Why don't more cars use solar panels to increase energy efficiency?

Question

For instance, solar panels on the roof could give much needed energy to take some stress off of the car battery. And also, what about wind power? When driving down the highway, wouldn't it be possible to use some of that wind resistance for power? Any thoughts on this?

Answer 1

The weight of the vehicle would not be conducive to solar or wind power as we now have vehicles designed. But it is a thought why couldn't an electric car be charged with solar power and designed with the wind as a complement to electric power to counterbalance and prevent charge loss thereby reducing the amount of charging needed in the first place.  Sort of a recycling charger giving back electrical power to the vehicle.

Answer 2

Roscoede has it pretty good!   I have a small solar panel I plug into my cig lighter to run the radio when I'm working near the vehicle, help the alternator when I'm driving into the sun and charge the battery when I leave the lights on by mistake.   Its saved me many times its cost by not having to call a tow truck to give me a jump.   The wind power idea wouldn't work though.   You can't get energy for nothing.   The wind turbine would be around 30% efficient maybe so you would get back 1/3 of the energy wasted in the drag it would cause the vehicle.

Answer 3

Good question.  There are cars which run solely on solar power, but as you know, they are hand built ultra-lightweight cars.  Putting a solar panel on the roof  of a regular car would not, at this time produce enough power to make a significant difference.  HOWEVER - a smaller solar panel on the dashboard, which would plug into the cigarette lighter socket -could charge the battery if it were dead, or keep a weak battery from going dead.  

I don't know about wind power, but it would depend if the equipment -the "windmill" the turbine and generator and the wiring and bracing etc. would not offset the amount of power generated.  Worth looking into.  Lemme know if you figure anything out.

Answer 4

maybe the oil campanies are preventing this from happening... just a thought

Answer 5

The output of solar panels is negligible.  Even if I covered the roof of my car with solar panels, they would put out only about 2-3% of the power of which my car's alternator is capable of putting out.  The only practical use of solar panels on motor vehicles is to trickle charge the batteries when the vehicles are parked for extended periods of time, which has become more important as modern electronics, such as GPSs, cell phone chargers, etc. can place loads on a vehicle's battery even when the vehicle is parked and the alternator is not providing power.

As for obtaining wind power from a moving vehicle, the wind resistance of the windmill would place an additional load on the vehicle's engine in excess of the wind power obtained from the windmill.  That result is dictated by the laws of thermodynamics.  Proposed systems that violate the laws of thermodynamics are commonly known as "perpetual motion machines" and have been debunked every time they have been proposed.  The proposal to add a windmill to a motor vehicle is very similar to the "self-blowing windmill" that Mark Anthony Zimara proposed in 1518, which has never been successfully realized in the nearly 500 intervening years, as it violates the laws of thermodynamics, and is, therefore, impossible.

Answer 6

Cost is too high and not much benefits, for eg. a normal Solar panel would have peak wattage of say around 15 Wat/sq ft. how much area can a car roof provide ? not much to matter a lot. A much better and simpler solution is to make car engines more efficient the current efficiency is about 30% and a whopping 70% is wasted as heat !! can you imagine all that gasoline you put into your tank and pay for most of it gets wasted as heat energy which you then try cooling thru better coolants.

If some one can reduce this wastage or use this heat to do something else you have better efficiency.

Answer 7

I think its not much used now a days since its too costly.. It will become more cheap once its common..

Answer 8

Logistics prevent it- solar panels would not be worth having because of their own size and wind resistance. wind power requires some kind of turbine, and again, the size and where to put it to be useful? maybe in the future, but we don't have it yet.

Answer 9

My husband and I were just talking about this. I know that certain trains have solar panels on their roof that really cut down on the gas mileage. Maybe cars don't have enough surface area to make it worth it.

I also agree that energy from wind-harvesting would be useful. I'm not sure why people aren't jumping on this.

There has got to be a better alternative! I hate spending so much on gasoline!

Answer 10

The amount of cost and increased wind resistance would outweigh the benefit.