Electric bus rapid transit supported by solar generation: A scalable economic model for zero-emission urban transit

The transition to zero-emission public transport, particularly through electrification, presents environmental and economic challenges, especially in emerging economies, where financial constraints and policy gaps restrict the deployment of large-scale solutions. This study develops a scalable economic model for implementing solar-powered electric Bus Rapid Transit (BRT) systems, using the Brazilian city of Cuiabá as a case study. The selection of Cuiabá as the case study is based on its representativeness as a medium-sized Brazilian city characterized by rapid population growth, ongoing expansion of mass transit infrastructure, and a predominantly clean energy matrix. Technical and economic simulations indicate that integrating photovoltaic (PV) generation into the fleet’s charging infrastructure can reduce the Total Cost of Ownership (TCO) by 19.17 % over 10 years. The proposed system supplies 64.12 % of the fleet’s energy demand from solar generation, resulting in monthly savings of USD 176,490.57 compared with a diesel-powered fleet. Despite higher initial capital costs, the model yields a payback period of 7 years and an Internal Rate of Return (IRR) of 34.21 %, confirming financial feasibility. Under a distributed generation rental scheme, the IRR increases to 36.73 % and cumulative savings reach USD 231,000 per bus over 10 years. The results provide quantitative evidence that integrating renewable energy sources can enhance the financial viability of electric BRT systems, supporting policy and investment decisions for sustainable urban transport. • Proposes a scalable techno-economic model for integrating solar generation into electric Bus Rapid Transit (BRT) systems in medium-sized cities. • Introduces a methodology for PV–BRT coupling, combining technical simulation and financial modeling to assess system feasibility. • Demonstrates significant cost reduction, achieving a 19.17 % decrease in Total Cost of Ownership and a 7-year payback period under Brazilian market conditions. • Assesses alternative financing structures, showing that a distributed generation rental model improves profitability and supports public–private partnerships. • Provides policy-oriented insights, offering a replicable analytical framework to guide decision-making on electric public transport adoption in emerging economies.