By Lesley Smith, Water New Zealand insight and sustainability advisor
With smart water metering understood to deliver a range of benefits, the technology is increasingly being deployed to help manage water use, both in New Zealand and abroad.
A smart water meter measures water consumption in households – sending usage data back to water network operators much more frequently than conventional meters. Smart meters will typically send hourly readings once every day, whilst conventional meters are read periodically, typically between monthly and quarterly.
This regular flow of information allows water network operators and customers to more accurately monitor water usage, supporting earlier leak identification and unlocking a broad range of benefits.
Costs and benefits of smart water metering.
One of main advantages offered by water metering is that it helps reduce water usage and identify leaks. A recent BRANZ project examining water usage in Kiwi homes, found median water use in non-metered households in the study (551 litres) was 72 percent higher than in metered households (319 litres).
Smart water meters extend the benefits of metering further than conventional meters, bringing numerous flow on benefits to customers and water service providers alike. Watercare is on a journey to replace all conventional meters with smart meters over the next decade. Watercare has broken down some of the many drivers of its project.
Over in the UK, the costs and benefits of a co-ordinated national smart water meter roll-out have been analysed by FrontierEconomics and Artesia. The study found a nearly two to one benefit to cost ratio, with every £1 spent delivering £1.73 in social benefits. The list of benefits goes on; management of backflow prevention, reduction of stress on local water environments, reduction in energy usage and ultimately emissions associated with water use. A recent study by Waterwise and Arqiva found smart meters could reduce UK greenhouse gas emissions by up to 0.5 percent.
Across the country, customers are already seeing the benefits of water metering. Both Wellington Water and Watercare already have smart meters in place with many of their institutional and commercial customers. Fast leak identification demonstrates its not just network providers who benefit from smart meter installation.
Massive leak at school
Ahead of a roll-out of residential smart meters, Auckland schools and other commercial customers have been fitted with smart meters. Over the next decade Watercare will be gradually replacing mechanical meters with smart meters, starting with the installation of 44,000 residential meters this year.
Smart metering on schools enabled Watercare’s schools account manager, Ange Hibberd, to quickly spot skyrocketing water use at Mt Eden Normal Primary School, going from an average daily usage of 6000 litres a day to about 74,000 litres a day.
Ange got in touch with the school to let them know they might have a leak and gave advice on how to check for one. The school’s property manager was on to the case straight away, but no leak was immediately apparent.
However, the data was clear – the school was losing thousands of litres of water every day. When a specialist leak detection agency was called in, a massive leak was found under volcanic rock, believed to be losing about 46 litres every minute.
Had it not been for the new smart meter, this leak would likely have gone unnoticed for months, until the school’s next meter reading. But with early warning, the school was able to identify the problem and arrange for the pipe to be repaired promptly. Left unnoticed, the leak would have been costing the school about $347 every day.
Escalating leaks at Wellington business
Wellington Water has built a dashboard for analysing water usage of 167 commercial customers that are automatically read through smart meters. Amongst these is a business precinct, comprising a collection of cottage businesses.
These businesses are fed by a private network, which is metered through the Wellington Water network, and has a typical day peak of around 10 litres per minute. The new dashboards enabled Wellington Water to quickly identify when the base flow jumped up to 170 litres per minute.
Contractors were sent to the site and found copper service pipes into many of the abandoned buildings had been removed, leading to the jump in water usage. Further pipes were found to have been leaking that night causing water usage to jump again to 480 litres per minute.
Without remedy, the leaks would have cost the customer $1990 per day in additional water charges. Updates given to the customer enabled them to see the immediate impact of their actions. Within the week they were able to reduce the flow from 400 litres per minute down to just half a litre per minute.
This significant reduction in water use represents an absolute percentage reduction of 1.9 percent in leakage for all WCC.
Smart water eco-system
Experiences with smart water metering ecosystem, from both water suppliers and suppliers of metering technology, were recently brought together in a workshop hosted by two Water New Zealand Groups; the Water Efficiency and Conservation Network and the Smart Water Infrastructure Group.
Their webinar wanted to highlight the need for more than a digital meter for smart water metering, rather, a smart metering ecosystem that will measure water demands in a way that is used to influence customer water use behaviour and improve network management.
Through the experiences of suppliers, New Plymouth District Council, Watercare, and Sydney Water, the discussions helped to untangle the sweet spot between what the customer wants and what the technology can provide. They explored practical approaches to meter roll-out, ownership models, and questions you might ask on your own smart meter journey. A recording of the workshop is available on the Water New Zealand knowledge base.
Indeed, there is much to learn from each other as this game changing technology takes flight. Links to the resources shared in this article can be found below.
Webinar: Smart water metering solutions: it’s not just about the meter, Water New Zealand Water Efficiency and Conservation Network and Smart Water Infrastructure Group: bit.ly/3HTKujK
Report: Cost benefit analysis of water smart metering produced by Frontier Economics and Artesia, supported by Arqiva:
Report: Smart Metering and the Climate Emergency (2021), Waterwise and Arqiva: bit.ly/3HXvTnE
To read more on this and other articles go to https://issuu.com/water_new_ze...