower of a coal-powered powerplant
