A Primer on Sustainability Components and Measurements
Last week we launched an article series on metrics and mechanisms that data center operators can use track progress towards their environmental, social, and corporate governance goals. This week we'll look at specific sustainability components and measurements.
Sustainability goals can be broken down into five basic impact areas.
- Energy refers to the energy required — typically in the form of electricity — to power the data center and equipment.
- Greenhouse gas emissions, which are also called “carbon emissions,” encompass elements that contribute to atmospheric warming such as carbon dioxide, methane, perfluorocarbons, and hydrofluorocarbons.
- Water consumption is a growing concern as supplies in some areas of the country are dwindling. Water is used not only for data center cooling but also for electricity generation, making it a cousin to sustainable power use.
- Waste refers to materials contributed to landfills as a result of data center operations. Reuse and recycling can minimize the impact of waste. The metrics that are evolving in this area are likely to become a more critical part of corporate sustainability reporting in the future.
- Land & biodiversity metrics are fairly new in the data center industry and generally apply to the characteristics of land appropriated for data center use, the impact of the operation on ecosystems, and minimizing the impact of renewable energy usage on land and the environment.
The goal for data center operators shouldn’t be to achieve best-in-class performance initially but to strive for steady improvement across each of these areas. It is also recommended that operators request regular reports from their supply chain partners that show the progress of each.
Whether the organization’s goal is standards compliance, reporting to stakeholders, or guiding internal practices, a set of fundamental metrics is useful for measuring progress in a way that is comparable across organizations. Here are the basics to consider.
Total energy consumption
This includes primary energy use, purchased electricity, and electrical system energy losses from activities such as energy conversion and the generation, transmission, and distribution of purchased electricity.
Power usage effectiveness (PUE)
This ratio determines the energy efficiency of a data center. It is calculated by dividing the total amount of power entering a data center by the power used to run the IT equipment inside. A maximum efficiency ratio is expressed as 1.0.
PUE is also often used as a baseline for government agencies to grant permits for industrial development. The ISO 30134-1:2016 standard provides guidelines and requirements for calculating the key performance indicator correctly.
Total renewable energy consumption
This refers to the amount of energy obtained from renewable sources owned by the data center operator or purchased through carbon credits. The operator’s objective should be to steadily increase this number.
Renewable energy factor
This ISO metric consists of the ratio of total renewable energy consumption to total energy consumption. A factor of 1.0 indicates all the data center power is renewable.
Energy reuse factor
Also an ISO standard under ISO/IEC 30134-6:2021, this metric represents the ratio of energy reused divided by the sum of all energy consumed in a data center. A 1.0 ratio means all energy brought into the data center is reused for purposes such as heating nearby buildings.
Greenhouse gas emissions
This measures direct emissions from sources controlled or owned by the data center operator, such as the combustion of fuels and leakage of sulfur hexafluoride and hydrofluorocarbons. There are three scopes to this metric: direct emissions, location/ market-based emissions, and all other indirect emissions from sources such as business travel, waste management, and the value chain.
Location-based and market-based carbon intensity
Adding up the first and second scopes described above and dividing by total energy consumption yields this metric, which is useful in site selection, planning, and design.
Carbon usage effectiveness
Another metric from the ISO 30134 family, this measures the carbon gas a data center emits daily and is calculated as a ratio of the total IT load obtained by dividing the total carbon dioxide emission equivalents of the facility’s energy consumption by the total IT energy consumption.
Total site water usage
Data centers and power utilities are both major users of water. This calculation measures on-site usage including water withdrawal, evaporation, and discharge. The figure can be reduced by using reclaimed water for cooling or by returning it to the neighboring area.
Water usage effectiveness
Defined as a standard under ISO/IEC 30134-9:2022, this is the ratio of data center water consumption to the sum of energy consumed by IT equipment. It is a simple metric for reporting the water intensity of data center operations and is useful in tracking usage reductions.
Download the entire special report, "Beyond Greenwashing: Sustainability Meets Compliance," courtesy of Iron Mountain Data Centers, to learn more. In our next article, we'll key sustainability standards and regulations.
