# Capacitor Pyramids as Energy Source. Why or why not? **URL:** \ **Category:** Factual Questions\ **Created:** [July 18, 2006, 3:57pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029 "2006-07-18T15:57:40Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Blue\_Blistering\_Barnacle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/blue_blistering_barnacle/32/3386_2.png) [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)\ **Post date:** [November 22, 2017, 7:32pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/21 "2017-11-22T19:32:51Z")
> [@Kevbo](#): > > Lightning bolts represent a huge amount of power, but only over microsecond-millisecond time scales. Thus the ENERGY is not nearly of the same scale, and much of that energy is wasted heating air (creating thunder). A moderatly sized solar array could easilly collect in a day what such a system would collect in a thunderstorm…and do so far more economically and safely. > > Combine this with the fact that few places have reliable lightning storms and there are lots better ways to obtain the power needed to reanimate my ghoulish creations. Hmmm… you’ll have to share your work. In my experience, only lightning has the “oomph” needed to restore that spark of life in the higher orders. Although, I’m certain that ultimately the limitless energy of NUCLEAR FUSION is the way to go. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [November 22, 2017, 7:40pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/22 "2017-11-22T19:40:23Z")
> [@TimeWinder](#): > > That’s not a theory, that’s drivel. Theories have evidence and data to back them up. The more important point is that theories have explanatory power, and good theories explain things better than bad theories, or previous theories. Theories generate testable hypotheses. If a thing does not generate any testable hypotheses, it isn’t a theory, and is, perhaps, a cheese danish or a particularly dyspeptic goat. ---
**Author:** ![DrCube](https://avatars.discourse-cdn.com/v4/letter/d/a3d4f5/32.png) [@DrCube](https://boards.straightdope.com/u/DrCube)\ **Post date:** [November 22, 2017, 9:31pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/23 "2017-11-22T21:31:16Z")
> [@engineer\_comp\_geek](#): > > A typical lightning bolt is a few million volts at a few hundred thousand amps, which puts you up in the several hundreds of trillions of watts range. So close! It’s actually one point twenty-one jiggawatts. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 22, 2017, 9:41pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/24 "2017-11-22T21:41:43Z")
The quote is “gigawatts”. Yes, there are some who pronounce “giga” as “jigga”, though it’s not common any more. And thanks to a misplaced decimal point, your “calculation” actually turns out to be closer than **ecg** ’s (hint: A thousand times a million isn’t a trillion). ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [November 22, 2017, 9:45pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/25 "2017-11-22T21:45:40Z")
> [@Chronos](#): > > The quote is “gigawatts”. Yes, there are some who pronounce “giga” as “jigga”, though it’s not common any more. So close! It’s actually “what the hell’s a jiggawatt?” ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [November 22, 2017, 10:39pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/26 "2017-11-22T22:39:03Z")
> [@Blue\_Blistering\_Barnacle](#): > > In my experience, only lightning has the “oomph” needed to restore that spark of life in the higher orders. It helps to have Leyden jars, though. Which might explain the Great Pyramids, maybe it’s just a really huge Leyden jar. Built to power that MASER[sup][capitalization required][/sup] in the [new chamber](http://boards.straightdope.com/sdmb/showthread.php?t=840703) they recently discovered. It’s going to shoot vortexes at all you guys who scoffed at the possibility. ---
**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:** [November 22, 2017, 11:14pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/27 "2017-11-22T23:14:40Z")
> [@TimeWinder](#): > > That’s not a theory, that’s drivel. Theories have evidence and data to back them up. I don’t think you understand. Its _plausible_ - the _most_ plausible. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [November 23, 2017, 12:05am UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/28 "2017-11-23T00:05:11Z")
> [@Marvin\_the\_Martian](#): > > This. According to the relevant [Wikipedia page](https://en.wikipedia.org/wiki/Harvesting_lightning_energy) the energy from a typical lighting bolt is equivalent to the energy in about 12 gallons of gasoline. Not worth the effort of building a collection system. > > Although maybe enough energy to re-animate a zombie. Per the cited Wiki, the energy comparison equates to 38 gal. (US) of gasoline, not 12. Nitpicking on metric to US conversion factors aside, it would be interesting to know how the (Wiki) contributor manages to convert a lightning strike of **“5 billion joules over 10 microseconds is equal to 5×1014 (or 500 trillion) watts”** of electrical energy into an equivalent **“145 liters”** of gasoline. My Harbor Freight generator 🙂 pales in comparison. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [November 23, 2017, 12:31am UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/29 "2017-11-23T00:31:02Z")
