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From harmonics to ROI – unpacking the technoeconomic case for cleaner power in wastewater plants
By: Suvern Moodley - EcoConsult Business Development, Field Services, for Anglophone Africa at Schneider Electric
Behind every reliable wastewater plant is an electrical system exposed to the effects of harmonics, voltage distortion and overloaded networks caused by fleets of variable‑speed drives on pumps and aerators.
At plant level, harmonics are not just an abstract electrical theory issue, but a very real reliability risk, causing transformers to run hotter, motors and equipment to age more quickly, and cables to experience unnecessary stress. Protection systems start tripping more often, increasing the need for maintenance and the likelihood of unexpected failures and service interruptions.
While none of these issues will trigger dramatic alarms, together they steadily drive up maintenance demands and elevate the risk of failure.
In large facilities, such failures can have a ripple effect, disrupting production lines and amplifying losses over time. Without proper mitigation, the cumulative impact becomes significant.
More than just compliance
So, when we talk about power quality, we are really talking about plant stability, uptime and life‑cycle cost, not just compliance. The most common symptoms of poor power quality are those that quietly undermine reliability by causing equipment stress that makes plant performance unpredictable.
For municipal plants already operating on tight budgets, these unseen electrical stressors lead directly to higher life‑cycle costs and increased reliability risk. They erode stability long before anyone notices, and by the time the symptoms are obvious, the damage is already baked in.
By bringing real customer data into scenario modelling, the conversation shifts from “cost of mitigation” to “return on investment (ROI)” for power quality solutions. Once we move from theoretical assumptions to real facility data, we can model actual operating conditions and quantify far more than energy savings. We can measure avoided failures, longer equipment life and reduced maintenance.
Adding reliability to the equation
When reliability is added to the equation, energy mitigation stops looking like an engineering cost and starts looking like an infrastructure investment. That is when decision‑makers see the financial case, not just the technical one. Some solutions that seem expensive upfront actually deliver the strongest life‑cycle value, especially when rolled out as part of a phased infrastructure plan. Therefore, a true techno-economic assessment reveals value that energy-only analyses miss and often shortens the ROI.
In terms of available power quality solutions, many technology options have been evaluated as real implementation scenarios, not standalone devices. Using the plant’s data as the benchmark, we modelled each option, such as reactors, passive filters, active harmonic filters, low‑harmonic drives and hybrid combinations, to understand their true techno‑economic impact.
What stood out is that higher‑performing solutions do not just improve compliance; they also restore thermal margins, reduce stress on transformers and motors and stabilise maintenance cycles. It is the difference between running a car gently versus redlining it every day.
Real benefits for municipalities
For municipalities, these solutions translate directly into tangible benefits such as fewer failures, longer asset life and more predictable operating costs.
Schneider Electric’s work starts with understanding the plant, not pushing products before diagnosing the problem. We combine audits, digital modelling and life‑cycle analysis to pinpoint where the biggest reliability and financial gains lie. This gives utilities a clear roadmap for phased upgrades that align with budgets and asset‑replacement cycles. Instead of a once-off fix, it is a long-term strategy that strengthens reliability and improves financial performance.
Ultimately, power quality is fundamentally a reliability issue, not just a technical one, and that is why audits help customers see the real operational risk. Cleaner power strengthens equipment, stabilises operations, and ultimately supports more reliable water and wastewater services, which is the outcome that matters most.



