Michael Porter March 17, 2015 10:57 PM The idea of capturing energy from motion or heat from friction goes against the 2nd law of thermodynamics - you can't get something for free. The energy you harvest that way can only originate from the vehicle's drive system - i.e. you must use more electricity in the electric motor than you could ever collect in the tires. The one possible area you could win is collecting heat from the sun- but because you have to add a cooling system to the tires I am sceptical that would ever return more than it costs. Daishi March 17, 2015 11:54 PM Somehow this seems like it would be perpetual motion machine fallacy in that you would probably get less energy out of the tire than you are putting into it.Regenerative braking makes sense because brakes are designed to exchange energy for heat through friction so all that is lost is wear and tear on some brake pads (and heat) but wheels need to be efficient and any recouping of energy through the process would likely net an efficiency loss unless the guy selling it to you is doing your math.Even after they finish the tire they have to convince (less gullible) auto companies to use them rather than the general public because it would take some integration into the car. Schreibtribe March 18, 2015 04:33 AM @Michael Porter... you're correct that you can't get something for free. However, if overall EV drivetrain efficiency cannot be improved any further, and rolling resistance isn't compromised, then recapturing wasted heat elsewhere in the system *should* have a net positive effect on vehicle efficiency. @Daishi... regenerative braking occurs in the electric motor, not at the brake pads.This is a really cool concept!! If these can pull some lateral g's, I'll put them on my future Tesla Model P365D++ Martin Winlow March 18, 2015 12:53 PM This is just complete nonsense - as Daishi has pointed out. Even if the wheel could harness some energy, it would be so tiny that in the context of powering an EV it would be utterly irrelevant. That a mainstream publication such as GM could be had by this over-unity nonsense is unbelievable. Sir Issac Newton, come back! All is forgiven!! MW Daishi March 18, 2015 01:22 PM @Schreibtribe I meant replacing standard braking with regenerative braking. Michael Porter March 18, 2015 10:44 PM @Schreibtribe If it is collecting energy from motion and friction, then obviously rolling resistance is going to be higher. Dawar Saify March 19, 2015 08:30 AM Well the claim is to use waste heat so the physics is sound, whether this results in collection of credible amounts of energy is another matter, given that the technology has to be applied which will add greatly to the cost. Don Duncan March 20, 2015 06:12 PM If the goal is to use heat to generate electricity, and the tire is engineered to collect maximum heat for maximum electricity, then why would they want to cool down the tire? Wouldn't it be better to develop a more effective heat transfer-conversion device? Lumen March 21, 2015 03:00 AM Michael Porter, Daichi,Relax. Who's claiming perpetual motion, or getting something for nothing?There's a whole lot of energy out there... let's use it! Using heat that's developing at the tires anyway can be beneficial if the means of process does not consume more energy than is being converted. How much does the overall conversion apparatus weigh as opposed to not having it? How much energy is consumed moving that additional weight? Things like that. If the process is an overall net energy gain that's within affordability thresholds for the target market, then great!Another possible benefit is that the piezoelectric conversion might, even if marginally, reduce the surface heat of the tires. Its similar to perspiration but inverse: surface cooling through energy draw inward rather than energy release outward. I like your question Don. I don't get the cooling system either.Let's see how they do. This is Goodyear Tires, after all. Maybe observers would be dissuaded if a garage inventor came up with this, but do you think Goodyear would be putting time, money, and their reputation on the line for something that doesn't work?Godspeed to them. Michael Porter March 22, 2015 11:15 PM I just think they should concentrate only on collecting energy from heat that would have been lost anyway, and not worry about collecting energy from the tire deformation or doing modifications to increase friction or add cooling. My limited experimenting in the heat-to-electricity conversion area makes me think it would be very difficult to collect enough energy to be worth the effort - but I wish them luck anyway. Possibly the cooling they mention is not for cooling the tire but for cooling a Peltier-like device as part of the electricity generation from heat.