Household-Perceived Success of Rooftop Solar Systems: Scale Development and Validation

This study develops and validates a scale to measure household-perceived post-installation success of rooftop solar systems. Critical success factor literature informs the selection of its five evaluative domains. The study covered rooftop solar system users in three districts of Kerala, India. Ten experts reviewed 21 preliminary items and retained 17. Exploratory structural equation modeling with 244 users refined the scale to 15 items. The five dimensions are Operational Efficiency, Economic Viability, Interaction Effectiveness, System Agility, and Stakeholder Participation. Confirmatory factor analysis with 480 users supported the five-factor structure (CFI = 0.999, RMSEA = 0.011, SRMR = 0.020). Reliability and convergent and discriminant validity were also supported. The five-factor model outperformed the one- to four-factor alternatives. Configural, metric, scalar, and strict invariance were supported across Off-Grid, Hybrid, and On-Grid users. The scale provides a multidimensional tool for assessing post-installation experience and identifying areas for improvement. It can inform households, installers, vendors, and policymakers working towards sustainable household energy transitions.