We investigate the use of photovoltaic systems as auxiliary power generators in hybrid and electric vehicles. This technology provides an as yet unexploited possibility with the advantages of a new power source, which is light, noiseless, maintenance-free and continuously working. A notable reduction of air emissions can be achieved through a synergy of various technological breakthroughs, such as the method we present of introducing photovoltaic arrays and additional electrochemical energy storage capacity in vehicles. Solar cars are also considered as a case study in order to demonstrate the use of solar panels in electric cars. However, solar cars cannot be used extensively in practice, while hybrid and electric cars have already been used for many years and their market share is increasing. In order to reduce further the fuel consumption and emissions from hybrid vehicles we propose the use of solar panels and additional battery capacity. Finally, we examine if the reduction in the fuel consumption and air emissions from the use of solar panels compensates for the additional cost involved. (C) 2011 Elsevier Ltd. All rights reserved.