I'm Slightly Terrified of Electrolysis

[Hayley]

I'm not that intelligent of a person, and I'm still in high school if this helps rest your doubts. I'm doing a project for class that involves hooking a solar panel to a copper tube in order to boil salt water, filthy water (dirt + water), and average water. However, the more I research about this, the more of a chicken I become. One of the solar panels is 12 volts and I'm not offsetting the current any, so it'll be 12 volts constantly going into water. Not to mention the 12 volts are DC. If electrolysis does occur, will the hydrogen gas and oxygen ever condense into water( I feel like an idiot for asking that), and if it does occur will it be dangerous to have a constant 12 volts reverberating in the water. Will it be dangerous just to have hydrogen gas lying around, it seems really unsafe! This will all be in a glass jug so the gasses wouldn't be able to escape anywhere, only to another jar. I figured the copper tube that the wires are connected to would act as some kind of resistance heater, the water would only come in contact with it, but I'm not sure if it will still occur. I only want to BOIL this water, I didn't want all of this!

 

[anorlunda]

Don't be to hard on yourself. Your questions are fair questions.

Electric current flows in a circuit from the source, through the circuit, then back to the source. That is why there are two wires from the solar panel, not one wire.

If the current flows from the panel to the copper tube, then back to the panel, there should be no electrolosis. If the current flowed through the water instead of the tube, then you could get electrolosis.

So, maybe you could draw us a diagram, or show us a picture of the setup, to verify that current goes through the copper tube and not the water. If so, then we can tell you it is OK.

What is the pupose of this? Are you condensing fresh water from the steam produced by boiling the salt water.

Do you know that to make a resistance heater to boil water, a copper tube is a very bad choice. Copper has low resistance. You need high resistance.

 

[Hayley]

I just pushed a bunch of images together, but this is (kind of) what it's supposed to be like. The tube connects the jugs and the tube is technically supposed to be in the jug, but I can't draw and I haven't set it up yet because of my hydrogen gas explosion fears. And copper is the only material I'm able to get my hand on, so I thought it would work because it's a strong conductor. And, yes, I am trying to condense water from the steam.

 

[anorlunda]

Why two jugs? Where will the two wires from the solar panel connect?

Edit: Is the idea for one jug to hold salt water, and the other to collect fresh water?

 

[Hayley]

Why two jugs? Where will the two wires from the solar panel connect?

I have two jugs because I don't want to have the vapor condense into the same jar with the dirty/ salty water. I was just going to wrap the wires around the part of the copper tube that was sticking out of the jug.

 

[anorlunda]

No, that won't work to wrap wires around the tube. I'll try to draw a picture for you, but it will take me a few hours.

You should be glad that you asked questions. You could get injured if it is done wrong.

 

[anorlunda]

Is this what you are trying to make? If so, I misunderstood your question becase I thought you meant a solar-electric panel. The system above uses a different type of solar panel to heat water, not to make electicity. There are no wires and no danger of electrolosys of the water.

Here is how the owner says that it works.

"The basic principles of solar water distillation are simple yet effective, as distillation replicates the way nature makes rain. The sun's energy heats water to the point of evaporation. As the water evaporates, water vapor rises, condensing on the glass surface for collection. This process removes impurities such as salts and heavy metals as well as eliminates microbiological organisms. The end result is water cleaner than the purest rainwater. The SolAqua still is a passive solar distiller that only needs sunshine to operate. There are no moving parts to wear out." ​

 

[Hayley]

Is this what you are trying to make? If so, I misunderstood your question becase I thought you meant a solar-electric panel. The system above uses a different type of solar panel to heat water, not to make electicity. There are no wires and no danger of electrolosys of the water.

Here is how the owner says that it works.

