DC power brings applications for superconductors

The requirement for high-density power delivery to IT racks brings a number of challenges as conductors grow in size — busways and cables capable of supporting racks of 100 kW or more are costly, large and heavy. A related development in rack densification is the reenergized interest in direct current (DC) power distribution systems. The initial aim is to simplify IT power supplies and reduce their size, followed by an overhaul of the entire data center electrical chain in some future facility power architectures.

High-power DC distribution is where superconductivity becomes an interesting option. High-temperature superconductors (HTS) that operate above 77 K (approximately -196°C or -321°F, the boiling point of nitrogen at 1 atm) have been proposed to reduce conductor sizes and distribution losses in future high-power distribution systems without the need to step up voltage levels. These systems include the electrical backbones of data centers operating at medium voltage (10-35 kV). While superconductivity can be deployed in alternating current (AC) settings, it is better suited to DC — HTS cables are more efficient and can be smaller when DC is used.