It is not surprising given the pressures towards greater energy efficiency that facilities in 2009 appear more efficient than those reported in research in 2007. The modal PUE rating has moved year-on-year below 2.00 to lie within the 1.85-1.90 range by 2009. The proportion of facilities above 2.00 has moved by last year from over 50% closer to 40% while the proportion below 1.50 has increased. A strong indication of the industry's most recent paradigm shift but possibly not as emphatic as the continued priority given to increasing energy efficiency would suggest or the urgency with which in most markets it is now being considered. Yet there are a number of factors which contribute to the restrained improvement indicated by research.

Firstly, the sample base in 2009 includes almost eight times as many facilities as in 2007, while comparatively only twice as many respondents completed questionnaires. So, the PUE metric has gained greater industry currency and a greater application across facility portfolios.

Secondly, the process of (where possible) validating research findings against other sources of industry information suggest that the attitude towards the PUE and towards sharing of information on it has changed and moved from something akin to 'a badge of honour'towards a more balanced situation in terms of sharing both good and less good results. This seems linked to the process whereby metrics of this kind have gained currency as measures specific to the particular facility which can be tracked over time and in the context of actions taken in regard to that facility, rather than as a broader and imposed 'judgement'on the facility and its management.