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Old 02-18-2018, 06:40 PM   #3 (permalink)
All Darc
Join Date: Feb 2018
Location: Brazil
Posts: 1,476
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Thank you both, Angel And The Wolf & Old Tele Man. I will search about CDa.

I was wondering if was possible to create a better, "crazy", coefficient, for aerodynamic electric car assisted by solar energy.
Think with me. A car to be economic and ecologic can be electric, low weight, good in aerodynamic and have a fine surface to solar panells.
A car have very low CD, like that SHell Eco-marathon's Ecorunner V and VI model with 0,05 drag already with wheels. But Ecorunner V&VI it's almost "a torpedo with wheels", for just 1 person in lying position. Even if we increase scale to 3x , it would be small to sit and would end up too long even for a typical car. Besides, the upper surface area it's small, allowing just very few watts of solar energy.

Type ecorruner on Google image search, since I'm not allowed to post images yet.

Now take SolarWorld NO1. It have probably a drag of 0,1 or 0,11 or less (need to check with their team), similar to Aptera Type 1 and MIT's Solar Aztec (drag 0,12 with nude wheels without streameline covers). Despite have probably the double drag and larger frontal area, it have a fine upper area for solar panels.

Search SolarWorld NO1 and Solar Aztec Car, on Google image search, since I'm not allowed to post images yet.

With few interior modifications Solarworld No1 it could probably fit 2 persons.

So how could we creat a coefficient or something to help determine effectivines of a vehicle shape, considering also the top surface area ?
I imagine it for 21% efficient solar cells (SunPower), since cheapers are not flexible and are just 16,5% efficient, and the 26% (gallium arsenid) are too expansive, and the 39% (mult junction) just for satellite or milionaires.

Such "coefficient" would require to take in account available area for solar cells, drag, perhaps solar power output, body weight, but probably not electric motor power consumption. It would take in account a average speed, enough to use almost exclusivelly solar power or just 50% of battery to assist.

The idea it to judge not only drag&drag for area, but also judge the solar capability (surface area). With more power, and still acceptable low drag (despite not the best ever) we would need less powerfull motors, less battery power, reducing cost and getting more green.

I know it sounds crazy, too complex for a coefficient, a challenge to a scientist, but I believe something like this could be of help. Maybe I'm just being nonsense... I don't know. Fell free to critic my idea.

Last edited by All Darc; 02-18-2018 at 07:05 PM..
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