Solar Car Design

“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

Keep It Simple!

Key Ideas To Focus On

Safety Is this safe?

Reliable Must first finish the race.

Efficient Performance Considerations.

Execution Can we do it?

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.

Overview

Array Position Wheel Layout Frame Suspension Electrical

Array Position

A Few Concepts Above Body Body Contour Below Driver's Head/Canopy

Array Position

Above Body No Shadows

from Driver or other components.

Design Freedom below array

Array Position

Body Contour Aerodynamic Shaded by

General Shape of Car

Many Angles to sun

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

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

Hybrid Array

Increase overall array efficiency by placing higher efficient cells in most optimal position.

Wheel Layout

3 Wheel 2 in front 1 in front

4 Wheel

3 Wheel Layout

1 in Front Generally less

stable Unstable in

most turns at decent speed

3 Wheel Layout

2 in Front Generally

Stable “Gets it done” Popular

4 Wheel

Possibly heavier than 3 wheels due to extra suspension

Potential to provide better support and ride Road Debris benefit

Frame Space Frame

Triangles Usually welded metal

Aluminum Steel

Tub Usually composite

Carbon Fiber Fiberglass

Tube-like shapes/sections

Frame

Space Must be

designed to support all necessary loads

Frame

Tub/Composite Lighter Stronger Easier to

design Harder to

execute Higher cost

Important Cargo

Driver Batteries Suspension mounts Array mounts Motor/Motor controller

Suspension

Do you need one? Not necessarily.

Good idea? Solar Cells are fragile Road Debris Driver Comfort and ultimately Driver Safety

Suspension Types

Double Wishbone Popular

MacPherson Strut or McPherson strut

Suspension

Double Wishbone

Suspension

MacPherson Strut or McPherson strut

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.

Electrical

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

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.

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.

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.

Electrical

Wire Size wire for worst case scenario.

Temperature Voltage Current

Wire should be capable of carrying more current than fuses at operating temperatures.

Summary

Keep It Simple Safe Reliable Efficent

Questions