"The basic principles of solar water distillation are simple yet effective, as distillation replicates the way nature makes rain. The sun's energy heats water to the point of evaporation. As the water evaporates, water vapor rises, condensing on the glass surface for collection. This process removes impurities such as salts and heavy metals as well as eliminates microbiological organisms. The end result is water cleaner than the purest rainwater. The SolAqua still is a passive solar distiller that only needs sunshine to operate. There are no moving parts to wear out." ​

Not really, I plan on using an actual electrical energy producing solar panel. I have done research on those though, and they look really effective. I obviously don't know enough about circuitry to actually charge the rod/ tube though. Does the tube need some type of prong?

 

[anorlunda]

I have done research on those though, and they look really effective

Show me some of the links where you did research. Do the sites have diagrams or pictures?

 

[Hayley]

I have a few sites, although I'm not going to use this type of solar panel, and I'm still curious about the wiring.

http://www.mygenerationenergy.com/faq/

http://science.howstuffworks.com/environmental/green-tech/energy-production/solar-thermal-power.htm

http://www.heliodyne.com/solar-hot-water-panels.html

http://www.revisionenergy.com/at-home/solar-hot-water/

http://www.ruralenergy.wisc.edu/renewable/solar_thermal/default_solar_thermal.aspx

http://www.chb-uk.com/heating/solar-water-heating/

 

[anorlunda]

All of those links point to places that talk about solar heating panels, not photovoltaic solar electric panels.

The first paraphrase in the first link describes the difference between solar photovoltaic and solar water heating.

 

[Hayley]

All of those links point to places that talk about solar heating panels, not photovoltaic solar electric panels.

The first paraphrase in the first link describes the difference between solar photovoltaic and solar water heating.

Oh, I'm sorry I thought you meant solar heating panels :O, give me a second.

 

[Hayley]

http://www.seia.org/policy/solar-technology/photovoltaic-solar-electric

http://science.nasa.gov/science-news/science-at-nasa/2002/solarcells/

http://energy.gov/eere/energybasics/articles/photovoltaic-technology-basics

http://www.fsec.ucf.edu/en/consumer/solar_electricity/basics/how_pv_system_works.htm

http://www.builditsolar.com/Projects/PV/pv.htm

http://etap.com/renewable-energy/renewable-energy-images/solar-panel-diagram-large.jpg

 

[anorlunda]

Yes but it makes no sense to use that kind of panel to heat water electrically when a direct solar heater does it better.

Go to YouTube.com, search for solar distillation. There are lots of videos of projects where people make clean water for their villages.

 

[Hayley]

Yes but it makes no sense to use that kind of panel to heat water electrically when a direct solar heater does it better.

Go to YouTube.com, search for solar distillation. There are lots of videos of projects where people make clean water for their villages.

I'm just testing it, that's what the project's about. MIT created something extremely similar.

 

[meBigGuy]

I won't comment on direct solar versus electric (although I favor direct solar)

Discussing the electrical approach:

Are you saying that you will wrap heating wire around the copper tube and it will conduct heat into the bottle?
Not sure what purpose the copper tube plays. It there current going through it?
(Note that connecting a wire to the water and a wire to the pipe will not heat the water)

Have you calculated the amount of energy you need to heat a volume of water to boiling, and whether your panel can even come close to supplying that energy in a reasonable amount of time? (How many watts can the panel supply under the conditions you will be using it, and what volume of water do you want to heat)

Assuming you have done the math and have enough power, I think a more traditional water heating element is in order.
Google for "12V water heating element" , for example

Regardless of the elements used, no electricity should be conducted by the water. There is no reason to do that.

Also, heating cheap glass bottles is difficult and they can shatter from uneven heating, so use proper glass containers.

 

[sophiecentaur]

Will it be dangerous just to have hydrogen gas lying around, it seems really unsafe!

Yes, it is, potentially a dangerous thing to do. Unvented rooms in which batteries are trickle charged are potential explosion hazards because of the H gas that is produced (in the vicinity of O2 too.)
But your project doesn't, ifaics, involve any electrolysis. It certainly doesn't need to, if you use a 12V heating element.