Technical fact sheet for energy management and optimisation of wastewater treatment works

This technical fact sheet by GreenCape provides guidance for municipal officials, funders, and businesses on conducting energy efficiency (EE) audits and implementing process optimisations at wastewater treatment works (WWTWs) in South Africa to reduce electricity costs and greenhouse gas emissions.

• Wastewater treatment works (WWTWs) are significant energy consumers, with water supply and wastewater treatment accounting for approximately 17% of the total energy used by South African municipalities. Within WWTWs, the activated sludge process typically distributes energy consumption across aeration (13-80%), sludge treatment (5-35%), pumping (4-31%), and other processes (1-38%).
• Energy efficiency (EE) opportunities in WWTWs represent about 48% of the known electricity efficiency opportunities within overall municipal operations, particularly for metropolitan municipalities. Implementing EE interventions can result in potential energy savings of up to 75%, with payback periods ranging from a few months to approximately 7 years.
• The document outlines several technical strategies for process optimisation to reduce energy demand: - Process controls: Using real-time monitoring and automation for pumps, blowers, and aeration. - Peak shaving: Employing load shifting to off-peak hours and loadshedding of non-critical equipment. - Aeration: Installing variable frequency/speed drives (VFDs/VSDs) and fine-bubble diffusers. - Motor systems: Replacing inefficient motors and pumps and maintaining piping to reduce pressure drops. - Sludge management: Using gravity thickeners, optimising conditioning agents, and implementing heat recovery or anaerobic digestion for biogas generation.
• Various financing mechanisms are available for EE projects in municipalities, including municipal budgets (via IDP, WSDP, SDBIP), government or donor grants (such as MIG, RBIG, WSIG, Green Fund, and EEDSM), concessional loans from foreign funders (e.g., AFD, SEFA, DBSA), commercial bank loans, and Energy Performance Contracts (EPCs) through Energy Services Companies (ESCos).

APA

GreenCape (n.d.). Technical fact sheet for energy management and optimisation of wastewater treatment works. https://greencape.co.za/wp-content/uploads/2023/08/Factsheet-1_Energy-Audits-and-Process-Optimisation.pdf

Chicago

GreenCape. Technical fact sheet for energy management and optimisation of wastewater treatment works. n.d. https://greencape.co.za/wp-content/uploads/2023/08/Factsheet-1_Energy-Audits-and-Process-Optimisation.pdf.

Wikipedia

{{cite report |author=GreenCape |title=Technical fact sheet for energy management and optimisation of wastewater treatment works |url=https://greencape.co.za/wp-content/uploads/2023/08/Factsheet-1_Energy-Audits-and-Process-Optimisation.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{greencapendtechnical, author = {{GreenCape}}, title = {{Technical fact sheet for energy management and optimisation of wastewater treatment works}}, institution = {GreenCape}, url = {https://greencape.co.za/wp-content/uploads/2023/08/Factsheet-1_Energy-Audits-and-Process-Optimisation.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }