- Automatic meter reading
smart meter( [http://www.elstermetering.com/en/1914.shtml Elster REX type R15] ) with 900MHz mesh networktopology for AMR] Automatic meter reading, or AMR, is the technology of automatically collecting data from water meteror energy metering devices (water, gas, electric) and transferring that data to a central database for billing and/or analyzing.This saves employee trips, and means that billing can be based on actual consumption rather than on an estimate based on previous consumption, giving customers better control of their use of electric energy, gas usage, or water consumption.
AMR technologies include handheld, mobile and network technologies based on telephony platforms (wired and wireless), radio frequency (RF), or powerline transmission.
With touch based AMR, a meter reader carries a handheld computer or data collection device with a wand or probe. The device automatically collects the readings from a meter by touching or placing the read probe in close proximity to a reading
coilenclosed in the touchpad. When a button is pressed, the probe sends an interrogate signal to the touch module to collect the meter reading. The software in the device matches the serial number to one in the route database, and saves the meter reading for later download to a billing or data collection computer. Since the meter reader still has to go to the site of the meter, this is sometimes referred to as "on-site" AMR.
Radio Frequency Network
Radio frequencybased AMR can take many forms. The more common ones are Handheld, Mobile, and Fixed network. There are both two-way RF systems and one-way RF systems in use that use both licensed and unlicensed RF bands.
In a two-way or "wake up" system, a radio
transceivernormally sends a signal to a particular transmitter serial number, telling it to wake up from a resting state and transmit its data. The Meter attached transceiver and the reading transceiver both send and receive radio signals and data. In a one-way “bubble-up” or continuous broadcast type system, the transmitter broadcasts readings continuously every few seconds. This means the reading device can be a receiver only, and the meter AMR device a transmitter only. Data goes one way, from the meter AMR transmitter to the meter reading receiver. There are also hybrid systems that combine one-way and two-way technologies, using one-way communication for reading and two way communication for programming functions.
RF based meter reading usually eliminates the need for the meter reader to enter the property or home, or to locate and open an underground meter pit. The utility saves money by increased speed of reading, has lower liability from entering private property, and has less chance of missing reads because of being locked out from meter access.
The Technology based on RF is not readily acceptable everywhere. In several Asian countries the technology faces a barrier of regulations in place pertaining to use of the Radio Frequency of any radiated power. For example in India the Radio Frequency which is generally in ISM band is not free to use even for Low Power Radio of 10 milliwatt. Pricipally majority of manufacturer of electricity meters have radio frequency devices in the frequency band of 433/868 MHz for obvious large scale deployment in european countries.The frequency band of 2.4 GHz can be now used in india for outdoor as well as application but no maufacturer have shown products with in this frequency band. But Now Secure Meters Limited had used 2.4 ghZ frequency for meter reading. Initiatives in Radio Frequency AMR in such countries are being taken up with regulators wherever the cost of licensing outweighs the benefits of AMR.
In handheld AMR, a meter reader carries a handheld computer with a built-in or attached receiver/transceiver (radio frequency or touch) to collect meter readings from an AMR capable meter. This is sometimes referred to as "walk-by" meter reading since the meter reader walks by the locations where meters are installed as they go through their meter reading route. Handheld computers may also be used to manually enter readings without the use of AMR technology as an alternate but this will not support exhaustive data which can be accurately read using the meter reading electronically.
Mobile or "Drive-by" meter reading is where a reading device is installed in a vehicle. The meter reader drives the vehicle while the reading device automatically collects the meter readings. Often for mobile meter reading the reading equipment includes navigational and mapping features provided by
GPSand mapping software. With mobile meter reading, the reader does not normally have to read the meters in any particular route order, but just drives the service area until all meters are read. Components often consist of a laptop or proprietary computer, software, RF receiver/transceiver, and external vehicle antennas.
Fixed Network AMR is a method where a network is permanently installed to capture meter readings. This method can consist of a series of antennas, towers, collectors, repeaters, or other permanently installed infrastructure to collect transmissions of meter readings from AMR capable meters and get the data to a central computer without a person in the field to collect it.
