That is an interesting system (which I had never heard of), but it seems pretty different from this. The London system used water under pressure and was used f

That is an interesting system (which I had never heard of), but it seems pretty different from this. The London system used water under pressure and was used for power distribution, whereas this one compresses air and is for energy storage. And the Wikipedia article says the London system used "large vertical pistons" with weights to store energy, whereas this one pressurizes air.