Cycling Power and Speed Calculator

Solar vehicle version, 8'x16' body - so 1000W of solar panels.

This would go at 25 mph with a 300 lb vehicle weight, 165 lb rider weight, with 5 square foot frontal area with 500W of power according to this calculator -

https://www.gribble.org/cycling/power_v_speed.html

Example

High Speed

• Drag coefficient of 0.1 from an airfoil type body
• Vehicle 300 lb, rider 165 lb
• 150W of leg power
• Frontal area of 8 square feet
• Crr = 0.1 for mountain bike tires
• 1000W (10 panels, 8'x16' = same length as a typical car) gives 50 mph -realistic but best case scenario of solar car at high noon
• Adding more length at back gets more power, no more drag
• Thus, a practical car can be made, esp if it has batteries or small generator (1kW) for extra power.

Low Speed

• Same parameters as above, 500W of power - gets you 35 mph

Notes

• Biggest gain is obtained from reducing coefficient of drag due to wind. Air foil (wing) has the lowest drag - less than 0.1
• Best cars are at cd=0.22 - [1], and VW XL1 cd=0.19 [2]. Impractical cars can do better.
• Aptera - lowest cd=0.15 in history for a production car[3], which is 850 mpg equivalent.
• Stingray/Stealth bomber/airfoil mix type bodies can be around 0.1

Links

• Book - Solar Car