# Seismic energy storage **URL:** \ **Category:** Great Debates\ **Created:** [December 7, 2005, 10:54pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577 "2005-12-07T22:54:33Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Thinktank](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Thinktank](https://boards.straightdope.com/u/Thinktank)\ **Post date:** [December 7, 2005, 10:54pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/1 "2005-12-07T22:54:33Z")
I was curious if there is currently a way to store energy produced via seismic activity? I’m not just talking about Earthquakes or giant movements. Take something like a freeway, now there’s a whole lot of free energy in my opinion just going to waste in such an environment. But I won’t take this too far for now. I just wanted to point out that there are more and more roads and freeways have an almost constant flow of traffic. Could you not arrange a device in such a way so that vehicles that are moving over the road and moving it in all sorts of ways contribute to a energy storage device? I understand that a rolling vehicle’s seismic activity in terms of duration and intensity would be quite minor, but we’re talking about free energy here and almost a constant flow of it if my local freeway is any indicator to everyone else’s. Is this possible and the answer is usually “yes”; So then I will ask “Is it feasible?” =) Thanks all ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [December 7, 2005, 11:05pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/2 "2005-12-07T23:05:07Z")
Would arrays of [piezoelectric crystals](http://en.wikipedia.org/wiki/Piezoelectricity) under the freeways of LA generate enough power to light the city? I don’t know, but it seems like something that should be looked into. ---
**Author:** ![Harmonious\_Discord](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@Harmonious\_Discord](https://boards.straightdope.com/u/Harmonious_Discord)\ **Post date:** [December 7, 2005, 11:06pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/3 "2005-12-07T23:06:18Z")
You can rig up something like a self winding watch or the paddle system used to harvest waves. The mechanisms are easily possible with today’s technology. It all comes down to a high expense in manufacture, implementation, and collecting the stored energy into a big pool thats useful. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [December 7, 2005, 11:13pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/4 "2005-12-07T23:13:59Z")
Energy = force \* distance. Something has to _move_ to absorb energy. That means the road surfaces will have to be softer, and it’ll require more energy to move across that road. So fuel economy will suffer. You can’t get something for nothing. ---
**Author:** ![Thinktank](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Thinktank](https://boards.straightdope.com/u/Thinktank)\ **Post date:** [December 9, 2005, 9:26pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/5 "2005-12-09T21:26:24Z")
Well, thanks for the formula **scr4** , but I’m familiar with how energy in generated. It was also the gist of the Q, to encourage creativityand additional ideas. Blacktop btw, moves quite alot in a day: It expands and contracts, compresses and rebounds; it even vibrates- just not as efficiently as the piezoelectric crystals **Squink** referred to. I also don’t believe that blacktop would have to be softer for this process to bode results (how well I can’t be sure) but the objects mixed in with the blacktop could easily be as hard or harder than the blacktop. I would have to say the more brittle the object the better since brittle materials vibrate better. Soft objects could be made to generate energy through the compression/decompression action, but as you stated would probably reduce the over-all hardness of the blacktop which would in terms of blacktop probably be a shorter-lived blend as well. The object here is to improve upon the current recipe, with enough thought it could even improve the duration between re-paving;saving tax-payer dollars. That would perk a few ears wouldn’t it? ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [December 9, 2005, 9:41pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/6 "2005-12-09T21:41:29Z")
There are two ways to generate energy from cars passing on your road: (1) find roads that already flex, and attach generators to them, or (2) make roads more flexible and extract power from them. Option 2 is worthless, because all you’ve made is an expensive and inefficient gasoline-powered electric generator. Option 1 is not much better - I’d guess it’s cheaper to simply reinforce those roads, thus reducing gasoline usage. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 9, 2005, 10:31pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/7 "2005-12-09T22:31:24Z")
