We live in a culture where more is usually better. Bigger cars and SUVs, more choices when shopping on the web, super-sized burgers at the fast food place - and even bigger clothes to contain our bodies after we consume all the super-sized burgers!
Is bigger usually better? Is bigger better when it comes to metering and AMR? That’s what we thought in the 1980s. Keep piling on the features – the accumulators, registers, data ports, display options, tamper detection mechanisms, internal clock/calendars, interval metering capabilities, load control outputs. Competition? My feature list is longer than yours!
And then along came Enscan, a US company that had a very different idea: to stay focused on just two or three features, to keep it very simple, and to keep it cheap. They developed the ERT (Encoder Receiver Transmitter), a small battery-powered module that could be retrofitted to a gas meter in the field. It communicated with a roving vehicle or a hand-held data collector, and made it possible for a single meter reader to read 10,000 meters per shift. The product concept was equally attractive for electricity and water metering. Enscan licensed Schlumberger to offer an electric ERT to the electric power industry. ITRON later acquired the Enscan technology, and the rest is history. The ERT module is the single most successful meter reading product in the history of the utility industry. Why? Because it did just a few things well, and it did them inexpensively.
So more is not always better. When more also means more complexity, more components, more cost, we start to chase our own tails. The need is to keep it simple – to ignore the features for which there is limited demand or which can more readily be accomplished in some other way.
Two-way AMR systems have been available for 40 years. They are two-way because their designers chose a communication architecture that provided important system advantages, and two-way was part of the choice. These are valid approaches that produce fine AMR systems.
There are also very successful and widely deployed one-way AMR systems that periodically send meter data upstream, without any interrogation. Their designers opted for this one-way architecture for some of the same reasons the pioneers at Enscan did – to keep it simpler and cheaper, and still get the critical jobs done.
So what’s my point? If you are specifying an AMR/AMI system, it shouldn’t matter if that system is one-way or two-way. Specify the functions, not the implementation. There are plenty of excellent one-way, data inbound approaches to acquiring meter data. You want to talk to a thermostat? There are also plenty of very effective, inexpensive, low cost ways to get addressable outbound messages to customer locations for other applications. These alternatives – including low cost one-way outbound paging, the large installed base of VHF radio, and various techniques that take advantage of existing commercial broadcast stations’ power and range – are in productive economic use for more than 10 million points of direct control/demand response in the US. To require that any AMR system be a two-way system so that it can perform some non-AMR functions is to ‘supersize’ it—a bad idea that forecloses many other attractive system alternatives!
You will probably not be surprised to learn that the staunchest advocates of requiring that AMR/AMI systems be two-way are either manufacturers of two-way AMR systems, or unenlightened disciples of the ‘more is better’ school of thought. Mixing communication technologies to get the job done is not rocket science. In fact, most installed AMR/AMI systems are mixtures of licensed and unlicensed RF, PLC, fibre, telephone, microwave and hardwire. So the separate use of one of these technologies for outbound signalling is no stretch.
Utilities and regulators must focus on what needs to be accomplished, and avoid being unnecessarily prescriptive about how it will be accomplished. Only in this way do the technically optimum and most economical solutions rise to the top. Those who require two-way in specs or standards either have a stake in the game or are naïve to the options. Their promotion of their view is harshly exclusionary to some attractive and economical approaches. They are saying that you must do as they say or get out of the way: “Two-way, My Way or the Highway.”
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