By Guerry Waters

Growing environmental concerns have focused global attention on smart metering for electricity. Granted, smart metering has the potential to help lower per capita electricity use and its harmful emissions. But what about water?

The environmental issues surrounding water are just as important as those surrounding electricity. And, as is the case in electricity, smart metering for water has the potential to prevent waste and promote wise, efficient use. Should water utilities – many of which are relatively small and cash strapped – use scarce time and resources to investigate smart metering? There are a number of compelling reasons why they should look carefully at both the hardware and software options for smart metering as well as the benefits that smart metering can bring.

REQUIREMENTS FOR WATER SMART METERING
Smart metering for all commodities has two common features: 

  • Interval meters that measure and record consumption during specific, relatively short time periods 
  • A two-way communications channel that sends consumption measurements to the utility on a regular schedule. It also permits the utility to request reads and other actions from the meter and, for premises with additional equipment, to send signals beyond the meter to monitor or control individual pieces of equipment.

That does not mean, however, that electricity and water smart metering are identical. The difference lies in the required length of the interval.

INTERVAL LENGTH
Smart metering intervals in electricity are relatively short – 15 to 30 minutes. Short intervals better reflect volatile market pricing. They also help in the highly complex analysis of electricity use in a home or office. Short intervals help isolate the use of specific appliances and demonstrate the impact of use on a customer’s overall bill.

AMR water1

Figure 1: In the US, automatic meter reading (AMR) is widely used at water utilities. A substantial number, however, are in various stages of deploying advanced metering. (Source: Chartwell, The Chartwell AMI Report, 13th Edition, January 2009).

Water is different. Storage is readily available. Prices are stable. And water uses are generally fewer and more visible. Customers wishing to conserve can readily grasp the impact of bathing or flushing on total consumption. Those same customers, wishing to reduce electricity use, might have no idea which of their two refrigerators uses more electricity or how turning off lights might affect their bills.

These differences enable water utilities to use much longer intervals than electric utilities. Intervals of one to six hours are common. In fact, utilities and customers can accomplish many of their conservation goals using 24-hour intervals. That makes it feasible to institute smart metering using an existing automatic meter reading (AMR) system capable of daily reads.

DATA REQUIREMENTS
Electric utilities switching to smart metering must dramatically alter IT systems in order to move from the 12 annual data points per customer required for monthly reads to the 35,000 annual points required for quarter-hour measurement – an approximately 3,000-fold increase. Think of it as suddenly increasing a utility’s customer count from 100,000 to almost 300 million.

AMR water2

Figure 2: Global climate change and population growth are both expected to exacerbate existing water supply problems. Smart metering can play an important role in helping consumers and businesses conserve resources.
(Source: B.C. Bates et al. “Climate Change and Water IPCC,” Technical Paper VI of the Intergovernmental Panel on Climate Change, as reprinted in Water Scarcity & Climate Change: Growing Risks for Businesses & Investors, Ceres and Pacific Institute, Feb. 2009).

The data strain on water utilities is far less. Six-hour intervals increase the annual customer meter read data points only to 1,460 – comparable to increasing that 100,000 customer count to about 12 million. That is still a lot, of course, especially for utilities with software that cannot scale to handle high data volumes.

OPTIONS
Few utilities make do with a bare-bones smart metering system. Useful add-ons include: 

  • An in-premises display that customers can easily read. These can help customers check for leaks, reduce consumption, and monitor compliance with local restrictions 
  • A stand-alone data collection and processing application, such as meter data management (MDM). MDM isolates the existing billing system from the meter data volumes smart metering introduces while also packaging billing determinants and other data for use by many different utility departments.

WHY USE SMART METERING?
Display devices help customers conserve: 

  • Display devices that show water use in real time help customers detect leaks. Granted, a few diligent customers may occasionally turn off all water and check an outside meter to ensure there is no flow. The vast majority of customers do not, and if they were so inclined, water meter locations – frequently difficult to access – would discourage them from doing so. 
  • A conveniently located on-premises monitor, in contrast, can help a customer notice a leak because, for instance, the meter records consumption when no one is on the premises. 
  • Displays also serve as a constant reminder about the need for water conservation. They can help parents instil water conservation habits in children. They also enable jurisdictions to win customer compliance with water use advisories or restrictions, such as a weekly maximum use per occupant. 
  • Displays tailored to the specific needs of users, such as that of comparing current water use with neighbourhood averages or with consumption in previous months, may help consumers to further focus on conservation.

DETECTING LEAKS
Utilities can use time-of-use or interval data to: 

  • Detect customer premises leaks: If a utility using hourly intervals, for instance, finds customers whose usage never drops to zero, there is almost certainly a leaking appliance or pipe on the premises. Customers may already know about a dripping faucet, but notification from the utility pointing out the cost and long term community implications can encourage repair. Utility notifications to customers unaware of leaks can be even more valuable to property owners concerned about damage to walls and foundations.

Should the water industry follow the path of their electric brethren toward offering services behind the meter, water utilities might also use smart metering for sensor-based leak detection accompanied by automatic water shut-off. For property owners with storm-related wet basement problems, utilities could offer a service that double-checks a sensor-based leak report against an on-demand meter reading and shuts off water service only when the meter reports high and steady flow.

