Further update on the European MID


Further update on the European MID

A previous article in Smart Energy International (Issue 3 2005) reported on developments with the Measuring Instruments Directive (MID), which applies to the placing on the European market and putting into use of a wide range of measuring instruments subject to metrological controls, including electricity, gas, water and heat meters. The MID comes into force in October 2006 and this article gives an update on activities being carried out in preparation, mainly relating to electricity meters. The views expressed are those of the author.

The MID will establish a Measuring Instruments Committee (MIC) with powers to agree normative references which presume conformity and to amend the requirements of the instrument-specific Annexes. This committee cannot meet until the MID comes into force, but an interim ‘working group’, convened by the European Commission, met in January 2005 with the aim of coordinating work on guidelines being prepared by WELMEC (see later) to interpret the MID requirements in particular cases. This group is to meet again on 25 September to review progress.


The MID must be transposed into the laws of individual Member States, and proposals should have been ready for Commission agreement in April this year. A metering group of EURELECTRIC – the trade association for the European electricity utilities – has been observing general progress as regards legislation for electricity meters, and it is understood that several Member States are having difficulty in meeting the timescales.

In the UK work for gas and electricity meter legislation has been progressing through National Weights and Measures Ltd (NWML) advised by the regulator (Ofgem). For gas meters, NWML has formally notified the Commission regarding the enabling regulations, on the basis that the proposals for in-service error limits involve a significant policy change which will be subject to a 3-month standstill. There is no such problem for electricity meters, and draft regulations have been circulated for comment; the final version was published recently.


On a general level both sets of regulations will set out a framework for the designation of notified bodies to carry out conformity assessment and the performance of market surveillance to ensure that non-conforming products are not placed on the market. At a more detailed level, the electricity regulations will presume that a MID-compliant meter meets the existing primary legislation requiring all UK meters to be approved and certified (verified), and will set out the in-service accuracy limits which such meters must meet, related to the maximum permissible errors of the MID. They will also specify that the MID will not apply in the UK for metering of customers taking above 100kW demand.


Assessment of conformity to the MID is assisted by reference either to European standards which interpret them, or – unusually for a ‘new approach’ European directive – to other international normative documents.

Both CEN (for gas) and CENELEC (for electricity) obtained a formal mandate from the Commission to produce standards in support of the MID. CENELEC has produced three new standards – EN 50470-1, 50470-2 and 50470-3 – interpreting accuracy requirements, and earlier this year these were given a positive vote by national committees. The Commission’s expert has examined them to ensure they cover the essential and particular requirements of the MID, and has given a favourable opinion.

The next step will be to publish them in the EU’s official journal, following which conformity to the MID may be presumed for products complying with them as regards metrology. As regards other aspects such as reliability (durability) and inspection testing, reference may be made to IEC standards which are now being reviewed by working groups of IEC TC13.


The other body able to produce normative references for the MID is OIML (the international organisation of legal metrology representatives) which has continued work on update of its international recommendations (IRs), including IR46 for electricity meters. This is now at the third redraft stage, and comments have been invited ahead of the next meeting of the WG, expected to be in autumn 2006. The mechanism for presumption of conformity differs from the ‘CENELEC route’ in that the MIC must identify those parts of the IRs which meet the specific requirements of the MID, and publish them in the official journal. This cannot be done until the MIC is formed, but WELMEC groups have begun a cross-referencing exercise.

WELMEC, the Western European Legal Metrology Co-operation, is a voluntary grouping of representatives of European legal metrology bodies whose role is to exchange information to promote consistency of legal metrology practice and, where appropriate, to issue guidelines. This role is assuming great importance as a vehicle for providing interpretations of the MID, and WELMEC has reviewed its structure and assigned various aspects of the MID to working groups. Some of these are general for a range of measuring instruments – for instance relating to procedures for notified bodies – but two are directly relevant to metering:

  1. WG7, which deals with how software conformity can be assessed.
  2. WG11, which deals with ‘utility meters’. WG7 has produced recommendations in the form of a general guide and some specific proposals for simple electricity meters. WG11 – which last met in London on 28/29 July – is still working on guidelines relating to interpretation of aspects of the specific annexes for gas, electricity, water and heat meters, and has been producing cross references of MID requirements to relevant clauses of OIML IRs, essentially to be used by the MIC when it is convened.


The MID is not the only piece of legislation affecting electricity metering in Europe! In May this year the Energy End Use Efficiency and Energy Services Directive (ESD) was adopted. Article 13 of this requires utility suppliers, under certain conditions, to provide time of use metering so that customers can make more informed choices about energy usage than are provided by a ‘basic’ meter. As yet the exact impact of this is not clear, and it has passed to individual Member States to interpret what is required in their own legislation.

This coincides with an increasing general interest across Europe in how so-called ‘smart meters’ might assist in meeting Member States’ environmental policy targets.

Further reports on the MID and the ESD will feature in sessions at Metering Europe, to be held in Copenhagen from 10-12 October 2005. The concept of ‘smart meters’ is also a major theme of the conference.