Carbon footprint

Equipment Categories and CO2 Emission Calculation

Equipment Categories

A Data Center uses three main categories of equipment:

• Compute equipment (e.g., ESX servers based on X86 processors, IBM servers based on Power processors, etc.), which host the various instances.

• Storage equipment (e.g., data storage arrays, object storage arrays, backup and archiving storage arrays).

• Network equipment (e.g., network switches, firewalls, BigIP, etc.), which enable internal and external flow exchanges between services and instances.

• Note: These three categories themselves consist of subcategories that allow for a more detailed calculation of CO2 emissions per user instance. For simplicity, these subcategories will not be included in the calculation method outlined below.

Energy Consumption Collection

The energy consumption of each piece of equipment is collected every minute (instantaneous power in watts) and stored in a database (MIMIR key-value database).

Additionally, we collect the following elements to calculate the associated CO2 emission:

• The PUE (Power Usage Effectiveness), calculated daily for the data centers we operate and monthly for colocation data centers.

• The CO2 emission factors (in kgCO2e/kWh), which are updated annually based on data from ADEME and suppliers.

CO2 Emission Calculation for Equipment

The CO2 emission of a piece of equipment is calculated on a daily basis:

• Convert the instantaneous consumption into kWh/day from the data collected in the key-value database.

• Apply the PUE of the data center:

  • If a piece of equipment consumes 1000 kWh/day and the PUE of the data center is 1.3, the actual consumption of the equipment will be 1300 kWh.

• Convert the kWh/day into CO2 (kg) using the CO2 emission factor from the supplier:

  • If 80% of the energy used by the data center comes from a supplier who emits 0.008 kg of CO2 per kWh, and the remaining 20% comes from a second supplier who emits 0.01 kg of CO2 per kWh, the equipment’s emission will be: 1300 * 0.008 * (80 / 100) + 1300 * 0.01 * (20 / 100), which equals 10.92 kg of CO2 per day.

CO2 Emission Calculation for a Global Service

Reminder

A Global Service is the logical grouping of resources (primarily Instances) that use resources from different categories of physical equipment (Compute, Storage, and Network). The carbon footprint of a Global Service will therefore be the sum of the CO2 emissions of its resources.