October 2020

44 n WATER INDUSTRY October 2020 www.drivesncontrols.com Adapting to changing water demands A recent United Nations report revealed that global water usage has increased by a factor of six over the past 100 years. Climate change is undoubtedly a key consideration for water management, but low rainfall, high population density, and intensive agricultural or industrial activity, may also result in sustainability issues – without throwing a global pandemic into the mix. In July, the Met Office reported that most UK water companies have seen increases in average water consumption during lockdown – especially those that operate in suburban areas. It’s clear that Covid-19 measures have resulted in societal changes that are directly impacting when and how much water people are consuming. Faced with these challenges and an ageing infrastructure, the UK water industry has been focusing on rejuvenating its existing assets, building resilient systems, and improving its operational and energy efficiency. So where should a water company start when implementing such upgrades? Firstly, it’s important to build an effective strategy. The totex (total expenditure) approach continues to reshape the water industry. This framework considers total costs throughout the lifecycle of a project, allowing water companies to be assessed against long-term outcome indicators. As well as cutting costs, the framework looks to provide better value to consumers, and to improve operating efficiencies. Implementing totex frameworks allows intelligent design decisions to be made, giving water utilities added flexibility, better performance and cost savings. Reducing wastage Waste, in the form of unnecessary use of energy or pesky pipe leaks, can be a real problem, affecting a water utility’s maximum output. According to the International Energy Agency, a quarter of the electricity consumed by the water sector is for wastewater collection and treatment. For this reason, it is especially important that utilities consider investing in energy-efficient technologies. Reducing energy wastage not only offers environmental and cost-saving benefits, but also allows businesses to commit more resources to meet changing demands. Opting for energy-efficient motors that conform to the IE4 or IE5 standards is a good place to start, but it’s also important to ensure that the motors are matched to their loads. For example, a water pumping station in Surrey has recently installed three 900kW IE4 super-premium efficiency motors with IP55 protection, that operate with 96.9% efficiencies. By installing new pump impellers, gearboxes, drives at the same time as the WEG W50 motors, the station’s capacity was upgraded from 400 to 750 megalitres/day, and its efficiency rose from 80% to 86%. Condition monitoring To ensure that their pump motors are running optimally, water plant managers can retrofit specialised sensors. Using smart IIoT (Industrial Internet of Things) technologies, they can monitor their assets and processes in real-time, allowing them to ensure that their systems are performing optimally and can respond rapidly to unexpected events. Key metrics such as changes in vibration and temperature can be early indicators of more serious system faults. Predictive maintenance reduces the risks of downtime and consumer disruption. Pumps account for a large proportion of the energy used by electric motors. Upgrading from fixed-speed motor controls to VSDs (variable-speed drives) allows utilities to adapt to varying process loads. A VSD can control the speed of the motor automatically, and respond rapidly to changes in demand. This also leads to more efficient operation, instead of running continuously at a water flow designed for maximum demand of the system. Going one step further, companies can invest in sophisticated process control software, such as WEG’s Pump Genius. This software, built into VSDs, enables engineers to increase the accuracy and protection of their processes, while also providing system monitoring. The software, allows one VSD to control up to five pumps, monitoring their operating hours and adding or removing pumps as demand changes. An automatic broken pipe detection function in the VSD can also identify fluid leaks and adjust motor performance accordingly. n How can water companies prepare for unexpected surges or drops in demand, as has happened during the Covid pandemic? Marek Lukaszczyk, WEG’s European and Middle East marketing manager, explores three ways in which they can increase their agility and efficiency. The water industry is having to adapt to changes resulting from the Covid pandemic and other factors such as climate change and increasing population densities

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