Solar Solutions for Informal Settlements: Advancing Climate Resilience in Global South Cities

Systematic Evidence-mapping Review

This study employed a literature-based comparative analysis, complemented by empirical survey evidence, to examine the transformative potential of decentralised solar energy for climate resilience and energy justice in informal settlements. Rather than a full PRISMA-style systematic review, a systematic evidence-mapping approach was used to identify, screen and synthesise academic and grey-literature sources across multiple disciplines.

Searches were conducted in Scopus, Web of Science and Google Scholar, supplemented by targeted searches of institutional repositories and organisational websites (e.g., United Nations, World Bank, International Renewable Energy Agency, municipal governments and community-based organisations). The main search period extended from the inception of each database to 2025, reflecting the long historical arc of energy transitions (Bhutada, 2022) while ensuring the inclusion of recent research.

Boolean operators (AND, OR, NOT) and truncation (*) were used to refine and expand search terms across databases by capturing related keywords and variations. Illustrative keyword combinations included: ‘solar energy’ AND (‘informal settlements’ OR ‘slums’ OR ‘favelas’); ‘energy poverty’ AND ‘urban Global South’; ‘decentralised energy’ OR ‘microgrids’ AND ‘informality’; ‘energy justice’ AND (‘community-led’ OR ‘cooperative solar’); ‘climate resilience’ AND ‘informal settlements’ AND ‘renewable energy’.

Titles and abstracts were screened using the following inclusion criteria: (a) focus on urban informal settlements or comparable low-income contexts in the global South; (b) substantive engagement with decentralised solar energy or other small-scale renewable energy systems; (c) relevance to energy justice, energy equity, energy poverty, climate resilience or just energy transitions; (d) peer-reviewed articles, book chapters, or robust institutional/community reports.

Exclusion criteria included purely technical studies with no socio-spatial or governance analysis, purely rural electrification cases and opinion pieces without empirical or conceptual depth.

Case Selection and Empirical Context

From the reviewed literature, four cases were selected: Dharavi (Mumbai, India), Rocinha (Rio de Janeiro, Brazil), Diepsloot (Johannesburg, South Africa) and Lephalale (Limpopo, South Africa). Case selection followed an iterative process guided by the conceptual framework and research questions. These cases were chosen because they represent dense, low-income settlements characterised by informality, climate vulnerability and energy poverty; demonstrate the presence of decentralised solar initiatives (including community-scale interventions); offer sufficient academic and grey literature to enable triangulation of governance, financing, participation and justice outcomes; and collectively reflect diverse sociopolitical and energy-governance contexts across the global South.

Qualitative content analysis was conducted using a coding framework derived from the conceptual framework and research questions. Key thematic categories included: (a) types and scales of decentralised solar interventions; (b) baseline energy poverty and patterns of energy apartheid; (c) governance structures across municipal, community and national levels; (d) the roles of intermediaries, federations and grassroots organisations; (e) financing mechanisms and ownership models; (f) tenure and regulatory constraints; and (g) distributional, procedural and recognitional justice outcomes, including gendered dimensions. Coding was undertaken using Microsoft Excel to organise, compare and refine themes, supported by colour-coding and pivot tables to enable systematic cross-case analysis.

Despite being the fourth case study, empirical survey data from Lephalale are incorporated as supporting evidence. The survey, conducted as part of a broader study on just energy transitions in a coal-dependent municipality, provides insight into community perceptions of energy access, affordability, governance and transition risks. Structured questionnaires were administered across formal and informal areas, capturing perspectives on energy access and affordability, coal dependency and anticipated employment impacts, participation in decision-making, attitudes towards renewable energy and spatial inequalities in electrification.

Key findings reveal pronounced patterns of energy injustice and transition tension: 74.1 per cent of respondents perceived unequal energy access, particularly affecting informal settlements; 83.3 per cent reported exclusion from energy decision-making, with 70.4 per cent identifying government as the dominant actor; and 85.2 per cent expressed support for renewable energy despite widespread concerns about affordability. At the same time, 87 per cent anticipated job losses linked to coal phase-out, underscoring the socio-economic risks of transition. Spatial disparities were particularly stark, with full electrification in formal areas compared to no access in the Thulare Park informal settlement.

