The sun can help - Sähköautot - Nyt!
In many countries, in South America and Africa, the sun shine all the year. The cars should have fotovoltaic cels on the top to produce energy for mix with the electricity.
Piilota The sun can help luonut
Anonyymi (201.20.205.x), 23 Jul 2008 21:02
In Australia, we have around 2kw/m2 of solar radiation when it is sunny. Assume it's sunny - conversion efficiency of solar panels say at 10%, and lets not worry about additional wind resistance. This gives us 200 watts/m2 of available electrical energy. Assuming we have a large car and cover all horizontal surfaces with solar panels, we would have around 7.5m2 available. (again let's forget about optimum angle to the sun etc.) which gives us a maximum of 7.5m2 x .2kw = 1.5kw of power from the sun. Realistically expect only 50% of this to really be availalbe and take away the extra power for added wind resistance and there is very little power left. Let's take a stab and say we have .5kw left.. My car needs around 13kw to move at 100km/hr on a flat road with no wind, so you can see that there is little to be gained from solar panels on a typical vehicle.
Piilota Re: The sun can help luonutImagine then that you put a 1 m^2 panel on the roof and line it flush with the panel so it doesn't add any more resistance. Heck, make that two square meters and put one on the boot lid as well. Then assume that you're getting 130 watts out of it through the sunny day. That's just 65 watts per square meter - quite likely.
13 kWh per hour at 100 km/h is 130 Wh per kilometer, which is incidently the same amount of energy your panels would be generating, in an hour.
When your car sits eight hours on the parking lot of the company you work for, you have generated 8 kilometers of free electricity, or more if you don't need to drive so fast. A car that spends its days outdoors would generate about 16 kilometers of free range each day, assuming it gets dark for 8 hours and the average production is 65 W/m^2.
That means, if you live closer than 8 kilometers from your job, you wouldn't have to recharge the car the whole summer. The only downside is that you can't leave it in the shade.
Your math is way out. 130wh /km is NOT equal to 130w since the 1 km takes 1/100 of an hour the consumed rate is 130wh/0.01h = 13kw, so the solar panel contributes 1%. It is far more cost effective to put solar panels on your property, aimed at the sun and then store that power (preferably in the hydro grid) for use in your car. Obviously you can have much larger area this way, and you often park your car in shady spots or in garage, so you cannot count on optimum useage of solar cells on a car.
Piilota Re: The sun can help luonutNo it isn't.
One hour of solar charging generates 130 Wh of energy, and one kilometer of travel requires 130 Wh of energy. It's that simple.
I never ever claimed that 130 Wh/km equals 130 Watts. You must've read it wrong.