There are several types of
network topologiesin use to get the meter data back to a central computer. A star networkis the most common, where a meter transmits its data to a central collector or repeater. Some systems use only collectors which receive and store data for processing. Others also use a repeater which forwards a reading from a more remote area back to a main collector without actually storing it. A repeater may be forwarded by RF signal or sometimes is converted to a wired network such as telephone or IP networkto get the data back to a collector.
Some manufacturers are developing
mesh networks where meters themselves act as repeaters passing the data to nearby meters until it makes it to a main collector. The Swedish city of Gothenburgis having their electric meters connected in this manner, using the ZigBeeprotocol. [ [http://www.theregister.co.uk/2007/10/05/zigbee_city/ Forget municipal Wi-Fi, welcome to Zigbee City] ] A mesh network may save the infrastructure of many collection points, but is more data intensive on the meters. One issue with mesh networks it that battery operated ones may need more power for the increased frequency of transmitting. It also requires that the meter devices be receivers as well as transmitters potentially making individual transceivercost higher. However, the additional cost may be outweighed by the savings of multiple collectors and repeater antennas and finding places to mount them.
Some fixed network systems are also capable of being installed as a hybrid AMR system where mobile and fixed network are intermixed by design. In a hybrid system, part of the system is read by fixed network, and parts may read by mobile or other technology, or both. Utilities with low density rural areas may not cost justify the fixed network infrastructure for parts of their service area, using it only for higher density zones or commercial accounts. Some hybrid networks allow reading of a meter by both methods concurrently as a source of redundancy. In the event of a failure of the network due a natural disaster, sabotage, power failure, or other network interruption, the mobile reading system is available in their disaster recovery plan as an alternative means of data collection to the fixed network.
RF technologies commonly used for AMR
* Narrow Band (single fixed radio frequency)
** Direct Sequence Spread Spectrum (DSSS)
** Frequency Hopping Spread Spectrum (FHSS)
There are also meters using AMR with RF technologies such as cellular phone data systems,
zigbee, bluetoothand others. Some systems operate with FCC licensed frequencies and others under FCC Part 15 which allows use of unlicensed radio frequencies.
The city of Corpus Christi became one of the first cities in the
United Statesto implement city wide Wi Fi, which had been free until May 31, 2007, mainly to facilitate AMR after a meter reader was attacked by a dog. [ [http://www.informationweek.com/story/showArticle.jhtml?articleID=201400236 EarthLink Dedicates Wi-Fi Network In Corpus Christi] ] Today many meters are designed to transmit using Wi Fi, even if a Wi Fi network is not available, and they are read using a drive-by local Wi Fi hand held receiver.
It is noteworthy that the meters installed in Corpus Christi are not directly Wi-Fi enabled, but rather transmit narrow-band burst telemetry on the 460 MHz band. This narrow-banded signal has a much greater range than Wi-Fi, so the number of receivers required for the project are far fewer the number of Wi-Fi access points covering the same area. These special receiver stations then take in the narrow-band signal and report their data via Wi-Fi.
Most of the automated utility meters installed in the Corpus Christi area are battery powered. Compared to narrow-band burst telemetry, Wi-Fi technology uses far too much power for long-term battery-powered operation.
Power Line Communication
(PLC) AMR is a method where electronic data is transmitted over power lines back to the substation, then relayed to a central computer in the utility's main office. This would be considered a type of fixed network system -- the network being the distribution network which the utility has built and maintains to deliver electric power. Such systems are primarily used for electric meter reading. Some providers have interfaced gas and water meters to feed into a PLC type system.
The primary driver for the automation of meter reading, is not so much to reduce labor costs, but to obtain data that is otherwise unattainable. Many meters, especially water meters, are located in areas that require an appointment with the homeowner. Gas and Electricity tend to be more valuable commodities than water, and the need to offer actual readings instead of estimated readings can drive a utility to consider automation. While early systems consisted of walk-by, and drive-by AMR for residential. Telephone based AMR served well for commercial or industrial accounts. What was once a need for monthly data became a need for daily and even hourly readings of the meters. Consequently, the sales of drive-by and telephone AMR has declined in the US, while sales of fixed networks has increased. The US Energy Policy Act of 2005 asks that electric utility regulators consider the support for a "...time-based rate schedule "(to)" enable the electric consumer to manage energy use and cost through advanced metering and communications technology." [ [http://www.epa.gov/oust/fedlaws/publ_109-058.pdf] US Congress, Energy Policy Act of 2005] The trend now is consider the use of advanced meters as part of an
Advanced Metering Infrastructure.