These empirical insights complement the case study analysis by grounding the conceptual framework in lived experience, illustrating how energy poverty, energy apartheid and governance exclusion shape both perceptions and the practical feasibility of decentralised solar transitions in South Africa.

Limitations and Scope

As a primarily literature-based and survey-supported analysis, this study is subject to several methodological limitations. Three of the four case studies (Dharavi, Rocinha and Diepsloot) rely predominantly on secondary sources, including academic literature, NGO reports and grey literature, which vary in depth, methodological rigour and temporal coverage. Many decentralised solar initiatives are documented through project-based reporting with limited longitudinal evaluation, making it difficult to assess long-term performance, durability and scalability across contexts.

While the inclusion of survey data from Lephalale provides important empirical grounding, it is also constrained by the challenges of primary data collection in complex and resource-limited settings. These include potential sampling biases, reliance on self-reported perceptions and limitations in capturing rapidly evolving socio-economic and energy dynamics. As such, the empirical component is intended to provide contextual insight rather than statistically generalisable findings.

The cross-case comparison enables the identification of recurring structural patterns related to energy justice, governance and decentralised solar implementation. However, it cannot fully capture the internal heterogeneity of each settlement, nor the diversity of actor interests, informal practices and temporal dynamics that shape energy transitions on the ground. Furthermore, differences in data availability across cases limit the extent to which direct comparisons can be made.

Accordingly, the findings and policy recommendations should be interpreted as analytically indicative and context-sensitive, rather than universally generalisable. Their applicability is most relevant to urban contexts characterised by similar configurations of informality, structural inequality and governance constraints.

These limitations point to the need for future research that is longitudinal, participatory and mixed-method in design, with greater emphasis on in-situ data collection, comparative ethnographic work and the tracking of decentralised solar initiatives over time. Such approaches would enable a deeper understanding of how socio-technical systems evolve, how justice outcomes materialise in practice, and how unintended consequences or trade-offs emerge across different contexts in the global South.

Dharavi, Mumbai

Dharavi exemplifies the convergence of climate vulnerability, energy poverty and spatial inequality that characterises many informal settlements in the global South. With an estimated population approaching one million residents in a compact area, overcrowding, insecure tenure and overstretched infrastructure heighten exposure to heat, flooding and environmental hazards (Abunyewah et al., 2018; Dovey & Tomlinson, 2012). Irregular grid supply, overloaded networks and the presence of informal electricity cartels reproduce entrenched energy injustice (Kovacic et al., 2016; Nutkiewicz et al., 2018).

Within this context, decentralised solar initiatives have emerged as a means of improving energy access and resilience. A distinctive feature of Dharavi is its strong network of intermediary and grassroots organisations, particularly the National Slum Dwellers Federation and the women-led Mahila Milan (World Economic Forum, 2025). These federated groups facilitate resident mobilisation, coordinate savings schemes, negotiate regulatory barriers and support community engagement in upgrading initiatives.

Projects such as Project Brighten, implemented in partnership with technical experts and national ministries, illustrate how intermediaries bridge the gap between state institutions, private providers and residents to support decentralised solar adoption in highly constrained settings (Abramova et al., 2021). Rooftop PV installations and community-scale systems have been piloted on selected buildings, with an emphasis on improving lighting, safety and indoor comfort. However, scaling remains limited by tenure insecurity, informal cartels and fragmented regulatory frameworks (Dovey & Tomlinson, 2012).

Dharavi thus demonstrates how federated savings groups and women-led intermediaries can simultaneously address financial, organisational and recognitional dimensions of energy justice. Their roles extend beyond implementation to include the articulation of justice claims within broader urban planning and decarbonisation debates (Peddibhotla et al., 2024).