Just something to ponder, when dismissing offhand a question based upon a Wiki cite. ---
**Author:** ![TimeWinder](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@TimeWinder](https://boards.straightdope.com/u/TimeWinder)\ **Post date:** [November 23, 2017, 1:59am UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/30 "2017-11-23T01:59:30Z")
> [@Mangetout](#): > > I don’t think you understand. Its _plausible_ - the _most_ plausible. Well, it certainly gave me plause. ---
**Author:** ![Lickety\_Split\_1](https://avatars.discourse-cdn.com/v4/letter/l/67e7ee/32.png) [@Lickety\_Split\_1](https://boards.straightdope.com/u/Lickety_Split_1)\ **Post date:** [November 23, 2017, 2:48am UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/31 "2017-11-23T02:48:57Z")
> [@internetslacker](#): > > Today on England’s Daily Mail news website there is a very interesting picture of a lightning storm in Las Vegas. It shows the pyramid-themed casino (Luxor, I think) being struck by lighting, at the very apex of the pyramid. This image got me to thinking… > > Would it be feasible to build ‘Capacitor Pyramids’ in areas with many annual lightning storms to collect electricity? Since lightning/electricity looks for the shortest path, it seems to me a pyramid-structure would work well: the apex is the highest point, and there’s a lot of room in the pyramid to place energy collecting equipment. > > Pyramids are also very long lasting if built properly; hell, if the one at Giza has been around for thousands of years and it’s built out of stone, I’m sure we could built ‘energy pyramids’ that last longer… > > I know there’s probably some physic-al limitations, but geez, all those lightning strikes full of free energy… all those 1.21 gigawatt lightning strikes begging to be collected… I long ago thought of the notion of taking advantage of the immense power that lightning provides by somehow storing this power in large capacitors. But I was told by my Electrical Engineer nephew that only a tiny fraction of lightning-strike power could be stored in even the best, cutting-edge technology capacitor capability we now have. Though I am a bit sketchy on the scientific details of exactly why this is so, I recall it has something to do with the fact that electricity stores poorly and is given to immense entropy when forced to be confined or stored in a static state. That is…in order for it to remain at anywhere near its original levels, it must be “dynamic”–that is, kept moving, as in a continually-fed circuit. Thus, given the unpredictability and often-times scarcity of lightning strikes in a given area…these hypothetical capacitors would almost certainly “bleed out” before they could be utilized or recharged. You will recall that real capacitors are only now used in electronics—not really in macro-level electricity. That is, these capacitors are only good on a micro level. Dealing in mV and mA and not lighting-level amounts. Hope this helps. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [November 23, 2017, 4:24am UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/32 "2017-11-23T04:24:49Z")
> [@Lickety\_Split](#): > > You will recall that real capacitors are only now used in electronics—not really in macro-level electricity. That is, these capacitors are only good on a micro level. Dealing in mV and mA and not lighting-level amounts. This is incorrect. Capacitor banks are utilized in many high voltage/amperage applications, such as power conditioning for motor drives and on an even larger scale, industrial power factor correction. ---
**Author:** ![Lickety\_Split\_1](https://avatars.discourse-cdn.com/v4/letter/l/67e7ee/32.png) [@Lickety\_Split\_1](https://boards.straightdope.com/u/Lickety_Split_1)\ **Post date:** [November 23, 2017, 5:13am UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/33 "2017-11-23T05:13:08Z")
> [@ZurBob](#): > > This is incorrect. Capacitor banks are utilized in many high voltage/amperage applications, such as power conditioning for motor drives and on an even larger scale, industrial power factor correction. But are you sure those systems are capacitors and not transformers? I have never heard of a true capacitor outside of electronics. Maybe you could throw me a link or a source? Thanks! ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [November 23, 2017, 7:10am UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/34 "2017-11-23T07:10:33Z")
