# 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:** 18\ **Page:** 2
**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, 3:48pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/21 "2005-12-10T15:48:32Z")
I feel like a moron for writing “jam section” so I felt inclined to correct myself. For all those that didn’t understand I was leaning towards jam “session” …_sigh_…coffee… need coffee… later guys ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [December 10, 2005, 4:11pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/22 "2005-12-10T16:11:37Z")
> [@Hombre](#): > > Why not a pendulum-type device or something akin to a self-winding watch mechanism on the roof? Sounds like a [tuned mass damper](http://en.wikipedia.org/wiki/Tuned_mass_damper#Examples_of_buildings_that_have_dampers) > [@](#): > > A tuned mass damper is a device mounted in structures to prevent discomfort, damage or outright structural failure by vibration. Typically, the dampers are huge concrete blocks mounted in skyscrapers or other structures, and moved in opposition to the resonant frequency oscillations of the structure by means of springs, fluid or pendulums. Many building already have them, and I suppose some kind of generator could be rigged to recover energy. It would probably change the tuned nature of the damper though, and reduce the anti-sway capability. But if you tuned the damper with the generator in mind, you could recover energy and reduce sway at the same time. The only drawback would be that energy would only be generated during times of significant sway, which might be intermittent, depending on the location. ---
**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, 4:26pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/23 "2005-12-10T16:26:38Z")
> [@Fridgemagnet](#): > > 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…) I think it is questionable whether such systems would work on a commercial basis. Yes, a farmer can recover energy from cows walking over a grate. He installed it does the maintenance on his down time. In order to be commercially useful there would need to be thousands and mayber millions of recovery devices. With all of the attendant electrical connections and all of the devices there would be a lot of maintenace needed. The energy used getting repair crews to and from the repair site could easily use up a lot of the energy that is generated. ---
**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, 4:46pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/24 "2005-12-10T16:46:34Z")
> [@David Simmons](#): > > 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. Not that I think it’s practical or feasible, but you will note that I was speaking of placing these in areas where the cars already have stored potential energy that IS wasted, as heat in the brake linings. Parking garages, freeway off ramps, hills, etc. I do understand that on level ground, they would be robbing kinetic energy from the cars which would have to be made up by the car’s engine, but once the car has driven up to the 6th level of a parking garage, most of the potential energy it has gained will end up as heat and brake dust. ---
**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, 4:55pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/25 "2005-12-10T16:55:39Z")
> [@Rhubarb](#): > > Not that I think it’s practical or feasible, but you will note that I was speaking of placing these in areas where the cars already have stored potential energy that IS wasted, as heat in the brake linings. Parking garages, freeway off ramps, hills, etc. I do understand that on level ground, they would be robbing kinetic energy from the cars which would have to be made up by the car’s engine, but once the car has driven up to the 6th level of a parking garage, most of the potential energy it has gained will end up as heat and brake dust. Ok, but if the potential energy stored in the car is used to operate a generator while is rolls down the parking or freeway ramp then it isn’t available to make the car roll a little further when it hits the level street and the driver has to use the foot pedal just a little sooner than otherwise would be the case. ---
**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, 7:01pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/26 "2005-12-10T19:01:02Z")
> [@David Simmons](#): > > Ok, but if the potential energy stored in the car is used to operate a generator while is rolls down the parking or freeway ramp then it isn’t available to make the car roll a little further when it hits the level street and the driver has to use the foot pedal just a little sooner than otherwise would be the case. Or a little less brake in order to stop at the light. I never said it was practical, just that someone had invented 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, 10:48pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/27 "2005-12-10T22:48:24Z")
> [@David Simmons](#): > > I’ve been out of the game for 24 years so what do these things do? Are the entirely passive? A charge pump is just an electronic circuit that stores up a charge from a low-power source and releases it periodically as brief pulses of higher power. [Here](http://homepage.ntlworld.com/gary.huston/index.htm) are some examples of small robots where a charge pump circuit is used to drive motors from a low voltage solar cell. ---
**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, 11:52pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/28 "2005-12-10T23:52:54Z")
> [@Mangetout](#): > > A charge pump is just an electronic circuit that stores up a charge from a low-power source and releases it periodically as brief pulses of higher power. A passive device can’t do this. You must mean it delivers the stored energy at a higher voltage than that which stored the charge in the first place. ---
**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, 11:58pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/29 "2005-12-10T23:58:23Z")
What’s the difference between that and what I said? ---
**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\ **Post date:** [December 11, 2005, 10:59pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/30 "2005-12-11T22:59:57Z")
> [@Thinktank](#): > > \*\* > 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. Let’s continue this jam session over in Great Debates. Factual answers are permitted there and so are opinions, blue-skying, and Rube Goldberg devices. **samclem** GQ moderator ---
**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 12, 2005, 12:12am UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/31 "2005-12-12T00:12:26Z")
> [@Mangetout](#): > > What’s the difference between that and what I said? What you said was, "A charge pump is just an electronic circuit that stores up a charge from a **low-power source** and releases it periodically as brief pulses of \*\*higher power.\*\*Power and voltage are not the same thing. Power is the rate of doing work and voltage is the amount of work done in moving electrical charges. Passive devices cannot raise a low power output to a higher power output. ---
**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 12, 2005, 8:40am UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/32 "2005-12-12T08:40:00Z")
So it’s impossible for a constant, low-voltage, low-current source to be chopped up into brief, higher-voltage pulses with more available current? ---
**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 12, 2005, 8:57am UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/33 "2005-12-12T08:57:22Z")
> [@Mangetout](#): > > So it’s impossible for a constant, low-voltage, low-current source to be chopped up into brief, higher-voltage pulses with more available current? It is impossible in a passive device for the product of input low voltage_low current over any period of time to be less than the output high voltage_high current over the same period of time. If you input 1 volt and 1 milliamp for 1000 seconds the output can’t be more than 1 joule no matter how high the output voltage. My objection is to the statement that the device transforms the output from a low power to a higher power. ---
**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 12, 2005, 9:20am UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/34 "2005-12-12T09:20:21Z")
> [@David Simmons](#): > > It is impossible in a passive device for the product of input low voltage_low current over any period of time to be less than the output high voltage_high current over the same period of time. I did explicitly state that it _wasn’t_ delivered over the same period of time. ---
**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 12, 2005, 9:28am UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/35 "2005-12-12T09:28:29Z")
> [@Mangetout](#): > > I did explicitly state that it _wasn’t_ delivered over the same period of time. Aha light comes. We’ve been talking about different things. I missed your statement about different times. Yes, you can trickle charge for a month and then deliver a whomping surge for a microsecond. ---
**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 12, 2005, 9:30am UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/36 "2005-12-12T09:30:16Z")
However, I still think that “low power” to 'higher power" is a tad misleading as a bald statement without a lot of caveats. ---
**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 12, 2005, 9:38am UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/37 "2005-12-12T09:38:23Z")
Fair enough. Suffice it to say that charge-pumping devices do something like that; accumulating a comparatively useless trickle and delivering it as brief pulses at a useful level. ---
**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 12, 2005, 2:58pm UTC](https://boards.straightdope.com/t/seismic-energy-storage/334577/38 "2005-12-12T14:58:21Z")
This particular charge pump circuit is what used to be known as a[voltage multiplier](http://www.maxim-ic.com/appnotes.cfm/appnote_number/2026/ln/en) back in the Jurassic Age. [Previous page](https://boards.straightdope.com/t/seismic-energy-storage/334577.md?page=1)