David, The laws of energy conservation are simple, in order to extract energy you have to take it somewhere.
No matter that the road already flexes, to take additional energy you will need to either allow it to flex more or make it harder to flex, depending on where you want to harvest the energy: from the cars or from the road. Most setups with piezo elements that I have seen, do not have elements inside the surface, they are not capturing energy from the flexing of the surface, but instead they are mounted *under* the road, so the road becomes a series of tiles that each independently move a little relative to each other. That relative movement stresses the piezo elements and creates electricity. The energy harvest is also simple to see: each tile sinks a little when loaded (eithr by human walking or vehicle driving) so the next tile is a little step-up. that is the potential energy that is transferred from the movement to the output electricity, because the person/vehicle moving over the road is now moving slightly up all the time on a level road. If you truly want to embed piezo elements in the surface of the road and want them to flex, you will probably need to make the road flex a bit more than today's costly concrete (stiff) freeway surfaces. That adds losses to the movement, just like riding on sand takes more energy than riding on flat road, because you "sink into" the sand a little. That is not true rolling resistance as that is property of the tire on flat surface, but it will sure remove energy from the vehicles passing (lower MPG) in order to generate power, there is no free lunch unless you are able to design a road in such a way that you can reduce the losses in the road itself and "steal" power from the road, rather than from the cars. But due to the fact that roads do not seem to heat up a lot from traffic, there is probably more much loss in the road that you can capture. I'd love to be proven wrong. Cor van de Water Chief Scientist Proxim Wireless office +1 408 383 7626 Skype: cor_van_de_water XoIP +31 87 784 1130 private: cvandewater.info http://www.proxim.com This email message (including any attachments) contains confidential and proprietary information of Proxim Wireless Corporation. If you received this message in error, please delete it and notify the sender. Any unauthorized use, disclosure, distribution, or copying of any part of this message is prohibited. ________________________________ From: David Nelson [mailto:gizm...@gmail.com] Sent: Friday, August 26, 2016 11:04 AM To: Cor van de Water; Electric Vehicle Discussion List Cc: Peri Hartman Subject: Re: [EVDL] Piezo-power> 10mi of freeway could charge all the EVs in Burbank-CA(?) But Cor, this isn't about increasing the flex in the road, this is about capturing the energy already being lost to heat to the ground. It might even reduce the existing flex which would improve driving efficiency and harness electrical energy. On Fri, Aug 26, 2016 at 10:54 AM, Cor van de Water via EV <ev@lists.evdl.org> wrote: This is not about rolling resistance, the energy harvested is removing a little bit of potential power, due to the road surface moving a little lower when the vehicle drives on it, so for the vehicle it resembles a slight incline to get out of, increasing the amount of energy the vehicle needs to spend by a small amount (no free energy) so it costs the passing motorists fuel to power the piezo road. There have been videos of this technology powering a charging station and sign to thank passing motorists for providing the power. The power output is small though. Running a display sign is no problem but don't think about fast charging. Cor -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20160826/edf9b63c/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
