Journal Design Engineering Masthead
African Civil Engineering Journal | 26 April 2004

Quasi-Experimental Evaluation of Cost-Effectiveness in Rwanda's Power-Distribution Equipment Systems

M, a, r, i, e, C, h, a, n, t, a, l, N, i, y, o, n, s, e, n, g, a, ,, J, e, a, n, d, e, D, i, e, u, U, w, i, m, a, n, a
Power DistributionCost-EffectivenessQuasi-ExperimentalInfrastructure Investment
Quasi-experimental design applied to power-distribution equipment in Rwanda
Difference-in-differences analysis reveals 17.3% lifecycle cost reduction
Fault-tolerant switchgear outperforms conventional upgrade strategies
Methodology enables robust field evaluation in developing economies

Abstract

{ "background": "Power-distribution systems in many developing nations face significant challenges in balancing infrastructure investment with long-term operational efficiency. There is a notable scarcity of rigorous, field-based evaluations of the cost-effectiveness of different equipment strategies within these constrained contexts.", "purpose and objectives": "This study aimed to develop and apply a quasi-experimental methodology to empirically evaluate the comparative cost-effectiveness of alternative power-distribution equipment systems deployed within a national utility's network.", "methodology": "A difference-in-differences framework was employed, analysing operational and cost data from multiple network segments before and after the installation of new equipment types. The core statistical model was $Y{it} = \\beta0 + \\beta1 \\text{Treat}i + \\beta2 \\text{Post}t + \\beta3 (\\text{Treat}i \\times \\text{Post}t) + \\epsilon{it}$, where $Y_{it}$ is the total cost per unit of reliable energy delivered. Robust standard errors were clustered at the substation level to account for serial correlation.", "findings": "The intervention employing modernised, fault-tolerant switchgear demonstrated a statistically significant reduction in total lifecycle cost per MWh delivered. The estimated average treatment effect was a 17.3% cost reduction (95% CI: 12.1% to 22.5%) compared to conventional equipment upgrades in control segments.", "conclusion": "The quasi-experimental design provided robust, field-derived evidence that strategically selected, higher-capital-cost equipment can yield superior long-term cost-effectiveness in this operational environment by drastically reducing failure-related operational expenditures.", "recommendations": "Utilities should integrate prospective quasi-experimental evaluations into procurement planning to guide capital allocation. Policymakers should support regulatory frameworks that consider total lifecycle cost, not just initial capital outlay.", "key words": "cost-benefit analysis, difference-in-differences, distribution networks, lifecycle costing, power infrastructure", "contribution statement": "This paper