Power in a data centre – understanding the terminology

This agreement between our data centres and our clients guarantees uninterrupted availability of power, network connectivity, and other critical services. In essence, it promises that we will maintain continuous operations without any service interruptions.

Power redundancy refers to the implementation of backup power sources or systems to ensure continuous and uninterrupted power supply to critical equipment or infrastructure. Redundancy is essential in situations where a power outage can result in significant disruptions.
2N power refers to a redundant power configuration in which the power infrastructure is designed with two independent power paths to ensure redundancy and minimise the risk of power failure – even if one power source or power distribution unit (PDU) fails, the critical equipment remains powered and operational. It provides a robust infrastructure for applications that require continuous uptime and cannot tolerate power disruptions.

Power distribution units (PDUs) are responsible for distributing power to the IT equipment – the power from each source is connected to its respective PDU. Each PDU is connected to different power feeds to maintain separation and redundancy.

An uninterruptible power supply (UPS) system provides short-term emergency backup power in the event of any disruptions to the main electricity supply – it offers a buffer period for switching to generator power or safely shutting down equipment to prevent data loss. In a 2N UPS system, two UPS systems operate in parallel to support the load, with each UPS capable of independently supplying the entire power requirement.

This is a fundamental concept in ensuring uninterrupted power supply to our data centres and refers to having two independent power feeds entering our facilities. This redundancy is vital for maintaining operations during power outages or maintenance on one of the feeds. By having a dual power source, data centres can switch seamlessly between sources, minimising downtime and enhancing reliability.

These go hand in hand with dual power sources. They are installed within critical equipment, such as servers, to maintain functionality even if one supply fails. Each power supply unit (PSU) is connected to a different power source. This setup ensures that if one power supply encounters a fault, the other takes over immediately, maintaining continuous operation and safeguarding data integrity.

This involves distributing the electrical load evenly across multiple power supplies or circuits. This prevents any single power source from being overloaded, which could lead to equipment failure or inefficiencies. By effectively managing load distribution, we can optimise performance and extend the lifespan of our power infrastructure.

If one power path fails, the equipment automatically switches to the alternate path without any interruption or downtime. This failover can be achieved through automatic transfer switches (ATS) or intelligent power distribution units that detect power loss and switch to the backup path.

Each of our standby generators is capable of independently supplying the full power load to ensure continuous operations during outages. We have rarely had to call on our generators to provide backup power (in fact, the majority of the hours they run is for maintenance and testing), but the generators need to be available in case they are ever needed. In 2022 we made the switch to environmentally friendly Hydrotreated Vegetable Oil (HVO) for our backup generators at our south east facility in place of red diesel.

Active/Active power distribution paths refer to a configuration in which power is distributed across multiple paths simultaneously, with each path actively providing power to the load. An Active/Active configuration includes multiple independent power sources, redundant PDUs, load balancing, and fault tolerance and redundancy, to ensure continuous power availability. These provide a higher level of redundancy compared to single-path configurations, as multiple independent power sources and PDUs are actively delivering power to the load.