By Philip Crowson

For some years the electricity metering industry has been developing smart meters for various applications. Water metering technology has always lagged behind. Smart water meters are now increasingly common but tend to be limited to collecting basic meter information and offer little beyond automated meter reading (AMR) functionality. However, recent technological breakthroughs enable two-way communication with meters and pave the way for the introduction of advanced metering infrastructure (AMI). At the same time, improvements to the functionality of the meters have created the opportunity for intelligent metering to become the norm for water utilities.

Intelligent metering offers water utilities and consumers benefits similar to those enjoyed by the electricity sector: 

  • Benefits for utilities Elimination of paper billing Real time leak detection Real time fault and tamper reporting Remotely open or close supply as required Remote software upgrades and changes 
  • Benefits for consumers Remote purchase and loading of credit (prepay) Remote payment of bills (postpay) Proactive reporting of faults Remote selection/application of operating modes Remote access to consumption/billing information.

Across the world there is a growing awareness that water is a finite resource. While the population increases every year, the quantity of water available remains pretty much the same. All that can be done on the supply management side is to increase storage facilities and improve reticulation systems to handle the water more efficiently. However, there is also a realisation that a large amount of the water supplied, at great expense, to the end user, literally goes down the drain without being used for its intended purpose.

Water demand management has become the mantra for water authorities across the globe as they come to terms with levels of unaccounted for water (UFW) that can easily exceed 60%. While it is possible to reduce the UFW levels by fixing up main reticulation systems, there can still be a lot of wastage at consumer level. In most communities there seems to be little concern for water conservation. It’s not unusual to visit residential areas at all levels on the economic ladder and see water leaking from taps.

Wastage at consumer level is exacerbated by the fact that revenue collection rates for conventional metering systems are often as low as 30%. Even when the collection rate exceeds 90%, the effort and expense required to ensure that revenue is collected absorbs resources that could be usefully employed in other service delivery areas. Added to this is the problem of water theft, either through illegal connections to the main supply or by simply by-passing an installed meter.

In the consumer environment, there is a move towards providing unique solutions for unique individuals – even in areas such as service delivery. There are growing demands from end users to have a number of choices that can accommodate their unique requirements. For example, in many countries in Africa social and cultural practices require people to provide support for extended families. This often results in the need for additional water for eventualities such as catering for family funerals or providing care for HIV patients. Conventional meters and traditional billing systems do not have the ability to cater for the unique requirements of users, but this could be possible in an intelligent metering system.

There are two popular approaches for trying to manage consumption at the consumer level. The first is to limit the amount of water that the consumer can access on a daily or monthly basis. This is commonly used in low income areas where there is a need to provide a life-sustaining quantity of water to users who do not have the means to pay for their water. In some countries, there is an increasing demand from communities for an uninterrupted supply to be given to all consumers, and authorities are investigating ways of providing a constant, but restricted flow.

The second approach is to manage the supply to the consumer in such a way that the authority can ensure that the consumers pay for the water they use. This can be done on either prepay or postpay basis. For the consumer, the purchase of water credit (for prepay) or the settlement of outstanding debt (for postpay) needs to be as convenient and pain-free as possible, for example using cell phone technology. For the utility the system should ideally be paperless and self-regulating. To date, most prepayment meter systems have relied on the physical presence of the customer at a vending point and some form of interaction with the meter, and most postpay meters require paper billing.

The automation of water meters – a move beyond the conventional water meter – has often involved the addition of a separate valve and some form of electronic control system to a traditional meter. These units have suffered from poor reliability – a common problem whenever components are “bolted together” – and an inherent attraction for users to try and tamper with them. The new generation of intelligent meters use an integrated meter and valve system in a single unit specifically designed to improve reliability and reduce the opportunity for tampering.

Any attempt by manufacturers to add “smart” functionality to water meters has been hampered by the meter’s finite source of power. An electricity meter can use as much power as it needs to perform all its functions but water meters usually have to provide their own power source, traditionally in the form of an on-board battery. This has forced those manufacturers at the forefront of meter development to push the envelope in optimising power consumption and extending battery life.

The challenge for the water metering industry is to produce a metering system that is flexible enough to accommodate the requirements of both water supplier and water consumer. Requirements range from a basic water management device that releases a pre-set amount of water on a daily or monthly basis, to a fully flexible payment solution. The payment solution needs to ensure 100% revenue collection and reduced administration costs by eliminating the billing cycle. At the same time, the collection of revenue – either pre- or postpay – requires the meter control system to be fraud-proof and self managing, while the meter itself needs to maintain accuracy over an extended period of operation.

One function that places large demands on a meter’s battery is automatic meter reading (AMR). In order for the meter data to be of real use to a utility a number of requirements need to be considered. The amount of data transmitted is relatively large, particularly when advanced functionality is being used. Also, the transmitting of data needs to be fairly frequent (either scheduled or on demand). If the two-way communication is to be implemented in order to optimise the advanced meter functionality then this will place even greater demands on power management and battery technology.

At the same time, the meter that forms the heart of the system often needs to contend with a hostile operating environment. Climates that include prolonged UV exposure, extremes of temperature and torrential rain pose many challenges. On top of this, many water authorities are only able to pump water of variable quality and with frequent disruptions to supply. This can result in sand becoming entrained in the supply or air flowing through the pipes. The meter needs to operate in such a way that it can handle these events while maintaining its accuracy.

In addition, many countries regard access to water as a basic human right. The demands to provide an amount of free water to consumers, particularly those at the bottom of the economic ladder, are becoming increasingly vocal. Water utilities often need to accommodate this in their demand management planning.

Intelligent scheme

Figure 1 – Schematic of how a utility can operate intelligent meters in different modes using a single management system. In this example, a prepay customer purchases credit using their cell phone, but a similar process could be used by a postpay customer to pay for water already consumed

For the supply authority, there are a number of key features that make an intelligent metering system attractive:

  • A range of payment and functioning modes available within a single meter footprint 
  • Ease and flexibility in moving customers between payment and functioning modes as a result of changing user or utility circumstances 
  • The ability and ease to upgrade functionality of the installed meter base without removing the meter (reduced life cycle capital costs) 
  • A robust and secure meter management system to ensure 100% collection 
  • Full flexibility in programming the system, and the ability to accommodate unique local requirements such as multiple step tariffs, debt terms and free water allowances 
  • AMR capability to provide consumption data, plus fault and tamper reporting 
  • Two-way communication with individual meters to change operating parameters on the meter 
  • The option to provide relief measures to customers who are unable to pay for water, either permanently or temporarily 
  • A system that allows for the rapid replacement of any faulty meters in the field

While from a customer perspective it is important to be able to offer: 

  • An increasing ability to allow for unique requirements for unique users (personalised meters) 
  • A meter that is simple and easy to use 
  • The facility to manage their own consumption – self management 
  • A number of options for purchasing water or settling outstanding debt 
  • Access to the full range of rebates and allowances offered by their water authority.

These would be in addition to the “non negotiables” such as reliability, technical support and ongoing development. A number of meter manufacturers are now competing to provide a solution that addresses all the shortcomings of the existing meters, as well as providing a number of innovations that make the intelligent meter as attractive to all role players as the tried-and-tested smart electricity meter.