Power isn't a particularly helpful metric here, energy is. Power doesn't tell you anything about how long the batteries will last, it only tells you how quickly they can drain. Also there's a limit to how much power you can draw through residential lines so regardless of whether or not batteries can deliver power on the same order of magnitude as a coal-fired plant, it's highly dubious that these specific batteries can do that.

>Batteries do indeed compete with power plants, every day of every moment they are on the grid. They are also consumers from power plants, they go both ways.

Hey don't tell me that, tell the BBC. They're the ones who wrote an entire article about "replacing power plants with home batteries".