Naar aanleiding van dit bericht op Instagram, vond ik het nodig om uit te leggen dat PaveGen vanuit natuurkundig oogpunt volslagen onzinnig is. Gelukkig was iemand het niet me eens. Er ontstond een leuke dialoog… =)

jonasvoorzanger: “Extreme waste of energy. There is no such thing as ‘passive energy’. This requires people to burn extra calories and therefore consume extra food. This only good for PR reasons.””

infernal_clockwork: “OR people would be walking there anyway, and the kinetic energy would be otherwise wasted. You know… one or the other.”

jonasvoorzanger: “That would be nice, but with a normal floor, no kinetic energy (KE) is ‘wasted’. KE is simply what people need to move from A to B. When you start walking, you turn sugar into KE and when you stop walking, your KE is turned into heat. This floor is continuously stealing your KE (so walking gets harder) and is using a very inefficient way to turn your KE in a little bit of electricity. Taking to extremes, this floor might as well be a drill sergeant that requires people to turn a dynamo when they walk. Sure, it would generate electricity (probably more efficiently than this floor), but people would be very tired when they reach their destination. In short, since energy can only be converted, and never created, there is no such thing as ‘free’ energy. That’s actually another thing this floor might help with: teaching physics. ?”

infernal_clockwork: “Might I ask who said anything about free energy?”

jonasvoorzanger: “You mentioned that we are currently wasting energy that we might as well use. That sounds like ‘free’ energy. Unfortunately, this is impossible. Might I ask why you are such a big fan of this system? :)”

infernal_clockwork: “Once again you make assumptions. I never said “free energy” nor did I say I was a “fan of this system”. I simply stated that if this is located in a high traffic area, you will have people walking there regardless. If that’s the case, then capturing energy that would otherwise by wasted as unused radiation is what we’re talking about here. It is no different than the regenerative breaking system in my electric car. The energy that would have been wasted as heat (etc) is instead captured and stored back in the car’s battery. Did it take more energy to move the car than I got back from stopping? Of course, but its still energy captured that would have been otherwise wasted. Your nitpicking logic and assumptions seem to be stymying you ability to see this.”

jonasvoorzanger: “The regenerative brake system is amazing and very functional, but completely different from this floor. When a car brakes, the goal is to loose KE. Turning this KE into electricity in stead of radiation is a big win. However, when a person walks, the goal is not to stand still all the time. A normal floor doesn’t change shape when you walk on it, so hardly any KE is absorbed. This kinetic floor, however, is making it harder to walk because it’s changing its shape when you walk and thereby absorbing your KE continuously. In that sense, it is similar to putting little wind turbines on top of cars. “The cars are driving anyway, so why not tap into that potential wind power, right?” Wrong. Why? Because adding the wind turbine increases the drag on the car, requiring more energy to power the car in the first place. This floor is exactly the same. And then there is still the whole question wether the energy required to produce and install this floor is ever ‘won’ back. With efficient solar panels, this energy payback time is a few years, so with this inefficient floor I expect it to be many decades. Still good for PR reasons though. :)”

infernal_clockwork: “Efficient solar panels… Interesting point. How long ago was it that the input/ourput of solar made it an unviable technology?”

jonasvoorzanger: “Indeed not to long ago. At first the radiation-to-electricity efficiency was too low to be economically viable, but we made it there (slightly depending on location and subsidies). Unfortunately, there is no similar option with the floor. Even if the conversion elements in the floor were 100% efficient, the net energy energy win would be negative, as people need to eat more and the producing/installing the floor costs energy.”