Rocinha, Rio de Janeiro

Rocinha is one of the largest informal settlements in Latin America, located on a steep hillside in Rio de Janeiro. It faces chronic climate exposure, including landslide and flood risks, as well as persistent energy inequality, with unreliable grid access and high electricity tariffs (Arcidiacono et al., 2017). Many residents spend a disproportionately high share of their income on electricity, exacerbating energy poverty and reinforcing social vulnerability.

Within this environment, decentralised solar projects have offered an alternative pathway for enhancing energy justice and climate resilience. Central to these initiatives is the role of local organisations, especially Revolusolar and the Sustainable Favela Network, which function as key intermediaries in the deployment of community-owned solar systems (Catalytic Communities, 2018; International Cooperative Alliance, n.d.). These organisations coordinate participatory governance processes, train local technicians, mobilise grant and cooperative financing and negotiate with municipal and regulatory bodies.

Solar cooperatives on community buildings have reduced energy costs, improved supply stability and created local employment opportunities, including for women and youth (Arcidiacono et al., 2017; IRENA, 2024). Revolusolar’s model of cooperative ownership and benefit-sharing illustrates how decentralised solar can be embedded within existing social infrastructures, generating distributional and procedural justice gains. Nonetheless, coverage remains partial, and initiatives must navigate complex regulatory regimes and political volatility.

The case of Rocinha highlights the importance of cooperative governance and intermediary networks in translating the technical potential of distributed solar into durable community benefits. It exemplifies how grassroots agency can problematise existing norms and push for more democratic energy futures (Kovacic, 2022; Peddibhotla et al., 2024).

Diepsloot, Johannesburg

Diepsloot is a rapidly growing settlement on the northern periphery of Johannesburg, characterised by a mix of formal Reconstruction and Development Programme (RDP) housing, backyard shacks and informal structures. It reflects the enduring spatial inequities and energy injustices shaping South Africa’s urban landscape (Barnard-Naudé & Chryssostalis, 2022; Kovacic et al., 2016). Despite formal electrification efforts, many households continue to rely on unsafe or informal sources, including candles, paraffin and illegal connections, which contribute to fire hazards, crime risks and heightened vulnerability to extreme weather (Gilili, 2022).

Two contrasting solar initiatives in Diepsloot illustrate the importance of governance and intermediaries. A municipal-led solar street-lighting programme failed almost immediately due to poor maintenance, institutional fragmentation and unclear responsibilities for operations and repair (Gilili, 2022). By contrast, Project Sunshine, led by Greenpeace Africa and the Philile Foundation, successfully installed crowdfunded solar lights in key public areas, enhancing safety and mobility (Ngakane, 2017). Here, NGOs and local committees acted as intermediaries, mobilising residents, coordinating installations and framing energy access as a matter of justice.

However, the long-term sustainability of Project Sunshine has been challenged by funding constraints and the absence of formalised maintenance frameworks. Diepsloot thus highlights two critical insights: (a) decentralised solar systems require clear, long-term governance and maintenance structures; and (b) community-led intermediaries are essential for initiating and sustaining decentralised energy solutions in contexts where municipal support is limited or ambivalent.

Lephalale (Limpopo), South Africa

Lephalale illustrates how informal settlements across the global South face escalating climate risks, persistent energy poverty and deep spatial inequalities. Although the municipality reported high grid connectivity (93%) (Lephalale Local Municipality, 2023), many low-income households—particularly in informal areas—continue to struggle with affordability, unreliable supply and limited alternatives. As a result, access to electricity does not translate into meaningful energy security.

The town’s economy remains heavily dependent on coal, with major infrastructure including the Matimba and Medupi power stations and the Grootegeluk Coal Mine. Recent developments, such as the Exxaro Resources and Cennergi Lephalale Solar Project (Exxaro, 2023), reflect a shift towards renewable energy. However, the project primarily supplies electricity to the coal mine under a long-term agreement, raising concerns about who benefits from the transition. While it may reduce emissions and support industry, it does little to address energy access challenges faced by the surrounding low-income and informal communities.

This uneven distribution of benefits highlights how energy transitions can reinforce existing inequalities if not carefully governed. Wealthier households are more able to adopt alternative energy sources such as solar, while poorer communities remain dependent on costly and unreliable grid electricity. In this context, decentralised solar has the potential to improve access, reduce vulnerability and support climate resilience.

However, as this case demonstrates, decentralised renewables can only advance equitable and climate-resilient urban futures when embedded within broader socio-technical and political transformations. Without addressing issues of affordability, governance and inclusion, such interventions risk reproducing the very inequalities they seek to resolve.

Comparative Analysis

The comparative analysis shows that decentralised solar energy can contribute to climate resilience and energy justice, but only under specific sociopolitical and governance conditions. Across Dharavi, Rocinha and Diepsloot, decentralised solar emerges as a context-responsive solution to energy poverty in dense informal settlements, where unreliable grid access, high costs and unsafe energy alternatives increase vulnerability to climate and socio-economic risks. However, Lephalale—examined through empirical survey evidence—demonstrates that similar patterns of exclusion persist even in a coal-dependent municipality, highlighting that energy transitions are shaped as much by governance and inequality as by technology.

The case studies highlight both shared challenges and context-specific pathways. In Dharavi and Rocinha, strong intermediary structures and community-based governance play a central role in enabling decentralised solar initiatives. Federated savings groups, cooperatives and local networks facilitate participation, mobilise resources and support co-ownership models, contributing to improved energy access, reduced costs and enhanced local resilience. These cases illustrate how decentralised solar can support climate adaptation and livelihood resilience, particularly when embedded in collective action and flexible governance arrangements.

In contrast, Diepsloot reflects the fragility of decentralised solar interventions where institutional support is weak, and maintenance responsibilities are unclear. While NGO-led initiatives such as solar street-lighting demonstrate potential benefits—particularly for safety and mobility—the lack of sustained governance and financing mechanisms limits long-term impact. This underscores that decentralised solar alone is insufficient without stable institutional frameworks and accountability mechanisms.

Lephalale reinforces these insights by illustrating the constraints of transitioning within a coal-dependent and centralised energy system. Despite high levels of grid connectivity, survey findings reveal persistent energy poverty, affordability challenges and strong perceptions of exclusion from decision-making. The absence of intermediary structures and limited decentralised solar implementation highlights how procedural and distributional injustices constrain the uptake of alternative energy solutions, even where community support is high.

Across all four cases, a consistent pattern emerges: Decentralised solar can enhance climate resilience, energy access and social inclusion, but its outcomes are uneven and contingent. Where governance is participatory, intermediaries are active, and financing models are inclusive (as in Dharavi and Rocinha), solar initiatives are more likely to deliver equitable and sustained benefits. Where these conditions are absent or weak (as in Diepsloot and Lephalale), interventions remain limited, fragile or exclusionary.

Overall, the comparison demonstrates that decentralised solar should not be understood as a standalone technical fix, but as part of a broader socio-technical and political transformation. Advancing climate-resilient and just urban futures in informal settlements requires not only technological deployment but also inclusive governance, equitable financing and sustained institutional support that address the structural drivers of energy inequality.

Distributional Justice: Conditional Benefits and Climate-resilient Livelihoods

Across the cases, decentralised solar contributes to distributional justice by improving access to energy, reducing costs and enhancing climate resilience—but only under specific enabling conditions. In Dharavi, rooftop PV and micro-grid initiatives reduce reliance on hazardous informal connections and improve thermal comfort (Abramova et al., 2021; Nutkiewicz et al., 2018). In Rocinha, cooperative solar models lower energy costs and stabilise supply, delivering measurable benefits to households (Arcidiacono et al., 2017). In Diepsloot, solar street-lighting enhances safety and mobility, particularly for women and children (Gilili, 2022; Ngakane, 2017).

