Decision-making frameworks for assessment of small-scale off-grid photovoltaic home system-based design concepts in rural context of north-east India

Energy security plays an influential role in developing sustainable cities and promoting a better quality of life for the population. The United Nations' sustainable development goal focuses on energy security. Against the backdrop of India's energy concerns in the northeastern region, the study investigates the user-centric challenges related to the designs of solar photovoltaic home system concepts to facilitate access to energy. This is followed by the proposal of design concepts for solar photovoltaic home systems that take due cognizance of the identified challenges. To facilitate determining the optimal design concept in the context of small-scale off-grid photovoltaic home systems the paper proposes and applies an extended TOmada de Decisao Interativa Multicriteria (TODIM) methodology wherein the linguistic evaluations have been modelled using T-Spherical fuzzy sets. The information was aggregated using T-Spherical Fuzzy Aczel-Alsina Hammy Mean and T-Spherical Fuzzy AczelAlsina Weighted Hammy Mean operators. Ten design concepts were developed and evaluated through the proposed decision-making frameworks. Five performance metrics arising out of the field study: Functionality, Reliability, Affordability, Novelty and Usability have been chosen to appraise the conceptualized design concepts. Design concept 3 has been revealed to be the optimal design concept for the application of the proposed approach. Sensitivity analysis of the ranking results revealed that although both the proposed methodologies are robust, the methodology based on T-Spherical fuzzy Aczel-Alsina Weighted Hammy Mean operator was revealed to be the superior of the two. By presenting an effective method to address the complexities in design assessment for off-grid PV systems, this research offers practical insights to guide context-specific design in the region.