[k0stas]

Beware of talk about benefits without mention of drawbacks.

Connecting grids could significantly increase the fragility of the system resulting in higher risk of large-scale power outages. Some of you might have experienced the 2003 blackout in northeast North American (https://en.wikipedia.org/wiki/Northeast_blackout_of_2003), which luckily happened in the summer. Tail risks should not be swept under the rug.

Even a single widespread event could completely wipe out the benefit gained from connecting grids.

[api]

This is a general principle: making things bigger and/or more centralized tends to increase efficiency and decrease the frequency of failures but greatly increase the cost and severity of failures.

In computing think about, for example, centralizing identity management in the hands of a few large companies. These companies have large security teams and mature well built infrastructures, but a huge failure or a huge security compromise of, say, Google’s OIDC system, could be utterly catastrophic, paralyzing and destroying vast swaths of our digital infrastructure. Entire companies, services, or even sectors would be paralyzed or worse.

Small, decentralized, and diverse is overall more costly and experiences many smaller failures but is more robust for the long haul.

This is probably why life, having evolved over a billion years, is mostly this way. Giant super organisms and super-optimized monocultures are possible but fragile.

Our economies, having only existed for hundreds of years and being incentivized to only care about next quarter, tend to go all in on anything that makes numbers superficially better.

[Havoc]

Blackouts & instability can happen on isolated grids too - if not easier given less options. See the texas grid drama.

It does seem sensible to beef up resilience on large interconnects though agreed to mitigate cascading risk.

[lizknope]

I remember we were at work and the power flickered and all the UPS's started beeping for about 10 seconds. Then it went back to normal. Then about 30 minutes later people looked at the news and saw a massive blackout. We were hundreds of miles away and that's all we felt but I had a relative tell me about walking a few miles home because the subways were down and the traffic lights not working made it even crazier.

[natch]

In 2003 they didn’t have grid scale batteries.