Mechanical meters have long been the choice for water meters but new technology has seen a number of companies in Australia trial their replacement with electronic versions. Adelle King reports.

A change is occurring in water metering around the world, whereby mechanical meters are being phased out and replaced by digital and electronic devices.

These meters do not use pistons, turbines or discs to measure water and then transfer the movement into gears and odometer wheels for a meter reading. Instead, digital water meters use pulse registers to send an electronic pulse to a recording device, while electronic meters have an encoder register that allows an external device to obtain the position of the wheels or a stored electronic reading remotely.

Whereas mechanical meters are read manually, meter reading technologies for electronic and digital meters fall under two broad categories; automatic meter reading (AMR) and advanced metering infrastructure (AMI). AMR transmits data to a remote reading device and is then manually collected, while AMI transmits data through a communications network to a central collection and management system.

Both are considered smart metering.

According to ABI Research in its 2017 Utilities and Smart Grids report, smart metering connections in the global water, electricity and gas markets will see double-digital growth through to 2022, lead by the installation of smart water meters. The report states water security concerns are fuelling this growth, with North America and Europe having the largest install base of smart water meters.

Additionally, Global Market Insights’ 2017 industry report found the global smart water metering market will be worth more than $US14 billion ($A18.5 billion) by 2024 and predicts residential market size will surpass 90 million units during the same period. In Australia, the adoption of smart meters has been led by the electricity industry; however, recently water companies have begun to embrace digital metering. Trials to replace mechanical meters with digital ones are underway by SA Water, Sydney Water, Icon Water, Barwon Water, Goulburn Murray Water, Cairns Regional Council, WA Water Corporation, South East Water, Yarra Valley Water and City West Water.

In Tasmania, the state has moved beyond trials and since 2011 has been implementing a water renewal program that will see the Tasmanian Water and Sewerage Corporation (TasWater) replace 40,000 mechanical meters with AMR digital meters by 2019.

TasWater said in a press release that the digital meters will significantly reduce the time and resources needed for meter reading and will help detect leaks within private plumbing.

Since digital and electronic water meters measure significantly lower flows of water than mechanical meters, they increase the accuracy of readings. While this has lead to concerns about water bill increases, the improved accuracy means there is a higher chance of leaks being caught, saving customers money in the long run.

According to estimates by the World Bank, approximately 32 billion cubic metres (bcm) of water is lost every year around the world due to faulty distribution networks, inaccurate systems and theft. This seriously undermines the sustainability of water supply and water saving initiatives.

In Melbourne, the benefits around leak detection that digital metering can deliver were quantified during trials conducted by South East Water (SEW). The company found 12% of water supplied to properties within the Belgrave South trial area in 2014 was lost due to water leaks, while 10% was lost in the Seaford trial area in 2013.

To explore new ways to improve the performance of Melbourne’s water network and ensure it operates more efficiently, SEW, together with City West Water and Yarra Valley Water, formed the Metropolitan Melbourne Digital Metering Joint Program in 2016 to jointly explore the value digital water meters can deliver to customers.

“With the city’s population set to double within 50 years and scientists forecasting more extreme weather conditions, we need to find new ways to improve our water network, operate more efficiently and preserve our precious drinking water supplies,” says Yarra Valley Water managing director Pat McCafferty.

The technology of the existing mechanical meters hasn’t changed significantly since the 1940s and customers are now demanding operational efficiency, leak alerts and increased bill certainty. Pat says it therefore makes sense to explore the option of a fully integrated digital metering solution.

“Our customers are telling us they expect us to make greater use of digital capabilities to achieve efficiencies and manage water resources into the future. Two-thirds of customers in Melbourne support upgrading our networks to digital meters to help us manage our water more sustainably.”

The three water utility companies had been conducting individual exploration into digital water meters but the joint program will see them work together to explore the feasibility of a Melbournewide solution.

This will involve collaboration on technical trials, as well as business case development and customer research to thoroughly assess if digital water meters are viable and can deliver benefits to customers.

Trials are being undertaken in a number of suburbs across Melbourne to evaluate different communications platforms and technologies within the meter, as well as to examine how realtime usage information can be used by customers and to quantify the benefits of digital metering on leak detection.

Already, a trial in Craigieburn has found 8% of homes less than five years-old had leaks and 30% of homes aged around 30-years-old had leaks.

“The large leaks in some of the older households cost around $100 or more in wasted water per month,” says Pat.

The digital water meters being trialled link to telecommunications networks to transmit water meter readings and communicate information about the water network on a more regular basis than mechanical meters. They use low-power wide area communications technology, have two-way communications capability and support 15 year meter life.

The digital meters are similar in size to current meters, with the existing meters simply removed and replaced with a digital version in the same location. The installation of the new digital meters will require some additional training to be provided to licensed plumbers, to commission the meter to communicate wirelessly.

“By conducting trials, we’re able to evaluate which communications and battery technologies might best be suited to Melbourne’s water networks. This way, if a decision is made to roll out digital meters on a broader basis we’ll be able to select the technology that delivers the best long-term value to our customers,” says Pat.

As well as providing benefits in the form of leak detection, digital water meters do not require mains electrical power, cannot cut off the supply of water and can be replaced with minimal disruption to households. They can also detect reverse flow, trigger alerts and monitor trends.

“Digital meters can offer a range of benefits, both to customers and water utilities. The granular information they capture enables network operators to detect and fi x problems earlier, often without customers even knowing, which can reduce the costs associated with pipe repairs and damage to the property,” says Pat.

“Digital meters can provide more timely information on water usage via a website or app, which enables customers to make better choices about their water consumption.”

However, there are concerns that there is not enough data currently available about how digital meters might deteriorate over time.

“At this stage, there hasn’t been enough long-term testing of digital water meters and there is not enough data to see trends emerging, particularly regarding how different climates will affect the meters,” says Prove Engineering plumbing test consultant Terry Nguyen.

That said, the Metropolitan Melbourne Digital Metering Joint Program is trialling meters across multiple geographical regions to test different topography for coverage, as well as functionality, maturity, service specification, asset life and battery load.

Additionally, laboratory trials that simulate real-life conditions are being conducted to test various metering and communications technology combinations. These trials are also testing the impact on battery power consumption of the water meter component, communications component and communications chip again various test scenarios.

“By combining the knowledge and insights these trials deliver, the three metropolitan Melbourne water utilities will be able to thoroughly assess if digital water meters can deliver benefits to our customers, businesses and stakeholders,” says Pat.

The three companies say they will be making a decision by early 2019 about if or when an upgrade to the meter fleet will occur. “It’s definitely going to be an interesting space to watch,” says Terry.