Renewable energy and energy efficiency technologies for wastewater treatment works in South Africa

This factsheet by GreenCape provides technical and financial guidance on implementing mini-hydro and wind power technologies in South African wastewater treatment works (WWTWs) to reduce energy costs and carbon footprints.

• Water supply and wastewater treatment account for approximately 17% of the total energy consumed by municipalities in South Africa. Adopting energy efficiency (EE) and renewable energy (RE) technologies in WWTWs can lower energy bills, support climate change mitigation by reducing greenhouse gas emissions, and improve resilience against planned power outages known as loadshedding.
• Mini-hydro technology generates electricity from flowing water using turbines and generators, with capacities typically ranging from 5 kW to 100 kW for micro-hydro and 100 kW to 1000 kW for mini-hydro. In WWTWs, these systems can be integrated into existing infrastructure—specifically at headworks, aeration tanks, and clarifiers—to make installations more cost-effective. The business case for mini-hydro indicates an internal rate of return (IRR) of 10–20% and a payback period of 5–10 years.
• Small-scale wind generation is less common in South Africa due to its complexity and cost, requiring multi-year wind studies for validation. While it does not affect WWTW operations, it serves as supplementary infrastructure to offset grid energy use. Capital costs for these systems range from 6,000 to 30,000 R/kWp, though the document notes a lack of sufficient case studies on successful projects.
• Financing for energy efficiency projects in municipalities can be sourced through several mechanisms: municipal budgets (via IDP, WSDP, SDBIP, and project business plans), 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, climate financiers, and energy performance contracts with Energy services companies (ESCos).

APA

GreenCape (n.d.). Renewable energy and energy efficiency technologies for wastewater treatment works in South Africa. https://greencape.co.za/wp-content/uploads/2023/08/Factsheet-8_Mini-Hydro-and-other-Alternative-Generation.pdf

Chicago

GreenCape. Renewable energy and energy efficiency technologies for wastewater treatment works in South Africa. n.d. https://greencape.co.za/wp-content/uploads/2023/08/Factsheet-8_Mini-Hydro-and-other-Alternative-Generation.pdf.

Wikipedia

{{cite report |author=GreenCape |title=Renewable energy and energy efficiency technologies for wastewater treatment works in South Africa |url=https://greencape.co.za/wp-content/uploads/2023/08/Factsheet-8_Mini-Hydro-and-other-Alternative-Generation.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{greencapendrenewable, author = {{GreenCape}}, title = {{Renewable energy and energy efficiency technologies for wastewater treatment works in South Africa}}, institution = {GreenCape}, url = {https://greencape.co.za/wp-content/uploads/2023/08/Factsheet-8_Mini-Hydro-and-other-Alternative-Generation.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }