New technology widens the range of applications

Until relatively recently, automated meter reading (AMR) systems were generally only used where meters were particularly hard to read or difficult to access, or for high revenue industrial applications which required billing on a monthly basis. The initial market penetration for AMR was in North America, where such systems are now used extensively by electricity, gas and water utilities operating in the industrial sector. However, as deregulation and privatisation of the energy markets across the USA and parts of Europe gathers pace, utilities and resource providers are coming under considerable pressure to reduce their operational costs and improve customer service.

Automated meter reading systems – with their inherent accuracy, flexibility and advanced information handling capabilities – directly address these issues, and now look set to become as indispensable to the commercial and residential markets as they have proved to be in the industrial sector. Even in countries which have retained public ownership of energy utilities, such as Germany and Italy, contracting out meter reading and billing functions to private organisations is becoming more popular, and these third party companies are fuelling a trend towards more frequent meter reading and a consequent greater use of automated reading technologies.

Principal AMR technologies

AMR systems essentially fall into two categories: those intended to expedite collection of meter data by an operator; and those involving completely automated data transfer. All are designed to significantly increase utilities’ operational efficiency by eliminating the need for meter readers to gain access to the inside of customers’ premises. The principal AMR technologies for mobile meter reading applications – ie those involving a human operator – are keyed and probed (also known as touch-read) walk-by systems, and radio frequency (RF) walk-by and drive-by systems.

In contrast, fully automated AMR systems can employ a wide variety and mix of communications technology, including fixed RF links, distributed RF networks, power line carrier (PLC) over mains supply networks, the public switched telephone network (PSTN), the cellular telephone network, and leased copper or fibre-optic lines. Fully automated AMR systems can also employ hard-wired bus-based data collection methods, but these are generally only employed for applications involving relatively large numbers of customers located at the same site, such as in apartment blocks and condominiums, and the lack of definitive world-wide bus standards has so far tended to limit their growth.

Probed AMR

Probed technology represents the simplest form of remote reading for meters, involving the lowest capital expenditure on the part of the utility, and demanding the least change in working practices. A typical system comprises a meter linked via cable to an inductive pad mounted on a physically accessible site such as the manhole cover. The meter reader obtains the reading simply by touching the pad with some form of handheld electronic probe; the embedded electronics in the meter are energised by inductively-coupled power from the probe for the duration of time it takes for the information to be transferred to a data recorder carried by the meter reader. The readings are subsequently uploaded to the utility’s central information management system when the meter reader returns to base.

Although probed systems tend to be limited to a single resource – such as water – and do not yet provide the tariff-setting flexibility or multi-resource capabilities of other types of technology, they are currently proving popular as a low-cost entry into AMR, especially in the UK. The advantages of probed systems include low hardware costs, no need for additional infrastructure, and ease of upgrade to radio-based AMR at a later date. However, the technology demands that each meter site is easily accessible and visited by a meter reader on a regular basis, which means that it is not usually cost-effective for utilities serving widely-dispersed customers in rural areas.

Radio-based AMR

Radio-based AMR systems essentially replace the inductive pad of the probed system with a radio transponder. The transponder is generally a battery-powered unit which is either integrated with the meter or mounted locally; it is interrogated – instructed to turn on and transmit consumption data – by a second transponder operated by the utility. This can take the form of a handheld unit carried by the meter reader, a vehicle-based system, or a permanently installed network with outstation links. Radio-based AMR offers the same low cost installation advantages as probed systems, but also enables the meters to be located in difficult-to-access locations. And although most installations to date involve unidirectional data flow from the meter to the utility, bi-directional communication is possible.

