On 30 October 2008, the European Commission issued the new Code of Conduct on Data Centres Efficiency ("the Code") along with an introductory guide and a set of best practice guidelines for industry to follow.

All of the above was in response to a growing awareness that data centres are fast becoming a major source of energy consumption and therefore a major contributor to carbon emission levels.

Electricity consumption as a whole in Western Europe is estimated to increase from a level of 56 Terawatt hours ("TWh") per year in 2007 to 104 TWh per year by 2020, with data centre power consumption playing a major part in this increase.

To put data centre power consumption into perspective, it is estimated that in Western Europe, servers are now the second largest users of electricity behind television sets and in Germany alone, the level of power consumed by servers will double from 2005 levels by 2010.

This all creates a powerful argument that businesses can no longer afford to ignore the implications of inefficient data centres from both a cost and environmental perspective.

The Code

For the purposes of the Code, a 'data centre' has been defined as including 'all buildings, facilities and rooms which contain enterprise servers, server communication equipment, cooling equipment and power equipment and provide some sort of data service'.

The Code focuses on two main areas. These are:

  1. IT Load – which looks at the consumption efficiency of the IT equipment in the data centre and can be described as 'the IT work capacity available for a given IT power consumption'. An example of this could be Mips1 per watt.
  2. Facilities Load – which looks at mechanical and electrical systems that support the IT infrastructure and includes such things as cooling systems (chiller plants, fans and pumps), air conditioning units, Uninterruptable Power Supplies and Power Distribution Racks.

The Code is concerned with the efficiency of the data centre as a whole and the assets within the data centre. In order to do this, it looks at the 'facility efficiency rating' and the 'asset efficiency rating' of a data centre.

This analysis feeds into an overall Data Centre Infrastructure Efficiency ("DCiE") measurement, which is the main reporting metric, which will show the percentage of power consumed by a data centre in producing useful IT services – with a higher figure providing an indication of better efficiency for that particular facility. This is expressed in the following calculation:

 DCiE = main IT equipment energy consumption / total facility energy consumption2 x 100%

It is expected that future versions of the Code will have additional measures which will include an IT productivity metric, which will provide an indication of how efficiently IT equipment provides IT services, and also a total energy productivity metric, which will look at the total energy consumption of the facility compared to the amount of useful IT services it produces.

The Code is a voluntary code and is aimed at data centre owners and operators who can elect to become 'Participants´ and also provides other entities who work with or contribute to data centres the ability to elect to become 'Endorsers' of the Code.  

As a 'Participant', data centre owners and operators commit to a range of best practices that are outlined in the supporting best practice guidelines. This document contains a full list of best practices and categories of efficiencies that data centre owners and operators should concentrate on achieving, in order to achieve a meaningful contribution to a more efficient data centre.

The list also sets out guidance as to which categories are expected to be achieved if the data centre owners and operators are to maintain their 'Participant' status.

The main categories of efficiencies are:

  • data centre utilisation, management and planning;
  • IT equipment and services;
  • Cooling (air flow management and design, temperature and humidity levels etc);
  • data centre power equipment;
  • data centre building;
  • and monitoring.

Within these categories, there are various sub categories, some of which are, as set out above, expected to be undertaken.

So, by way of further example, a 'Participant' would have to ensure that in relation to data centre utilisation, management and planning, it should carry out an audit of 'existing equipment to maximise any unused existing capability by ensuring that all areas of optimisation, consolidation and aggregation are identified prior to new material investment'.

In addition, each category has an indication (rated 1 – 5, with 5 being the maximum value) of the expected level of benefit from each activity set out in the various categories, which also serves to provide some sense of priority for data centre owners and operators who elect to become 'Participants'.

As for 'Endorsers', these can be vendors, consultancies, utilities, Government, industry associations or educational institutions who wish to apply and who are expected to use the Code in order to develop products, solutions and programmes to provide help, assistance and best practice guidelines to data centre owners and operators to assist them in meeting the expectations of the Code.

The role of the 'Endorser' is very much seen as one of supporting the aims of the Code and encouraging its customers to sign up to the Code as 'Participants'.

Data collection and analysis

The Code also provides for a level of monitoring to be undertaken by 'Participants' and 'Endorsers' who are expected to report periodically on their activities and the level of achievement of the targets set out in the best practice guidelines.

'Participants' are expected to report monthly to the Data Collection Working Group within the European Commission. This working group will then collate and perform analysis of the results, provide reports on the data centre energy efficiencies being achieved and establish a regime of performance benchmarking going forward. 


The Code is a first attempt by the European Commission to bring about a greater degree of realisation of the cost of inefficiently run data centres, both from a business perspective and the environmental costs.

The hope is that the Code becomes a de facto standard which will be followed by all data centre owners and operators and encourage them to take control of their own facilities – before the situation becomes so serious as to require mandatory regulation, reporting and targets.

Useful links  

The Code:

Best practice guidelines:

Introductory guide for applicants: