A smart meter is an electronic device that records consumption of electric energy in intervals of an hour or less and communicates that information at least daily back to the utility for monitoring and billing. Smart meters enable two-way communication between the meter and the central system. Unlike home energy monitors, smart meters can gather data for remote reporting. Such an advanced metering infrastructure (AMI) differs from traditional automatic meter reading (AMR) in that it enables two-way communications with the meter.
The term Smart Meter often refers to an electricity meter, but it also may mean a device measuring natural gas or water consumption.
Similar meters, usually referred to as interval or time-of-use meters, have existed for years, but "Smart Meters" usually involve real-time or near real-time sensors, power outage notification, and power quality monitoring. These additional features are more than simple automated meter reading (AMR). They are similar in many respects to Advanced Metering Infrastructure (AMI) meters. Interval and time-of-use meters historically have been installed to measure commercial and industrial customers, but may not have automatic reading.
Research by Which?, the UK consumer group, showed that as many as one in three confuse smart meters with energy monitors, also known as in-home display monitors. The roll-out of smart meters is one strategy for energy savings. While energy suppliers in the UK could save around £300 million a year from their introduction, consumer benefits will depend on people actively changing their energy use. For example, time of use tariffs offering lower rates at off-peak times, and selling electricity back to the grid with net metering, may also benefit consumers.
The installed base of smart meters in Europe at the end of 2008 was about 39 million units, according to analyst firm Berg Insight.Globally, Pike Research found that smart meter shipments were 17.4 million units for the first quarter of 2011. Visiongain has determined that the value of the global smart meter market will reach $7bn in 2012.
Smart meters may be part of a smart grid, but alone, they do not constitute a smart grid.
Of all smart meter technologies, one critical technological problem is communication. Each meter must be able to reliably and securely communicate the information collected to some central location. Considering the varying environments and locations where meters are found, that problem can be daunting. Among the solutions proposed are: the use of cell and pager networks, satellite, licensed radio, combination licensed and unlicensed radio, and power line communication. Not only the medium used for communication purposes, but also the type of network used, is critical. As such, one would find: fixed wireless, mesh network or a combination of the two. There are several other potential network configurations possible, including the use of Wi-Fi and other internet related networks. To date no one solution seems to be optimal for all applications. Rural utilities have very different communication problems from urban utilities or utilities located in difficult locations such as mountainous regions or areas ill-served by wireless and internet companies.
In addition to communication with the head-end network, smart meters may need to be part of a Home Area Network which can include an In-Premises Display and a hub to interface one or more meters with the head end. Technologies for this network will vary from country to country but include Power line communication and ZigBee.
ANSI C12.18 is an ANSI standard that describes a protocol used for two-way communications with a meter, mostly used in North American markets. The C12.18 standard is written specifically for meter communications via an ANSI Type 2 Optical Port, and specifies lower-level protocol details. ANSI C12.19 specifies the data tables that will be used. ANSI C12.21 is an extension of C12.18 written for modem instead of optical communications, so it is better suited to automatic meter reading.
IEC 61107 is a communication protocol for smart meters published by the IEC that is widely used for utility meters in the European Union. It is superseded by IEC 62056, but remains in wide use because it is simple and well-accepted. It sends ASCII data using a serial port. The physical media are either modulated light, sent with an LED and received with a photodiode, or a pair of wires, usually modulated by EIA-485. The protocol is half-duplex. IEC 61107 is related to, and sometimes wrongly confused with, the FLAG protocol. Ferranti and Landis+Gyr were early proponents of an interface standard that eventually became a sub-set of IEC1107.
The Open Smart Grid Protocol (OSGP) is a family of specifications published by the European Telecommunications Standards Institute (ETSI) used in conjunction with the ISO/IEC 14908 control networking standard for smart metering and smart grid applications. Millions of smart meters based on OSGP are deployed worldwide. Numerous major security flaws in the OSGP protocol have been identified.
There is a growing trend toward the use of TCP/IP technology as a common communication platform for Smart Meter applications, so that utilities can deploy multiple communication systems, while using IP technology as a common management platform. A universal metering interface would allow for development and mass production of smart meters and smart grid devices prior to the communication standards being set, and then for the relevant communication modules to be easily added or switched when they are. This would lower the risk of investing in the wrong standard as well as permit a single product to be used globally even if regional communication standards vary.
Some smart meters may use a test IR LED to transmit non-encrypted usage data that bypasses meter security by transmitting lower level data in real time.
