The battery invented 120 years before its time—OR NOT

So, BBC implicitly suggests we use a battrolyzer to compressively store green ~30% of wind nameplate capacity (its capacity factor) at a battrolyzer efficiency of maybe 65%, netting (0.3*0.65*0.9) ~18% energy storage efficiency. Then we use that at about at best ~60% efficiency to regenerate electricity for the grid, a net round trip efficiency of maybe (0.18*0.6) 0.11% from the originally subsidized renewable generation. What a great deal–NOT.