Note that in regions with competitive or partially competitive utility markets, utilities might use this leak detection ability to upsell leak insurance to property owners. 

  • Detect small leaks in mains: A utility comparing a day’s consumption for a group of customers (such as residences on a block) with readings from a water main serving that block may be able to identify small leaks (or possibly theft) before they become too large to be overlooked. 
  • Identify the location and extent of a water main break: This is especially the case when meters detecting a significant drop in pressure send “last gasp” messages to the utility. 
  • Automatically dispatch field crews to the site of a suspected leak and automatically notify customers about the duration of water shut-off during a repair. Leak detection is becoming an increasingly important issue.

Regulators concerned about reducing water waste may establish performance-based incentives for utilities to reduce water loss. The faster utilities can detect, size, and prioritise repairs for leaks, the greater their ability will be to earn these incentives.

AMR water3

Figure 3: Leak detection is a particularly high priority in Europe, where infrastructure issues in a number of countries result in significant water waste. (Source: C. Lallana et al., Environmental issue report No 19: Sustainable water use in Europe, Part 2: Demand management, European Environment Agency, 2001).

CUTTING COSTS
Utilities can use smart metering to:
 

  • Obtain off-cycle, “final” meter reads for customers moving or leaving the area. It is common for utilities to couple these real time final meter reads with websites for on-line bill payment or with call centres that accept payment over the phone. Utilities frequently find it is easier and less costly to obtain rapid final payments from customers before they leave the area. 
  • Remotely disconnect or restrict water flow when permitted by law or regulation. Remote disconnects reduce the cost of field worker trips to the premises of customers who have either requested disconnection or who are being disconnected (or ratcheted back) for bill non-payment. 
  • Check meter status (“ping the meter”) prior to sending a repair crew in response to a customer call. These checks can sometimes prevent needless field crew dispatch to customer sites where problems are not the utility’s responsibility. 
  • Remotely detect theft. 
  • Ensure that almost all bills are based on actual meter reads rather than on estimates. This reduces calls to the contact centre and improves customer satisfaction. 
  • Help control electricity costs. This applies to utilities that pump water to a high point to take advantage of gravity feeds. However, utilities can thwart attempts to limit pumping to times of off-peak electricity rates by consumers who use water imprudently during the day. Advanced water meters minimise this problem by enabling pricing structures that discourage excess on-peak water consumption.

OTHER APPLICATIONS

  • Regulatory compliance: Smart metering helps water utilities monitor compliance with local water restrictions against, for instance, outdoor watering on specific days of the week, without sending inspectors into every back yard. Rapid detection of violations and immediate imposition of fines is a very strong incentive for compliance 
  • Prepayment: Smart metering can also be a low cost route to prepayment. No special meters are required. Instead, meter data management systems send bill determinants to billing systems, which subtract daily consumption from an existing customer deposit. Those systems then use utilitydetermined processes to notify customers – usually via phone, e-mail, or text message – when the deposit approaches zero.

Prepayment for water has not been a common practice in the past. A combination of rising costs and supply shortages, however, are almost certain to escalate the interest of budget and conservation minded consumers. Water utilities attracted to a reduction in bad debts plus faster and paper-free revenue receipts will be equally interested 

  • Time-of-use pricing: Many water utilities use off-peak electricity to pump water to a high point for later gravity feeding to customers. High water use during the day can force a utility to turn pumps on during peak periods, significantly increasing electricity costs. Water utilities facing this situation may want to institute time-of-use water rates that interval-based smart metering can readily accommodate.

COSTS AND BENEFITS
The costs of new meters plus the costs to install them loom large for many financially strapped water utilities. But the benefits can have significant monetary value. Be sure that business plans appropriately weigh the value of: 

  • Ensuring that all meters are recording water flow following repair of a break in a main 
  • The remote programming that can provide a pathway to new products and services. For utilities reluctant to take on newproduct risks, question whether a third party might be willing to pay access fees for the opportunity to use the meters’ capabilities 
  • Opportunities to increase worker productivity: - Eliminating human meter reading requirements makes a number of employees available for cross-training - Remote rather than on-site disconnects or flow restrictions frees up field workers for far more important tasks in infrastructure maintenance and repair 
  • Less wasted time in attempts to pinpoint the size and source of leaks and breaks 
  • Lower risk to public safety from flooded intersections or lack of service to hydrants 
  • Better meter reading accuracy, resulting in fewer calls to the contact centre 
  • Faster theft detection 
  • Lower electricity costs (for those utilities attempting to limit pumping to off-peak use) 
  • Less use of chemicals currently used to treat water that is then wasted through leakage from water mains or via customer premise leaks from pipes or fixtures 
  • Longer lifespans for water treatment equipment.

VALUING CONSERVATION
Ultimately, the most important smart metering benefit is its value in conservation. As governments and citizens become increasingly conscious of the potential for water shortages, the perception grows that water is a terrible thing to waste. Smart metering can help ensure that we do not.

REFERENCES
1 Customers reporting such leaks, however, should be questioned about “automatic” uses like ice-cube makers or sprinkler systems.
2 Disconnection is not universally practiced. In the UK, for instance, the Water Act 1991 and NRSWA Section 79/80 do not allow utilities to disconnect residential customers for non-payment of their water bills.