I probably have posted on the electricity generating speed bump more times than it deserves, but Glen Reynolds linked this story and I am seeing it linked uncritically all over. Here was the email I dashed off to Instapundit:
The speed bump / power device at the Burger King in New Jersey is the silliest technology I have ever seen and I am amazed that so many people praise it or write uncritically that it provides free power. Energy is never free, it comes from somewhere. In this case, the energy is actually stolen from the car. The electricity power produced is equal to or less than the extra power the car has to expend going over the bump.
This electricity might be "free" if it is used where cars are braking anyway, say on a long down ramp in a parking garage, or on a suburban street or school zone where speed bumps already exist. But the Burger King example, and in fact most of the examples I have seen of this installation, are just vampiric theft, very similar to what the US Government does in many of its programs, creating a large benefit for a single user and hoping that distributing the costs in small chunks across a wide number of people makes these costs invisible.
I wrote more about the technology here.