[CyanLite2]

That's DC power not AC needed to power homes, and even then only 2 minor junction points.

The power plants and substations are still needed to act as a giant DC-to-AC inverter. So if the plants are offline then the grid is effectively down, as it was in the Feb 2021 blizzard.

[pfdietz]

The DC is converted to AC after it crosses the bridge. The use of DC interconnects means the AC on the two grids doesn't have to be synchronized.