Network Storage Energy Consumption (Wh) = ( (Power Draw of Provider Network Storage in W * GB of Network Storage) * Hours of Utilization) * Network Storage Power Supply Efficiency Factor
Power Draw of Provider Network Storage
As detailed in Onboard Storage, storage can be added to an instance in two ways: with an onboard drive attached to the server’s motherboard, or through reserved network storage on a specific storage rack. If you have network storage attached to your instance, Tailpipe draws the storage type and volume from your usage and billing files. For AWS, these are the CUR files.
However, usage and billing files do not state the number of storage drives used to host an organization’s data – only the total volume of storage in GB. This means that network storage cannot be measured in the same way as onboard storage. Tailpipe therefore looks to the available data on provider hardware to calculate the power draw of network storage.
The average facility size for a data centre is now 32 MW, with an average rack density of 16 kW, or 16,000 W (AFCOM, 2025). In 2024, AWS announced that they have integrated the Seagate Exos X System for their cloud storage capabilities. Seagate’s Exos X System hard drives have a capacity of up to 24 TB (24,000 GB), and their largest enclosure – the 5U84 – can store 2,016 TB of data (84 x 24 TB disks). Taking a 42 unit rack as the industry standard, Cloud Service Providers are likely to fit eight 5U84 enclosures in one rack, leading to a total of 16,128 TB of storage across 672 drives.
Based on this configuration, Tailpipe calculates:
16,000 W is divided amongst 672 drives = 23.81 W per drive
This 23.81 W figure is doubled for storage redundancy = 47.62 W per drive
47.62 W per drive is divided by the 24,000 GB capacity of the drives = 0.002 W/GB
Tailpipe therefore assumes that AWS’s network storage generates 0.002 W/GB. This figure is multiplied by the number of GBs of network storage the organization has reserved:
Network Storage Energy Consumption (Wh) = ((0.002 W * GB of Network Storage per hour) * Hours of Utilization) * Network Storage Power Supply Efficiency Factor
Tailpipe uses this same formula to calculate the power draw of Azure network storage. Azure does not publish information about its network storage hardware, and although the 0.002 W/GB figure is calculated based on AWS hardware, Tailpipe considers it to be a plausible industry standard for network storage servers.
Network Storage Power Supply Efficiency Factor
As with the instance calculation, Tailpipe assumes an average PSU efficiency of 96%. This means that a 4% power supply loss is integrated into the methodology by multiplying the total power consumption of the network storage components by 1.04.
