Solar Car Design

1. “Any intelligent fool can make things bigger and more complex... It takes a touch of genius - and a lot of courage to move in the opposite direction.” -Albert Einstein Solar Car Design

2. Keep It Simple!

3. Key Ideas To Focus On • Safety • Is this safe? • Reliable • Must first finish the race. • Efficient • Performance Considerations. • Execution • Can we do it?

4. Process • Learn general solar car concepts • Spends time observing successful executions • Read Event Rules! • Work on design • Read Event Rules! • A lot of design problems and considerations can be solved simply by applying the constraints found in the rules.

5. Overview • Array Position • Wheel Layout • Frame • Suspension • Electrical

6. Array Position • A Few Concepts • Above Body • Body Contour • Below Driver's Head/Canopy

7. Array Position • Above Body • No Shadows from Driver or other components. • Design Freedom below array

8. Array Position • Body Contour • Aerodynamic • Shaded by General Shape of Car • Many Angles to sun

9. Array Position • Below Driver's Head • Shaded by any items above array • Can be bright for driver • Driver is exposed to more direct sun without canopy

10. Flat Array vs. Curved • Flat Solar Arrays • Easier to execute • Angle to sun less of a concern • Curved Solar Arrays • Higher the angle the greater chance for breaks without ideal support. • Angle to sun more of a concern • Power Tracker Considerations

11. Hybrid Array • Increase overall array efficiency by placing higher efficient cells in most optimal position.

12. Wheel Layout • 3 Wheel • 2 in front • 1 in front • 4 Wheel

13. 3 Wheel Layout • 1 in Front • Generally less stable • Unstable in most turns at decent speed

14. 3 Wheel Layout • 2 in Front • Generally Stable • “Gets it done” • Popular

15. 4 Wheel • Possibly heavier than 3 wheels due to extra suspension • Potential to provide better support and ride • Road Debris benefit

16. Frame • Space Frame • Triangles • Usually welded metal • Aluminum • Steel • Tub • Usually composite • Carbon Fiber • Fiberglass • Tube-like shapes/sections

17. Frame • Space • Must be designed to support all necessary loads

18. Frame • Tub/Composite • Lighter • Stronger • Easier to design • Harder to execute • Higher cost

19. Important Cargo • Driver • Batteries • Suspension mounts • Array mounts • Motor/Motor controller

20. Suspension • Do you need one? • Not necessarily. • Good idea? • Solar Cells are fragile • Road Debris • Driver Comfort and ultimately Driver Safety

21. Suspension Types • Double Wishbone • Popular • MacPherson Strut or McPherson strut

22. Suspension • Double Wishbone

23. Suspension • MacPherson Strut or McPherson strut

24. Electrical • All solar cars are electric (battery) cars with an added array. • All solar car main electrical systems look schematically the same. • Difference is in the details and execution.

25. Electrical • Solar Cars are cars first, battery powered/electric cars second, and solar cars third.

26. Electrical • Power Trackers • Converts and optimizes array power for system. • Not needed, but a good idea. • High cost. • Power Tracker for each array string/angle, or one large Power Tracker for the whole array.

27. Electrical • Fuses • Specific Fuse Detailed by Event Rules. • Add fuses where it makes sense for added safety. • Switches • Specific Switches Detailed by Event Rules. • Add switches when it makes sense for added safety.

28. Electrical • AC vs. DC • We're working with DC. • Make sure components are DC rated for your application. • Contact manufacturer or trusted consultant to make sure your components will work reliably with your DC application.

29. Electrical • Wire • Size wire for worst case scenario. • Temperature • Voltage • Current • Wire should be capable of carrying more current than fuses at operating temperatures.

30. Summary • Keep It Simple • Safe • Reliable • Efficent

31. Questions