Modular data centers have come a long way.
Modular data centers have been in use by the government since the 1960s. Now they are commercially available for companies of all sizes. Here is a video that provides a great description of some of the options available to CIOs and Data Center Operations managers.
This is a far cry from the first ones that I saw in the late 60’s. The US Army had them with an IBM 1401, a workstation, communications gear, a generator, air conditioning, and a satchel charge to blow it up if the position was over run. They unit was flow in by helicopter for artillery calculations.