The 70% thing came from a business development official in Loudoun County, a person whose job is to promulgate misleading boosterism. It doesn't make even a sliver of sense to someone who thinks it over for a moment.

Cooling is a major data center cost, but it's not 40% any more. All of the major datacenter operators claim a PUE of 1.11 or less. Facebook has been the most open and vocal about how they achieve this, for example at https://tech.fb.com/hyperefficient-data-centers/ (scroll down to "Systems").