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Banking capacitor for household electricity Answered

anyone here knows how to make a banking capacitor for residential? what is the right capacitor and value for the electricity banking?

3 Replies

iceng (author)2018-02-18

You should get 23 megajoules of capacitor = C*V*V/2 = Energy

So once you decide what voltage capacitor is available to you, then you will need ?

To calculate capacitance ...... C = (46 * 10^6) / (V * V) !!!!


A good idea is a generator to keep the Fridge up and avoid freezing of pipes..The rest of lights and assorted non-essentials can be run off of a damaged Tesla battery pack or a solar collector system about the same price..

You just joined and appear to have a deficient concept of the energy needed and the cost in capacitance to do what you asked for..

Suffice it to be said that I live next to the Gigafactory and recommend that you acquire the $3000 powerwall_1 which is good for 6.4 kilowatt hours..

And a good deal less then 23 megajoules of capacitors, that would still need an inverter.

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Jack A Lopez (author)2018-02-17

I am guessing you are asking about a device for energy storage, for a standalone power system,


Speaking vaugely, the kind of energy you want to store is electricity, and the quantity is maybe a few 10s of kilowatt*hours.

I think the usual trick is to use batteries, usually large quantities of them, and the resulting collection of batteries, or cells, wired in some arrangement of series and parallel, is often called a "battery bank". Although just calling it a, "battery", or a "big battery", might be technically correct too.

I have seen instructables here, of people building large batteries, and the usual recipe for that seems to be: a number of cells, plus thick wires to connect the cells together, plus some kind of charge controller, or battery management circuit, for to charge and discharge the cells in some controlled way.

Also I thought I would link to the Wikipedia article for, "Tesla Powerwall",


Obviously that is a commercial product, but the size of it, in terms of the amount of energy it stores, around 10 kW*hour, makes it an example of a battery, sized to provide enough electricity for a house, for around a day's worth of storage time.

It is possible to build the same thing out of lead acid cells, but it the volume of cells will take up a small room of the house, instead of just a "wall". I mean one of the goals Tesla (the company) has for this product, was, I think, to make it relatively compact, and this explains where the name, Powerwall(r), came from.

Final note, there is such a thing as a, "capacitor bank", an energy storage device made of a collection of capacitors. However that kind of device is used mainly for pulsed power; i.e. for applications where all the energy can be dumped from the bank in a very short amount of time, like, in a fraction of a second. And this sort of device is the domain of mad scientists, and weapons engineers.


As an example, the Sandia Z-Machine uses a capacitor bank that stores about the same amount of energy as house-sized battery; i.e. 10s of kW*h. (Note that 1 kW*h = 3.6 megajoules (MJ), and the numbers for the Z-Machine are quoted in MJ). The difference is the Z-machine can dump all that energy in a fraction of a microsecond (10^-6 s), thus achieving terawatts (10^12 watts) of instantaneous power.


Anyway, the people building off-grid houses, do not need to dump their whole energy supply that quickly, so they use batteries instead of capacitors.

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rickharris (author)2018-02-16

Are you looking to make a power correction capacitor bank?

If so it's not worth it.

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