These outcomes reflect partial reductions in energy poverty, understood here as a distributional injustice linked to inadequate access to affordable and reliable energy (Sovacool & Dworkin, 2015). However, the benefits remain uneven and fragile. Without sustained financing, governance support and maintenance systems, interventions fail to scale or endure.

Evidence from Lephalale reinforces this limitation. While respondents strongly support renewable energy and identify solar as a pathway to improved well-being (Valodia, 2023), high costs and persistent inequality constrain access. This highlights that decentralised solar can improve distributional outcomes, but cannot, on its own, resolve structurally embedded energy poverty.

Procedural Justice: Governance Exclusion and Participation

Procedural justice—relating to participation and decision-making—emerges as a critical determinant of outcomes. In Lephalale, 83.3 per cent of respondents reported exclusion from energy decision-making, reflecting highly centralised governance structures. Similar dynamics are evident in Diepsloot, where weak or inconsistent municipal support undermines local initiatives (Gilili, 2022).

This exclusion sustains conditions of energy apartheid, defined here as systemic and institutionalised disparities in access and service quality (Reboredo & Carmody, 2025). In these contexts, communities remain dependent on unreliable or unsafe energy systems, with limited capacity to influence alternatives.

By contrast, Dharavi and Rocinha demonstrate that procedural inclusion enhances both equity and system durability. Intermediaries such as the National Slum Dwellers Federation, Mahila Milan, Revolusolar and the Sustainable Favela Network facilitate participatory governance, enabling communities to co-design, implement and manage solar systems (Abramova et al., 2021; Catalytic Communities, 2018). These processes align with broader findings on ‘politics from below’, where community agency reshapes energy transitions (Peddibhotla et al., 2024).

Recognitional Justice: Intermediaries, Community Agency and Gender

Recognitional justice focuses on whose knowledge, needs and identities are acknowledged in energy systems. Across the cases, intermediaries and grassroots organisations play a central role in enabling recognition, particularly for marginalised groups.

In Dharavi, women-led organisations such as Mahila Milan embed gendered perspectives into energy governance, linking energy access to health, safety and livelihoods (IRENA, 2024). In Rocinha, cooperative structures ensure that local knowledge informs decision-making and that benefits are retained within the community (Arcidiacono et al., 2017). In Diepsloot, NGOs facilitate community mobilisation, although impacts remain constrained by weak institutional support (Ngakane, 2017).

These examples demonstrate that decentralised solar can support recognitional justice by validating local knowledge and addressing gendered dimensions of energy poverty. However, in Lephalale, the absence of strong intermediaries and limited community participation indicate a failure of recognition, where local needs and experiences are insufficiently incorporated into energy planning.

Structural Inequality and the Limits of Decentralised Solar

Across all four cases, the persistence of structural inequality constrains the transformative potential of decentralised solar. Conditions such as insecure tenure, high tariffs, infrastructural deficits and coal dependency reproduce patterns of energy apartheid and energy poverty, limiting who benefits from energy transitions (Kovacic et al., 2016; Reboredo & Carmody, 2025).

These dynamics are reinforced by dominant representations of informality as disorderly or deficient, which justify exclusionary planning practices and limit investment in informal areas (Altala, 2025; Kovacic, 2022). As a result, decentralised solar initiatives often remain small-scale, experimental or externally driven.

The Lephalale case illustrates these constraints clearly. Despite strong public support for renewable energy, coal dependency, high costs and governance exclusion prevent meaningful uptake. This confirms that decentralised solar cannot substitute for structural reform but must be embedded within broader socio-technical and political transformations (Healy & Barry, 2017; Peddibhotla et al., 2024).

Synthesis: Operationalising Energy Justice in Practice

Decentralised solar advances energy justice when the following conditions are present:

Distributional justice: improved affordability and access through inclusive system design.

Where these conditions are absent, interventions remain limited, fragile or exclusionary. This demonstrates that energy poverty and energy apartheid are not separate analytical categories, but outcomes of failures across the three dimensions of energy justice.

