A friend linked to this story about a Turkish company that makes wind turbines to be installed between lanes of traffic, where they turn the moving air from passing vehicles into electricity. He wondered whether it would just slow down the buses.
My reply turned into something much too long for a Facebook comment, so I put it here.
It sounds like you’re asking a sort of First-Law question: since energy can’t magically come from
nowhere, the energy turning these turbines has to come from
somewhere. In other words, you’re asking if this is a free lunch, which is always a good question in the face of a proposed source of energy.
I suppose it’s possible that the turbines alter the airflow in the bus lanes in a way that makes it harder for the buses to push through the air. It that’s true, then yes, the bus engines are having to work harder to cover the same distance at the same speed.
I can also imagine it’s possible that the energy contained in the airflow away from the buses is just being dissipated as waste heat, and these turbines are capturing a piece of that and making it useful.
Or maybe there’s
some drag on the buses, but not enough offset the energy generated by the turbines.
At any rate, it seems like it would be an interesting study for someone in aerodynamics (on the other hand, maybe someone who actually knows aerodynamics already knows the answer and would consider it a trivial question).
I was, however, taken aback by the video’s reference to “vertical access” turbines, because the term is “vertical AXIS,” which makes a whole lot more sense. Somewhere along the line in producing this video, there was a person who didn’t look at text, but just wrote down spoken language. Maybe it was the original reporter, in which case that person didn’t know enough about the technology to understand what was being described.
Along similar lines, it says, “1 turbine can create one kilowatt of electricity per hour.” This is a confused statement.