With ever increasing population growth and increase in per capita income, there is a lot of demand on energy requirements. Also due to depletion in fossil fuels, rocketing fuel prices and CO2 emissions standards, it is imperative to find solutions which are cost-effective and from sustainable energy sources. Being in the sunny tropical belt, India has high solar insolation, and so it should adopt a policy of developing solar power as a dominant component of the renewable energy mix. This paper describes the best possible ways to use solar energy for automotive application. This paper explains various types of photovoltaic (PV) technologies - crystalline and thin film solar cells for automotive use.A medium sized sedan vehicle with mild hybrid technology and roof mounted PV panel has been used for all experiments. The paper describe the benefits and limitations of each PV technology with experimental measurement and payback period analysis.During the experiments it was observed that PV panel's efficiency decreases with raise in ambient temperature . To address this issue, an innovative cooling system is developed, which is integrated with vehicle engine cooling system with a control system. The cooling system is designed in such way that it improves the PV panel efficiency; at the same time it preheats radiator water to reduce engine emission during first crank. This paper claim that the PV panel with mono crystalline technology having 16% efficiency and current PV panel cost, provides payback period of less than 3.5years. The paper also claims that with ongoing research if efficiency improves by another 2% and cost reduces by 10%; payback period will be less than 2.5years. Based on current trends it is believed that the same may happen in 3 years' time.The paper also covers the indirect benefits of the cooling system like reduction in cabin temperature due to PV panel and compares results with conventional and solar reflective painted vehicles.