Data centres improved greatly in energy efficiency as they grew massively larger

As you step into one of 42 data halls on a plot of 74,000 square metres near Sydney, Australia, you become immersed in a sterile science-fiction world. Towering rows of black server cabinets stand in meticulous order, containing thousands of whirring hard drives, the beating metal hearts of a massive “hyperscale” data centre. Overhead, fibre-optic cables carry data down into each cabinet; metal wires, electricity. Outside a substation delivers power; batteries and generators provide backup. The digital world pulses unceasingly on an uninterrupted flow of electricity.