Radio-based AMR systems are used extensively by the heating services industry in European countries – especially in Germany, Spain and Switzerland – and by electricity utilities in the USA; they are also now beginning to be employed in other resource sectors around the world. Schlumberger, for example, has recently won two contracts for large-scale radio-based AMR solutions for the water sector in North America. In June this year, the city of Niagara Falls in Ontario awarded Schlumberger a major contract to supply a metering management solution for the city, involving the installation of 24 500 water meters with remote-read devices placed on the outside walls of water customers’ premises. The programme will focus on the installation of water meters in residential homes, but there will also be some meter change-outs in the commercial and industrial sector. The project is expected to be completed by the end of this year, and is the largest single-order water meter installation contract in Canadian history. It uses technology specifically developed for use in cold climates.

In July this year, the Pittsburgh Water and Sewer Authority in Pennsylvania awarded Schlumberger a contract to supply wireless fixed network AMR services to about 83 000 residential, commercial and industrial customers across the utility’s entire service territory; once complete, this will be the largest installation of its kind for water meters in North America. The system will allow the Pittsburgh Water and Sewer Authority to access customer water usage information such as monthly consumption data, as well as perform on-request reads, and receive real-time theft notification and other value-added data. Schlumberger is manufacturing and installing RF interface units to the existing water meters; the communications system uses radio transmission technology licensed from Cellnet Data Systems Inc (a leading provider of low-cost telemetry services).

RF-based AMR systems are also starting to be employed in the gas sector. In France, for example, Gaz de France (GDF) recently awarded Schlumberger a contract for the provision of 20 000 gas meters equipped with radio communications modules in a large-scale field trial involving 25 000 residential customers. Starting in the last quarter of 1999, EDF GDF Services (the common distribution branch of Electricité de France and Gaz de France) is changing-out virtually all its residential gas meters in and around the city of Metz, north-east France, making this the largest radio-based remote meter reading system for gas in the country. The installation will use FS3 handheld computers made by AMR specialist Itron. The computers are fitted with a new portable network radio card developed by Itron, which complies with the Radian radio protocol. The Radian (Radio Application Network) association was formed in October 1998 (and became public in April 1999) by a number of leading utilities, metering and service providers. The founder members were Itron, Schlumberger, Electricité de France, Gaz de France, Raab Karcher Energy Services, Severn Trent Water, Sontex and Aquametro. The low power radio protocol originally developed by Itron is now wholly managed by the Radian association, and all members of the association have access to the protocol, which is set to become a de facto standard.

Multiple resource AMR

Until earlier this year, one of the drawbacks of mobile radio-based AMR systems was their inability to accommodate different manufacturers’ metering systems, which meant that utilities and resource providers were unable to implement a single, unified, meter reading scheme. The problem was particularly acute for companies selling multiple products (such as gas and electricity), because it precluded efficient data management across their full service offering. To overcome these problems, in June this year, Schlumberger launched an innovative mobile data acquisition and management system known as MAPS Mobile. The system encompasses all the principal types of mobile meter reading technology – including keyed and probed walk-by, and RF walk-by and drive-by – and accommodates both licensed and unlicensed RF communications standards, enabling water, gas and electricity utilities to use the data acquisition and management approach of their choice.

The MAPS Mobile system comprises three main components: the host software, handheld walk-by or drive-by data collection computers, and a large family of communicating meters and interface units. The software runs under Windows NT on any IBM-compatible PC and provides a powerful, yet easy-to-use, means of managing the entire meter reading process – from route planning and communication with handheld computers, through to processing of data acquired from the field.

For walk-by meter reading applications, the MAPS Mobile system uses DAP Technologies handheld computers. These data collection devices can be configured for keyed entry, probed-read for water, and RF-based data acquisition, and are extremely popular with meter service providers. They provide an ergonomic means of acquiring and storing information in the field, and are rugged enough to be used in harsh environments. MAPS Mobile accommodates any combination of these three meter reading techniques, giving utilities complete operational flexibility, including the option of only installing RF meter interfaces to overcome access problems on hard-to-read accounts.

