UNDERSTANDING AND MANAGING RESIDENTIAL SOLAR ROOFTOP PV

This briefing paper by WWF South Africa examines the challenges South African municipalities face as residential rooftop solar photovoltaic (PV) installations disrupt traditional electricity distribution and revenue models. It highlights the tension between the financial interests of municipalities, which rely on electricity sales to cross-subsidise low-income households, and the economic incentives for affluent homeowners to install PV systems, often without registration. The document proposes the use of strategic tariff design and a new computerised decision-making tool to help municipalities manage the technical, social, and financial complexities of the energy transition.

• A significant majority of residential rooftop PV installations in South Africa are unregistered with municipalities. Approximately 75% of households with these systems do not inform their electricity provider, partly because mechanical disk meters can "run backwards," effectively granting the user a higher net-metering tariff than the municipality's official feed-in tariffs.
• Rooftop PV installations create a financial strain on municipalities by eroding the revenue used for cross-subsidisation. Because affluent, high-electricity users are the primary adopters of PV, municipalities lose the high-tariff sales typically used to fund free basic electricity for indigent households and other underfunded municipal services.
• The proliferation of unregistered PV systems poses technical and safety risks to the electricity grid. These include the danger of live wires for technicians and the potential for local grid failure due to overloading when clustered installations feed electricity back into the grid without municipal coordination.
• The Inclining Block Tariff (IBT), originally designed to protect the poor and encourage energy efficiency, has become regressive due to rooftop PV. Wealthier consumers use PV to avoid the highest-priced electricity blocks, while the municipality loses the revenue needed to maintain the social objective of the IBT.
• Municipalities can use tariff redesign as a tool to influence consumer behaviour and ensure cost recovery. Options include implementing capacity charges to safeguard revenue regardless of energy consumption, or using time-of-use (TOU) tariffs to incentivise PV generation during peak demand periods.
• Researchers from the Centre for Renewable and Sustainable Energy Studies (CRSES) at Stellenbosch University are developing a computerised electricity decision-making tool. This simulation-based tool uses "agents" (such as consumers, policymakers, and utilities) to help municipalities visualise the long-term (20-year) financial, stability, and environmental impacts of different policy and tariff decisions.

APA

Kritzinger, K., Scholtz, L., & Korsten, N. (2020). UNDERSTANDING AND MANAGING RESIDENTIAL SOLAR ROOFTOP PV. WWF South Africa. https://wwfafrica.awsassets.panda.org/downloads/understanding_and_managing_rooftop_solar_pv.pdf

Chicago

Kritzinger, Karin, Louise Scholtz, and Nikkie Korsten. UNDERSTANDING AND MANAGING RESIDENTIAL SOLAR ROOFTOP PV. WWF South Africa, 2020. https://wwfafrica.awsassets.panda.org/downloads/understanding_and_managing_rooftop_solar_pv.pdf.

Wikipedia

{{cite report |last1=Kritzinger |first1=Karin |last2=Scholtz |first2=Louise |last3=Korsten |first3=Nikkie |title=UNDERSTANDING AND MANAGING RESIDENTIAL SOLAR ROOFTOP PV |publisher=WWF South Africa |date=August 2020 |url=https://wwfafrica.awsassets.panda.org/downloads/understanding_and_managing_rooftop_solar_pv.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{kritzinger2020understanding, author = {Kritzinger, Karin and Scholtz, Louise and Korsten, Nikkie}, title = {{UNDERSTANDING AND MANAGING RESIDENTIAL SOLAR ROOFTOP PV}}, institution = {WWF South Africa}, year = {2020}, month = aug, url = {https://wwfafrica.awsassets.panda.org/downloads/understanding_and_managing_rooftop_solar_pv.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }