How to produce static electricity with water

Water powered batteryYesterday, we ran a video showing you a water powered battery that can generate a 15kV spark using nothing more than some simple hardware and a professor who looks a bit like Einstein. Some readers may have worried that it was a spoof given the date (April 1) but this is a genuine piece of science based on the principles of static electricity.

Water is a polar molecule – there is a small difference in electric charge from one end to the other – but pure (deionized) water is also a very good insulator. As the droplets of water fall through the bottomless metal cans, their polarity induces a charge in the cans (which are by the way heavily insulated from earth (or ground). A positive charge builds up on the cans as the water molecules falling into the buckets become negative. This results in a charge separation or a potential difference between the paint cans and the buckets of water (which are also heavily insulated from earth).

Eventually the potential difference reaches a threshold at which point the insulating properties of the air between the two balls breaks down and a spark leaps across the gap. This spark, which has a temperature of several thousand degrees Celsius carries a voltage of between 10 and 15 thousand Volts, far more than you need to power even the biggest set of plugin speakers for your mp3 player.

Several questions remain. Where does the energy come from to create this enormous potential difference and could this form of electricity be tapped by building some kind of power station at the top of a waterfall and using two enormous cans and buckets? Well to answer the first question just look at the vertical arrangement of the equipment. The energy comes from gravity, from the potential energy of the water, which is above the paint cans. The second question is a little more complicated to answer. It would be possible to build a bigger generator, although insulating the components from earth would be tougher and the dissolved salts in river water would make it far less efficient than a generator using deionized water, but those are probably not the main issues.

Think about it, to make electricity generation useful we need a current to flow. How might you “tap” off a current from this type of generator when its product is effectively small-scale lightning? A capacitor in the spark zone, you say? But then isn’t the air acting as a capacitor, still doesn’t solve the problem of tapping off a current. Find an efficient and safe way to tap the power of lightning and you could make a fortune and solve the world’s energy needs. But, please don’t try those kinds of experiment at home!

Instead of generating static electricity, however, it is possible to use gravity’s power to move water to produce a current, much more readily…think water wheel, dynamo-type generator…think hydroelectric dam.

By the way, this experimental setup was originally devised by Lord Kelvin in the nineteenth century and is known as Kelvin’s Thunderstorm, it featured in Bill Beaty’s amateur scientist column in 1995, you can find a more detailed explanation here.

18 thoughts on “How to produce static electricity with water”

  1. does anyone know how to control this , so that I may have utilities, lights, heating, cooling,stereo, stuff like that

    Thank you!


  2. Hi, I’m amazed! I looked at the ariel pictures of Eyjafyallajoklt erpting with the flashes of lightning coming from it and imagined there must be a way of producing electricity from fragmented water particles. What you have demonstrated ( I think) is how this can be simulated artificially. I pondered the idea of how a short burst of energy producing millions of volts could be slowed to be used over a longer period of time. I think this science is very much in its infancy. Full marks for coming up first search!

  3. I want to build a generator using solar power and water with no moving parts and no solar cells and I think it can be done. What are your views on this.

  4. Ever hear of getting a shock on your lip/mouth from bottled water? I did and so did 2 other people drinking from the same bottle.

  5. Running the fuel pump is not the process of obtaining the chemical energy to drive a car? Ever heard of oil wells and petroleum refineries, pipelines and tankers?

  6. The energy in this system does not come from gravity, it comes from the man lifting the water up to a higher level – which he burned sugar in his bloodstream to do, which came from the Sun in the form of plants.

  7. “it takes a lot of energy to effectively convert stored chemical energy into other forms of energy.”

    Yes this author shown here in the quote is also an idiot. I mean, jeez, it takes a lot of energy to effectively convert a can of gasoline (chemical) into another form of energy. Like running an engine, I mean it takes so much energy to run the fuel pump you know.

    Stored chemical energy is a good source of energy but it does not always take a lot of energy to get it. It depends on the chemical entirely.

  8. batteries use a chemical reaction to force charge migration.

    generators use electromagnetic fields (changing magnetic field sets up an electric field inside a conductor) to cause charge migration/flow = current (dq/dt, change in current per time).

    the author is an idiot who does not seem to understand electrostatics… maybe its been a long time since that physics course where you learned F=qVxB?

    a static field is built between the water in the bottom bucket and the can in the top. just like a capacitor.

    a capacitor is JUST LIKE a battery, but only depends on the energy stored in an electric field, not redox potential (true battery)

    caps are used all the time in electronics to ensure that some device has enough current for all demand (example being high powered speakers, that may need a super burst of current when there is an especially loud note in the music)

    how do you use energy from this concept? hmm.. lets think… YOU CONNECT A WIRE BETWEEN THE BOTTOM BUCKET AND THE TOP BOTTOMLESS CAN.

    as charge gets transferred to the top bucket (author claims positive charge) and charge on the bottom, CHARGE CARRIERS FLOW THROUGH THE WIRE.

    connect a device to the wire, and you will get a current.

    why is this useless? because you would need to literally dump an entire lake through a contraption of this sort to get anything even remotely close to usable power.

    static depends on vanishingly small amounts of excess charge carriers being RIPPED away (like elcectrons or protons). a typical circuit sees MOLES of electrons moving through it in seconds. static-electricity type experiments for a typical laboratory scale demonstration result in the production of less than 10^5 excess electrons. that is 10^17 less than a typical circuit requires.

    think of that scaling and you will understand why this is not useful for electricity production.

    when someone can figure out a way to harness the energy stored in carbohydrates ELECTROCHEMICALLY it will save the world. there is literally as much energy in a loaf of bread as a small nuclear explosion… if it was possible to completely convert every single molecule in the bread into water, carbon dioxide, nitrogen (gas), etc… then you could get a fantastical amount of energy from it.

    as such, converting chemical energy into thermal or electrical energy is EXTREMELY innefficient. even inside the body. like .01% efficient or less.

    it takes a lot of energy to effectively convert stored chemical energy into other forms of energy.

  9. Water will end up with a negative charge in the conductive buckets. Though, both buckets and cans get charge positive. How then there is a potencial diference between both buckets ? Also whats the point on connecting opositive buckets to the opositive cans?

  10. what is the meaning of van der graff .how much energy can it prouduce and can i control the amount of energy in it?

  11. Berna, your original message was fundamentally spam, I fixed your name “extend outside electrical contractor” is not a likely name for a person is it? Anyway, simplest way is already described in quite simple terms in the post and comments above, I really doubt that I need to explain it to you in any more detail do I, especially as you’re an electrical contractor!

  12. Try rubbing a balloon on a woolly jumper, or a comb through nice, dry hair. That will produce static electricity. Alternatively, find yourself a van der Graaf generator. They’re great for producing static electricity. Have fun!

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