Recognise Informal Settlements in Climate–Energy Strategies

Informal settlements must be explicitly recognised within national, provincial and municipal climate–energy strategies. Tenure-sensitive regulations that legitimise community-scale solar installations are crucial in contexts where land titles are uncertain (Agegnehu, 2025). The relative success of Dharavi and Rocinha—where flexible regulatory arrangements enabled experimentation and community-scale projects—contrasts sharply with Diepsloot and Lephalale, where the absence of policy inclusion and secure rights has often locked informal areas out of energy programmes. Formal recognition within plans and budgets is therefore a precondition for scaling just decentralised solar solutions.

Design Pro-poor Financing and Ownership Models

Solar affordability is central to achieving energy justice. Capital subsidies, lifeline tariffs, microfinance and revolving community funds can reduce upfront cost barriers (Creutzig et al., 2017; Louie, 2025). Cooperative and trust-based ownership structures, as seen in Rocinha, enable residents to share costs, negotiate fair tariffs and maintain systems collectively (Catalytic Communities, 2018; ICA, n.d.). Dharavi’s federated savings groups further demonstrate how grassroots financial mechanisms can support small-scale but durable energy improvements (Abramova et al., 2021; World Economic Forum, 2025). Policymakers should design financial instruments around the economic realities of low-income households, including flexible payment schemes, targeted subsidies and support for community energy trusts.

Institutionalise Intermediaries and Gender-responsive Governance

Intermediaries—including informal-settlement federations, women’s groups, cooperatives and NGOs—should be formally recognised as governance partners rather than peripheral actors. Their involvement through co-production agreements, local energy committees and participatory planning processes enhances procedural and recognitional justice (Ahmad et al., 2024; Peddibhotla et al., 2024). Gender-responsive mechanisms, such as reserving seats for women in governance structures and supporting women-led enterprises in solar installation and maintenance, are crucial for addressing the gendered dimensions of energy poverty (IRENA, 2024). Rocinha and Dharavi illustrate how intermediary-led coordination sustains decentralised systems, while Diepsloot and Lephalale show the consequences of weak or absent intermediary structures.

Secure Long-term Operations and Maintenance

Sustainable decentralised systems require clear operations and maintenance frameworks. Policy instruments should define roles, responsibilities and cost-sharing arrangements among households, communities, intermediaries and municipalities. Community-based technical training programmes—such as those initiated in Dharavi and Rocinha—can build local expertise, create livelihoods and reduce reliance on external contractors (Abramova et al., 2021; Arcidiacono et al., 2017). Diepsloot’s experience demonstrates how solar initiatives deteriorate rapidly when maintenance responsibilities are ambiguous or underfunded (Gilili, 2022). Robust operation and maintenance contracts and dedicated funding streams are therefore essential for ensuring system reliability and user satisfaction over time.

Use Data and Networks to Challenge Deficit Narratives

Data-driven and networked approaches can be used to challenge deficit-based representations of informality. GIS mapping, remote sensing and community-led surveys can identify hotspots of energy poverty and climate vulnerability that are often obscured in official statistics (Abunyewah et al., 2018; Altala, 2025). The Lephalale survey illustrates how community-generated data can expose energy apartheid and governance exclusion, informing more targeted interventions. Comparative learning networks between settlements—such as the Sustainable Favela Network in Rio—can support the transfer of effective governance, financing and maintenance models (Catalytic Communities, 2018).

Crucially, policies must move beyond framing informal settlements as unstable or deficient spaces requiring expert intervention. Instead, they should recognise the institutional capacities, social networks and technical knowledge that exist within these communities (Kovacic, 2022). The achievements in Dharavi, Rocinha and parts of Diepsloot demonstrate that informal settlements are capable of co-producing energy solutions when recognised as legitimate urban actors. Lephalale shows the limitations that arise when communities remain excluded from planning and governance processes.