European Standard on Energy Audits: EN16247

Vilnis Vesma explains EN16247-1:2012, the new Standard regulating the conduct of energy audits

First things first: in this context the term energy audit signifies the “systematic inspection and analysis of energy use and energy consumption of a site, building, system or organisation with the objective of identifying energy flows and the potential for energy efficiency improvements – and reporting them”. In other words, what would commonly be called an “energy survey” in the UK (or a ‘scan’ in the Netherlands or ‘diagnostic’ in France). The activity has different names, but it is this class of technical investigation and analysis that the new European Standard is seeking to harmonise.

I was involved from the outset, funded by the Energy Services and Technology Association to write an initial draft and then chair the joint working group of CEN and CENELEC, the standardisation bodies who developed the document with expert input and consultation. Our aims were several. One was to harmonise the nomenclature. Another was to create more clarity and certainty in a market where, in part thanks to naive promises from bodies providing grants and subsidies, clients usually had higher expectations than consultants could afford to satisfy in the time they were given.

Rigorous approach

After providing a list of terms and definitions, the Standard outlines the quality requirements relating to the energy auditor and the audit process, and then goes on to discuss the elements of the audit process itself. Quality requirements for the auditor include an obligation to disclose commercial conflicts of interest.

In my original draft I sought to define three levels of audit, with a quick walk-round survey at the bottom and a full investment grade audit—in other words a full feasibility study and outline design—at the top. In the event the participating countries’ experts decided that the lowest-level surveys and audits should be outside the scope of the Standard. There is nothing to stop people doing the sort of “drive-by” audit that characterises English Energy Performance Certificates, or the one-day energy surveys cranked out during the days of the Carbon Trust, but they cannot claim that these comply with EN16247. On reflection, this is a good outcome. Nor, eventually, were investment-grade audits specified separately from mid-level studies. Instead there is a general duty on the parties to agree on the required ‘depth and thoroughness’ and on the consultant to carry out the work in a manner consistent with that agreement.

The deliberate exclusion of quick surveys means that the requirements of a compliant energy audit are relatively rigorous. For example, it is mandatory to have a start-up meeting to brief all interested parties about the objectives, scope, boundaries and depth of the energy audit being undertaken. Such a meeting can obviously only be undertaken after these issues have already been discussed and agreed by the client and consultant. The Standard in fact stipulates more than a dozen other aspects of the audit which are supposed to be addressed during preliminary negotiations, ranging from the time commitment and resources required from the client to the required format of the report.

So before work on the energy audit even begins, the consultant will have already spent a day or two on what one might term “mobilisation”.

Field work, data collection and analysis

The Standard lays down requirements for data collection. These are very thorough. One of the nine categories covered is “historical data” which includes consumption data and what it calls “adjustment” factors (meaning driving factors like degree-day figures, production throughputs and the like). The client is implicitly expected to enumerate what these factors are for each energy-using system being studied, and to be able to explain how they are thought to influence consumption.

There are requirements relating to field work, which includes inspection of every object being audited. There is a general obligation on the consultant to carry out measurements and observations under appropriate conditions, which may include out-of-hours tests.

A significant section of EN16247 deals with the analysis of energy performance, firstly to establish what it is currently and secondly to enable the effect of each proposed measure to be estimated. There are requirements both for comparison of alternative solutions and for evaluating interactions between multiple actions. The analysis methods used have to be transparent and technically appropriate, and they must be documented. Both the data and the results have to be checked for validity.

Finally, following lengthy stipulations about the energy audit report and its contents, the Standard calls for a final meeting when the consultant hands over the report, presents the results “in a way that facilitates decision making”, and if asked, explains the results.

Next steps

This part of the Standard deals with everything common to all energy audits. Three further subsidiary parts are being published, focussing on the special requirements relevant to buildings, industrial processes, and transport respectively.

If EN16247 has a weakness, it is that it fails to place explicit obligations on the client. So, for example, although the consultant is obliged to “ask for drawings, manuals and other technical documentation” the client can refuse to provide them and yet—bizarrely—the audit could still comply with the Standard. This situation is the result of pseudo-legalese nit-picking by standards editors who said that a standard cannot put obligations on two different parties. Why not? I think their inflexibility undermined the intention and purpose of the document. But apart from that, EN16247 is a solid step forwards and I would like to thank all those volunteers on the working group who contributed their wisdom and experience.

Vilnis Vesma
31 October 2012