The energy requirements of developing countries underpin progress towards achieving the Millennium Development Goals (MDGs). Rural electrification is acknowledged as key to providing a source of reliable, affordable and sustainable energy. Many planners and decision makers agree that the off-grid PV system has the potential to become a valued and straightforward source of electricity for remote rural communities. However, there are several challenges that need to be addressed to realize the potential of PV as a sustainable solution. These challenges are illustrated and highlighted by many reported cases of poor sustainability/longevity of PV installation in sub-Saharan Africa. This paper reviews the sustainability of off-grid renewable energy deployments in sub-Saharan Africa along with recent attempts to define sustainable energy frameworks. The specific case of off-grid PV systems for improved educational and health facilities are considered and a community based approach for improved sustainability is proposed. Case studies illustrating practical implementation of this approach in Gambia and Malawi are described

This paper assesses the impact of the location and configuration of Battery Energy Storage Systems (BESS) on Low-Voltage (LV) feeders. BESS are now being deployed on LV networks by Distribution Network Operators (DNOs) as an alternative to conventional reinforcement (e.g. upgrading cables and transformers) in response to increased electricity demand from new technologies such as electric vehicles. By storing energy during periods of low demand and then releasing that energy at times of high demand, the peak demand of a given LV substation on the grid can be reduced therefore mitigating or at least delaying the need for replacement and upgrade. However, existing research into this application of BESS tends to evaluate the aggregated impact of such systems at the substation level and does not systematically consider the impact of the location and configuration of BESS on the voltage profiles, losses and utilisation within a given feeder. In this paper, four configurations of BESS are considered: single-phase, unlinked three-phase, linked three-phase without storage for phase-balancing only, and linked three-phase with storage. These four configurations are then assessed based on models of two real LV networks. In each case, the impact of the BESS is systematically evaluated at every node in the LV network using Matlab linked with OpenDSS. The location and configuration of a BESS is shown to be critical when seeking the best overall network impact or when considering specific impacts on voltage, losses, or utilisation separately. Furthermore, the paper also demonstrates that phase-balancing without energy storage can provide much of the gains on unbalanced networks compared to systems with energy storage

Background: A novel project sustainability framework is used to evaluate 65 off-grid solar photovoltaic (PV) energy system projects in Malawi. This study addresses PV projects serving rural public facilities, a solution known to have had historical issues with poor sustainability. A recent countrywide program targeting such facilities was evaluated against existing projects to determine whether this latest iteration offered better results. Method: Sustainability is defined at the project-level with metrics justified under the main themes of technical, economic, social, and organizational. Data captured for each project is based on a custom survey and interview of key stakeholders. Projects are grouped according to age, project implementer, income level, and PV system size to compare relative results. Results: The sustainability outlook for each project is evaluated. We find sustainability for most projects to be low. Social sustainability was weak with many projects due to low local community stakeholder engagement in terms of numbers of stakeholders, meeting frequency, and community contributions. Organizational challenges included a lack of key management positions in place and extremely limited training provisions. Furthermore, the evaluation highlights the economic health of the system to be key to sustainability, with the "healthiest" projects affording only 37% of expected operations and maintenance costs. Relative to expected demand, systems were found to be undersized for both panels (53% of required) and batteries (57%). Users reported achieving only 60% of their desired consumption. Poor sizing standards related to the lack of load profiles for first-time electricity users as well as poor quality components reduced the overall technical sustainability. Conclusion: Rural public facilities with solar PV in Malawi are not well served by isolated community management. Improved sustainability requires the establishment of a robust financial framework prior to project development that includes formal local government support. This paper discusses ideal management frameworks and their ultimate implications for project developers, policy makers, and the research community.

The anticipated impact of low-carbon technology and the advent of the Smart Grid has provoked increased interest in the low voltage (LV) power distribution networks. Probabilistic and long period time-series analysis of LV networks is becoming increasingly common, as is the use of unbalanced, three-phase network modeling. This paper reviews some recent approaches to probabilistic analysis of LV networks and considers the uncertainty introduced by the underlying assumptions. A specific case study analysis of electric vehicle (EV) penetration on a generic UK distribution network is used to investigate the effect of key assumptions on the results of a probabilistic analysis. The paper concludes that probabilistic LV network analysis is a powerful tool for distribution network planning, however the trade-offs between imperfect modeling data and the reliability of results need to be well understood and incorporated into the interpretation of results

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