In the context of access to electricity, mini-grids have emerged as an electrification

strategy in the developing world. However, various technical, economic, sociopolitical

and governance issues militate against the sustainability of mini-grids.

Sustainability here is defined as the ability of mini-grids – specifically, those powered

wholly or partly by renewable sources - to meet present and future needs for domestic

and productive energy uses in a reliable, accessible, efficient and cost-effective

manner. The purpose of this paper is to critically review and synthesise the available

literature on the technical sustainability of mini-grids with a special emphasis on sub-

Saharan Africa (SSA), and highlight lessons for mini-grid projects in the region.

The paper has followed a structured review approach inspired by the systematic

review methodology. The review is based on studies published since 2000 (when minigrids

began gaining sustained attention in the SSA region) covering both academic

and policy-oriented literature which were identified through searches of various

databases and websites using predefined search strings. Specific inclusion and

exclusion criteria were then applied to the identified literature and the selected

material was analysed using NVivo. The content was analysed around four themes

considered important for technical sustainability as follows:

1. Quality of equipment and design or installation issues;

2. Technical indicators used;

3. Technical operations, repair and management;

4. Technical sustainability.

The paper found that the technical sustainability of mini-grids is influenced by system

design, construction quality, operations and maintenance and future capacity

expansion of the systems. Various choices at the design stage in terms of demand to

be serviced, system sizing, construction, component matching, demand

management, smart features, and consideration of non-technical issues affect the

technical sustainability of mini-grids. Trade-offs for cost minimisation often compromise

the flexibility of the system, affecting long-term prospects of the plant. A lack of

accurate data on load, resource availability and adequate local skills have also

affected mini-grid projects. Although smart systems have been introduced, their

effectiveness depends on user-friendliness, robustness, and durability. Furthermore,

the quality of installations and construction quality have also adversely affected

performance where local skills are in short supply and the quality of supply is

compromised. However, the embeddedness of the technology in the socio-cultural,

political and environmental context also influences the technical sustainability of minigrids.

The quality of service (in terms of availability, reliability, power quality and

adequacy) is directly influenced by the quality of maintenance and system

operation. Inappropriate operation of the system for various reasons such as a lack of

skilled operators, inability to strictly adhere to operating instructions and local

enforcement issues of good practices or absence of user engagement and

cooperation affects the plant performance and technical sustainability. Similarly,

irregular or inadequate maintenance of the plants due to financial, skills or other

4

constraints (e.g. remoteness of the plant, availability of spare parts, etc.) significantly

influences performance. Studies have reported the prevalence of poor operating

and maintenance practices in the mini-grid space, resulting in poor consumer

satisfaction. Although modular systems offer the advantage of easy capacity

expansion to meet future needs, in reality such expansion remains aspirational due to

poor financial resources of mini-grids.

Crucially, the paper identifies the limitations of existing frameworks for assessing the

technical sustainability of mini-grids and proposes a streamlined yet expanded

framework for measurement that incorporates the elements of renewability and

adequacy of electricity supply over the long term.