Alternative Energy Source: Can we use the air rushing past highway vehicles to generate useful wind energy?

Question

For example, placing small wind turbines right next to the high-speed highways.

Answer 1

You can't use an turbine attached to a moving car, as it takes more power to push the turbine through the air then it could generate.

Yes, you could locate small turbines near highways, and they would generate some power. But only intermittently, when a big truck when by.  And the air swirls around so much, even that may be doubtful.

I doubt the cost would pay for the investment. Plus each one would have to be approved by the zoning boards in each area, a long slow process.

There are plenty of other locations where you can put a large turbine that gets a fairly steady wind, and would pay for the investment.

Answer 2

Wind turbines would leech power from passing cars by impeding air movement.  To work at all, the blades must slow down free air movement.  That means the passing cars lose gas mileage because they build up a higher vacuum behind them.  Wind energy alongside the highway is not free.  The passing cars are using energy to spin the turbines.

The more free the air is, the less wind resistance the car has.  In the ideal case, the air is perfectly fluid so the car is perfectly streamlined.  The ideal case only occurs in a vacuum.  Limiting air movement next to the highway is going in the wrong direction.

Sorry to burst your bubble.