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Standard method and online tool for assessing and improving the energy efficiency of wastewater treatment plants

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Reducing energy wasted during wastewater treatment

The EU uses large amounts of energy to treat wastewater for reuse and disposal into the environment. Researchers have created a system to monitor this energy use and increase efficiency.

Climate Change and Environment icon Climate Change and Environment

Wastewater treatment plants are one of the most expensive public industries in terms of energy requirements, accounting for more than 1 % of total electricity consumption in Europe. EU water regulations make wastewater treatment obligatory for cities and towns, causing a major drain on power utilities. “As it stands, there an estimated 22 558 wastewater treatment plants in Europe, which use an estimated 15 000 gigawatt hours of energy a year,” says ENERWATER project coordinator Dr Almudena Hospido. The EU-funded initiative set out to boost the energy efficiency of wastewater treatment plants to reduce carbon emissions and protect the environment. The team created a freely available online tool to help the wastewater sector measure a plant’s energy efficiency, and to make recommendations for cost and energy savings. Finding consensus in Europe “Achieving consensus has been our priority and this has been promoted by the organisation of several stakeholder events, one per country included in the consortium,” says Dr Hospido. The researchers consulted with stakeholders in Germany, Spain, Italy and the United Kingdom to reach energy saving goals using ENERWATER. The consensus mission showed the ENERWATER team that their system should not only label the energy efficiency of a treatment plant but also recommend ways to make it more cost-effective. The researchers then developed their efficiency benchmarking system to support routine measurements and detailed ‘energy hotspot’ monitoring in plants. After studying the standardisation landscape in the EU, the researchers found no specific framework for energy efficiency within the wastewater sector. As a consequence, the team consulted with the CEN/TC 165, a wastewater engineering committee, which resulted in a technical report to be used as a basis for training auditors. A freely available online tool The team created the easily accessed online platform to be used by any wastewater utility that wants to calculate its energy efficiency. Team members presented their results at several international conferences, and wrote a paper that provides details on ENERWATER state-of-the-art methods for energy benchmarking. The researchers also created better methods to deal with the large amounts of data to diagnose factors impacting energy efficiency. The project was not without its challenges. The researchers faced difficulties with installing equipment and multiple delays due to different water treatment plant layouts. Of the 50 wastewater treatment plants identified, the researchers successfully monitored 49 plants, with 46 of them being monitored for more than a year. Moving forward, the researchers plan to get their ENERWATER methodology approved as a European standard. The team hopes to promote the use of the ENERWATER online tool where users are guided step by step to enter energy measurements and view analytics.


ENERWATER, energy, wastewater, water treatment, energy efficiency, energy saving, CEN/TC 165, energy measurements

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