Industry comment by Craig Mellor, Director, Deer Technology Ltd
Automated meter reading for monitoring consumption of water and electricity (sub-metering) provides better data visibility than conventional analogue meters that are read manually. Meters that must be read manually can be particularly problematic if they are difficult to access or their location is unknown. Customers dislike bills that are based on estimates because the meter has not been read.
Even where meters are read regularly, whether that is annually, quarterly, or monthly, patterns of consumption and trends can be hard to identify. In contrast, automated meter reading (AMR) systems providing half-hourly readings give a far better picture of consumption that enables usage patterns to be analysed – but is the information reliable and can it be relied on for accurate billing?
Depending on the utility and the design of the meter itself, different technologies can be used to generate the data for AMR (also sometimes referred to as automatic meter reading or advanced meter reading). The base assumption is that the meter itself is accurate, or at least sufficiently accurate that recalibration is not necessary during its operating life, which might be 10 years for an electricity meter and 25 years for a water meter. However, AMR systems that rely on a rotating magnet to actuate a reed switch and generate a pulsed output can suffer from a problem known as drift. This is because the magnet does not actuate the reed switch 100 per cent reliably, so the number of pulses generated is often slightly less than it should be. As a result, the AMR system can under-read, which is why periodic confirmatory manual reads are required. Under-reading is detrimental to the retailer’s cashflow, while customers dislike receiving occasional bills that are higher than expected because they are based on manual reads rather than those from the AMR system. Over-reading is also problematic, though not as common as under-reading.
Another issue with many water AMR systems is that although there is no need for the meter to be read manually, it is still necessary to collect ‘drive by’ readings. This requires a reading device installed in a vehicle, to identify meters and their readings and ensure customers are billed correctly.
However, such mobile meter reading, as with manual reads, is dependent on a person and a vehicle. This is relatively costly and, furthermore, the vehicle emits polluting exhaust gases. Utilities retailers are under pressure to improve their green credentials, so they are eager to find ways to reduce their use of vehicles. With self-driving electric vehicles not yet market-ready, the preference is to eliminate the need for vehicles.
An alternative to the drive-by system is an AMR device that automatically transfer the pulse output data to a centralised database. This reduces the number of person/vehicle visits but does not eliminate them because this type of system does not satisfy the non-household market code for readings. Manual (visual) check reads are still required at least annually due to the AMR devices’ potential for drift.
One other issue with AMR systems that is of concern to both retailers and consumers is the installation cost. Typically, it costs around £1000 to £1500 to install a conventional AMR device. If a business or landlord is considering installing AMR for submetering, the costs can quickly become prohibitive. Moreover, some meters cannot be retrofitted with AMR, meaning they must be replaced at even greater expense, and with the added inconvenience of supply interruption.
Clearly AMR systems do not solve all the meter reading problems for end users or retailers. Smart metering has often been portrayed as a panacea, particularly for electricity metering, but smart metering has limitations too. First-generation SMETS1 meters quickly gained a reputation for not being user-friendly when households switched supplier, and now SMETS2 meters are being found to have issues, particularly when switching supplier. In the non-household (NHH) market, consumers are sometimes charged relatively high fees for accessing the data from smart meters, which negates some if not all the benefits that can accrue from efficiency savings.
Fortunately, there is another way to improve access to water and electricity consumption data, and the same technology will be available for gas meters soon. Deer Technology’s LimpetReader is a cost-effective, battery-powered opto-electronic device that attaches to the meter’s faceplate with optical tape or adhesive. Installation takes around 10 minutes, with no need to dismantle the meter or interrupt the supply, and the meter’s register remains visible should a visual read be necessary. Dual-register meters are fitted with two LimpetReaders to capture readings from both registers. The LimpetReader is battery-powered, maintenance-free, and immune to drift because it simply reads the value displayed by the meter. If a LimpetReader was removed or tampered with, this would be identifiable from the data output.
For regulatory purposes, the patented LimpetReader is unique among automated reading systems in that readings are classified as ‘visual’. This means suppliers never need to send anyone to read the meter manually.
To make the LimpetReader as compact as possible, it incorporates multiple micro-cameras for imaging the register. The images are date- and time-stamped before being transmitted to Deer Technology’s secure server by an AutoReader transmitter.
Images are sent over any of the UK’s four mobile phone networks using proven, reliable 2G (GSM) technology – though 4G and 5G systems are currently in development and a Wi-Fi option is also available. In the event of a network outage, the LimpetReader devices can be read locally via Bluetooth using an Android app on a smartphone or tablet, or with a low-cost dedicated handheld reader. Multiple LimpetReaders can be linked to a single AutoReader transmitter, which can be ideal for some submetering applications.
Once on the server, the images are stitched together to create a high-quality, distortion-free image of the meter’s register. This is then decoded into a numerical value, which is stored together with the high-quality image of the register. Data and images can be accessed by the customer in a variety of ways, depending on the requirements. For instance, an API (application programming interface) can be provided, data sent as spreadsheet files, or dashboards created for high-quality reporting.
Deer Technology provides a comprehensive service covering everything from meter installation through to data management. The service starts with a customer consultation to establish the optimum overall solution to the problem of meter reads and data management. Deer Technology installs the LimpetReaders and AutoReaders, then provides a data service for reporting, visualisation and delivering data to the customer’s databases as required. In many cases, the cost of using the intelligent LimpetReader system is less than retailers charge for accessing smart meter data, so there can be advantages in installing LimpetReaders even if smart metering has already been implemented. It is estimated that 99 per cent of all the electricity sub-meters and water meters currently in use in the UK could be retrofitted with LimpetReaders.
A helpful feature of Deer Technology’s system is that the reading frequency is normally set at monthly intervals, but customers can request other frequencies. For example, if electricity consumption patterns are to be investigated, quarter- or half-hourly meter readings could be requested during normal operating hours. For checking water consumption, meter readings could be requested at the start and end of each working day, enabling potential leaks to be identified through excessive overnight consumption. In contrast, conventional AMR systems on water meters can generate vast amounts of data that are difficult to manage.
If a meter is classified as long unread, the LimpetReader is attractive because the meter only has to be accessed once for the device to be installed. After that, it never needs to be accessed again. Compared with alternative technologies, therefore, it is worth making the extra effort to locate and access long unread meters because it only has to be done once. It is also quicker and easier to fit the LimpetReader than to retrofit other AMR technologies or swap the meter for a smart meter.
Find out more about Deer Technology’s LimpetReader for converting analogue meters to smart meters or for use alongside smart metering at www.deertechnology.com, telephone 01639 363146 or email hello(Replace this parenthesis with the @ sign)deertechnology.com.