Advanced AMR and AMI
Originally AMR devices just collected meter readings electronically and matched them with accounts. As technology has advanced, additional data could then be captured, stored, and transmitted to the main computer, and often the metering devices could be controlled remotely. This can include events alarms such as tamper, leak detection, low battery, or reverse flow. Many AMR devices can also capture interval data, and log meter events. The logged data can be used to collect or control time of use or rate of use data that can be used for water or energy usage profiling, time of use billing, demand forecasting, demand response,
rate of flowrecording, leak detection, flow monitoring, water and energy conservation enforcement, remote shutoff, etc. Advanced Metering Infrastructure, or AMI is the new term coined to represent the networking technology of fixed network meter systems that go beyond AMR into remote utility management. The meters in an AMI system are often referred to as smart meters, since they often can use collected data based on programmed logic.
The Automatic Meter Reading Association (AMRA) endorses the National Association of Regulatory Utility Commissioners (NARUC) resolution to eliminate regulatory barriers to the broad implementation of advanced metering infrastructure (AMI). The resolution, passed in February 2007 [ [http://www.naruc.org/Resolutions/res.to.remove.regulatory.barriers.to.the.broad.implementation.of.advanced.metering.infrastructure.pdf Resolution to Remove Regulatory Barriers To the Broad Implementation of Advanced Metering Infrastructure] (from [http://www.naruc.org/resolutions.cfm?action=doit&AdoptedDate=2007-02-21&committeeID=50&criteria= NARUC Committee on Energy Resources and the Environment Resolutions of 2007-02-21] )] , acknowledged the role of AMI in supporting the implementation of dynamic pricing and the resulting benefits to consumers. The resolution further identified the value of AMI in achieving significant utility operational cost savings in the areas of outage management, revenue protection and asset management. The resolution also called for AMI business case analysis to identify cost-effective deployment strategies, endorsed timely cost recovery for prudently incurred AMI expenditures and made additional recommendations on rate making and tax treatment of such investments.
Benefits of Advanced Metering
Advanced Metering systems can provide benefits for utilities, retail providers and customers. Benefits will be recognized by the utilities with increased efficiencies, outage detection, tamper notification and reduced labor cost as a result of automating reads, connections and disconnects. Retail Providers will be able to offer new innovative products in addition to customizing packages for their customers. In addition, with the meter data being readily available, more flexible billing cycles would be available to their customers instead of following the standard utility read cycles. With timely usage information available to the customer, benefits will be seen through opportunities to manage their energy consumption and change from one REP to another with actual meter data.
Construction practices, weather, and the need for information drive utilities in different parts of the world towards AMR at different rates. In the US, there have been significant fixed network deployments of both RF based and PLC based technologies [ [http://www.pplelectric.com/NR/rdonlyres/202A6200-A8EE-4433-9FDA-0DA738570592/0/StatementofReasons.pdf] PPL 1.3 million residential and commercial electric meters] . Some countries have either deployed or plan to deploy [ [http://tdworld.com/customer_service/power_swedish_utility_amr/] Sweden, (Vattenfall) 850k meters] AMR systems throughout the entire country.
AustraliaAMI in Australia has grown from both government policy, seeking to rectify observed market inefficiencies and distribution businesses, seeking to gain operational efficiencies. Currently (July 2008), there is a mandated program being planned in Victoria with a planned deployment of 2.6 million meters over a 4 year period. The anticipated peak installation rate of AMI Meters is 5,000 per day across Victoria. The program governance is provided by an Industry Steering Committee.
Addition Notable Deployments
[http://www.puc.state.tx.us/electric/projects/34610/Commission_Report_on_Advanced_Metering.pdf] PUCT Report 2006; Pennsylvania, (Exelon-PECO) 2.2 million meters deployed; Missouri, (Ameren) 1.7 million meters deployed.
Nonintrusive load monitoring
Power line communication
* [http://www.utilimetrics.org Utilimetrics - "Alliance for advanced metering and data management solutions"] (Formerly the "Automatic Meter Reading Association") - Non-profit industry trade association
Meter Solutions Pros - Professional Installers of Water Gas and Electric Meters - [www.metersolutions.com]
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