>Pavegen pivoted to collecting info about people walking on their sidewalks, rather than energy.

Wow. Switching from saving the world, to spying on everybody in it. That's almost a perfect microcosm of how the tech industry seems to have morphed in the last decade.

Ouch, yeah, that's pretty bad. I've actually been at a fair number of events with these folks, as my own startup often gets put into the same bucket with them (also London-based and associated with "green" transport infrastructure). I've always avoided having a conversation with them, because it just seems so ...sad.

As a straight-up marketing device -- say, a way of creating some interactivity at your storefront in order to get people to linger there longer -- then I guess it's fine, or at least no worse than any number of other things. I actually find that less objectionable than painting it with a green "we're helping to save the world" veneer that is either very cynical or very deluded. It takes a trivial amount of cognitive effort to understand that energy recovered from footfall will never, ever, pay back the embodied energy to produce and install the device. (Even moreso if you include the metabolic efficiency of human power in the energy calculations). This shouldn't be hard to figure out: it was pretty well understood by the end of the neolithic. But I suppose people are capable of remarkable feats of mental gymnastics.

Talk about ethical whiplash. I feel especially bad for any engineers that joined to make the world a better place then found out they would be designing tracking systems...

"recovering energy"

Under airliners seems even worse.