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


Reliable


Must first finish the race.
Efficient


Is this safe?
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