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A 100% renewable energy-based stand-alone microgrid system can be developed by robust energy storage systems to stabilize the variable and intermittent renewable energy resources. Hydrogen as an energy carrier and energy storage medium has gained enormous interest globally in recent years. Its use in stand-alone or off-grid microgrids for both the urban and rural communities has commenced recently in some locations. Therefore, this research evaluates the techno-economic feasibility of renewable energy-based systems using hydrogen as energy storage for a stand-alone/off-grid microgrid. Three case scenarios in a microgrid environment were identified and investigated in order to select an optimum solution for a remote community by considering the energy balance and techno-economic optimization. The "HOMER Pro" energy modelling and simulating software was used to compare the energy balance, economics and environmental impact amongst the proposed scenarios. The simulation results showed that the hydrogen-battery hybrid energy storage system is the most cost-effective scenario, though all developed scenarios are technically possible and economically comparable in the long run, while each has different merits and challenges. It has been shown that the proposed hybrid energy systems have significant potentialities in electrifying remote communities with low energy generation costs, as well as a contribution to the reduction of their carbon footprint and to ameliorating the energy crisis to achieve a sustainable future.A modern microgrid is an integrated energy system consisting of localised grouping of distributed electricity generation with storage and multiple electrical loads [11,12]. It can be controlled as one entity or grid, either standalone, completely separate from, or connected to, the existing utility grid [13]. The development of the microgrid has been largely dominated by energy demand-side management, RE penetration and its integration into the utility grid [14,15]. In cases where it is not possible to connect the microgrid to the utility grid for any reason such as the remote or isolated location, a stand-alone microgrid (SAM) is an answer to the power supply challenges [16]. The authors of this research envisioned that the SAM is a good starting point to transit from the classic trend of fossil-fuelled powered systems to 100% RE powered systems.The SAM is a low-voltage power system that supplies a specific localised area [17]. It comprises local power generation systems with load demands, that can operate in islanded mode or off-grid [18,19].In the transition to a 100% RE SAM system, hybrid distributed (decentralized) or centralized energy generation and storage systems are used to meet the energy need [18]. The SAM is presented as a viable and effective solution to the utilisation of renewable energy resources (RER), by minimizing the problems associated with variability and intermittency of the renewables [16]. The main challenge in a SAM system is the optimal sizing of the system components to make the...

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This study examines diffusion theory as an explanatory framework for the adoption of an ecological toilet by ‘first-moving’ customers in an urban setting in Malawi. The study was conducted during the early stages of a social marketing programme. A pragmatic paradigm was applied to address three research questions using mixed methods. The qualitative investigation formed the primary component of the study and interviewed 14 customers who were selected to receive micro-finance loans to purchase the ecological toilet. These 14 customers were labelled ‘first movers’. The study identified that ‘first movers’ only partially displayed characteristics of ‘innovators’ and the product met three of five characteristics associated with successful rates of diffusion. Improving the trialability and simplicity of the product, through field-testing, human-centred or participatory design approaches could improve the likelihood of the product attaining the characteristics that support successful diffusion. Organisations that apply social marketing approaches to improve urban sanitation coverage may improve their efficacy, equity and cost-effectiveness by utilising diffusion theory as the theoretical framework to design, implement and evaluate their programmes.

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