In addition to providing cost savings through higher efficiency, DC systems may also provide an opportunity to expand datacenter capacity: Many existing datacenters are using only part of their available square footage because they can't get more power or cooling capacity. Some telecommunications centers are finding that newer rack systems require 100 watts per square foot rather than the old standard of 40 watts per square foot. Due to lack of space, their buildings can't support the 4-foot-thick bundles of cabling necessary for that much 48-VDC power. Moving to high-voltage DC could get around these limitations, because the required cabling would be just 1.5 inches thick.
In many areas, including New York, the San Francisco Bay Area, and Los Angeles, companies are unable to get additional power from the local utilities. Increasing the efficiency of existing systems could also allow companies to continue to use existing buildings and still expand datacenter capacity.
A high-voltage power system like that from Validus requires substantial installation and investment, including running large diameter cabling from the utility pad outside into the datacenter, installing the 575-to-48-VDC converters for each rack, and converting servers to 48 VDC. However, saving 50 percent or more on power over many years represents a big return. For companies that are unable to increase datacenter capacity by buying more power capacity, turning to DC may be the only solution.