It’s lucky we caught this now, before there are enough PowerWalls to seriously destabilise the grid if this attack were to occur.
ROCOF works well to keep things safe when only a small percentage of the grid demand is met by residential solar/powerwalls.
As soon as any significant proportion is residential solar (and thats already the case in some countries at some times of day) it acts as a cascading failure mechanism. As soon as any failure occurs, embedded generation sees a rapidly decreasing frequency, and rather that increase supply as traditional generators would be instructed to do to stabilise the grid, ROCOF protection requires they cease supply, making the issue far worse.
Within a fraction of a second, all embedded generation will disconnect, likely causing a near total blackout nationwide. Since system frequency that ROCOF measures is nationwide, failures won't be local to one geographic area.
I suspect these rules were made when people thought "consumers feeding energy back into the grid will never be more than 0.1% of the total - we'll always have enough spinning reserve to make up for that". Thats no longer the case, and unless the ROCOF limits are changed, and the majority of home solar/wind/powerwalls get a firmware update, expect a few very large blackouts.
That gold code could be received and decoded anywhere on the network. If power islanding occurs, embedded generation will detect the loss of the gold code (since they are no longer connected to the generator injecting the code), and cease supply.
The only disadvantage is it introduces a security vulnerability by design: Anyone could transmit the gold code from their house, effectively disabling islanding protection in their neighbourhood. If power islanding were to occur, and if there was sufficient embedded generation to keep a stable power island, grid hardware could be destroyed through overvoltage, overheating, and circuits closing without frequency synchronisation. I think it's a worthwhile tradeoff though - damage will be localized and minimal, and a very unusual set of circumstances have to happen outside the attackers control for the attack to do damage.
Sometimes I think that a DC grid would be better. Issues like frequency synchronization wouldn’t exist.
There is currently no way to control the frequency or phase of the island.
> It’s lucky we caught this now, before there are enough PowerWalls to seriously destabilise the grid if this attack were to occur.
I could be misunderstanding you, but do you seriously think that there are not more destabilizing attacks already available? From my reading the US power grid is already extremely vulnerable to attack.
If you can make power usage unexpectedly go up by more than ~10% within a minute, most power grids will fail.
I'm struggling to think of any companies who could do that though... Someone with malicious access to teslas servers couldn't even do that... For example, instruct all plugged in tesla cars to start charging all at once. Assume 400k tesla cars are plugged in overnight, with an average 10kw charge ability. That means tesla could add 4 gigawatts to the grid demand instantly, which is only 0.4% of the USA's ~1TW generation capacity.
Wouldn't that behave identically to a sudden loss of generation? The power grids I know of have schemes to deal with that, by automatically shedding large blocks of load in several stages.
If just 10% of a nationwide grid is down, there's a good chance the phone network won't work, internet will be down, trains won't run, credit card/payment systems won't work, etc. All those things have primary and backup systems, but somewhere in the chain of dependencies there will be both a primary and backup that have been shed, and the system designers thought "these two data centers are 500 miles apart, so won't fail together".
A major infrastructure cyberattack seems effective either as an opening salvo in a traditional military war or to multiply the chaos after a terrorist attack. Taking out the power grid would worsen traffic congestion and create increased demand on emergency services in the short term, and have major economic impacts and high visibility in the long term.
What happens if the attacker generated a (e.g. periodic) pattern of load changes that excites control mechanisms at their resonant frequency?
Maybe the book "Blackout" [1] (which I haven't read myself) has more (fictional) details about what can go wrong.