Energy storage systems

This factsheet by GreenCape provides technical and financial guidance on implementing energy storage systems, specifically Lithium-ion (Li-ion) batteries, at wastewater treatment works (WWTWs) in South Africa to improve energy security and integrate renewable energy.

• Lithium-ion (Li-ion) batteries are the dominant choice for energy storage in the South African backup sector due to their operational stability, faster charging times, and short-duration performance. The cost of these batteries has decreased by 90% since 2010.
• Energy storage systems do not reduce the overall energy consumption of a wastewater treatment work; instead, they are used to provide backup power or to increase the penetration of renewable energy technologies.
• The financial viability of energy storage varies by scenario: stand-alone storage has a payback period of 12–20 years and an IRR of 0–3%, while storage combined with solar PV offers a shorter payback of 6–12 years and an IRR of 8–10%. Capital costs for Li-ion storage range from R4000 to R8000 per kWh, with balance of system costs between R4500 and R6000 per kW.
• Energy storage can reduce carbon emissions by offsetting grid power (118–207 kgCo2 per kW per annum) or by offsetting diesel generation (605–1058 kgCo2 per kW per annum).
• To optimize costs and sizing, energy efficiency measures should be implemented before installing energy storage. Financing for such projects can be sourced via municipal budgets, grants (such as MIG, RBIG, and WSIG), concessional loans from entities like the DBSA or AFD, commercial bank loans, energy performance contracts, or climate financiers.

APA

GreenCape (n.d.). Energy storage systems. https://greencape.co.za/wp-content/uploads/2023/08/Factsheet-10_Energy-Storage-Systems.pdf

Chicago

GreenCape. Energy storage systems. n.d. https://greencape.co.za/wp-content/uploads/2023/08/Factsheet-10_Energy-Storage-Systems.pdf.

Wikipedia

{{cite report |author=GreenCape |title=Energy storage systems |url=https://greencape.co.za/wp-content/uploads/2023/08/Factsheet-10_Energy-Storage-Systems.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{greencapendenergy, author = {{GreenCape}}, title = {{Energy storage systems}}, institution = {GreenCape}, url = {https://greencape.co.za/wp-content/uploads/2023/08/Factsheet-10_Energy-Storage-Systems.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }