:c,kno>wle TechnicalJleportContributors (:Paul'Basore(SandJAN4tion� Laboratories) (EDS) a . niversity of Pennsylvania) {CaliforniaState University :'""Northrjdge) {orniaStatePolytechnicUniversity�romona) Motofs'Acce �� �r i ffi � ?� ·· ·· · OUrsineerethanks}o �1 who made this.report. possible, Many team ,Mof�r�iN1l��f Dj�si!)tf.,�, · ·· advisors t �j r bl� i eto a \\'er Indianapolis Power membef�.flld �0,3C?� ��� ,f � � n���rousques· · !Ulci11ghf;. tions abo�ftheirsolarccm: �a!teati{�i�we'areparncular1yt�et€. Land Rover those at!d tqEDS .qualifyingand Rocky Mountain w4o:�so sent:ph{;t§gffipbs, Jor�e News scoringcresults.iThankSztoLinda Bolander and Don Gwinner,NREL, Sandia NationalLaboratories ' the�·expertise;massemb,l�g.il!ld �iti�� this d ument Than�s.�l$�tto;fd SoleGtria Corporation � ;romSheffler (GM), BillJ)ye,(EDS), and Mike White (EDS)for their .... .. U.ShEnv:ironm.ental Prote�tionAgency . reviewof th�manuscript. Inc. u&iq�e,; Mobility, i:H : ii T a b 1 e 0 ·f Acknowledgements.•.•.... .... •.... ... , .. ............•..•...•.• � ...........•,, ... :............ i Introduction . .. .. .... .. .. ; ......... ... .......... ·.. ... ...... .... , ... ;' .. , .. ,........ l Chapter1: Sunrayce 95-ATwo-Year Endeavor ................•........ , .•......................2 1.1: TheFirst Year: Team- andCar-Building Begins . ... .. .. ...... ; .............. 2 1.2: TheS ec ond Year:Race. Preparations Begin •. ...•...•........... ........ .........4 ;,, ·Chapter2: Scrutineering •..................................•. , ..........•. ..; ..... .•........ 7 .•...•.•' . ,,, ... ' .•..... ' .•••..,: ........•...•.. ; ' ..•.• dmpte�3:flualifying ,. ••. .. 9 , .�Chap�r4: Th�·Race. '. ,,, .. ' ....... ' .. ' ....... ' ....... ' .. ' .. ' ........ ' ... ; ... ' ... 13 ; 4.1: >Th� Roufe. • ................ ..... ..............o; ••••• ••••••••• 13 4:2: �pa);pne' .. ' ....... ; ........ , .. '' ....... 13 ' f.S: D�yTwo ... ·' A,t Day Three ..· 45: , Day Four•· .. �.6: Th��t;S Day . ; .. � ' · .4;7: Day¥!ve .. :.. ..... : . ...... 4.8: Day Six 4.9: >bay Chap����11J�J'eami���e�·So1arCars.·; 5.1: The. Pre-Race Favorites • · Chapter6: Performance Comparison ......................... 6.1: Project dBu get ... .... .. ... .. 6.2: SolarResource andPerformance ...•....... 6.3: SolarArrays ...... , . .. , ... ., . • , : ......•.., , 39 6;4: Batteries .•...., ...,.......... ... ......... ; . ;, , ........... 41 6.5: BodyShapes andAerodynamics.. ... � .. .. 6.6: . ...... 48 SoJar,Ca:fWeighta n d ChassisDesign<............................. 6.7: Powertrain . • . • • . • . ··,":". • . • . • . • • . • . • . • • . ..•..... 50 6.&: Tiresand Wheels . .... ; ......................': ......................... :.. 52� 6.9: Solar�Ca:fTesting ........ ........ " ....... ' ............................. 54 6.10: Brakes ................. : ....................,•. ! .. 6Jl: References .. .•.•...�; ..• � ........................... , Appendix: Technicalon Data Each Team. • . • • . • . • ..••.. From June 20-29, 1995, more than a thousand college and univer­ applying classroom knowledge to real-world applications. Racing sity students from across North America tested their solar cars and a solar car requires a strategy for energy management. Although strategies against the environment in Sunrayce 95. The1,250- the sun's energy is plentiful, it is oftendispersed and may also be mile race, from Indiana to Colorado, is the third in a seriesof col­ unpredictable, thus requiring carsto have a means of storing ener­ legiate solar-car races across theUnited States. The tradition gy. Because only solar power is allowed, thecars must be energy began in 1990 with theGM Sunrayce USA fromFlorida to efficient. And to finish the race, the cars must also be reliable. Michigan. In 1993, the tradition continued as 34 solarcars raced The most powerful car did not win Sunrayce 95, nor did the light­ more than 1,100 miles fromTe xas to Minnesota in Sunrayce 93. est, nor did thecar with the most battery energy, nor did the car The U.S. Departmentof Energy, GeneralMotors Corporation, and with the greatest number of test miles. And for the ftrsttime in other organizationsteamed together in a unique partnership Sunrayce history, the winning team had far from thelargest pro­ between governmentand industry to sponsor Sunrayce 95. Their ject budget. The top-2 finishers did not modifytheir solar cells, goal was to make learning excitingand relevant to today's con­ and the chassis construction techniques were vastly different cerns and to demonstratethat brain power is more important than among the top teams. However, there is one feature that four of horsepower. the top-5 cars had in common-body style. MIT,Minnesota, Cal Poly Pomona, and Stanford all had central-canopy, "short-car" This