If you want to exrtract work out of the cars as they pass, then the cars are going to use more fuel in doing that work. That may not actually be true in practice, because the road surface takes work out of the cars already and converts it to sound waves and heat, however, as **scr4** says, devices that work by flexing are going to make it harder for the car to travel over them - like the difference between walking on a hard floor and walking on soft sand. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [December 9, 2005, 11:18pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/8 "2005-12-09T23:18:03Z")
> [@Mangetout](#): > > If you want to exrtract work out of the cars as they pass, then the cars are going to use more fuel in doing that work. > > That may not actually be true in practice, because the road surface takes work out of the cars already and converts it to sound waves and heat, however, as **scr4** says, devices that work by flexing are going to make it harder for the car to travel over them - like the difference between walking on a hard floor and walking on soft sand. I think the OP is trying to recover the energy that is now wasted in moving the ground under a road without changing the road in any way that would make it harder for the cars to move. Piezoelectric accelerometers under the road might possible supply enough energy to power the roadside emergency phones. It would sure take a lot of them with the consequent miles and miles of wiring. I’m trying to visualize how you would get the voltage high enough to charge a battery and can’t at the moment. I think feasibility would be right on the razor’s edge. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 9, 2005, 11:30pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/9 "2005-12-09T23:30:25Z")
Well if you can put these things where people must slow anyway (downgrades on a hill, toll barriers, deceleration ramps, reduce speed ahead zones and the dreaded school zone), it might be worth it. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 10, 2005, 12:01am UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/10 "2005-12-10T00:01:33Z")
> [@David Simmons](#): > > I’m trying to visualize how you would get the voltage high enough to charge a battery and can’t at the moment. I think feasibility would be right on the razor’s edge. Charge pumps I suppose, same as you can use with solar cells or even radio waves. ---
**Author:** ![Phnord\_Prephect](https://avatars.discourse-cdn.com/v4/letter/p/df705f/32.png) [@Phnord\_Prephect](https://boards.straightdope.com/u/Phnord_Prephect)\ **Post date:** [December 10, 2005, 2:31am UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/11 "2005-12-10T02:31:32Z")
Why not buildings, too? Especially taller ones, which tend to sway in the breeze? Just a thought. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [December 10, 2005, 3:09am UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/12 "2005-12-10T03:09:58Z")
> [@Mangetout](#): > > Charge pumps I suppose, same as you can use with solar cells or even radio waves. I’ve been out of the game for 24 years so what do these things do? Are the entirely passive? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [December 10, 2005, 4:04am UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/13 "2005-12-10T04:04:52Z")
This is one of those ideas that get suggested over and over again, yet have never been put into practice, even in small demonstration projects. That tells me a lot. ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [December 10, 2005, 2:32pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/14 "2005-12-10T14:32:41Z")
> [@Phnord Prephect](#): > > Why not buildings, too? Especially taller ones, which tend to sway in the breeze? Just a thought. Unless you intentionally let the building sway from the base you’d need to capture motion at the top. You would need an even more rigid structure to do so. ---
**Author:** ![Rhubarb](https://avatars.discourse-cdn.com/v4/letter/r/59ef9b/32.png) [@Rhubarb](https://boards.straightdope.com/u/Rhubarb)\ **Post date:** [December 10, 2005, 2:50pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/15 "2005-12-10T14:50:37Z")
In the mid-to late 70’s, during the height of the first oil crisis, an engineer in New York, I think, came up with an idea to collect some energy from cars on roadways. The device was a simple spring-loaded strip running the breadth of the freeway. When a car passed over this strip, it drove a hydraulic pump which spun a turbine to generate electricity. the amount of energy from one car was insignificant, but on a busy freeway, like the Verrazano Narrows bridge, it could add up to quite a bit. The article appeared in Popular Science or Omni (it’s been almost 30 years! I have slept since then!) and IIRC, there was funding for a pilot project. I haven’t heard a sinfle thing about it since then. I can see a lot of problems with this system, like the amount of wear and tear it would be subjected to, adding a bump to the freeway, the first snowplow to hit it, etc. However, if it could be made to work reliably, these devices could be placed where they could recover wasted potential energy - like on the down-slope of a hill, or on the ramps of parking garages, freeway offramps, etc. The only reason I can think of that something like this doesn’t exist is that it isn’t practical - the energy generated doesn’t pay for the initial investment and upkeep of the device. ---