2. Data management
The other critical technology for Smart Meter systems is the information technology at the utility that integrates the Smart Meter networks with the utility applications, such as billing and CIS. This includes the Meter Data Management system.
It also is important for Smart Grid implementations that power line communication (PLC) technologies used within the home over a Home Area Network (HAN), are standardized and compatible. The HAN allows HVAC systems and other household appliances to communicate with the smart meter, and from there to the utility. Currently, there are several broadband or narrowband standards in place, or being developed, that are not yet compatible. In order to address this issue, the National Institute for Standards and Technology (NIST) established the PAP15 group, which will study and recommend coexistence mechanisms with a focus on the harmonization of PLC standards for the HAN. The objective of the group is to ensure that all PLC technologies selected for the HAN will coexist as a minimum. The two main broadband PLC technologies selected are the HomePlug AV / IEEE 1901 and ITU-T G.hn technologies. Technical working groups within these organizations are working to develop appropriate coexistence mechanisms. The HomePlug Powerline Alliance has developed a new standard for smart grid HAN communications called the HomePlug Green PHY specification. It is interoperable and coexistent with the widely deployed HomePlug AV technology and with the new IEEE 1901 global standard and is based on Broadband OFDM technology. ITU-T commissioned in 2010 a new project called G.hnem, to address the home networking aspects of energy management, built upon existing Low Frequency Narrowband OFDM technologies.
Google.org's PowerMeter, until its demise in 2011, was able to use a smart meter for tracking electricity usage, as can eMeter's Energy Engage as in, for example, the PowerCentsDC(TM) demand response program. Google PowerMeter was retired in September 2011.
Implementing security protocols that will protect these devices from malicious attacks and new exploits has been a problematic task due to their limited computational resources and long operational life spans.
The current version of IEC 62056 includes the possibility to encrypt, MAC or sign the meter data.
One proposed smart meter data verification method involves analyzing the network traffic in real time to detect anomalies using an Intrusion Detection System (IDS) By identifying exploits as they are being leveraged by attackers, an intrusion detection system (IDS) will mitigate the suppliers' risks of energy theft by consumers and denial-of-service attacks by hackers. Energy utilities will have to choose between a centralized IDS, embedded IDS, or dedicated IDS depending on the individual needs of the utility. Researchers have found that for a typical advanced metering infrastructure, the centralized IDS architecture is superior in terms of cost efficiency and security gains.
In the United Kingdom, the Data Communication Company, which transports the commands from the supplier to the smart meter, performs an additional anomality check on commands issued (and signed) by the energy supplier.
4. Advanced metering infrastructure
Advanced Metering Infrastructure (AMI) are systems that measure, collect, and analyze energy usage, and communicate with metering devices such as electricity meters, gas meters, heat meters, and water meters, either on request or on a schedule. These systems include hardware, software, communications, consumer energy displays and controllers, customer associated systems, Meter Data Management (MDM) software, and supplier business systems.
Government agencies and utilities are turning toward advanced metering infrastructure (AMI) systems as part of larger “Smart Grid” initiatives. AMI extends current advanced meter reading (AMR) technology by providing two way meter communications, allowing commands to be sent toward the home for multiple purposes, including “time-of-use” pricing information, demand-response actions, or remote service disconnects. Wireless technologies are critical elements of the “Neighborhood Area Network” (NAN), aggregating a mesh configuration of up to thousands of meters for back haul to the utility’s IT headquarters.
The network between the measurement devices and business systems allows collection and distribution of information to customers, suppliers, utility companies, and service providers. This enables these businesses to participate in demand response services. Consumers can use information provided by the system to change their normal consumption patterns to take advantage of lower prices. Pricing can be used to curb growth of peak consumption. AMI differs from traditional automatic meter reading (AMR) in that it enables two-way communications with the meter. Systems only capable of meter readings do not qualify as AMI systems.
5. Opposition and concerns
Some groups have expressed concerns regarding the cost, health, fire risk, security and privacy effects of smart meters and the remote controllable "kill switch" that is included with most of them. Many of these concerns regard wireless-only smart meters with no home energy monitoring or control or safety features. Metering-only solutions, while popular with utilities because they fit existing business models and have cheap up-front capital costs, often result in such "backlash". Often the entire smart grid and smart building concept is discredited in part by confusion about the difference between home control and home area network technology and AMI. The attorneys general of both Illinois and Connecticut have stated that they do not believe smart meters provide any financial benefit to consumers, however, the cost of the installation of the new system will be absorbed by those customers.
- Health and safety
- Privacy concerns
- Opt-out options
- Lack of savings in results
- In the media
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