Metering Systems have changed in 10 years
So – it was good for the meter manufacturers, but was it good for the energy manager, and equally importantly was it good for the country’s carbon footprint, the downsizing of which Part L2 was ultimately designed to achieve? The government of the day clearly recognised that was going to be a tough call and the “General Information Leaflet 65” (GIL65) which was published as a guide to the then new Building Regulations made it clear from the outset that installing sub-meters is the easy bit. In an uncharacteristically forthright opening statement the leaflet admits that “Metering per se does not save energy”. However, in a rather more positive note it then goes on to describe how savings of 5-10% can be expected, with improvements of up to 60% in some cases, if a metering strategy is employed by energy managers There then follows over twenty pages of just what those in the corridors of power considered a “metering strategy” to be back in 2000. In fact GIL65 contains a lot of good information and is well worth reading if you’re installing sub-metering for energy management or you want to get the best out of the meters you already have, but it is lacking in one specific area. Automatic meter reading (AMR) was then, and remains now, aspirational rather than mandatory, so a large proportion of the guidance deals with how to work around a lack of AMR, rather than how to best implement this essential additional ingredient to monitor and potentially reduce energy usage
All the benefits of sub-metering espoused in GIL65 - the benchmarking, the waste elimination, the evaluation of pilot schemes and the on-going monitoring of energy saving projects have been shown to be real, and these successes have in turn produced further meter-based strategies for improving energy efficiency and reducing carbon footprints across the board. Systems offering realtime meter displays and reduce energy management dashboards are encouraging ‘behavioural change’ – the holy grail of energy management, but like the effective sub-metering systems that preceded them, these new weapons in the fight to reduce carbon emissions rely on one thing – effective AMR. There is an old cliché that says something like “stand-alone meters gather dust, AMR meters gather data” but as clichés tend to be, it’s basically true. As one might expect, the UK has seen significant growth in the number of sub-meters installed since 2000, but unfortunately a large proportion of those meters has yet to make a positive contribution to energy and carbon management because they have no AMR connection.
So what went wrong? Why aren’t all these meters attached to a suitable data acquisition system, if the concept is so well proven? Considering the number of retrofitted AMR systems installed by the likes of Elcomponent, it seems on the face of it, that adding AMR to meters that are being installed anyway would be far more prevalent than it actually is. Perhaps predictably, the answer is not straightforward, but we are getting to grips with the issue. It’s not really about the data collection itself – Elcomponent’
Surely we should therefore expect that brand new meters installed because they have to be will be data-connected by default? Yes and no… In fact, where new-build is concerned, and a BMS is available, meters usually are connected either to the BMS or a dedicated AMR system, but where existing plant rooms are refurbished or old switchgear replaced with new, the meters often stay in glorious isolation, giving no insight on how to monitor and reduce carbon output. Unfortunately it is not yet part of our psyche that a meter – any meter – must connect to a data acquisition system. We fit meters because the regulations require it, but we do not always see things through to a logical conclusion. The reasons are many and varied; the number of different trades between the meter itself and the energy manager’s PC screen is one, and the lack of standard interface between meter and system is another. A pulse output is as standard as it gets but there are as many pulse output specifications as there are MODBUS register options, or data file formats. It can be bewildering and because meters are not an intrinsic part of the building infrastructure they tend to end up at the bottom of the list, if indeed they are on the list at all. The HVAC has to work, or the building is effectively unusable, but getting the AMR system right has less immediate consequences. Those consequences may ultimately be at least as critical in providing opportunity for reduce energy reduction, but less immediately obvious.
But we are making progress… the roll-out of smart metering at the fiscal level has made the whole subject of reading meters remotely significantly more ‘mainstream’
AMR, when combined with Monitoring and Targeting software - otherwise known as aM&T if you’ll forgive yet another acronym - is proven, and the impact of the Part L requirements over the last ten years has ensured we have more sub-meters than ever before.
Seems a shame to waste them…..
Photo:
http://www.prlog.org/