For drive-by reading – which can significantly increase the number of meters that can be read per day – Schlumberger has developed a new vehicle-based package known as RoadMAPS, which provides an extremely efficient means of reading water, gas and electric meters without the need to invest in expensive, specialised vehicles. The company has recently begun using the RoadMAPS unit to provide reading services for several utilities in Georgia, USA. The large family of meter interface units (MIUs) that Schlumberger produces or licenses is key to the unique flexibility of MAPS Mobile; the system’s introduction marks the first time that a complete suite of compatible MIUs for water, gas and electric meters has been placed on the market.

PLC-based AMR

Power line carrier (PLC) technology, which facilitates two-way communications over the existing electricity supply network, enables utilities to implement automated remote meter reading schemes very cost-effectively, since it obviates the need to invest in fixed wireless networks. The technology is not currently used much in the USA, except by electricity supply companies serving small communities in isolated rural locations, where access can prove especially difficult during the winter months. However, in Europe, the picture is somewhat different, and PLC technology is now beginning to be viewed by many utilities as an ideal tool for last-mile customer connection in AMR schemes.

In response to this interest, Schlumberger has just launched an innovative PLC-based AMR solution on the European market. Known as MAPS-PLC, the system is specifically designed to provide electricity, heat, gas and water utilities with a fully-integrated solution to demand side management, and is particularly suitable for companies operating within multiple resource environments.

MAPS PLC comprises three main elements: a host system running the supervisory software; one or more MAPS CP100 data concentrator units; and the utility’s meters at the customers’ premises, fitted with Schlumberger P100 or P200 meter interface units. The host system manages the entire data flow between the meter interface units and the utility’s information technology systems; it is based on a three-tier architecture, employing an Oracle database engine running on one or more database servers, linked via a TCP/IP network to a number of applications and communications servers. This distributed implementation of a full client/server architecture – based entirely on industry standards – provides utilities with a very flexible and scaleable energy management solution, and facilitates easy integration with their customer information systems. It also combines fast operational speeds with a high level of security, by allowing several client applications to access the database servers concurrently, using transactional processing techniques.

The supervisory software runs under Windows NT, and employs an intuitive user interface to simplify operation. It enables users to easily control all aspects of meter reading and contract management, including accurate load profiling for electricity and heat consumption, the acquisition of consumption and diagnostic data from electricity, gas, water and heat meters, and value-added services such as customer messaging. Separate reading schedules can be specified for each type of meter on the network, and consumption data can also be obtained on demand if required.

The system’s communications servers exchange information with the data concentrator units – which are normally located in the transformer sub-stations of the consumer’s electricity supply company – via the public switched telephone network, leased copper or fibre-optic lines, a fixed radio-frequency link, or a cellular network. The data concentrator units subsequently communicate with the meter interface units (MIUs) at the customers’ premises using PLC techniques, over the electricity supply network. This approach provides an extremely flexible and cost-effective means of implementing AMR systems, and allows the infrastructure to be easily expanded whenever necessary; any new MIUs added to the network are automatically recognised by the supervisory software.

Schlumberger is currently installing an advanced PLC-based AMR system in Stockholm for Birka Energi, the Swedish energy utility. This project, due to be fully implemented by January 2000, involves replacing temperature sensors at Birka Energi's 8000 district heating substations around Stockholm, which handle delivery of hot water to around 370 000 users, with CF50 electronic heat energy calculator units. These use high frequency power line carrier technology for on line meter reading and other services, eg two-way communications for "real time" control and tariff adjustment. Data from the district heating substations will be collected using the existing mains supply as the communications channel for transferring data to a central location for analysis and classification. It is then automatically forwarded to Birka Energi's customer information system. Schlumberger will assume responsibility for the collection, consolidation and delivery of energy consumption data to Birka Energi.

Flexible technology

AMR technology is now available to suit all types of remote meter reading applications, and promises to be an essential tool for utilities and resource providers as they prepare for the deregulated and privatised energy markets of the future.