Book - Solar Car
Contents
Concept
- Solar/human hybrid, practical 35 mph cruising, 45 mph noon max speed
- 8 foot by 16 foot body, 1 kW of solar panels, flexible panels at 4 lb/100W
- Panels are close to ground for good wind stability.
- Light weight, aluminum frame
- According to Cycling Power and Speed Calculator - 500W take you 25 mph with a 300 lb vehicle.
- Worst case scenario from calculator is 0.02 rolling resistance, 16 sf frontal area, and drag coefficient of 0.6 - which still gets you to 22 MPH with no engineering required. Just by using mountain bike tires, open cab and no aerodynamics - 1kW of solar + pedal power gets us 22mph. With a 1 kWhr battery pack, we still get 30 mph. Thus, solar NEVs (solar neighborhood electric vehicles) or SUVs - Solar Utility Vehicles - are completely feasible. With an on-board 1 kw generator - we get 35 mph at a total of 3kW of power. When designed for aerodynamics and drag, we get 65 mph in this case.
Discussion
Use 300W panels - dimensions of 1650x99ox38 mm panels- Neighborhood hybrid human vehicle, capable of 45 mph max, 35 cruising at 1000W/m2 sun.
- Telescopes for more power, from 16' to 30'. 8' wide. 9.14 m x 2.4 m. For untelescoped - 4.9m
- 16' is the length of a mid-size car
- Bottom-monted panels for low center of mass in windy conditions
19kg per panel above- too heavy- Flexible panels - lighter - [1] - $1/watt for 200W, 109x80x3 cm
- Flex panels are 75% lighter. Ex - 100W is 4 lb. Makes sense. [2]
- This is great news for the solar car. Just need to mount them in an effective way on the car.
- Can fit - 2 across and 11 long for telescoped, and 6 untelescoped. 22 and 12. Subtract 2 for the driver - so have 20 or 10 panels -
or 2 kw in the extended form.. Each panel is 200W - so it is actually 2kW peak for the short form and 4 kW for the long form! - Can fit a silent Honda EU1000 or 2000 1kW or 2kW generator for backup.
- Basic weight: 4 lb x 20 = 80 lb for panels. 10 kg motor. Capacitor bank or 5 kg of batteries (1kWhr) - light weight for extra power, pumped by human generator for passing. 5 minute human generator at 100W yields a 2kW boost every 5 minutes for 15 seconds of passing power.
- Cycling Power and Speed Calculator - power to attain a certain speed on a bicycle, given frontal area, air drag, and wheel friction
Working Document
Links
- Older thoughts based on the Solar Challenge - Solar Car
- Cycling Power and Speed Calculator