report details the excitement and enthusiasm-as well as the designs that evolved fromthe 1990 MITand Waterloo concepts. setbacks-of thestudents involved in Sunrayce 95. We have Similar to the weight conclusion, the main reason for the short-car attempted to make this report as complete as possible. However, teamsplacing higher is probably because those teams did a better each person who participated has his or her own memories and overall job of engineering and coordinating their entire solar-car experiences. The authors and event sponsors hope that this report project, including the choice of body shape. will be used as both a documentary anda usefulguide for teams involved in future races. The fact thatno single vehicle or team statistic can overcome otherdeficiencies is a good sign thatthe Sunrayce title is trulyup Sunrayce 95 is more than the race-it's an engineering and busi­ for grabs to any team thattakes the time to thinkand create a ness challengethat starts almost 2 years before the race. well-balanced solar car and team. Colleges, universities, community colleges, tradeschools, and otherpost-secondary schools were invited to design, build, and race a solar-powered car. Designing and building a car requires 1 Sunrayce 95-A Two-Year Endeavor 1.1 The First Year: Team· and Car-Building Begins Any large project, such as building a solar car for Sunrayce, requires proper planning fromstart to finish.A schedule with milestones must be developed As soon as one race ends, planning for the next one begins. Barely 2 months early and adheredto. The sooner teams begin their projects, the more suc­ after34 solar-car teams crossed the Sunrayce 93 finishline, another group of cessful they arelikely to be. Figure 1.1.1 contains an example schedule for a solar-car teams were preparing to enter Sunrayce 95. On September 19, Sunrayce project. 1993, registrationfor Sunrayce 95 began. A request for proposals (RFP) was sent to every college and university in North America, with registration for Many teams started working on their projects early. For example, Mankato Sunrayce requiringa written proposal describing a team's project. The State University, which had participated in the 1990 and 1993 Sunrayces and school's proposal not only satisfies an important administrative function; it finished 16th in both, began work on their 1995 carin August 1993-before also asks students to conceptualize their whole project beforebeginning to they even received the RFP.Faculty advisor Bruce Jones said they con­ build a vehicle. ceived the design on the flight home fromthe World Solar Car Rally in Ogata, Japan, where they received top honors for their class of vehicles and Sixty-five schools submitted proposals on February 8, 1994, for registration. sixth place overall. Jones claims the students were inspired by some of the Allteams that submitted proposals were officiallyregist ered. These 65 car desigus they saw in Japan. Those ideas helped them conceptualize their teams were later invited to attend the Sunrayce qualifierto securestarting next solar car. positions in the race. For the 1995 race, Mankato decided to team up with Winona State University to double their effortsin building "NorthernLight III."They Figure 1.1.1: Sample milestone schedule. 2 divided tasksbetween the schools and used inter­ Michigan team began workingon their Solar solar car appeared in the Journal every day of the active television for group meetings.The Winona Vision in September 1993. The team spent 9-day event. team took the lead on the car's frame,while months researching possible improvements over The South Dakota team researched the fust two Mankato focused on the composite shell. What their last two carsand focused theirefforts on Sunrayce competitions and decided to design for they couldn't buy, extractfrom previous solar building something better. As defending champi­ reliability. They recognizedthat cars with rela­ cars, or dredge up fromdumpsters at high-tech ons, they knew they were the team to beat. tively few, ifany, breakdowns were the top fm­ companies, they built themselves. Team members The South DakotaSchool of Mines & ishers in 1990 and 1993. They also realizedthat remember salvaging scraps of expensive light­ Technology was another team that got offto an the chancesfor cloudy weather were high, so weight material being discardedby Northwest early start. Faculty advisorDan Gerbec heard they chose a catamaran design to give them an Airlines. "It's allpart of being resourceful,"they about Sunraycein 1993 and wanted his school to advantage on diffuse, cloudy days. claim. participatein 1995. He started recruiting students When more students were needed to help build and makingplans beforereceiving the RFP, their car-theSolar Rolar-the team