The Winning Solar Car

A Design Guide for SolarRace Car Teams

Other SAE books of interest:

Lightweight Electric/Hybrid Vehicle Designby Ron Hodkinson and John Fenton

(Order No. R-316)

Alternative Fuels Guidebookby Richard L. Bechtold

(Order No. R-180)

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The Winning Solar Car

A Design Guide for SolarRace Car Teams

Douglas R. Carroll

Warrendale, Pa.

All rights reserved. No part of this publication may be reproduced, stored in aretrieval system, or transmitted, in any form or by any means, electronic, mechanical,photocopying, recording, or otherwise, without the prior written permission of SAE.

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Library of Congress Cataloging-in-Publication Data

Carroll, Douglas R.The winning solar car : a design guide for solar race car teams /

Douglas R. Carroll.p. cm.

Includes bibliographical references and index.ISBN 0-7680-1131-01. Solar cars—Design and construction. I. Title.

TL222.C37 2003629.22'95—dc21 2003052648

SAE International400 Commonwealth DriveWarrendale, PA 15096-0001 USAE-mail: CustomerService@sae.orgTel: 877-606-7323 (inside USA and Canada)

724-776-4970 (outside USA)Fax: 724-776-1615

Copyright 2003 SAE International

ISBN 0-7680-1131-0

SAE Order No. R-343

Printed in the United States of America.

To my wife Karla,

for putting up with me as I spent an awful lot

of our time learning about solar cars.

Preface

Development of this book began in 1997, after the 1997 Sunrayce event. Ihad then been involved in designing and building three solar cars that partici-pated in the 1993, 1995, and 1997 Sunrayce events, respectively. As the coachand advisor for a university solar car team, I had the problem of losing somekey students with each project. The new students joining the team had thesame design misconceptions that the veteran students had when they beganand would want to make the same design mistakes that had been made onprevious cars. Making the same design mistakes again provides a good edu-cational experience for the students but does not further knowledge of solarcar design. To make progress and continually improve our design efforts, Ideveloped a course on solar car design and wrote notes to support the course.The purpose of the course was to get the new students up to speed, and thecourse focused on what is important in designing a competitive solar car.The notes became a little more formal each time I offered the course, andevolved into this book on solar car design.

The material in this book is based on my experiences designing and buildingfive solar cars over the last twelve years. I have tried to keep the book gen-eral and offer design options so that it is not just about how the University ofMissouri-Rolla team designs solar cars, but there is a certain amount of biasin our design philosophy. The book was designed to be used in a course thatis open to upper-level students majoring in any field of engineering, math-ematics, or science. Solar car design is an interdisciplinary topic, and thebook was written to be suitable for the junior, senior, and graduate studentswho would be responsible for designing the car. Students entering the courseare assumed to have a fundamental understanding of calculus, differentialequations, physics, and chemistry. The book provides an introduction to allaspects of designing, manufacturing, and racing solar cars but does not pro-vide all of the details on any topic. Design groups will have to go deeper thanwhat is provided in this book to design any of the systems on the car. Every-one on the team needs to have a fundamental understanding of what isinvolved in designing, building, and racing the car. Understanding the "bigpicture" will help team members make design and manufacturing trade-offs

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The Winning Solar Car

to stay on schedule and allow time to test and practice racing the car. Testingand practice are an important part of being successful in the competition.

To do well in a solar car race, the team must have a good car, good drivers,good weather information, good strategy, and a well-trained support team.Doing a poor job on any of these elements will hurt the performance of theteam in the race. The main focus of this book is on designing the car becausethat is the most difficult and time-consuming part of the project, but theteam needs to recognize that the car is not the whole project. Driver train-ing, accurate weather forecasting, race strategy, and practice in driving therace route make a huge difference in how well the team performs in thecompetition.

The first two chapters in the book are on energy management, and the infor-mation in these chapters is helpful when doing design trade-offs and devel-oping a strategy for racing the car. Chapter 2 includes information on how todrive the car efficiently and is helpful in driver training. Chapter 3 focuseson design methodology and project management and provides an introduc-tion to the general design process. The remaining chapters are about design-ing the different subsystems of the car. In each chapter, I have referred thereader to books and articles that I have found helpful on designing and build-ing solar cars. The goal of the book is to provide an introduction to all aspectsof designing, building, and racing solar cars.

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