SolarCars:Batteries DAJ Rand, CSIRO Energy Technology, Clayton, VIC, Australia & 2009 Elsevier B.V. All rights reserved. In the Beginning On 19 December 1982, the Australian adventurer Hans Tholstrup manoeuvred the idea of a solar-powered land vehicle from concept to reality. With the assistance of fellow Australian Larry Perkins, an engineer and an ac- complished race driver, Tholstrup set out from Perth on the west coast of Australia in the fragile Quiet Achiever (Figure 1(a)) – now widely acknowledged to be the world’s first solar car. An immediate target was to beat the 28 days set by Francis Birtles in 1912 in the first motor vehicle to cross the Continent (Figure 1(b)). The Quiet Achiever weighed 125 kg and consisted of a tubular steel frame, four bicycle wheels, two 12-V lead– acid batteries, two simple power switches, and an electric motor. Twenty photovoltaic panels were placed across the top of the vehicle to form a horizontal roof. The chassis could be lifted out of the body quite easily and the car could be reassembled in 5 min. Tholstrup and Perkins arrived at the Sydney Opera House on 7 January 1983. The 4052-km transcontinental crossing had been completed at an average speed of 23 km h À1 in just 20 days, thus easily beating Birtles’s record. Moreover, the car had shown surprising reliabil- ity; there was not one breakdown during the long and arduous journey. The success of their epic energy-saving voyage ignited worldwide interest in solar cars and gave rise to the ‘brain sport’ of solar car racing. The first event was the Tour de Sol held in Switzerland in 1985 and over the years similar races have taken place at frequent intervals in Europe, Japan, Taiwan, and the United States of America (USA). Such competitions champion the creative integration of personal development with en- gineering and scientific expertise across a wide range of disciplines. Meanwhile, back in Australia, Tholstrup revealed the prime reason for his earlier adventure. His mission was to focus international attention on dwindling oil reserves and the environmental consequences of the profligate consumption of petroleum and, thereby, stimulate the development of sustainable road transportation for future generations. The solar car races taking place elsewhere were rally or track competitions. Tholstrup, however, considered that a gruelling, long-distance contest would provide a more realistic showcase and developmental tool for the latest in solar-powered transportation technology. Eventually, the lessons from such a ‘live laboratory’ would hopefully find their way into new automobile designs that would place lesser demands on the Earth’s environment and resources. And so the World Solar Challenge was born in 1987. It was dubbed the ‘Race for the Future’ and has become the international ‘green prix’ for solar cars. During the course of its nine meetings (1987–2007), the event has provided a remarkable record of the progress that has been made in rechargeable bat- tery technology, especially in terms of specific energy and reliability. Accordingly, this review of batteries for solar cars draws exclusively upon the experience gained from the World Solar Challenge. The World Solar Challenge The Stuart Highway – the course taken by solar cars in the World Solar Challenge – stretches some 3000 km, from Darwin in the north of Australia to Adelaide in the south; see Figure 2. The highway is named after John McDouall Stuart who, in 1862, and after five previous attempts, was the first to cross the continent from sea to sea. His journey took exactly 9 months. The first (a) (b) Figure 1 (a) The Quiet Achiever demonstrating that it was possible to cross a continent using only the power of the sun. (b) Francis Birtles on his journey from Perth to Sydney in 1912. 359 . this review of batteries for solar cars draws exclusively upon the experience gained from the World Solar Challenge. The World Solar Challenge The Stuart Highway – the course taken by solar cars. Solar Cars: Batteries DAJ Rand, CSIRO Energy Technology, Clayton, VIC, Australia & 2009 Elsevier B.V Earth’s environment and resources. And so the World Solar Challenge was born in 1987. It was dubbed the ‘Race for the Future’ and has become the international ‘green prix’ for solar cars. During the course of its