Following the COP26 conference in Glasgow, there is a renewed buzz about achieving Net Zero greenhouse gas (GHG) emissions. Governments, local authorities, businesses and other organisations are all aiming for the same target, though not necessarily by the same date. In England, the water industry is ahead of the game, having pledged in 2019 to achieve Net Zero by 2030, two decades ahead of the UK Government’s target date of 2050. Water companies in Scotland and Wales are aiming for Net Zero by 2040 and Northern Ireland is aligned with the UK’s target of 2050.
Local authorities, combined authorities, businesses and numerous other organisations have also announced their intentions to achieve Net Zero, with many pledging to do so sooner than 2050. Something that impacts everyone, from individuals through to large organisations and Governments, is water. Every litre of mains water delivered to the tap has an amount of greenhouse gas emissions associated with it, so this is something to which water companies, retailers and consumers of all sorts need to pay close attention.
According to the Water UK website, the water industry delivers 15 billion litres of water every day and treats sewerage from more than 28 million properties. Water is treated at over 7000 sites and there are hundreds of thousands of miles of buried pipework.
Greenhouse gas emissions are generated in many different ways by the water industry. Pumping is a significant contributor, but there are also emissions due to the need to power water treatment processes, service buildings and operate vehicles. In addition, water and sewage treatment result in emissions of methane and nitrous oxide, both of which are greenhouse gases. When infrastructure is repaired, upgraded or newly constructed, there are further emissions.
An Environment Agency report quotes from the Government’s 2008 Future Water strategy paper, saying the water industry used 7,900 GWh of energy in 2006/7 and emitted over 5 million tonnes for greenhouse gases. Supplying water and treating wastewater accounts for 0.8 per cent of the UK’s greenhouse gas emissions. That may sound like a small percentage but, according to Waterwise, Scottish Water is Scotland’s largest user of electricity, which demonstrates the significance of the water industry’s contribution to the UK’s greenhouse gas emissions.
According to the UK Government conversion factors for greenhouse gas reporting, 0.344 kg CO2e can be attributed to each cubic metre of mains water. Water companies are tackling their emissions in a number of ways, including upgrading vehicle fleets, installing on-site solar power systems and advanced anaerobic digestion plants, and establishing natural wetland treatment sites. However, there is another important area where
water companies are seeking to reduce their carbon footprints and that is by saving water.
First, water companies are investing in better techniques and technologies for finding and fixing leaks in the network of underground pipes. Second, there is a drive to reduce demand from consumers.
Metering is a key weapon in the fight to reduce demand and consumption – and thereby achieve Net Zero. On the one hand, the meter data can indicate if there is a leak while, on the other hand, visibility of consumption data encourages users to save water. Smart metering also opens the door to new tariff structures, such as rising block tariffs in which the unit charge rises for progressively higher volumes of water taken by customers. This acts as a further incentive to use less water.
In an ideal world, every user would have a meter that would be read sufficiently frequently to provide a clear picture of consumption – and leakage. However, it is not an ideal world and there are still households without meters, as well as commercial and industrial (C&I) users with meters that are classed as Long Unread Meters (LUM), or whose bills are based on Business Assessed price bands or estimates, rather than meter readings. Waterwise has recommended allowing water companies to introduce full metering, and for meters to be installed in the majority of homes by 2030 and the proportion of smart meters to be increased.
Whereas the electricity industry has gone a long way down the road with smart metering, there are significant challenges for implementing smart metering in the water industry. For example, water meters do not have an integral power supply unlike electricity meters, so smart water metering needs to be battery-powered. In addition, meters are typically installed below ground level, often submerged in water or mud.
Where water meter readings have been semi-automated, the systems have been proven to be less than ideal. For household meters fitted with sensors that transmit data over low powered radio or Bluetooth, it is still necessary for a person with a reading device to drive or walk close enough to the meter to collect the reading. C&I meters equipped with data loggers that calculate consumption based on pressure and flow or via the pulse output, but this technology can only calculate consumption, so periodic manual reads are still required.
Despite these known issues, Water UK strongly supports the use of smart metering rather than manual meters . A report prepared for Water UK concluded that smart metering, in conjunction with a mandatory water labelling scheme (with minimum standards), was the best strategy for maximising demand reductions, with a forecast saving of 82 litres of water per household per day by 2065 .
Fortunately, there is now a technology that enables existing water meters to be retrofitted with smart functionality at far lower cost and without the drawbacks of conventional approaches. The hardware is battery-powered, withstands long-term submersion in water or mud, transmits a time/date stamped image of the register read via the GSM (mobile phone) network at intervals defined by the client. Installation only takes around 10 minutes, with no need to dismantle the meter or interrupt the supply.
Deer Technology’s patented LimpetReader is an ultra-compact opto-electronic device that attaches to an existing meter faceplate with optical tape or adhesive. Each LimpetReader incorporates multiple micro-cameras for imaging the register. The images are date- and time-stamped before being transmitted by an AutoReader to Deer Technology’s secure server. When water meters are situated close together, multiple LimpetReaders can be connected to a single AutoReader.
Once the individual images have been uploaded to the server, they are stitched together to create a high-quality, distortion-free image of the meter’s register. Software then converts the register image to a numerical value, which is stored with the image. Data and images can be accessed by the customer in a variety of ways, depending on the requirements. Deer Technology’s comprehensive service covers everything from installation through to data management.
Water companies and consumers can utilise this technology to help identify leaks and reduce demand. LimpetReaders can play a significant role in helping to save water and, in turn, help the water industry achieve Net Zero.
The Environment Agency says water metering alone can reduce a household’s consumption by 10-15 per cent, and smart metering and structured tariffs could achieve further reductions. Importantly, a proportion of the water saved by reducing demand and fixing leaks will be hot water. The carbon footprint of hot water is in the order of ten times higher than that of mains water due to the energy required to heat it.
Of course, there is another benefit of upgrading meters for remote reading: reduced emissions associated with meter readings. With conventional meters, somebody needs to travel in a van to and from the meter’s location. Despite multiple meters being read during each trip, the emissions per meter soon add up. Even if the vans are electric, there is still a significant carbon footprint associated with their manufacture, maintenance and end-of-life disposal.