> [@Lickety\_Split](#): > > But are you sure those systems are capacitors and not transformers? I have never heard of a true capacitor outside of electronics. Maybe you could throw me a link or a source? Thanks! I work on a daily basis on the above mentioned capacitor smoothed 480 volt motor drives in a facility that has a 9 megawatt load @ 11,100 primary volts with a 480 volt secondary that is power factor corrected by a large bank of capacitors _ **and** _ inductors (we call them reactors), so yes, I’m aware of the difference between a cap and a transformer (and a reactor). I know it is considered inappropriate here on SDMB to reply to a query for a cite with GOOGLE IT… But do your own homework. I suggest “motor drive capacitor” and “power factor correction capacitors” as keywords. If you can’t find a suitable explanation, reply and I’ll guide you through it. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [November 23, 2017, 10:51am UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/35 "2017-11-23T10:51:21Z")
> [@Lickety\_Split](#): > > But are you sure those systems are capacitors and not transformers? I have never heard of a true capacitor outside of electronics. Maybe you could throw me a link or a source? Thanks! > **[Capacitor](https://en.wikipedia.org/wiki/Capacitor#Power_factor_correction)** > > In electrical engineering, a capacitor is a device that stores electrical energy by accumulating electric charges on two closely spaced surfaces that are insulated from each other. The capacitor was originally known as the condenser, a term still encountered in a few compound names, such as the condenser microphone. It is a passive electronic component with two terminals. > The utility of a capacitor depends on its capacitance. While some capacitance exists between any two electrical conductors ... [http://www.aerovox.com/Products/PowerFactorCorrectionCapacitors.aspx](http://www.aerovox.com/Products/PowerFactorCorrectionCapacitors.aspx) ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [November 23, 2017, 11:35am UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/36 "2017-11-23T11:35:02Z")
> [@Lickety\_Split](#): > > You will recall that real capacitors are only now used in electronics—not really in macro-level electricity. That is, these capacitors are only good on a micro level. Dealing in mV and mA and not lighting-level amounts. Rather large capacitors are used for both power factor correction and for motor starting/running. A very simple inductor is just a coil of wire. A very simple capacitor is just two metal plates parallel to each other. These are both energy storage devices. In an inductor, if you run current through the wire, energy ends up being stored in a magnetic field. Remove the current, and the magnetic field collapses, and the energy ends up getting converted back into electrical current. A capacitor is somewhat similar in that if you apply a voltage to it, energy gets stored, but unlike in an inductor, it is instead stored in an electric field. Remove the voltage and the field collapses, releasing the energy back into the circuit. If you have an AC sine wave, like in power systems, inductors and capacitors kinda work opposite of each other. During the part of the sine wave where the inductor is charging, the capacitor is discharging, and when the inductor is discharging, the capacitor is charging. Residential power loads tend to be slightly inductive, due mostly to motors in things like appliances and vacuum cleaners. When the load is slightly inductive, the power generators have to put out more current to charge up the magnetic fields in those inductors, which ends up being wasted energy since it is dumped back into the system later on in the AC sine wave cycle. So, power systems are at their most efficient when you balance out the inductive loads with capacitors. If you balance it exactly right, then the capacitors will be charging up while the inductors are discharging and the inductors will be charging when the capacitors are discharging, and all of that reactive energy effectively ends up just bounding back and forth between the inductors and capacitors. The generators therefore only have to supply the “real” (resistive) power, which increases the overall efficiency of the power system by eliminating the reactive current load on the generators. Some of the capacitors that power companies use are located on utility poles. Others are located at the distribution substation. These are not tiny electronic type capacitors. They are large capacitors, operating at distribution voltages (somewhere between 3,000 and 15,000 volts, typically). The fence in the front of this picture will give you an idea of the scale of these capacitors: [![](http://slideplayer.com/slide/5748646/19/images/12/Substation+Capacitor+Banks.jpg) ](http://slideplayer.com/slide/5748646/19/images/12/Substation+Capacitor+Banks.jpg) Here’s a pole-mounted capacitor bank: > **[Trinetics](https://www.hubbell.com/hubbellpowersystems/en/hps-brands/trinetics)** > > The Trinetics brand specializes in providing a wide range of targeted switching systems, using multiple technologies including oil, vacuum, mercury, dry contact and solid-state. This is a pole-mounted transformer, so you can see the difference: [![](https://upload.wikimedia.org/wikipedia/commons/9/99/Power_Transformer.jpg) ](https://upload.wikimedia.org/wikipedia/commons/9/99/Power_Transformer.jpg) Capacitor banks may operate at even higher voltages than that. Here is an image of a 35 kV capacitor bank: [http://www.hycapacitor.com/en/UploadFiles/2010226134431602.jpg](http://www.hycapacitor.com/en/UploadFiles/2010226134431602.jpg) A few years ago, a bunch of folks were advertising power factor correction devices for your home, which they claimed would make your electricity more efficient and save you money. While the concept of power factor correction is certainly valid, these devices most definitely would not save you money. First of all, they were just capacitors, without any switching, so they could not possibly balance out the changing inductive loads in your house. Second, the power company already uses capacitors, so they don’t need yours. Third, the power company doesn’t charge you for reactive loading. They only charge for the real power used. Even if you did have some sort of functioning capacitor-switching power factor device, it would only eliminate stuff that the power company isn’t charging you for anyway. So no possible savings, at all. If you are an industrial or commercial customer though, the power company does charge you for reactive power. And they charge you out the wazoo, too. If your power load is too inductive, and you are an industrial or commercial customer, it’s basically “bend over and squeal like a piggy” time as far as your bank account is concerned. This gives industrial and commercial customers a HUGE incentive to install their own power factor correction devices. These companies will buy their own power factor correction capacitor systems, so it’s not only utility companies that own huge capacitors like these. Certain types of motors also need capacitors to get them to start and to keep them running. This is true of some types of small motors used in hand tools, all the way up to huge motors used for things like crushing coal in power plants. This wikipedia article has a good explanation of motor run and motor start capacitors. It’s the same principle, whether it’s a small motor or a large motor: > **[Motor capacitor](https://en.wikipedia.org/wiki/Motor_capacitor)** > > A motor capacitor is an electrical capacitor that alters the current to one or more windings of a single-phase alternating-current induction motor to create a rotating magnetic field.\[citation needed\] > There are two common types of motor capacitors, start capacitor and run capacitor (including a dual run capacitor). > Motor capacitors are used with single-phase electric motors: 11  that are in turn used to drive air conditioners, hot tub/jacuzzi spa pumps, powered gates, large fans or forced-air... As far as lightning-level voltages go, they don’t make capacitors that can handle that. Not yet, anyway. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [November 23, 2017, 11:44am UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/37 "2017-11-23T11:44:03Z")
Them big ones [bite](https://farm4.staticflickr.com/3261/3085306385_897e39e62f_z.jpg) too … ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [November 23, 2017, 11:48am UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/38 "2017-11-23T11:48:46Z")
> [@watchwolf49](#): > > Them big ones [bite](https://farm4.staticflickr.com/3261/3085306385_897e39e62f_z.jpg) too … When I was in college (back in the days of dinosaurs), they would take old electronics and would leave them in a room on the top floor of the engineering building for us EE students to tinker with and to use in our projects. I got a capacitor about that big in diameter and about twice as tall out of that junk pile. We had of course learned how capacitors store energy and how you can discharge them, so I charged that capacitor up and shorted it with a screwdriver just to see what would happen in the real world. It arc-welded the screwdriver to the capacitor terminals, and blew the tip off of the screwdriver while it was at it. It gave me a healthy respect for larger capacitors. 🙂 ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [November 23, 2017, 1:07pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/39 "2017-11-23T13:07:24Z")
> [@engineer\_comp\_geek](#): > > Rather large capacitors are used for both power factor correction and for motor starting/running. Rather large capacitors are also used for coin-shrinking. [No, really.](http://www.capturedlightning.com/frames/shrinker.html) The idea is that if you move enough current through a coil, and with a high enough ramp rate, you can generate a large, transient magnetic field in the rim of the coin; that field and the field of the coil repel each other, resulting in the coin being crushed radially (and the coil violently exploding). ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [November 23, 2017, 2:07pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/40 "2017-11-23T14:07:15Z")
Capacitors are used in many situations where you need a huge amount of power in very short bursts. Defibrillators, pulsed lasers and other pulsed light sources (including camera flashes), spot welders, explosive detonators, etc. And homemade railguns. (Probably the non-homemade ones too.) [Previous page](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029.md?page=1) [Next page](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029.md?page=3)