A Quasi-Experimental Cost-Effectiveness Evaluation of Power-Distribution Equipment Systems in Ghana

{ "background": "The selection of power-distribution equipment in developing economies is often based on initial capital cost, with limited rigorous analysis of long-term cost-effectiveness. This creates significant lifecycle cost uncertainties for utilities, impacting grid reliability and financial sustainability.", "purpose and objectives": "This case study aimed to develop and apply a quasi-experimental methodology to evaluate the comparative cost-effectiveness of two prevalent medium-voltage distribution equipment systems in a West African context: conventional pole-mounted transformers versus compact substations.", "methodology": "A quasi-experimental design was employed, matching installation sites based on load profile, environmental conditions, and network topology. Lifecycle cost analysis was conducted over a defined period, incorporating capital, installation, maintenance, failure, and energy loss costs. Cost-effectiveness was modelled using a generalised linear model: $C{it} = \\beta0 + \\beta1 Ti + \\beta2 X{it} + \\epsilon{it}$, where $C{it}$ is the total cost for site $i$ at time $t$, $Ti$ is the equipment type, and $X{it}$ is a vector of covariates. Robust standard errors were used for inference.", "findings": "The compact substation system demonstrated a 23% lower mean normalised lifecycle cost per kVA. The cost difference was statistically significant at the 5% level, with a 95% confidence interval for the relative cost saving ranging from 17% to 29%. Higher initial capital expenditure for compact substations was offset by substantially lower aggregate technical and commercial losses and reduced maintenance interventions.", "conclusion": "The quasi-experimental approach provided a robust framework for comparative economic evaluation of infrastructure systems in a real-world utility setting, moving beyond theoretical costing models.", "recommendations": "Utilities should adopt structured lifecycle cost-effectiveness analyses, using quasi-experimental designs where randomised trials are impractical, to inform procurement and asset management policies. Regulatory frameworks should incentivise the adoption of equipment with superior long-term economic performance.", "