The Carbon Footprint of Servers

What is the carbon footprint of your company’s servers? And how easy is it to find out? By sorting out a few questions regarding your company’s servers, you can get a rough estimate of your servers climate impact.
Server hall

Last updated: 2024-05-13


There are two factors that you need to take into consideration when estimating the climate impact of your servers; 1. if the electricity used is green or not 2. if the servers are in the cloud or not.

When calculating the emissions from your servers, there are four categories to take into consideration to make a rough estimate:

  • Cloud server using 100% green electricity: 160 kg CO2e / year and server
  • Cloud server using non-green electricity: 487 kg CO2e / year and server
  • On premise or data center-server using 100% green electricity: 320 kg CO2e / year and server
  • On premise or data center-server using non-green electricity: 975 kg CO2e / year and servers.

You find the calculations and assumptions for these numbers further down at this page

How do I know if the electricity our servers are using is 100% green?

With green electricity we mean fossil free electricity, so both renewable energy sources and nuclear energy are considered green – and are in our calculations considered having a zero climate impact. This is not 100% true since both renewable sources and nuclear sources have a carbon footprint from construction and maintenance, but the climate impact is negligible in comparison with electricity from fossil sources. Depending on where your servers are located, there are different ways of finding out if the electricity your servers use is green:

  • On premise-server – check your electricity contract or contact your electricity-provider
  • Data center-server – check your contract or contact your provider
  • Cloud servers - see table beneath, source The State of Data Center Energy Use in 2018 (updated 2020)
Cloud providerGradeSustainable servers?
GoogleA-100% with offsets today, with commitment to ‘real time matching’ (i.e. no carbon release)
AzureA-100% with offsets and energy certificates today, with commitment to be carbon negative by 2030
AWSC-100% with offsets only in four public regions today, elsewhere unknown with estimates in the less than 30-50% range. New commitment to carbon neutrality by 2030 and carbon zero (no carbon release) by 2040. The rating here would be higher but for the continuing lack of transparency on energy usage.
OracleC-100% with offsets in a few regions <30% overall
IBMC-~50% overall
AlibabaD-Unknown but China a major market, and not known what energy is purchased

How do I know if my servers are in the cloud?

This might sound like an easy question, but there are many local providers that have smaller cloud-like solutions that might be as energy effective and utilize servers as good as the larger ones. So the question you should ask yourself here – if you are unsure if your servers can be considered being in the cloud or not – is if your provider can utilize servers about as effectively as the larger providers and if they can have the same energy efficiency as the larger ones.

Calculations and assumptions

An on-premises data center is 29 % less efficient in their use of power compared to a typical large cloud provider that uses top facility designs, cooling systems, and workload-optimized equipment. Source: Wikipedia: Power usage effectiveness We have decided to apply a simple factor of 0.5 for the energy consumption and server utilization of servers in the cloud. Amazon AWS claims a reduction of 84% in the amount of power required, but since we don’t have data for other providers we prefer to be a bit more conservative here. We have used the Nordic Residual Energy mix as the factor for CO2e emissions per kWh. The factor is 0,37199 CO2e / kWh (updated 2022). The reason for us using this is that most businesses using our calculator are expected to be in the Nordics.

So, if we use these number and assumptions from above:

  • Emissions from production of servers for use on premise: 320 kg CO2e/year
  • Emissions from production of servers for use in cloud (since 50% is manufactured for use in cloud): 160 kg CO2e/year
  • Emissions from green power consumption: 0 kg CO2e/year
  • Emissions from non-green consumption for premise power or self-managed servers: 1760,3 kWh / year * 0,37199 CO2e / kWh = 655 kg CO2e
  • From non-green cloud power consumption: 1760.3 kWh / year * 0,37199 CO2e / kWh * 0,5 = 327 kg CO2e

This results in these factors for our four categories:

1. Cloud server using 100% green electricity: 160 kg CO2e / year and server 2. Cloud server using non-green electricity: 487 kg CO2e / year and server 3. On premise or data center-server using 100% green electricity: 320 kg CO2e / year and server 4. On premise or data center-server using non-green electricity: 975 kg CO2e / year and servers.

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