Server spec power includes fans operating at maximum power. The entire data center power distribution system, including the UPS, must be sized for this “nameplate power”. Fan-free, i.e. liquid cooled systems, can recapture this stranded power and enable more, and hotter, processors to be installed without any increase in the data center power or cooling infrastructure.
All power goes to the IT load resulting in the stranded capacity being made available for extra compute capacity. As cooling is much more efficient, CPU heat rise is limited permitting them to run in turbo mode continuously yielding more capacity or fewer servers. Alternatively higher power CPUs can be used adding another 40% compute power within the same power envelope as the original air cooled version.