Cars are becoming a primary focus in sustainable design and pollution prevention. According to WikiAnswers there were over 240 million cars registered in 2005 in the US alone and that number has continued to grow in subsequent years. While there have recently been developments in hybrid and electric cars (even solar powered cars) there has always been a fascination with adding wind power to cars.
Somehow it seems feasible to attach a wind turbine to a car and generate electricity as the car drives. I’ve heard my friends bring it up and I’ve read about it. People wonder, wouldn’t the inertia from the car’s accelerated mass (which is enough to power through the air) also be enough to power the wind turbine without wasting energy? Unfortunately, the answer to this question is no. Placing a stationary wind turbine on a car and expecting it to generate additional electricity (compared with the energy spent to move the car) would constitute perpetual motion which is considered impossible based on known physics. That said, there are several ways that wind power can be used in combination with automobiles to create useful, efficient systems.
One French company called Venturi has added wind power to their electric car which allows it to charge in other ways than just solar. The end result is an urban short-distance car that is able to extract more renewable energy from it’s environment and thus become increasingly flexible and reliable. To read about the specs on this vehicle head on over to Inhabitat for a full review.
This type of wind power for cars is considered passive because it is only deployed when the car is parked. That’s the key, if the turbine was always erect it would slow the car down and create drag when in driving mode. Competing forces are at work while the car is in motion and since the car uses pure electric energy the value would be offset. If however, the car used some other fuel source such as gasoline and a wind turbine was used when in motion, energy would simply be converted from one form (gas) to another (electricity) and this would probably occur at a fairly inefficient rate.
Another way that wind energy can be captured for powering a car is in the braking system. Just like parachute packs are sometimes used to slow dragsters and the US space shuttle as it lands on a runway, rapid-deploy wind turbines could be use to slow a moving automobile as it approaches an obstacle or red light. This would be considered a form of regenerative braking and probably be less efficient than direct electric braking systems used on today’s most efficient cars (such as the Toyota Prius and Honda Insight). Considering the amount of energy consumed simply by deploying and then retracting a wind turbine, and the often short distances that braking power is needed, along with the need for additional direct braking (to guarantee safety in windy conditions) this type of wind power for cars would probably only be used for very specific limited systems… or perhaps just for fun :)
As Breakthroughs in automobile technology continue, wind power will surely play a role. In many ways the aerodynamic design of cars is a type of wind harnessing technology. If you have seen other wind powered cars or know of systems currently in development please share them here at Wind Power Authority.
