Just enough/just-in-time really really sucks; On principle. That 40% usage just about matches the requirements for "robust" service: true for electric service, true for roadway service, true for water/sewer service, true for restaurant service ... if you want unhurried server delivering a piping-hot meat-loaf and potatoes. Likewise, home electric users with 60% headroom can then add/subtract any personal comfort feature to their dwelling W/O fear of blowing fuses L&R. A last thought ... given current rates of improvement 40,000 squ-meter data-centers will be reduced to the size of a sound-card ( Homo.sapiens do this already). With NVIDIA about to announce their new CPU with built-in ......