Rail coaches with rooftop solar photovoltaic systems: A feasibility study

The performance of solar photovoltaic modules mounted on the rooftop of a rail coach of The Indian Railways is reported here. The focus of this experiment was to quantify the reduction in diesel consumption of the end-on generation system that powers the electrical load in the new generation coaches. A coach retrofitted with two flexible solar photovoltaic modules was run at speeds up to 120 km/h by coupling it to three popular trains of south India. Based on the experimental results, the benefits of operating solar rail coaches is projected. It is estimated that one solar rail coach can generate atleast 18 kWh of electricity in a day, leading to an annual diesel saving of 1700 litre. The Indian Railways operates 63,511 coaches and hence, under ideal conditions, can save around 108.5 million litre of diesel annually. This would help to control environmental pollution and mitigate climate change, as it reduces the carbon dioxide emission by 2.9 million tonnes in a year. A statistical model was developed to estimate the power output per unit rooftop area of the coach, to enable The Indian Railways to calculate the benefits of operating solar rail coaches on various routes.