**Author:** ![Hombre](https://avatars.discourse-cdn.com/v4/letter/h/ecb155/32.png) [@Hombre](https://boards.straightdope.com/u/Hombre)\ **Post date:** [December 10, 2005, 2:59pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/16 "2005-12-10T14:59:18Z")
> [@Padeye](#): > > Unless you intentionally let the building sway from the base you’d need to capture motion at the top. You would need an even more rigid structure to do so. I don’t understand why this would need to be so. Why not a pendulum-type device or something akin to a self-winding watch mechanism on the roof? ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [December 10, 2005, 3:02pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/17 "2005-12-10T15:02:02Z")
> [@Rhubarb](#): > > In the mid-to late 70’s, during the height of the first oil crisis, an engineer in New York, I think, came up with an idea to collect some energy from cars on roadways. The device was a simple spring-loaded strip running the breadth of the freeway. When a car passed over this strip, it drove a hydraulic pump which spun a turbine to generate electricity. the amount of energy from one car was insignificant, but on a busy freeway, like the Verrazano Narrows bridge, it could add up to quite a bit. The article appeared in Popular Science or Omni (it’s been almost 30 years! I have slept since then!) and IIRC, there was funding for a pilot project. I haven’t heard a sinfle thing about it since then. I can see a lot of problems with this system, like the amount of wear and tear it would be subjected to, adding a bump to the freeway, the first snowplow to hit it, etc. However, if it could be made to work reliably, these devices could be placed where they could recover wasted potential energy - like on the down-slope of a hill, or on the ramps of parking garages, freeway offramps, etc. The only reason I can think of that something like this doesn’t exist is that it isn’t practical - the energy generated doesn’t pay for the initial investment and upkeep of the device. The amount of energy lost by the car might be insignificant but it exceeds that derived from the generator. This method doesn’t capture otherwise wasted energy. ---
**Author:** ![SpectBrain](https://avatars.discourse-cdn.com/v4/letter/s/a87d85/32.png) [@SpectBrain](https://boards.straightdope.com/u/SpectBrain)\ **Post date:** [December 10, 2005, 3:09pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/18 "2005-12-10T15:09:52Z")
Instead of capturing seismic energy, how about taking advantage of the air turbulence generated by fast moving vehicles, especially big rigs? Energy could be used to power highway lighting systems using high efficiency LED’s. ---
**Author:** ![Fridgemagnet](https://avatars.discourse-cdn.com/v4/letter/f/22d042/32.png) [@Fridgemagnet](https://boards.straightdope.com/u/Fridgemagnet)\ **Post date:** [December 10, 2005, 3:31pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/19 "2005-12-10T15:31:00Z")
I have seen a practical application of seismic cow power. Someone has made a generator powered by cows walking over a cattle grid, and in doing so they generated just enough electricity to power the pump to their water trough. Similar schemes have been touted for human walkways, though I don’t know of any that have been implemented. This would, of course, mean stealing energy from pedestrians, but a lot of people could do with losing a bit of weight anyway, and it doesn’t cause any extra pollution. Devices that steal energy from cars are ultimately counter-productive from an efficiency viewpoint, but if they were fitted to pre-existing energy-sappers (like speed humps) then nothing is really lost. BUt I doubt I’d ever see such a scheme implemented; it’s feasible, but just too much hassle. We’re better off trying to tap wind, wave or solar power. That’s genuinely free (infrastructure costs aside…) ---
**Author:** ![Thinktank](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Thinktank](https://boards.straightdope.com/u/Thinktank)\ **Post date:** [December 10, 2005, 3:44pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/20 "2005-12-10T15:44:56Z")
HAH!- **SpectBrain** believe it or not I thought of this also, but why come out sounding crazier than I have to. Besides, I was trying imagine rows of big ugly windmill-type contraptions lining the roads. but yes, constant traffic on a freeway is largely expected so, so would the air the vehicles are stirring up all in the same direction- something like stirring water in a pot; after a little bit, it only requires minimal effort to maintain the swirling motion. Of course there is no “pot” and this is air not water, just so future posters understand that I am aware of these details. :rolleyes: \*\* Exapno Mapcase\*\* just getting people to talk about it is hard enough, let the post be what the post is; a “jam section” for energy conservation ideas. Of course if we keep switching ideas then no real focus happens on one particular thing but who am I to pick at details, heh. [Next page](https://boards.straightdope.com/t/seismic-energy-storage/334577.md?page=2)